The Potential of Green Roofs to Address Habitat Loss in Northern Ireland

MSc Sustainable Design Dissertation Queen University, Belfast Faculty of Engineering and Physical Sciences School of Planning, Architecture and Civil Engineering

The Potential of Green Roofs to Address Habitat Loss in Northern Ireland

The Potential of Green Roofs to Address Habitat Loss in Northern Ireland

MSc Sustainable Design Dissertation Faculty of Engineering and Physical Sciences School of Planning, Architecture and Civil Engineering

QUEEN’S UNIVERSITY BELFAST September 2011

Noel Hughes 15259021

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Abstract

The Potential of Green Roofs to Address Habitat Loss in Northern Ireland

The aim of this report is to assess the potential, if any, for green roofs in urban areas to act as habitat islands and the ability of such an approach to affect the local/regional ecology in regards to both flora and fauna species. An investigation into green roof construction and the characteristics of Northern Ireland’s natural habitats will be combined to evaluate whether or not natural environments can be replicated on Northern Ireland’s rooftops. The results of this exercise will be compared to international examples of urban green roofing programmes to assess the environmental value of such an undertaking in Northern Ireland.

The central goal of this report is to provide an informed argument on green roofs potential on Northern Irish ecologies and if any natural habitat is capable of being successfully recreated on rooftops. The study also seeks to explore whether green roofs can feasibly counteract natural habitat loss in Northern Ireland and if so what are the possible environmental benefits to urban centre and the surrounding landscape.

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Table of Contents

Chapters and Heading of the Dissertation

Introduction The Relationship between Green Roofs and Natural Habitats In‐01 Green Roofs connection to Habitat Creation

In‐02 Habitat Loss in Northern Ireland

In‐03 Impact of Existing Green Roof on Surrounding Habitats In‐04 International Approaches to Rooftop Greening

Methodology

Chapter 1 Habitat Creation on Green Roofs

1‐01 Green Roof Components

1‐02 Structural Considerations

1‐03 Roof Slope

1‐04 Nutrients & Water Requirements

1‐05 Substrate Makeup

1‐06 Soil Depth and Planting Regiments

1‐07 Biological Limitations

1‐08 Green Roof Maintenance

1‐09 Insulating Effects of Green Roofs

1‐10 Benefits of Green Roof to the Urban Environments 1‐11 Green Roofs effect on People

1‐12 Habitats Favoured by Rooftop Environments

Chapter 2 Habitat Loss in Northern Ireland

2‐01 Tidal Marine Habitats

2‐02 Coastal Habitats

2‐03 Freshwater and Wetland Habitats

2‐04 Woodland Habitats

2‐05 Grassland Habitats

2‐06 Heathland Habitats

2‐07 Peatland Habitats

2‐08 Rate of Habitat Change

Chapter 3 Green Roofs and Created Habitats

3‐01 Sand Dunes / Shingles Banks Habitat Case Studies 3‐02 Cliffs and Slopes Habitat Case Studies

3‐03 Wetland Habitat Case Studies

3‐04 Woodland Habitat Case Studies

3‐05 Grassland Habitat Case Studies

3‐06 Heathland Habitat Case Studies

3‐07 Practical Implications of Rooftop Habitat Recreation iv

…01 …02 …03 …04 …05

…07

…09 …10 …11 …12 …12 …13 …14 …15 …16 …16 …16 …17 …17

…20 …22 …25 …28 …31 …34 …37 …40 …43

…45 …47 …50 …53 …57 …60 …66 …70

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Chapter 4 Green Roof Habitat Creation for Northern Ireland

…72 4‐01 Urban Resources in Northern Ireland

…73 4‐02 Re‐establishment of Natural Habitats

…75 4‐03 Structural Viability of Green Roof Habitats

…76 4‐04 Expense of Green Roof Habitat Recreation

…77 4‐05 Northern Ireland Accommodating Green Roof Habitats

…79

Conclusions Are Green Roofs a Practical Ecological Recourse for Northern Ireland?

…85 Cn‐01 Green Roof and Habitats in Northern Ireland

…86 Cn‐02 Potential Benefits of Green Roof to Northern Ireland’s Urban Environments …88 Cn‐03 Envisioned Setback to Green Roof development in Northern Ireland

…88 Cn‐04 Conclusion of Dissertation

…89

References

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Appendix ‐A Detailed Descriptions of Northern Ireland’s Natural Habitats

…101

Appendix ‐B Description of Northern Ireland’s Management of Sensitive Sites (MOSS) Scheme …129

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Table of Figures

Introduction Figure 1 ‐ Northern Ireland Landscape

NIEA. (2007). Northern Ireland Countryside Survey. Belfast: Northern Ireland Environment Agency. [Photograph]

Figure 2 ‐ 3 ‐ 419 Lafayette St, Manhattan

Hurt, A. (2003, August 09). Green City. http://en.wikipedia.org/wiki/File:Green_City.jpg

Retrieved

August

22,

2011,

from

Wikipedia:

Figure 3 ‐ Lapwing breeding on the Green Roof

Brenneisen, S. (2006). Space for Urban Wildlife: Designing Green Roofs as Habitats in Switzerland. Urban Habitats , 4 (1), 27‐36. [Photograph] (Author)

Figure 4 ‐ Northern Ireland Grassland

Countryside Survey. (2007). Countryside Survey: UK Results from 2007. Countryside Survey UK: London.

[Photograph] (Mark Wright)

Figure 5 ‐ Moos Filtration Plant Wollishofen Zurich

Gedge, D. (2010, March 15). Green Roofs of the World 1 ‐ Moos Filtration Plant Zurich. Retrieved June 21, 2011, from Livingroofs.org: http://livingroofs.org/20100315195/green‐roofs‐of‐the‐world/moos‐zurich.html [Photograph] (Author)

Figure 6 ‐ Laban Dance Centre, London

Gedge, D. (2002). Roofspace: a place for brownfield biodiversity? Ecos , 22, (3/4), 69–74. [Photograph] (Author)

Figure 7 ‐ 47° pitched Roof Berlin‐Kreuzberg

Köhler, M. (2006). Long‐Term Vegetation Research on Two Extensive Green Roofs in Berlin. Urban Habitats , 4 (1), 3‐ 26. [Photograph] (Author)

Figure 8 ‐ Ufa‐Fabrik Center, Berlin‐Templehof

Köhler, M. (2006). Long‐Term Vegetation Research on Two Extensive Green Roofs in Berlin. Urban Habitats , 4 (1), 3‐ 26. [Photograph] (Author)

Chapter 1 Figure 1 ‐ M Central, Sydney

Callaghan, G. (2010, August 19). Gardens in the sky. Retrieved August 8, 2011, from The Australian: http://www.theaustralian.com.au/news/features/gardens‐in‐the‐sky/story‐e6frg8h6‐1225907217961

Figure 2 ‐ Intensive Green Roof Structure

Norphadrain® (2008) The inverted roof a sound construction for roof decks! [Photograph] (Norphadrain® Green Roof Systems ‐ Promotional Material)

Figure 3 ‐ Extensive Green Roof Structure

Norphadrain® (2008) The inverted roof a sound construction for roof decks! [Photograph] (Norphadrain® Green Roof Systems ‐ Promotional Material)

Figure 4 ‐ PVC Waterproof Membrane

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 5 ‐ Extruded Polystyrene

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 6 ‐ Synthetic Drainage Board

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 7 ‐ Mineral/Organic Medium

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 8 ‐ Green Roof Substrate Layers

Dunnett, N., & Kingsbury, N. (2004). Planting Green Roofs and Living Walls. Portland: Timber Press.

Figure 9 ‐ 8 House, Oerestad, Copenhagen

Carlson, D. (2010, August 10). BIG’s 8 House wins the 2010 Scandinavian Green Roof Award. Retrieved August 12, 2011, from David Report: http://davidreport.com/201008/big%E2%80%99s‐8‐house‐wins‐the‐2010‐scandinavian‐ green‐roof‐award/

Figure 10 ‐ Vancouver Convention

Zemtseff, K. (2010, May 20). Wonder what a six‐acre green roof feels like? Retrieved July 28, 2011, from Seattle Daily Journal of Commerce: http://www.djc.com/news/en/12018094.html

Figure 11 ‐ Climatologist Stuart Gaffin at Con Edison Power Plant, Long Island City

Moisse, K. (2010, February 2). Over the Top: Data Show "Green" Roofs Could Cool Urban Heat Islands and Boost Water Conservation.

Retrieved August 12, 2011, from Scientific American: http://www.scientificamerican.com/article.cfm?id=green‐roof‐climate‐change‐mitigation

Figure 12 ‐ Sedum Mat Installers

Dunnett, N., & Kingsbury, N. (2004). Planting Green Roofs and Living Walls. Portland: Timber Press.

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Figure 13 ‐ 70mm Sedum Roof

Roofing Superstore. (2011). Modular Sedium Green Roof. Retrieved July 15, 2011, from roofingsuperstore.co.uk: http://www.roofingsuperstore.co.uk/product/roofing‐accessories/environmentally‐friendly‐products/green‐ roofing‐systems/modular‐sedium‐green‐roof‐70mm‐substrate‐1‐metre‐square.html

Figure 14 ‐ Native wildflowers on the Multanomah Building

Dunnett, N., & Kingsbury, N. (2004). Planting Green Roofs and Living Walls. Portland: Timber Press.

Figure 15 ‐ Freezing Roof Vegetation

Dunnett, N., & Kingsbury, N. (2004). Planting Green Roofs and Living Walls. Portland: Timber Press.

Figure 16 ‐ Rockefeller Centre, New York

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 17 ‐ Mountain Plain grasses and shrubs on Paul Lincke Ufer, Kreuzberg, Germany Dunnett, N., & Kingsbury, N. (2004). Planting Green Roofs and Living Walls. Portland: Timber Press.

Figure 18 ‐ Costal Meadow grasses planted on the Nassau Icehouse Brewery

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 19 ‐ Grass sloped roof on the Vancouver Conference Centre

Zemtseff, K. (2010, May 20). Wonder what a six‐acre green roof feels like? Retrieved July 28, 2011, from Seattle Daily Journal of Commerce: http://www.djc.com/news/en/12018094.html

Figure 20 ‐ Heath Planting on Sloped Roof at Schiphol Plaza, Amsterdam Airport Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 21 ‐ University Hospital Basel

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 22 ‐ John Deere Works, Mannheim

Earth Pledge (2005) Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Chapter 2 Figure 1 ‐ Northern Ireland's Areas of Outstanding Natural Beauty

Countryside Survey. (2008). Countryside Survey: UK Results from 2007. Lancaster: Natural Environment Research Council.

Figure 2 ‐ Dundrum Bay, Down

CVNI. (2011). Priority Habitats ‐ Coastal ‐ Sublittoral Sands and Gravels. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/sublittoral_sands_and_gravels/

Figure 3 ‐ Eelgrass, North Strangford Lough

CVNI. (2011). Priority Habitats ‐ Coastal ‐ Seagrass Beds. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/seagrass_beds/

Figure 4 ‐ Millbay, Antrim

Northern Ireland Habitat Action Plan. (2003). Mudflats. Belfast: Northern Ireland Environment Agency.

Figure 5 ‐ Ballymacormick Point, Bangor

CVNI. (2011). Priority Habitats ‐ Coastal ‐ Coastal Saltmarsh. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/coastal_saltmarsh/

Figure 6 ‐ Strand Lough, Down

CVNI. (2011). Priority Habitats ‐ Marine ‐ Saline Lagoons. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/saline_lagoons/

Figure 7 ‐ Northern Ireland's Marine Habitats (Countryside Survey, 2008)

Countryside Survey. (2008). Countryside Survey: UK Results from 2007. Lancaster: Natural Environment Research Council.

Figure 8 ‐ Murlough Dunes, Dundrum Bay

CVNI. (2011). Priority Habitats ‐ Coastal ‐ Coastal Sand Dunes. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/coastal_sand_dunes/

Figure 9‐ Kearney, Down

Northern Ireland Habitat Action Plan. (2005). Coastal Vegetated Shingle. Belfast: Northern Ireland Environment Agency.

Figure 10 ‐ Carrick ‐a‐Rede Cliffs, Antrim

CVNI. (2011). Priority Habitats ‐ Coastal ‐ Maritime Cliffs and Slopes. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/maritime_cliffs_and_slopes/

Figure 11 ‐ Northern Ireland's Coastal Habitats (Countryside Survey, 2008)

Countryside Survey. (2008). Countryside Survey: UK Results from 2007. Lancaster: Natural Environment Research Council.

Figure 12 ‐ Upper Lough Erne

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CVNI. (2011). Priority Habitats ‐ Wetland ‐ Eutrophic Standing Water. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/eutrophic_standing_water/

Figure 13 ‐ Tower Lake, Newtownstewart

CVNI. (2011). Priority Habitats ‐ Wetland ‐ Mesotrophic Lakes. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/mesotrophic_lakes1/

Figure 14 ‐ Knockballymore Lough, Fermanagh

Northern Ireland Habitat Action Plan. (2005). Marl Lakes. Belfast: Northern Ireland Environment Agency.

Figure 15 ‐ Castle Espie, Down

CVNI. (2011). Priority Habitats ‐ Wetland ‐Reed Bed. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/reed_bed/

Figure 16 ‐ Insh Marshes, Scotland

NIEA. (2010, March 18). Freshwater and Wetlands. Retrieved July 23, 2011, from NIEA ‐ Conserving Biodiversity ‐ Habitats: http://www.doeni.gov.uk/niea/biodiversity/habitats‐2/freshwater_and_wetlands.htm

Figure 17 ‐ Northern Ireland's Freshwater & Wetland Habitats (Countryside Survey, 2008)

Countryside Survey. (2008). Countryside Survey: UK Results from 2007. Lancaster: Natural Environment Research Council.

Figure 18 ‐ Belvoir Park Forest, Belfast

Northern Ireland Native Woodland Group. (2008). Northern Ireland Native Woodland: Definitions and Guidance.

Belfast: Forest Service NI.

Figure 19 ‐ Bonds Glen, Derry

CVNI. (2011). Priority Habitats ‐ Woodland ‐ Wet Woodland. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/wet_woodland/

Figure 20 ‐ Glenarm Woodlands, Antrim

Northern Ireland Habitat Action Plan. (2005). Mixed Ashwoods . Belfast: Northern Ireland Environment Agency.

Figure 21 ‐ Breen Oakwood, Antrim

CVNI. (2011). Priority Habitats ‐ Woodland ‐ Oakwood. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/oakwood/

Figure 22 ‐ Northern Ireland's Woodland Habitats (Countryside Survey, 2008)

Countryside Survey. (2008). Countryside Survey: UK Results from 2007. Lancaster: Natural Environment Research Council.

Figure 23 ‐ Wangford Warren, Suffolk

CVNI. (2011). Priority Habitats ‐ Grassland ‐ Lowland meadows. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/lowland_meadows/

Figure 24 ‐ Little Deer Park, Antrim

CVNI. (2011). Priority Habitats ‐ Grassland ‐ Calcareous Grassland. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/calcareous_grassland/

Figure 25 ‐ Tees Valley, Middlesbrough

NIEA. (2010, March 19). Farmlands and Grasslands . Retrieved July 18, 2011, from Northern Ireland Environment Agency: http://www.doeni.gov.uk/niea/biodiversity/habitats‐2/farmlands_and_grasslands.htm

Figure 26 ‐ Slievenacloy, Belfast Hills

CVNI. (2011). Priority Habitats ‐ Grassland ‐ Purple moor grassland and rush pasture. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/purple_moor_grassland_and_rush_pasture/

Figure 27 ‐ Knockmore, Fermanagh

CVNI. (2011). Priority Habitats ‐ Grassland ‐ Limestone Pavement. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/limestone_pavement/

Figure 28 ‐ Northern Ireland's Grassland Habitats (Countryside Survey, 2008)

Countryside Survey. (2008). Countryside Survey: UK Results from 2007. Lancaster: Natural Environment Research Council.

Figure 29 ‐ Murlough National Nature Reserve

CVNI. (2011). Priority Habitats ‐ Peatland ‐ Lowland Heathland. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/lowland_heathland/

Figure 30 ‐ Bloody Bridge near Newcastle

Northern Ireland Habitat Action Plan. (2003). Upland Heathland. Belfast: Northern Ireland Environment Agency.

Figure 31 ‐ Mourne Mountains

Northern Ireland Habitat Action Plan. (2003). Montane Heath. Belfast: Northern Ireland Environment Agency.

Figure 32 ‐ Northern Ireland's Heathland Habitats (Countryside Survey, 2008)

Countryside Survey. (2008). Countryside Survey: UK Results from 2007. Lancaster: Natural Environment Research Council.

Figure 33 ‐ Fairy Water Bogs, Tyrone

CVNI. (2011). Priority Habitats ‐ Peatland ‐ Lowland Raised Bogs. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/lowland_raised_bogs/

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Figure 34 ‐ Cuilcagh Mountain, Fermanagh

Northern Ireland Habitat Action Plan. (2003). Lowland Raised Bog. Belfast: Northern Ireland Environment Agency.

Figure 35 ‐ Corbally Fen, Down

CVNI. (2011). Priority Habitats ‐ Wetland ‐ Fens. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/fens/

Figure 36 ‐ Northern Ireland's Peatland Habitats (Countryside Survey, 2008)

Countryside Survey. (2008). Countryside Survey: UK Results from 2007. Lancaster: Natural Environment Research Council.

Chapter 3 Figure 1 ‐ Chicago City Hall

GreenRoof. (2010). Chicago City Hall. Retrieved http://www.greenroofs.com/projects/pview.php?id=21

August

8,

2011,

from

GreenRoof.com:

Figure 2 ‐ Murlough Dunes, Dundrum Bay

CVNI. (2011). Priority Habitats ‐ Coastal ‐ Coastal Sand Dunes. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/coastal_sand_dunes/

Figure 3 ‐ Kearney, Down

Northern Ireland Habitat Action Plan. (2005). Coastal Vegetated Shingle. Belfast: Northern Ireland Environment Agency.

Figure 4 ‐ National Trust Visitor Centre, Portstewart Strand

GreenRoof. (2010). National Trust Visitor Centre at Portstewart Strand. Retrieved August 8, 2011, from GreenRoof.com: http://www.greenroofs.com/projects/pview.php?id=904

Figure 5 ‐ Carrick‐a‐Rede Cliffs, Antrim

CVNI. (2011). Priority Habitats ‐ Coastal ‐ Maritime Cliffs and Slopes. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/maritime_cliffs_and_slopes/

Figure 6 ‐ Gallie Craig Coffee Shop, Drummore, Scotland

GreenRoof. (2010). Gallie Craig Coffee Shop. Retrieved August 8, 2011, from GreenRoof.com: http://www.greenroofs.com/projects/pview.php?id=312

Figure 7 ‐ Castle Espie, Down

CVNI. (2011). Priority Habitats ‐ Wetland ‐Reed Bed. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/reed_bed/

Figure 8 ‐ Insh Marshes, Scotland

NIEA. (2010, March 18). Freshwater and Wetlands. Retrieved July 23, 2011, from NIEA ‐ Conserving Biodiversity ‐ Habitats: http://www.doeni.gov.uk/niea/biodiversity/habitats‐2/freshwater_and_wetlands.htm

Figure 9 ‐ BMW Düsseldorf Office Building

GreenRoof. (2010). BMW Düsseldorf Office Building. Retrieved August 8, 2011, from GreenRoof.com: http://www.greenroofs.com/projects/pview.php?id=500

Figure 10 ‐ Belvoir Park Forest, Belfast

Northern Ireland Native Woodland Group. (2008). Northern Ireland Native Woodland: Definitions and Guidance.

Belfast: Forest Service NI.

Figure 11 ‐ Bonds Glen, Derry

CVNI. (2011). Priority Habitats ‐ Woodland ‐ Wet Woodland. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/wet_woodland/

Figure 12 ‐ Glenarm Woodlands, Antrim

Northern Ireland Habitat Action Plan. (2005). Mixed Ashwoods . Belfast: Northern Ireland Environment Agency.

Figure 13 ‐ Breen Oakwood, Antrim

CVNI. (2011). Priority Habitats ‐ Woodland ‐ Oakwood. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/oakwood/

Figure 14 ‐ Hundertwasserhaus, Vienna

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 15 ‐ Wangford Warren, Suffolk

CVNI. (2011). Priority Habitats ‐ Grassland ‐ Lowland meadows. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/lowland_meadows/

Figure 16 ‐ Little Deer Park, Antrim

CVNI. (2011). Priority Habitats ‐ Grassland ‐ Calcareous Grassland. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/calcareous_grassland/

Figure 17 ‐ Tees Valley, Middlesbrough

NIEA. (2010, March 19). Farmlands and Grasslands . Retrieved July 18, 2011, from Northern Ireland Environment Agency: http://www.doeni.gov.uk/niea/biodiversity/habitats‐2/farmlands_and_grasslands.htm

Figure 18 ‐ Slievenacloy, Belfast Hills

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CVNI. (2011). Priority Habitats ‐ Grassland ‐ Purple moor grassland and rush pasture. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/purple_moor_grassland_and_rush_pasture/

Figure 19 ‐ Knockmore, Fermanagh

CVNI. (2011). Priority Habitats ‐ Grassland ‐ Limestone Pavement. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/limestone_pavement/

Figure 20 ‐ Ducks Unlimited National Headquarters, Winnipeg, Canada

GreenRoof. (2010). Ducks Unlimited Canada National HQ & Oak Hammock Marsh Interpretive Centre. Retrieved August 8, 2011, from GreenRoof.com: http://www.greenroofs.com/projects/pview.php?id=463

Figure 21 ‐ Murlough National Nature Reserve

CVNI. (2011). Priority Habitats ‐ Peatland ‐ Lowland Heathland. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/lowland_heathland/

Figure 22 ‐ Bloody Bridge near Newcastle

Northern Ireland Habitat Action Plan. (2003). Upland Heathland. Belfast: Northern Ireland Environment Agency.

Figure 23 ‐ Mourne Mountains

Northern Ireland Habitat Action Plan. (2003). Montane Heath. Belfast: Northern Ireland Environment Agency.

Figure 24 ‐ North German Bank, Hanover, Germany

GreenRoof. (2010). North German Bank ‐ NordLB. Retrieved August 8, 2011, from GreenRoof.com: http://www.greenroofs.com/projects/pview.php?id=112

Chapter 4 Figure 1 ‐ Belfast City

NIEA. (2010, April 29). Information for the General Public. Retrieved September 02, 2011, from Northern Ireland Environment Agency: http://www.doeni.gov.uk/niea/de/general_public.htm

Figure 2 ‐ Northern Ireland's Urban Centres (Countryside Survey, 2008)

Cooper, A., McCann, T., & Meharg, M. (2002). Habitat Change in the Northern Ireland. Belfast: Environment and Heritage Service.

Figure 3 ‐ Albert Bridge, Belfast

NIEA. (2010, March 19). Urban Biodiversity. Retrieved Ausust 12, 2011, from Northern Ireland Environment Agency: http://www.doeni.gov.uk/niea/de/biodiversity/habitats‐2/urban_biodiversity.htm

Figure 4 ‐ UFA Film Fabrik, Berlin

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Atglen, Pennsylvania : Schiffer Books.

Figure 5 ‐ Atago Building, Tokyo

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Atglen, Pennsylvania : Schiffer Books.

Figure 6 ‐ Canary Wharf, London

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Atglen, Pennsylvania : Schiffer Books.

Conclusions Figure 1 ‐ View of the David Kier Building and the greater Belfast area

Queen's University. (2004, January 31). Belfast panorama from queens tower. Retrieved September 02, 2011, from Wikipedia: http://en.wikipedia.org/wiki/File:Belfast_panorama_from_queens_tower.jpg

Figure 2 ‐ Costal Meadow grasses planted on the Nassau Icehouse Brewery

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 3 ‐ Heath Planting on Sloped Roof at Schiphol Plaza, Amsterdam Airport Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 4 ‐ Grass sloped roof on the Vancouver Conference Centre

Zemtseff, K. (2010, May 20). Wonder what a six‐acre green roof feels like? Retrieved July 28, 2011, from Seattle Daily Journal of Commerce: http://www.djc.com/news/en/12018094.html

Figure 5 ‐ Wood Wharf, London

Earth Pledge. (2005). Green Roofs: Ecological Design and Construction. Surrey, England: Schiffer.

Figure 6 ‐ Wildwood Community College, Missouri, USA

Gedge, D., & Kadas, G. (2005). Green Roofs and Biodiversity. Biologist , 52 (3), 161‐169.

Figure 7 ‐ Modular Green Roofing System

Green Roofs Ireland. (2010). Plants. Retrieved September 03, 2011, from Green Roofs Ireland: http://www.greenroofsireland.co.uk/

Figure 8 ‐ Dundrum Bay, Down

CVNI. (2011). Priority Habitats ‐ Coastal ‐ Sublittoral Sands and Gravels. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/sublittoral_sands_and_gravels/

Figure 9 ‐ Wangford Warren, Suffolk

CVNI. (2011). Priority Habitats ‐ Grassland ‐ Lowland meadows. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/lowland_meadows/

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Figure 10 ‐ Little Deer Park, Antrim

CVNI. (2011). Priority Habitats ‐ Grassland ‐ Calcareous Grassland. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/calcareous_grassland/

Figure 11 ‐ Murlough National Nature Reserve

CVNI. (2011). Priority Habitats ‐ Peatland ‐ Lowland Heathland. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/lowland_heathland/

Figure 12 ‐ Kearney, Down

Northern Ireland Habitat Action Plan. (2005). Coastal Vegetated Shingle. Belfast: Northern Ireland Environment Agency.

Figure 13 ‐ Tees Valley, Middlesbrough

NIEA. (2010, March 19). Farmlands and Grasslands . Retrieved July 18, 2011, from Northern Ireland Environment Agency: http://www.doeni.gov.uk/niea/biodiversity/habitats‐2/farmlands_and_grasslands.htm

Figure 14 ‐ Slievenacloy, Belfast Hills

CVNI. (2011). Priority Habitats ‐ Grassland ‐ Purple moor grassland and rush pasture. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/purple_moor_grassland_and_rush_pasture/

Figure 15 ‐ Bloody Bridge near Newcastle

Northern Ireland Habitat Action Plan. (2003). Upland Heathland. Belfast: Northern Ireland Environment Agency.

Figure 16 ‐ Carrick ‐a‐Rede Cliffs, Antrim

CVNI. (2011). Priority Habitats ‐ Coastal ‐ Maritime Cliffs and Slopes. Retrieved July 20, 2011, from Conservation Volunteers Northern Ireland: http://www.cvni.org/biodiversity/index.php/Habitats/habitat/maritime_cliffs_and_slopes/

Figure 17 ‐ Knockballymore Lough, Fermanagh

Northern Ireland Habitat Action Plan. (2005). Marl Lakes. Belfast: Northern Ireland Environment Agency.

Figure 18 ‐ Mourne Mountains

Northern Ireland Habitat Action Plan. (2003). Montane Heath. Belfast: Northern Ireland Environment Agency.

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Table of Tables

Chapter 1 Table 1 ‐ Material Loading (Dunnett & Kingsbury, 2008)

Dunnett, N., & Kingsbury, N. (2008). Planting Green Roofs and Living Walls. Portland: Timber Press.

Table 2 ‐ Required Roof Loading (Adler, 1999)

Adler, D. (1999). Metric Handbook: Planning and Design Data. Oxford: Architectural Press.

Table 3 ‐ Required Depth (Dunnett & Kingsbury, 2008)

Dunnett, N., & Kingsbury, N. (2008). Planting Green Roofs and Living Walls. Portland: Timber Press.

Table 4 ‐ Green Roof Summer Temperatures

Gaffin, S. (2006, July 31). NASA Earth Observatory. Retrieved October 19, 2011, from Whites Versus Greens: http://earthobservatory.nasa.gov/Features/GreenRoof/greenroof3.php

Chapter 2 Table 1 ‐ Leading Causes of Tidal Marine Habitat Loss

Cooper, A., McCann, T., & Meharg, M. (2002). Habitat Change in the Northern Ireland. Belfast: Environment and Heritage Service.

Table 2 ‐ Leading Causes of Coastal Habitat Loss

Cooper, A., McCann, T., & Meharg, M. (2002). Habitat Change in the Northern Ireland. Belfast: Environment and Heritage Service.

Table 3 ‐ Leading Causes of Freshwater and Wetland Habitat Loss

Cooper, A., McCann, T., & Meharg, M. (2002). Habitat Change in the Northern Ireland. Belfast: Environment and Heritage Service.

Table 4 ‐ Leading Causes of Woodland Habitat Loss

Cooper, A., McCann, T., & Meharg, M. (2002). Habitat Change in the Northern Ireland. Belfast: Environment and Heritage Service.

Table 5 ‐ Leading Causes of Grassland Habitat Loss

Cooper, A., McCann, T., & Meharg, M. (2002). Habitat Change in the Northern Ireland. Belfast: Environment and Heritage Service.

Table 6 ‐ Leading Causes of Heathland Habitat Loss

Cooper, A., McCann, T., & Meharg, M. (2002). Habitat Change in the Northern Ireland. Belfast: Environment and Heritage Service.

Table 7 ‐ Leading Causes of Peatland Habitat Loss

Cooper, A., McCann, T., & Meharg, M. (2002). Habitat Change in the Northern Ireland. Belfast: Environment and Heritage Service.

Table 8 ‐ Rate of Habitat Change in Northern Ireland (Cooper, McCann, & Rogers, 2009)

Cooper, A., McCann, T., & Meharg, M. (2002). Habitat Change in the Northern Ireland. Belfast: Environment and Heritage Service.

Chapter 3 Table 1 ‐ Habitats Capable of Existing on Green Roofs

Author

Table 2 ‐ Required Roof Type for Habitat Recreation Author

Table 3 – Imposed Roof Loading for Habitat Recreation Author

Chapter 4 Table 1 ‐ Extent of Urban Area in Northern Ireland (Cooper, McCann, & Rogers, 2009)

Cooper, A., McCann, T., & Meharg, M. (2002). Habitat Change in the Northern Ireland. Belfast: Environment and Heritage Service.

Table 2 ‐ Size of Major Urban Centres in Northern Ireland Multple Autors(see table)

Table 3 ‐ Northern Ireland Habitat Action Plan Required Restoration of Natural Habitats Northern Ireland Habitat Action Plan. (2005). Belfast: Northern Ireland Environment Agency.

Table4 ‐ Northern Ireland Habitat Action Plan Required Re‐establishment of Natural Habitats Northern Ireland Habitat Action Plan. (2005). Belfast: Northern Ireland Environment Agency.

Table 5 ‐ Required Roof Loading (Adler, 1999) xii

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Adler, D. (1999). Metric Handbook: Planning and Design Data. Oxford: Architectural Press.

Table 6 – Imposed Roof Loading for Habitat Recreation Author

Table 7 – Building Types Capable of Carrying Habitat Roofs Author

Table 8 – Estimable Cost Range for Habitat Recreation Author

Table9 ‐ Northern Ireland Habitat Action Plan Required Re‐establishment of Natural Habitats Northern Ireland Habitat Action Plan. (2005). Belfast: Northern Ireland Environment Agency.

Table 10 ‐ Estimated Costs of introducing wide scale Habitat Roofs to Northern Ireland

Author

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Introduction

The Relationship between Green Roofs and Natural Habitats

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The aim of this report is to assess the potential, if any, for green roofs in urban areas to act as habitat islands and the ability of such an approach to affect the local/regional ecology in regards to both flora and fauna species

Green roofs are a growing part of urban areas, providing numerous benefits to built‐up regions. They have been proven to be capable of mitigating the urban heat island effect (Skinner, 2006; Alexandri & Jones, 2008) and reduce rainwater runoff (Graceson, Hare, Hall, & Monaghan, 2011; Keeley, 2003). There are also studies indicating that green roofs can sequester carbon (Getter, Rowe, Robertson, Cregg, & Andresen, 2009) and can increase the Figure 1 ‐ Northern Ireland Landscape life span of the roofs, because of the longevity added to covered roof membranes (Porsche & Köhler, 2003). These factors will be further discussed in the first chapter of this report.

However the increase in popularity of green roofs is primarily because of the environmental benefits that they bring, particularly in urban areas (NIEA, 2005). This report will aim to establish the possibilities of green roofs to be used in a habitat creation role in Northern Ireland. While long‐term studies on small scale sites have proven that green roof can support complex habitats in London (Gedge D. , 2002) and Basel, Switzerland (Brenneisen S. , 2005) this study aim to gauge if a similar programme of greening would be suitable for the conditions associated with Northern Ireland’s natural habitats.

In‐01 Green Roofs connection to Habitat Creation English Nature defines green roofs as “…roofs that have been initially planted, as well as those that have been allowed to colonise and develop naturally” (Grant, Engleback, & Nicholson, 2003). While this is a broad definition, it can be said that the current generation of green roof were largely developed in Germany during the 1960s (Keeley, 2003). There initial reason for the installation was to meet the growing need for urban ecology and city centre gardens in many German cities, Figure 2 ‐ 419 Lafayette St, Manhattan principally Berlin (Johnston, 1993).

Green roofs are generally categorised into two formats, ‘Intensive’ (heavily planted) and ‘Extensive’ (lightweight planting), based on their structure and plant material. This will be discussed in detail in Chapter 1. Both are capable of supporting a wide variety (all be it very different species) of vegetation and present a potential platform for habitat creation (Francis & Lorimer, 2011).

There are numerous examples worldwide of habitats that have been adapted and installed on typical green roofs; these include examples form mountainous zones, coastal areas, dry grasslands, cliffs/scree slopes and many others. (Lundholm, 2006; Dunnett & Kingsbury, 2008). Wet/dry meadows and heath/moor habitats can also be re‐created on rooftops, when the drainage is restricted, or if the substrate provides sufficient water retention. An example of this recreated habitat zone is the green roof system at the water‐filtration plant in Wollishofen, on the outskirts of Zurich (Landolt, 2001).

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The type of environment that is created on a green roof is principally dictated by the structure of roof itself and the soil makeup, with weather and microclimate conditions being secondary concerns (Dunnett & Kingsbury, 2008). The physical properties of a green roof‘s growing medium will significantly impact plant growth, plant survival and water retention (Graceson, Hare, Hall, & Monaghan, 2011) and to these points will be discussed in chapter 1.

In theory given a high level of design and planning, green roofs can provide habitat compensation for rare and endangered species affected by land‐use changes. Numerous studies for various parts of the world (mostly extensive green roofs in Europe) have established through research studies that green roofs posses notable ecological compensation potential (Brenneisen S. , 2006; Jones, 2002; Kadas, 2006). A 20 year study of extensive green roofs in Berlin illustrated that a relatively diverse species populations can be achieved on roofs in urban areas (Köhler, 2006).

General statistics states that typically roof space represents up to 32% of the total surface areas in most urban locations (Frazer, 2005). In the Greater London region it is estimates that roofs cover 240 km2, or 16% of the land surface (Grant, 2006). While of course not all roofs are suitable for supporting green roofs; built‐up areas do represent zones of potential ecological expansion. Many regions of most towns and city can be simply redevelopment to support habitat creation. There is huge potential Figure 3 ‐ Lapwing breeding on the Green Roof for roof greening on industrial and commercial land on the outskirts of residential areas. It has been proved that extensive greening would lead to significant improvements in local bird populations (Brenneisen S. , 2006) an important factor for Northern Ireland and its importance for migratory bird populations (Countryside Survey, 2008).

In‐02 Habitat Loss in Northern Ireland Northern Ireland has a wide range of habitats and species, some of which are of special note (NIEA, 2010). The coastal regions of Northern are of international importance for waterfowl and waders, while upland areas and bogs are renowned for their diversity in plant life and invertebrates (NIEA, 2007).

Currently Northern Ireland is experiencing a loss of natural habitats, commonly due to urban expansion and modern farming practices (Cooper, McCann, & Rogers, 2009).

During the past decade, the UK as a whole recorded a 39% loss in area of natural environments and 27% of ‘priority species’ were found to now be in decline (Defra, May 2006). In many parts of the UK there has been a degradation in markers that indicate an environment’s health, such as the UK butterfly population dropping by 55% in the last 30 years (Defra, April 2008) and major Figure 4 ‐ Northern Ireland Grassland declines in bees and amphibians (Margerison, 2008).

Additionally the UK bird population has been depleted by an average of 6% in the last 30 years (Defra, March 2008).

Northern Ireland’s natural habitats face a number of risks. The leading cause of habitat loss is the increase in demand for housing over the past decade (NIEA, 2007), especially for new

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housing in coastal regions were construction was commonly on virgin land (MOSS, 2009).

Another general treat to Northern Ireland’s ecology is species invasion. Species such as the Zebra Mussel, Japanese Knotweed and the New Zealand Flatworm are all extremely invasive and damaging to native wildlife (Biodiversity NI, 2011).

Habitat concerns exclusive to Northern Ireland centre around the diminishment of habitats uniquely indigenous to this country, primarily wet grasslands, boglands and native forests.

Currently the peat bogs in Northern Ireland suffer from over grazing, excess harvesting of turf, and the machining of peat in gardening products (Biodiversity NI, 2011). Additionally, Northern Ireland is one of the least wooded countries in Europe, with only 6% tree cover and the majority of woodland is non‐native conifer species (MOSS, 2009). Finally the national wet grassland are crucial for migrating bird populations and the reduction in there range because of farming practices has had a knock on effect. The Curlew, Snipe, Redneck and Lepwing who breed on wet grassland and bogs have declined in numbers by over 50% in the Last 20 years and the common House Sparrow population has declined 19% between 1994 and 2006 (Biodiversity NI, 2011).

These statements express only a surface overview of the many issues facing the ecology of Northern Ireland’s natural habitats. There are numerous cases where local ecosystem have grown and developed alongside modern developments. A more in‐depth analysis of the importance and influences of habitat types in Northern Ireland will be undertaken later in this report.

In‐03 Impact of Existing Green Roof on Surrounding Habitats An extensive catalogue of case studies exists demonstrating the ecological consequences of installing green roofs. Most study either focus on flora, invertebrates or birds, there are two reasons for this; they represent good indicator to the health to a habitat (Defra, May 2006) and secondly they are the principle animal that occupy roof garden (Brenneisen & Hänggi, 2006). Although a fox was found wander on the Belfast Castle Court Centre roof in June 2009 (Biodiversity NI, 2009).

The ability for green roof to accommodate any plant species is a simple matter of carful design (Burgess, 2004; Dunnett N. , 2006), but it is common for plants to naturally migrate to roof garden and on occasion extremely rare plant species have unexpectedly been found happily living at roof level.

In Wollishofen, Zurich; nine near extinct orchid species were found existing alongside 175 other plant species on the grass roofs of four water plants.

Figure 5 ‐ Moos Filtration Plant Wollishofen Zurich This was a surprise as the green roofs were never intended to be an ecological centre when they were installed in 1914 (Landolt, 2001).

Research from both America and Europe has shown that green roofs are adept at attracting and supporting colonies of insect species, with the elevated locating of the vegetation having a negligible impact. Green roofs on the Ford assembly Plant, in Dearborn, Michigan was shown to become home to 29 insect species, seven spider species, and two bird species within the first two years of its installation. (Coffman & Davis, 2005). And construction laws in Basel, Switzerland were changed when a biodiversity study of seventeen green roofs found 78 spider and 254 beetle species. Of which 18% of the spiders species and 11% of the

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beetles were found to be rare and some considered as endangered (Brenneisen S. , 2006).

These finding will be expanded upon throughout this report.

Bird species can benefit greatly from the installation of green roofs. Swifts which migrate to Northern Ireland in late summer on their way to winter in Africa already inhabit the roofs of many existing buildings (Biodiversity NI, 2009). And green roofs can greatly enhance the habitability of many existing structures (Grant G. , 2006). Already the sedum roof at Belfast’s Victoria Centre is home to nesting jackdaws, blackbirds and finches (Biodiversity NI, 2009).

In‐depth research into the occupation of green roofs by birds has been undertaken in London. Two roofs in East and West Sussex studied during 2004 found that 70% of the total duration of all bird activity involved the use of resources provided by the vegetation on the roofs, i.e. birds spent most of their time feeding and collecting nest material (Burgess, 2004). Four species of high conservation concern and two of moderate conservation concern were observed using the roofs. The study concludes Figure 6 ‐ Laban Dance Centre, London that if careful consideration is taken over the design of green roofs, then they could play an important role in secure the future the most threatened birds species (Burgess, 2004). The most endangered species observed on a green roof was Black Red Start (Grant G. , 2006).

Between 50 and 100 breeding pairs of this highly endangered species was seen nesting (Frith & Gedge, 2000) on the on the Laban Centre and the Creekside Centre, both in the London Docklands.

In‐04 International Approaches to Rooftop Greening The potential value of green roofs in urban centres has not gone unnoticed by policy makers around the world. With their benefits towards the heat island effect (Skinner, 2006; Alexandri & Jones, 2008), runoff (Graceson, Hare, Hall, & Monaghan, 2011; Keeley, 2003) and ecology (Dunnett & Kingsbury, 2008), numerous planning and development bodies are accommodating and actively promoting green roofs in future Figure 7 ‐ 47° pitched Roof Berlin‐Kreuzberg building projects.

Because of the extensive body of research undertaken in Basel by Dr Stephan Brenneisen, the city has amendment its building and construction laws. Now as part of the city's biodiversity strategy, green roofs are now mandatory on all new buildings with flat roofs (Brenneisen S. , 2006). Also if new green roofs exceed 500m2, then there substrates must be composed of natural soils and accommodate vegetation which comes from the surrounding region (Brenneisen S. , 2005).

The London 2012 Olympics aims to construct at least 0.4ha (4,000m2) of green roofs on selected buildings as part of its Biodiversity Action Plan (Olympic Delivery Authority, 2008).

And in Japan, green roofs are favoured by developers are the increase the retail value of their properties by an averaging 8% (CABE, 2005). These and other policies will be explored in the fourth chapter of this report.

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However the most comprehensive standards for green roof growing media can currently be found in Germany (FLL, 2002).The German guidelines are regularly used by the green roofing industry throughout Europe and the UK as they provide excellent information on creating growing media, vegetation growing conditions, water retention requirements and load capacity (FLL, 2002). These benchmark were built‐up over the past number of decades, as the German have a widespread use of green roofs because of Figure 8 ‐ Ufa‐Fabrik Centre, Berlin‐Templehof policy, like those in Berlin, where green roofs were required to be constructed on apartments roof between 1983 until 1996 (Köhler, 2006).

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Methodology

Aims and Objectives of the Report

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As stated the aim of this report is to assess the potential to of green roofs to negate natural habitat loss in Northern Ireland, by providing an alternative to traditional methods of habitat recreation and maximise the benefit of urban areas to the local flora and fauna. This will be done through a series of examinations and comparative exercise.

The initial task is to investigate the limitations place on habitat creation by the physical conditions of a roof structure. This undertaking will provide a knowledge base for the development of habitats at roof level and highlight the types of ecosystems naturally adapted to the circumstances of Northern Ireland’s rooftops.

This undertaking will be combined with an examination into the current condition of natural habitats in Northern Ireland, examining their requirement, features and characteristics that classifies them as a unique eco‐zone. This undertaking will establish the feasibility of which environments can be recreated at roof level.

On completion of these two undertakings, a list of habitations that are capable of existing on roofs in Northern Ireland will be generated. This will then inform the second part of this report on the connotation of building such environments in Northern Ireland’s urban centres.

The latter chapters of this dissertation will consist of an examination into case study green roof projects. These examples will consist of high quality examples of habitat recreation rooftops, demonstrating the practical requirements of green roof construction.

Finally the discussion and analysis of the information produced in this report will be discussed, and the implications of the information produced in this report and the role that local government can have on the combination of ecology and the built environment.

The final goal of this report is to provide an informed argument on green roofs potential effect to the Northern Ireland ecology and where any natural habitat is capable of being successfully recreated on rooftops. Qualify whether green roofs can first feasible counteraction the habitat loss in Northern Ireland and secondly if embarking upon such an exercise would produce a gainful environmental benefit to urban centre and the surrounding landscape.

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Chapter 1

Habitat Creation on Green Roofs

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Figure 1 ‐ M Central, Sydney

Green roofs are a relatively new building element in Northern Ireland, with few examples of fully realised grass or vegetation covered roofs existing in the province (Biodiversity NI, 2011). However the implementation of green roofs is a mature part of the construction industry within continental Europe, particularly Germany (Gedge & Kadas, 2005). For example during 2001, 14% of all new flat roofs constructed in Germany were green roofs, accounting for 13.5million m2 as part of national and regional environmental legislation (Earth Pledge, 2005).

Completed examples of green roofs in Northern Ireland represent a limited level of ambition in regard to ecological resource creation (Gedge & Kadas, 2005). With the predominant form of green roofs consisting of thin, prefabricated vegetation mats (Emilsson, 2003). Examples of purpose developed habitat rooftops are sporadic, with a limit number of examples in the UK (Dunnett & Kingsbury, 2008).

Rooftops, especially those in dense urban centres, are a challenging environments for both flora and fauna species. Habitat that are created often have to accommodate period of drought, excessive temperature ranges and wind exposure; element that may be alien in their natural settings (White & Snodgrass, 2003). In practice, rooftop micro‐climates vary greatly depending local conditions and urban typology (Dunnett, 2006). However as mention during the introduction, the physical attributes of a green roof’s construction will have a greater impact on the range of supportable species than the local roof level climate conditions (Brenneisen S. , 2006; Köhler, 2006). This will be further discussed throughout this chapter

1‐01 Green Roof Components As briefly mentioned during the introductory chapter there are two prevailing forms of green roof structure, ‘Intensive’ and ‘Extensive’. While there are a number of variations of these systems the following descriptions are representative of the prevailing structural makeup of a green roof.

Intensive Green Roofs are the typical construction method for roof gardens and grass roof because they are capable of supporting complex vegetation such as groundcovers, small trees and shrubs. These roofs often possess a substrate (soil) layer deeper than 20cm and typically require irrigation systems, maintenance and additional reinforcement to the building’s roof structure to support the live loading of the plant material. (Oberndorfer, et al., 2007).

Figure 2 ‐ Intensive Green

Roof Structure Extensive Green Roofs are lighter than ‘Intensive’ roofs.

With substrate layers with thicknesses below 20cm, and are generally planted with sedum and herbaceous species such as mosses. These roof require minimal or no irrigation and no additional strengthen to a typical roof structure. (Dunnett & Kingsbury, 2008; Oberndorfer, et al., 2007). Also extensive green roofs do not necessarily require a flat roof, but can exist at an angle of up to 40 degrees. (Gedge & Kadas, 2005) Figure 3 ‐ Extensive Green Roof Structure

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In practice, a greater variety of planting can occupy intensive green roofs because of their deeper soil layers (Lundholm, 2006), however the shallow substrate of extensive green roofs can be advantages to specialised habitats such as rocky, scree and sand/grave based ecosystems (Dunnett N. , 2006).

All green roofs are comprised of the Waterproof Membrane Insulation following layers.  Waterproof Membrane  Root Protection Barrier; to prevent root penetration  Insulation

Figure 5 ‐ Extruded Polystyrene  Drainage and Retention Layer; Figure 4 ‐ PVC Waterproof Membrane Drainage Layer Substrate which may or may not act as a water reservoir for vegetation  Growing Medium/Substrate; varying in material and depth  Vegetation The thickness and weight of green roofs Figure 6 ‐ Synthetic Drainage Board Figure 7 ‐ Mineral/Organic Medium can differ significantly depending on the chosen planting. The divergence of physical properties of a roof’s structure due to the required habitat recreation shall be explored during this chapter.

Figure 8 ‐ Green Roof Substrate Layers

1‐02 Structural Considerations Green roofs’ impose a weight loading on its buildings structure, this value fluctuates from inconsequential for extensive roofs to the requirement of additional structural support for heavily planted intensive roofs (Peck & Kuhn, 2000).

kg/m2 lb/sq.ft Extensive roofs are relatively Substrate Materials Gravel 16‐19 8.4‐9.9 lightweight and are generally within 19 9.9 the normal load‐bearing capacity of the Pebbles 6.5 3.3 majority of modern roofs (Köhler, Pumice 18 9.4 2006). Extensive substrates with Brick (solid with mortar) Sand 18‐22 9.4‐11.4 depths of 5‐15cm will increase the 18 9.4 loading on roof by between 70kg/m2‐ Sand and Gravel Mixed Topsoil 17‐20 8.9‐10.4 170kg/m2 (Dunnett & Kingsbury, 2008).

Water 10 5.3

Lava 8 4.1 The greater substrate depths and Permute 5 2.54 vegetation densities of intensive roofs Vermiculite 1 0.51 are the principle reason for their larger Light Expanded Clay Granules 3‐4 1.5‐2.0 imposed loading. A comparatively Table 1 ‐ Material Loading (Dunnett & Kingsbury, 2008) shallow topsoil layer of 10‐15cm can add 500kg/m2 to a roofs weight (Kingsbury, 2001); the added loading of intensive roofs range between 290kg/m2 and 970kg/m2 (Dunnett & Kingsbury, 2008).

BS6399 Category (General Fig) N/m2 kg/m2 Within the UK, roof weight is Domestic 1.5 153 controlled by British Standard 6399; Offices 2.5 255 this states the required strengths for Retail 4.0 408 roofing system (Adler, 1999). While Warehousing 2.0 204 the data on green roof loading is Factories, Workshops 5.0 510 Table 2 ‐ Required Roof Loading (Adler, 1999)

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highly individualistic, an argument can be made that lightweight extensive green roof can be installed on the majority of Northern Ireland roofs without the need for additional strengthening (Peck & Kuhn, 2000). The most common roof‐greening technique is the installation of thin, prefabricated vegetation mats. These mats have a soil substrate layer of about 4cm (1.6in) and weigh around 50‐60kg/m2 (Emilsson, 2003), safely in the load capacity of even domestic roof structures.

1‐03 Roof Slope Public perception of green roofs is that they can only occupy flat roof spaces (Earth Pledge, 2005). However there are numerous examples of green roofs, which have been constructed on prominent slopes.

The ability of a green roof to withstand the shear forces imposed by residing on an angle is controlled by the friction coefficient between the two smoothest structural elements, typically membrane interfaces. Unaltered a green roof can resist creep at Figure 9 ‐ 8 House, Oerestad, Copenhagen slopes no steeper than 9.5O or 2:12 (Dunnett & Kingsbury, 2008).

Slippage can be counteracted by the use of horizontal strapping, laths, battens, or grids, increasing the potential gradient to 30O or 7:12 (Dunnett & Kingsbury, 2008). With specialised growing mediums, stake and appropriate plant selection it is possible to achieve slopes over 35O (ZinCo, 2011). In his 2006 report on Berlin green roofs, Mannfred O Köhler recorded buildings with 47 grass roof (Köhler, 2006).

Figure 10 ‐ Vancouver Convention

1‐04 Nutrients & Water Requirements Through the use of stress‐tolerant planting on green roofs the need for additional nutrients is generally unnecessary (Brenneisen S. , 2006; Köhler, 2006). If a green roof is design as a natural habitat and not subject to excessive landscape management, a natural equilibrium in the roof’s nutrient cycle will develop, with the decay of dead stems and leaves feeding new growth (Dunnett & Kingsbury, 2008). Conversely if a roof undergoes heavy pruning, mowing and the removal of plant litter, plant feeding may be required every two year with slow release nutrient packs (White & Snodgrass, 2003). The requirement for even low levels of landscape management would be rare on any roof design to recreate natural habitats, so add nutrients would not be typically required (Earth Pledge, 2005). However recreational roof gardens are typically highly managed environments and will require similar maintenance as specialised horticulture gardens (Dunnett & Kingsbury, 2008).

Research has proven that a reliably consistent water supply is more important to plant species diversity, than substrate depth on all green roofs (Dunnett & Kingsbury, 2008).

Characteristically there are difference in the type of vegetation found in urban centres and the surrounding rural habitats. Inner city plant species tend to be more adapted to dry conditions (Köhler, 2006). Thusly it is recommended that urban green roofs incorporate systems to address periods of relative drought (White & Snodgrass, 2003). A number of studies by Stephen Brenneisen in Switzerland have shown that plant vitality and invertebrate diversity can Figure 11 ‐ Climatologist Stuart Gaffin at Con Edison Power Plant, Long Island City

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be directly compared to the moisture level in a roof’s substrate (Brenneisen S. , 2001).

A number of systems are available for green roof irrigation, most including some form of rainwater storage and recycling systems (Miller, 2003). However as green roofs possess the ability to retain a high rate of rainwater (Graceson, Hare, Hall, & Monaghan, 2011; Keeley, 2003), many roof substrate systems store water in a drainage layer below their growing medium. Research programmes recorded that a 6cm (2.4in) vegetation layer retains 67% of rainwater and a 12cm (4.8in) growth media with a mix of grasses and herbs retains 70% (Scholz‐Barth, 2001), making the need for irrigation redundant. This property of green roofs in urban regions will be discussed later on in this chapter.

It is important to note that the need for additional irrigation and nutrients is dictated by local environmental conditions (Peck & Kuhn, 2000), substrate make‐up (Francis & Lorimer, 2011) and most importantly the type of green roof environment one desires (Dunnett & Kingsbury, 2008). The Laban Dance Centre has created a habitat for rare bird species through the use of an extensive gravel roof that requires no maintenance (Frith & Gedge, 2000).

1‐05 Substrate Makeup The knowledge base of the horticultural industry has revealed that the physical properties of a substrate will have a significant impact on the growth rates and survivability of planted vegetation (Blythe & Merhaut, 2007). A roofs substrate layer will effect water retention, nutrient requirement (Miller, 2003) and root temperature (White & Snodgrass, 2003). There are notable differences between the substrates of extensive and intensive roofs.

Extensive green roof are characterised by shallow substrate layer and are associated with a low biological diversity (Brenneisen S. , 2006). Typically populated by sedum, grasses, herbs and mosses (Emilsson, 2003), installed on mats of non‐organic mineral fibres which have moisture holding capacity that mimics organic materials (Hitchmough, 1994).

Figure 12 ‐ Sedum Mat Installers

Natural soil is not advisable for lightweight extensive roofs, due to their inherent weight and high fertility (which encourages vigorous and unsustainable growth). Medium to low fertility is also a requirement for the development of diverse meadow vegetation, a viable option for habitat recreation on extensive green roofs (Miller, 2003).

Options for intensive substrates range between mixtures of organic material and natural or artificial soils (Snodgrass. & Snodgrass, 2006). Studies of green roofs in Zurich, Switzerland, have shown that natural soils in substrates can benefit biodiversity, due to the acclimatisation of local flora and fauna to native soils (Dunnett & Kingsbury, 2008). Artificial soils, made from material such as sand Figure 13 ‐ 70mm Grass Roof and lava rock, have also proven to be excellent at promoting plant growth because of their tailored nature (Hitchmough, 1994).

The level of plant (Grant G. , 2006) and invertebrate diversity (Brenneisen S. , 2006) can be directly related to the soil depth, age, establishment of planting and the nature of a substrate, for both extensive and intensive roofing systems (Miller, 2003). Typically the species range of green roofs naturally evolves with time, through establishment and natural species migration and colonisation (Brenneisen S. , 2006). Presently the level of industrial

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data within horticultural is sufficient to meet green roof construction needs (Blythe & Merhaut, 2007); unfortunately it has be state that the crossover of experience to the building profession is questionable (Dunnett & Kingsbury, 2008).

1‐06 Soil Depth and Planting Regements Continuing on from the importance of substrate composition, the depth of a roof’s substrate layer also influences planting options. This is due to the requirements of root growth and the ability of a substrate to protect its root system from environmental stresses, namely temperature extremes (White & Snodgrass, 2003).

The importance of substrate depth is primarily Soil Depth Planting Possibilities an issue concerning intensive green roofs as 0‐5cm Sedum/Moss communities extensive generally do not exceed 20cm (0‐2in) (Oberndorfer, et al., 2007).

5‐10cm Dry meadow communities

(2‐4in) Low‐growing drought‐ The temperature ranges in Europe has prescribe tolerant Perennials that thin substrate (under 3cm) can only Grasses/Alpines support sedum and moss species, medium depth Small Bulbs substrates (5‐8cm) are capable of maintaining a 10‐20cm Semi‐extensive mixtures wider range of grasses, herbs and sub‐shrubs. of low to medium dry (4‐8in) habitat Perennials Depths of above 50cm are required for trees to Grasses and Annuals be grown (Dunnett & Kingsbury, 2008).

Small Shrubs

Lawn/Turf Grass Designing green roofs so that they have a varying 20‐50cm Medium shrubs substrate depths and drainage regimes, creating (8‐20in) Edible Plants a mosaic of microhabitats (both on and below Generalist Perennials and the surface soil layer) has been shown to Grasses facilitate the colonisation of a green roof by a 50+cm Small Deciduous Trees and more diverse range of flora and fauna species (20+in) Conifers (Brenneisen S. , 2006).

Table 3 ‐ Required Depth (Dunnett & Kingsbury, 2008)

An important discussion is ongoing between the uses of native or alien plant in green roof developments (Dunnett, 2006) especially as species invasion is a concern for Northern Ireland, as mention in the introductory chapter. The use of local planting can potentially promote the occupation of a roof by local fauna (Brenneisen S. , 2006); unfortunately many native species are highly invasive and dominant and may lead to a reduced planting diversity (Clement & Foster, 1994). Alternatively, many exotic species may be ideally suited to the environment created by the particular microclimate Figure 14 ‐ Native wildflowers on the conditions of a green roof (Dunnett & Kingsbury, 2008).

Multanomah Building

Studies undertaken in Switzerland have presented evidence that in dense urban areas; fauna species, especially birds, will dominate rooftops which has similarities to their natural habitats regardless to the proximity to matching ecosystems (Frith & Gedge, 2000). Urban biodiversity strategy can advise on the appropriate plant strategies, based on regional species research (Brenneisen S. , 2006).

Planting methods for green roofs are as varied as those for conventional gardens. Extensive roofs utilise vegetation mats, seeds and bulbs regularly being subject to monoculture planting. While intensive roofs are capable of availing of potted and transplanted plants

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(Dunnett & Kingsbury, 2008). Spontaneous or natural colonisation occurs frequently on all green roof type, with has led to the occupation of rare and unexpected plant species (Landolt, 2001), as described in the introductory chapter. This issue will be discussed in further detail in chapter 4.

1‐07 Biological Limitations Academic studies have illustrated a number of limitations of green roofs in regards to their biological opportunities when directly compared to ground level urban brownfield sites (Brenneisen & Hänggi, 2006). While certain aspects of green roofs can be improve with careful design and consideration of local environmental assets (Brenneisen S. , 2006), a number of constrains are characteristic to rooftop habitats.

The shallow nature of substrates on roofs, limit the ability of deep‐rooted plants to extract moisture, it also means that root systems will be subject to the extremes of temperature (Boivin, Lamy, Gosselin, & Dansereau, 2001). In order to survive Northern Ireland temperature ranges, the planting of green roofs need to capable of surviving a wide variation in thermal exposures, as roof substrates are not thermally stable (Snodgrass. & Snodgrass, 2006; White & Snodgrass, Figure 15 ‐ Freezing Roof Vegetation 2003).

The air/soil mixture level in roof substrates are lower than those of ground soil, this is partly due to the difference between the artificial and natural earth layers (Oberndorfer, et al., 2007), but principally the lack of burrowing invertebrates and earthworms (Brenneisen S. , 2006). Such invertebrates have difficulties surviving on green roofs due to the limited depth of the substrate; perishing during temperature extremes. Because earthworms are the fundamental for the aeration of subsoil, this places server restrictions on plant diversity (Miller, 2003).The practice of adding lava rock, pumice, gravel, broke brick or concrete to roof substrate are utilised, allowing air to penetrate soil layers (Schradera & Boningb, 2006).

The value of a green roof as a biological resource is restricted by its size, often hindering the potential of natural colonisation of a roof by new plant species (Brenneisen & Hänggi, 2006). English Nature published a report in 2003 that stated while individual green roofs offer local environmental benefits; any significant contribution to the wider environmental quality will only become apparent once a critical mass of urban roof space is greened (Grant, Engleback, & Nicholson, 2003). A 2009 study Figure 16 ‐ Rockefeller Centre, New York of a business/retail park in the Netherlands investigated the potential for a series of green roof islands as a means to negate the debilitating effect of size limitation. An increase in the local districts wildlife was recorded, with the reason being stipulated the green roofs were acting as areas of ecological sanctuary (Snepa, Van Ierland, & Opdama, 2009). The issues ecological viability on small green roofs will be further discussed later on in this report.

A more general barrier to the creation of roof level artificial habitats is poor expectation and a lack of ambition in regard to the development of green roofs (Dunnett & Kingsbury, 2008).

The UK construction industry currently possess no form of building control standards; high

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costs rates and a highly limited number of demonstration examples within the UK to provide confidence in the economic and environmental benefits of green roofs (Dunnett, 2006).

These factors combine to create a limited appetite for the adoption of green roofs amongst the UK public (Earth Pledge, 2005).

1‐08 Green Roof Maintenance While a completely maintenance free green roof is an unachievable goal, extensive and semi‐extensive roofs generally require highly limited upkeep (White & Snodgrass, 2003).

There are four aspects to green roof maintenance; feeding, plant protestation, drainage and weeding (Dunnett & Kingsbury, 2008). Plant nutrients and drainage has been previously discussed in this chapter.

Pests and diseases are a minor problem form green roofs, partially because of the stress tolerant nature of typical planting. The principle risk is fungal diseases from an accumulation of tree leaves (Groundwork, 2011). More importantly, green roofs are highly susceptible to wind‐blown seeding and can be colonised by unwanted or invasive species. Care must be taken during weeding to insure tree and shrub seedlings, such as Birch and Willow, or annuals like corn or wheat do not become established as they can dominate other plants and damage the roof membrane (Dunnett & Kingsbury, 2008).

1‐09 Insulating Effects of Green Roofs Research has shown that green roofs are capable of delaying thermal influence and providing an insulating effect in cold temperatures. This effect remaining constant in substrate depths between 120mm and 300mm and is greatest in roofs with substrates over 400mm. It is important to note that green roofs are insignificant in effecting indoor air temperatures during summer temperature highs (Yoshimi & Altan, 2011).

1‐10 Benefits of Green Roof to the Urban Environments While individual green roofs will offer local environmental benefits, the advantages of green roofs can affect a large urban area if a significant proportion of roof space is greened, with some attributes of green roofs requiring a critical mass of greenery to be become apparent (Grant, Engleback, & Nicholson, 2003).

Green Roofs and Heat Island Effect/Urban Air Quality/Carbon Sequestering The surface temperatures of green roofs are significantly less than those of conventional roofs during summer, and studies have shown that if a large area of a city’s roofs are greened they can reduce the ‘heat island effect’ (Skinner, 2006; Alexandri & Jones, 2008), this is the principle reason for development of green roofs in cities such as Tokyo (Tokyo Metropolitan Government, 2002) and Chicago (City of Chicago, 2010), these case studies will be further discussed in Chapter 4. This effect is due to the reduced heat reflectance from the surface of green roofs (Szokolay, 2008) and lower air temperatures because of the expiration of the planting (Skinner, 2006; Alexandri & Jones, 2008).

During the Penn State 2003 study, Gaffin and his collaborators measured the temperatures on both green and dark roofs. Both kinds of roofs warmed during the day and cooled overnight. While dark roofs cooled slightly more overnight, however, they warmed up much more during the day than their green counterparts. At their warmest, the dark o roofs reached roughly 70 C, whereas the green roofs only reached about 40oC. (Gaffin, 2006).

Table 4 ‐ Green Roof Summer Temperatures The ability of combining the respiration of plant to a buildings structure also directly influence the air quality and CO2 content of the surrounding urban area. The combined area

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of leaves from the numerous plant species found on typical green roofs creates a large surface area capable of filtering out dust, pollutants and some forms of airborne viruses (Doernach, 1979; Brookes, 1984). Furthermore there is growing evidence for the capacity of green roofs to act as carbon stores. Studies conducted on extensive green roofs in Michigan and Maryland; found that they were actively sequestered 375gC/m2 (Getter, Rowe, Robertson, Cregg, & Andresen, 2009).

Green Roofs and Rainwater Retention The water retention rate of green roofs is one of the most researches aspects of green roofs and is one of the documented reasons for Berlin developing green roofs (Earth Pledge, 2005); this case study will again be discussed in Chapter 4. Lightweight moss and heather extensive roofs have a retention rate of 18L/m² (Optigreen, 2011), and a grass roof can hold 30‐80L/m² (Optigreen, 2011). Green roofs also reduce the immediate discharge of rainwater to 25% that of conventional roofs (Kӧhler, 1989).

1‐11 Green Roofs effect on People While this report is concentrated on issues regarding the biological effects of green roofs, in regards to Northern Ireland’s native flora and fauna, they also have a psychological and physiological impact on people.

Numerous studies in hospitals, such as St. Luke’s Science Centre in Japan have shown a link between the calming effects between green plants can shorten patients’ recovery times (Earth Pledge, 2005). The introduction of planting to a building’s roof will reduce pollutants, dust particles and increase the humidity of air in a structure which has been proven to enhance people’s mood and physical responsiveness (Crowther, 1994) and cause a reduction in employee absenteeism as a result of “healthier” buildings (Keeping, 1996).

A study of employee satisfaction in a building that with access to a green roof in the Netherlands; found that the majority of employees used (89%) and appreciated (92%) the space (Jókövi, Bervaes, & Böttcher, 2002). There are more subtitle psychological benefits of green roof planting, for example the increase signing of wildlife can be beneficial to people, especially to those in office blocks with regular feel a disconnection with the outside world (Coppin, 1990; Natural Economy Northwest, 2008).

1‐12 Habitats Favoured by Rooftop Environments The environmental conditions at roof level favour the application of a number of habitat treatments (Dunnett & Kingsbury, 2008). Elements associated with urban centres, such as relative differences in temperature and rain distribution when compared to rural area, places requirement on plant selection (Murray, McCann, & Cooper, 1992). The following habitats present qualities which are applicable to ecological specification on green roofs.

Plant species that are acclimatised to the shallow soil, scree Mountainous Vegetation slopes or rock faces of mountainous environments possess the potential to successful occupy a green roof (Dunnett, 2006).

While rock face habitats may be slow to develop on rooftop, high altitude meadow wildflowers rapidly colonise north‐facing roof sections (Grant G. , 2006).

Figure 17 ‐ Mountain Plain grasses and shrubs on Paul Lincke Ufer, Kreuzberg, Germany

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Costal Vegetation

Figure 18 ‐ Costal Meadow grasses planted on the Nassau Icehouse Brewery

Limestone Vegetation

Figure 19 ‐ Grass sloped roof on the Vancouver Conference Centre

Shrub & Heath Vegetation

Figure 20 ‐ Heath Planting on Sloped Roof at Schiphol Plaza, Amsterdam Airport

Arid Vegetation

Figure 21 ‐ University Hospital Basel

Reed Bed Vegetation

Figure 22 ‐ John Deere Works, Mannheim

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Maritime and coastal habitats place a broad range of environmental stress on local vegetation. In order to survive in such ecosystems, plants must be capable of surviving in free‐ draining sandy soil, be tolerance to situation of both drought and heavy wind exposure (CVNI, 2011). Additionally the continuous exposure to salt‐laden air has created plant species tolerant to airborne city pollutants (Dunnett & Kingsbury, 2008).

The shallow soils that cover limestone slabs support a variety of grasses, mosses and shrubs. The limited space for root growth as well as grazing pressure often means that many plant species have become dwarfed (Northern Ireland Habitat Action Plan, 2005). A diverse range of stress‐tolerant vegetation has developed on limestone rich soils, resulting in an array of planting option for green roofs (White & Snodgrass, 2003).

Habitats that exist in exposed locations have developed an array of low dense vegetation, in lowland situations these include drought‐tolerant shrubs and woody plants and grasses (Gates, 1980), and at higher latitudes heaths and mosses are abundant (Cooper & McCann, 2001). All of which are capable of populating rooftop environments. Because of the thin soil and exposed aspects of these habitats, their flora and fauna can rapidly adapt to condition on most green roofs (Brenneisen S. , 2006).

Vegetation that is capable of surviving the harsh temperature ranges and drought conditions of both natural and manmade arid environment are capable of existing unmodified at roof level (Larson, Matthes, Kelly, Lundholm, & Gerrath, 2004).

Many of these habitats are dominated by one flora species and are adapted to exist in isolation, thusly are easily capable of be transplanted to a green roof setting (Dunnett & Kingsbury, 2008).

Providing a high water retention level at roof level it is possible to encourage the development of reeds and wetland grasses on green roofs. This habitat type has been exported to rooftops to meet a growing need of to conserve and clean water discharge in many regions (Earth Pledge, 2005). The minimal soil requirements and the ability to recycle nutrients in water runoff, results in the ability of flora and fauna that requires a permanent waterlogged environment to now exist on green roofs (Coffman & Davis, 2005).

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Northern Ireland and Green Roof Habitat Recreation

The following table illustrates the explored connections between the habitats capable of surviving on green roofs and the requirements of natural habitats in Northern Ireland.

Habitats favoured

by Green Roofs

Northern Ireland habitats capable of addapting to Green Roofs

Habitats Commonly Recreated on Green Roofs

Habitats Promoted

by Ease of Construction and Financing

Coastal Vegetation

Arid Vegetation

Reed Bed Vegetation

Mountainous Vegetation

Limestone Vegetation

Shrub & Heath Vegetation

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Chapter 2

Habitat Loss in Northern Ireland

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The objective of this chapter is to examine the nature and extent of habitat loss in Northern Ireland. Additionally the attributes and properties of individual habitat categories located across Northern Ireland will be studied. The physical environment and microclimate associated with urban roof level locations present factors which the recreation of habitat will have to accommodate. The result of this will mean that some habitat types will never be capable of occupying a building’s roof because of the incapability with the environmental condition associated with green roofs.

In addition to investigate the reasons for habitat loss in Northern Ireland, this chapter will explore the requirements, features and characteristics that classify each habitat as a unique ecosystem and each habitat type will be assess for there to potential to acclimatise in a green roof location.

There are seven groupings for land based habitats in Northern Ireland, Coastal, Marine, Wetland, Woodland, Grassland, Heathland and Peatland. Each contains a number of specific ecosystems, with their own associated flora and fauna.

Figure 1 ‐ Northern Ireland's Areas of Outstanding Natural Beauty (Countryside Survey, 2008)

Additional agricultural and urban habitats will receive some analysis within this chapter, as they affect the quality of surrounding natural habitats. The fact that these habitats are artificially created or highly managed does not mean they are without ecological merit, agricultural (Countryside Survey, 2008) and urban (Gibson, 1998; Gedge & Kadas, 2005; Harvey, 2001) areas can support a diverse array of flora and fauna species, all be it limited when compared to natural habitats (Cooper, McCann, & Rogers, 2009). Urban ecology will be further discussed in Chapter 4.

Agricultural and horticultural land represents the bulk of land use in Northern Ireland, encompassing 44% of the national landmass, with urban areas representing 5% of land use (Cooper, McCann, & Rogers, 2009).

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2‐01 Tidal Marine Habitats The marine life off the coast of Northern Ireland is extremely rich and diverse. And the actions of the sea have a great impact on the habitats that are directly connected to the coastline (NIEA, 2010). The habitats associated with coastal tides are one of the most susceptible ecosystems to the affects of global warming and alterations to the seas. (Randall, 2004).

The soil layer of these habitats provide for aquatic vegetation (Den Hartog, 1970) plus various species of worms, invertebrates, and isopods (National Museums Northern Ireland, 2010) all reliant on the saline environment. Many habitats also act as nursery regions for many fish species (CVNI, 2011).

Because of the richness of aquatic life within tidal habitats, these areas have come to support a significant volume of bird species. The mudflats at Strangford Lough alone support over 70,000 birds annually (Northern Ireland Habitat Action Plan, 2003).Thank to this fact, Northern Ireland’s tidal seagrass zones represent an important resource in the diet of many nationally important species (Northern Ireland Habitat Action Plan, 2003).

The principle habitats associated with marine tidal environments are: Tidal Sand/Shingle/Gravel Shores Tidal Shores Seagrass Beds Tidal beaches and sandbanks that have developed in shelter section of the coastline (Northern Ireland Habitat Action Plan, 2005) Seagrass Beds Areas of shallow, sheltered tidal sediments that have been Figure 2 ‐ Dundrum Bay, Down Figure 3 ‐ Eelgrass, North Strangford Lough occupied by aquatic seagrass Mudflats Saltmarshes species (CVNI, 2011) Mudflats A intertidal habitat created by sedimentary deposition of low energy waves, particularly found in estuaries and other sheltered areas (Northern Ireland Habitat Figure 4 ‐ Millbay, Antrim Figure 5 ‐ Ballymacormick Point, Bangor Action Plan, 2003) Saline Lagoon Saltmarshes Areas where vegetation has become established on tidal mudflats (Northern Ireland Habitat Action Plan, 2005) Saline Lagoon

Bodies of seawater that have Figure 6 ‐ Strand Lough, Down become disconnected from the sea (CVNI, 2011)

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For more information on individual Tidal Marine Habitats, please see Appendix A

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Saline Lagoon

Saltmarshes

Mudflats

Seagrass Beds

Tidal Sandy, Shingle & Gravel Shores

While beach shores occur all along Northern Ireland’s coastline, other tidal habitats have a more limited range.

Mudflats, Seagrass Beds and Saltmarshes all occupy in low energy coastal environments predominately along the eastern coast, in estuaries and sheltered areas such as sea loughs, (Northern Ireland Habitat Action Plan, 2003). Saline lagoons can be both naturally of artificially constructed and small brackish pools are frequent around the coast in saltmarshes, however large bodies of brackish water Figure 7 ‐ Northern Ireland's Marine Habitats (Countryside Survey, 2008) are rare (Bamber, Gilliland, & Shardlow, 2001).

Rate of Habitat Loss No significant data exists on the rate of habitat gain/loss due to the changing nature of tidal habitats, with the exception for saltmarshes which is estimated to occupy a 250ha region, comprise 0.5% of the total UK habitat area (Northern Ireland Habitat Action Plan, 2005)

The active threats and leading causes of tidal habitat loss in Northern Ireland are well documented (Northern Ireland Habitat Action Plan, 2005). These are listed below.

Causes of Habitat Loss

 Agricultural Improvement

  Climate Change



Disease

  

Fishing Activities

 Grazing

  Human Activities

 Human Construction Schemes

   Physical Disturbance

    Pollution

 Reclamation

  Reduction in Ground Quality

 Root Destruction

  Species Invasion

Table 1 ‐ Leading Causes of Tidal Marine Habitat Loss

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Ability to be recreated on a Green Roof Tidal Marine habitats present a series of problems when considered for relocation to a green roof setting. The principle issues are:

Recreating a Costal Wetland Environment Green roofs which support freshwater wetland habitats are currently commercially available (Earth Pledge, 2005); any permanently waterlogged rooftop provides nutrients and minerals through a closed loop water circulation system (Coffman & Davis, 2005). Such a system could be adapted to utilise a saline water mixture.

Corrosive Nature of Brackish Water Salt is corrosive to most building materials. While there are materials that are capable of withstanding salt exposure, this will add significant cost and maintenance requirements to any proposed green roof system (Deplazes, 2008).

Replicating the Actions of the Tide The action of tidal forces to provide resource and shape marine coastal habitats is the principle feature of these environments (NIEA, 2010).

From the aspect of habitat recreation, an alternative for the role played by costal tides does not exist (Gilbert & Anderson, 1998). This is means that no matter the success in recreating the water conditions, tidal habitats will not be practical on green roofs. An exception exists in regards to saline lagoons as this habitat type is not reliant on tidal forces. However issues of size and weight in relation of a static body of water needs to be addressed, these will be discussed in section 2‐03 on freshwater lakes.

Tidal Marine Habitats on Green Roofs Incompatible

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Tidal Sand/Shingle/Gravel Shores Seagrass Beds

Mudflats

Saltmarshes

Saline Lagoon

Possible

Highly Suitable

Tidal habitats require a number of resources (Gilbert & Anderson, 1998) that would be impracticable or impossible to replicate on a green roof. For this reason tidal habitats are predominantly incompatible with green roofs (Dunnett & Kingsbury, 2008). However Saline lagoon habitats are possible, with the limiting factor of salt corrosion, and dead loading imposed by a large body of brackish water (Deplazes, 2008).

It is important to note that green roof can act in a supporting role to tidal habitats as is the case with Ducks Unlimited National Headquarters and Conservation Centre in Winnipeg, Canada which acts as bird nesting ground around the Oak Hammond Marsh (Earth Pledge, 2005).

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2‐02 Coastal Habitats Northern Ireland’s coastal regions are noted for their rich biodiversity. More than 75% of the coastline is protected by some form of international or national conservation order (NIEA, 2010). The Northern Ireland coastline is 650km in length supporting a wide diversity of natural environments and wildlife (NIEA, 2010). The flora and fauna found in habitats associated with coastal habitats can vary vastly over short distances; this is due the soil composition and local geography (Northern Ireland Habitat Action Plan, 2005).

The physical differences between the coastal habitats of Northern Ireland are considerable, however their soil layers have a number of similarities, both being nutrient poor and have deficiencies in there supply of fresh water (Northern Ireland Habitat Action Plan, 2005).

Nonetheless many coastal habitats support a diverse array of species. For example, the sand dunes at Dundrum, Co. Down supports 55 species of bees, ants and wasps, 213 species of moths and 21 species of butterflies (Northern Ireland Habitat Action Plan, 2005). And Northern Ireland’s cliffs are an important habitat for breeding seabirds, and support bird populations which are of international importance (CVNI, 2011).

The principle habitats associated with costal environments are: Sand Dunes Sand Dunes Vegetated Shingles Sand dunes occur when a beach has the significant tidal power to allow sand to dry out complete.

The dry sand is then blown landwards by the wind, where it accumulates into dunes (Northern Ireland Habitat Action Figure 8 ‐ Murlough Dunes, Dundrum Bay Figure 9‐ Kearney, Down Plan, 2005).

Cliffs and Slopes

Vegetated Shingles Banks Vegetable shingle banks occupy the landward side of shores when coastal areas have powerful tides that push singles and aggregate beyond the high tide mark (National Museums Northern Figure 10 ‐ Carrick ‐a‐Rede Cliffs, Antrim Ireland, 2010).

Cliffs and Slopes Consists of cliff top grassy meadows and vegetated scree slopes and cliff faces, but the vegetation on cliffs can vary vastly over short distances; this is due the soil composition and local geography (Northern Ireland Habitat Action Plan, 2005).

For more information on individual Coastal Habitats, please see Appendix A

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Cliffs and Slopes

Shingles Banks

Sand Dunes

Sea cliffs occur all along the Northern Ireland coast and it is estimated that there is approximately 3000ha of sand dunes; with the area of vegetated sand dunes being between 1300ha and 1500ha (Northern Ireland Habitat Action Plan, 2005). With the largest dune systems located along the north and south‐east coasts, namely in north Antrim and South Down. (CVNI, 2011).

Shingle banks are an incredibly rare habitat in Northern Ireland with an estimated extent of 50ha (Northern Ireland Habitat Action Plan, 2005).

Figure 11 ‐ Northern Ireland's Coastal Habitats (Countryside Survey, 2008)

Rate of Habitat Loss Sea cliffs are one of the few natural habitats that have shown no significant habitat loss in recent years (Northern Ireland Habitat Action Plan, 2005), in fact the flora of sea cliffs are one of the few habitats that remain largely undamaged by modern human activities (National Museums Northern Ireland, 2010). And the range of coastal sand dunes has decreased by 2.4% or 1500ha between 1998 and 2007 (Cooper, McCann, & Rogers, 2009).

Shingle banks have undergone the large decline of coastal habitats; between 1991 and 1998 a habitat loss of 32% (29ha) was recorded in Northern Ireland (Murray, McCann, & Cooper, 1992).

The below table shows the leading causes of coastal habitat loss in Northern Ireland (Northern Ireland Habitat Action Plan, 2005)

Causes of Habitat Loss

 Agricultural Improvement

 Erosion



Fall in Water Table

   Grazing

  Land Development

  Natural Erosion

   Recreational Activities

 Sea Defence Works

 Sediment Extraction

  Species Invasion Table 2 ‐ Leading Causes of Coastal Habitat Loss

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Ability to be recreated on a Green Roof Habitats associated with coastal locations possess a number of qualities which are attractive to their recreation on urban rooftop locations. The principle issues are:

Shallow Nutrient Poor Soils The soil layers of costal habitats consist of free‐draining sandy or gravel soil which is typically nutrient poor (Northern Ireland Habitat Action Plan, 2005). Substrates of green roofs, especially those of lightweight extensive roofs, possess a similar soil structure as beach and cliff face environments (Dunnett & Kingsbury, 2008).

Hardy Resilient Vegetation The vegetation of cliffs and aggregate shores already actively colonise urban areas, such as pavements, walls, roofs, and lawns (Lundholm & Marlin, 2006). Studies have shown that of the range of species that naturally occupy green roofs are disproportionately drawn from rocky and costal habitats (Brenneisen S. , 2006). The conditions of coastal location have created plant species which are high adapted to the conditions of towns and cities, such as limited and poor quality soil etc. (Dunnett & Kingsbury, 2008).

Exposure to Weather Extremes The typical topology and hard‐surface environment of urban areas reflect those of cliffs, slopes and exposed gravel flats found along Northern Ireland’s coasts (Grant G. , 2006).

Additionally, the exposure to wind and temperature conditions in cities are similar to coastal habitats (Larson, Matthes, Kelly, Lundholm, & Gerrath, 2004).

Coastal Habitats on Green Roofs Incompatible

Sand Dunes

Vegetated Shingles Banks

Cliffs and Slopes

Possible

Highly Suitable

The requirement of both flora and fauna to survive in exposed conditions on limited nutrients and water supply has created species that are predisposed to exist within the confines of a green roof (Gilbert & Anderson, 1998).

Additional then ability of the habitat to be recreated on lightweight extensive green roofs will allow a wider range of building to support a recreated coastal habitat (Dunnett & Kingsbury, 2008).

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2‐03 Freshwater and Wetland Habitats Northern Ireland has an extensive network of freshwater habitats, such as lakes, ponds and wetlands. There are more than 1,600 lakes in Northern Ireland, ranging in size from small ponds to Lough Neagh, the largest freshwater lake in the British Isles (NIEA, 2010). Also most of Northern Ireland’s lakes are fringed by fen, marsh and swamp; these wetlands provide countless benefit to local ecosystems. For example they help prevent flooding by slowing down and absorbing regional water sources and maintaining summer water flows by gradually release stored water to rivers and streams (NIEA, 2010).

The areas surrounding lake habitats are important for non‐migratory bird species and international important populations of migratory wader and wildfowl species (CVNI, 2011).With reed beds and grazing marshes noted as containing a poor diversity in vegetation species, but support a rich array of fauna adapted to wetlands, notably breeding birds . All freshwater and wetland habitats are commonly rich with freshwater invertebrates and plants species, UK wide over 700 species of invertebrates are associated with reed beds and marshes (Northern Ireland Habitat Action Plan, 2005).

The principle habitats associated with freshwater and wetland environments are: Eutrophic Waters Eutrophic Waters Mesotrophic Lakes standing water Eutrophic describes a body of water with a high nutrient content (nitrogen and phosphate). Most of Northern Ireland’s larger lakes such as Lough Neagh and Lough Beg and Lough Erne are regarded Figure 12 ‐ Upper Lough Erne Figure 13 ‐ Tower Lake, Newtownstewart as eutrophic (Northern Ireland Marl Lakes Reed Beds Habitat Action Plan, 2005).

Mesotrophic Lakes Mesotrophic lakes are a body of water with a medium nutrient content. Both mesotrophic and eutrophic lakes support an

overlapping body of flora and Figure 14 ‐ Knockballymore Lough, Fermanagh Figure 15 ‐ Castle Espie, Down fauna species due to their similar Floodplain Marsh chemical composition (Northern Ireland Habitat Action Plan, 2005).

Marl Lakes Marl lakes are natural lakes which occur at low altitude and contain highly alkaline water Figure 16 ‐ Insh Marshes, Scotland Marl lake water bodies are characterised by very clear water but has a low nutrient status (Northern Ireland Habitat Action Plan, 2005).

Reed Beds A wetland habitat that is dominated by Common Reeds and other tall flowering plants which are adapted to growing in wet conditions. Reed beds are widely distributed along the margins of water bodies, streams, river and other forms of wetlands and bogs (CVNI, 2011).

Floodplain Grazing Marsh

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Wetland marshes characteristically connected to large slow‐moving rivers and lakes. Much of these habitats were formerly wet woodlands, fens or reed beds or redundant agricultural land that has flooded (Northern Ireland Habitat Action Plan, 2005).

Floodplain Marsh

Reed Beds

Marl Lakes

Mesotrophic Lakes

Eutrophic Waters

For more information on these Habitats , please see Appendix A

The majority (72%) of Northern Ireland lakes have a surface area of less than 2ha and represent only 1.2% of the total water surface in Northern Ireland.

The five largest lakes represent 89% of the total natural water volume of Northern Ireland (Northern Ireland Habitat Action Plan, 2005).

Wetland habitats such as reed beds and grazing marshes are widely distributed along the margins of water bodies, streams, river and other forms of waterlogged environments such as Figure 17 ‐ Northern Ireland's Freshwater & Wetland Habitats (Countryside Survey, 2008) fens and bogs. In Northern Ireland, they are especially associated with lowland areas around the large lakes and drumlins (Northern Ireland Habitat Action Plan, 2005).

Rate of Habitat Loss The total extent of lakes and other bodies of freshwater within Northern Ireland is estimated at 940 km2 (Northern Ireland Habitat Action Plan, 2005). Between 1998 and 2007, there was a 1% reduction in the Causes of Habitat Loss   

national extent of these Agricultural Activities    Climate Change

habitats (CVNI, 2011).      Drainage

   Discharge

The rate of wetland habitat loss  

between 1998 and 2007 was Dredging  Forestation of Habitat

more severe. The total are of 

wetland habitats within Habitat Fragmentation   Northern Ireland is estimated Land Development

at 47,255ha or 3% of Northern Natural Habitat Evolution 

Ireland, this reduced by 10% Nutrient Enrichment

  between 1998 and 2007 Pollution  

(Cooper, McCann, & Rogers, Poor Habitat Management 

2009).  Recreational Activities

 Sea Defence

The adjacent table shows the Species Invasion   

leading causes of freshwater Table 3 ‐ Leading Causes of Freshwater and Wetland Habitat Loss and wetland habitat loss in Northern Ireland (Northern Ireland Habitat Action Plan, 2005)

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Ability to be recreated on a Green Roof Freshwater and Wetland habitats present both challenges and opportunities of green roofs.

The principle issues are:

Large Water Bodies at Roof Level While numerous examples of pond at roof level exists (Earth Pledge, 2005), the majority of freshwater bodies in Northern Ireland range between 1ha and 2ha (Northern Ireland Habitat Action Plan, 2005) this means that artificial freshwater bodies will never be large enough to support the flora and fauna associated with freshwater lakes (Gilbert & Anderson, 1998).

Wetland Environment at Roof Level Artificial wetland habitat are currently commercial available and there exist a growing market for recreated wetland habitats on green roofs in continental Europe to aid in building cooling and rainwater discharge fees (Earth Pledge, 2005), this adoption of wetland green roof in Germany will be further discussed in chapter 3.

Freshwater and Wetland Habitats on Green Roofs Incompatible

Eutrophic Waters

Mesotrophic Lakes

Marl Lakes

Reed Beds

Floodplain Grazing Marsh

Possible

Highly Suitable

While artificial lakes are unlikely to be created at roof level, green roofs can provide habitats that will accommodate the flora and fauna associated with freshwater bodies. Again the example of Ducks Unlimited National Headquarters and Conservation Centre in Canada, described in section 2‐01, show cases this principle (Earth Pledge, 2005). The ability of green roofs to support freshwater lake habitats will be further discussed in chapter 3.

Reed beds and wet grassland are currently being successfully implemented on green roofs (Coffman & Davis, 2005).

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2‐04 Woodland Habitats Northern Ireland is the least wooded country in Europe. The average coverage of woodland in Europe is 44%, in Northern Ireland it is only 6% of the total land area (NIEA, 2010). Native forests consist of broadleaf trees, such as are Alder, Downy Birch, Hazel, Ash, Oak, and Rowan (Northern Ireland Native Woodland Group, 2008). The annual loss of leafs promotes flora on the forest floor, such as woodland flowers (National Museums Northern Ireland, 2010). There are few examples of native woodland surviving in Northern Ireland, the best example are located in the nature reserves at Rostrevor in Down; Breen in Antrim; and Boorin Wood in Tyrone (National Museums Northern Ireland, 2010). Modern commercial forests are planted with non‐native species, such as conifers, which provide good habitat opportunities for some species, for instance the red squirrels and hen harrier but are not as biologically diverse as semi‐natural woodland (NIEA, 2010).

Woodlands are not limited to one soil condition and are capable of developing on nutrient rich, mineral based, acidic or nutrient‐poor peat soils (Northern Ireland Habitat Action Plan, 2005). Many habitats will transition from their existing state to shrub land, and finally woodland if left to naturally evolve. Forestation is sited cause of habitat loss for wetland, grassland, heath and bog ecosystems (Cooper, McCann, & Rogers, 2009), as mention in other sections of this chapter.

The principle habitats associated with woodland environments are: Wet Woodlands Native Woodlands Wet Woodlands An assortment of woodland and scrubs which occupy seasonally flooded or waterlogged land (Northern Ireland Habitat Action Plan, 2005) Mixed Ashwood Forests located on base rich Figure 18 ‐ Belvoir Park Forest, Belfast Figure 19 ‐ Bonds Glen, Derry soils, generally dominant by Ash Mixed Ashwood Oakwood species, typically accompanied

by Oak, Downy Birch and Hazel (Northern Ireland Habitat Action Plan, 2005) Oakwood Woodland dominated by native Oaks supported by smaller tree Figure 20 ‐ Glenarm Woodlands, Antrim Figure 21 ‐ Breen Oakwood, Antrim species such as Holly, Rowan and Hazel (Northern Ireland Habitat Action Plan, 2005).

For more information on individual Woodland Habitats, please see Appendix A

The total extent of native broadleaf woodlands in Northern Ireland is estimated at 81,699ha or fewer than 6% of the total land area (Cooper, McCann, & Rogers, 2009). The area of broadleaf forests in Northern Ireland currently outmatches that of introduced conifer forests, by 21,000ha (Cooper, McCann, & Rogers, 2009).

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31

Oakwood

Mixed Ashwood

Wet Woodlands

Wet woodlands occur across Northern Ireland in scattered locations, at areas typically 3‐5ha. Recent estimates place the extent of wet woodlands to occupy an area of 2,600ha (Northern Ireland Habitat Action Plan, 2005). Ashwood forests occupy the basalts regions of Antrim, the limestone basins of Fermanagh, and sites in the Sperrins and County Down and Armagh, with an estimated range of 3,430ha, (Northern Ireland Habitat Action Plan, 2005).

Northern Ireland’s oak woodlands are concentrated in the north east, in rocky Figure 22 ‐ Northern Ireland's Woodland Habitats (Countryside Survey, 2008) and wet areas with slightly base soil (CVNI, 2011), their extent is estimated at 2,350ha (Northern Ireland Habitat Action Plan, 2005).

Rate of Habitat Loss Between 1998 and 2007 a 9% increase in both wet woodland and mixed ash wood habitats was recorded, and an 11% increase in the area of oak forests throughout Northern Ireland (Northern Ireland Habitat Action Plan, 2005). Over the same period a reduction of 2% was seen in Conifer forests (Cooper, McCann, & Rogers, 2009). The total area of broadleaf forests in Northern Ireland increase by nearly 29% between 1998 and 2007, the second largest expansion of land use in Northern Ireland during this period, surpassed only by housing which increased by 30% (Cooper, McCann, & Rogers, 2009). As mentioned earlier in this section, forestation is cited as a cause of habitat loss rather than succumbing to it (NIEA, 2010).

The below table shows the leading treats to woodland habitats in Northern Ireland, however as stated broadleaf forests have shown strong growth in recent years (Northern Ireland Habitat Action Plan, 2005)

Causes of Habitat Loss

   Air Pollution

   Climate Change

  Deforestation

   Disease

 Fall in Water Table

   Grazing

 Habitat Fragmentation



Illegal Dumping

   Nutrient Enrichment

   Poor Habitat Management

 Poor Water Quality

   Species Invasion Table 4 ‐ Leading Causes of Woodland Habitat Loss

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Ability to be recreated on a Green Roof Woodland habitats require a number of important issues to be addressed if they are to be recreated within a green roof environment. The principle issues are:

Shallow Soil and Root Depth The root depth requirement of certain tree species can be significant (Gilbert & Anderson, 1998). While substrate depths of 500mm to over a metre are recommended depending on tree species, method of using root balls and plastic strapping to induce dwarfism in planted trees are commonly required (GreenRoof, 2010). Unfortunately the reduce root area increase the maintenance, water and nutrient requirements of the green roof (Earth Pledge, 2005), as described during chapter 1.

Weight of Mature Trees The addition of tree species to a green roof will impose a considerable extra load on a buildings structure (Gilbert & Anderson, 1998). A building will have to support in excess of 1000kg/m2 (Earth Pledge, 2005), a requirement which while achievable, is grossly beyond typical roof loading requirements (Adler, 1999).

Meeting the requirements of a tree’s weight will add additional cost and possibly require structural strengthening if trees are included in retrofitted green roofs (GreenRoof, 2010). In addition to placing a practical limit on the size of planted trees (Dunnett & Kingsbury, 2008).

Woodland Habitats on Green Roofs Incompatible

Wet Woodlands

Mixed Ashwood

Oakwood

Possible

Highly Suitable

Example of trees plant on green roofs currently exist (Earth Pledge, 2005; GreenRoof, 2010) and will be discussed in detail during chapter 3. However these examples also show the limitations of planting such large scale vegetation at roof level.

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2‐05 Grassland Habitats Grasslands are the most abundant habitat types in Northern Ireland; agriculture grassland encompasses almost 60% of the land area of Northern Ireland (NIEA, 2010). Native grasslands are less agriculturally productive than managed land and are generally restricted to low value upland areas, which typically consist of waterlogged and thinner soils. The natural grasslands of Northern Ireland are dependent on low intensity domestic livestock occupation or traditional farming practices to preserve their diversity of short and slow growing and flowering grasses (NIEA, 2010).

Grasslands are area heavily dominated by herbs and fine‐leaved grasses with a lack of tall vegetation such as trees, shrubs and other dense bushes or bracken species (Northern Ireland Habitat Action Plan, 2005). With local fauna comprising principally of invertebrates such as butterflies and beetle species. Grasslands support a less diverse range of vertebrate species than other habitats described in this chapter, but are occupying but nationally important colonies of Irish Hare and Skylark (CVNI, 2011).

The principle habitats associated with grassland environments are: Lowland Dry Acid Grasslands Lowland Acid Grasslands Calcareous Grasslands Occurring on nutrient poor, free draining soils which are based on acid rocks or shallow deposits of sands and gravels (NIEA, 2010) Calcareous Grasslands Species‐rich grassland occurring Figure 24 ‐ Little Deer Park, Antrim Figure 23 ‐ Wangford Warren, Suffolk on shallow, lime rich soils the Lowland Meadows Rush Pastures majority of which derive from chalk and limestone rocks (Northern Ireland Habitat Action Plan, 2005) Lowland Meadows Areas of unfertilised grassland Figure 26 ‐ Slievenacloy, Belfast Hills who’s soil layers consist of well Figure 25 ‐ Tees Valley, Middlesbrough Limestone Pavements drained mineral soil, supporting a rich variety of herbs with few tall plant species (Northern Ireland Habitat Action Plan, 2005) Purple Moor‐grass & Rush Pasture Occur on poorly drained, usually Figure 27 ‐ Knockmore, Fermanagh acidic soils in lowland areas exposed to high rainfall (Northern Ireland Habitat Action Plan, 2005) Limestone Pavements Areas of exposed limestone stable which support grass species and plants adapted to rocky habitats (Northern Ireland Habitat Action Plan, 2005)

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For more information on individual Woodland Habitats, please see Appendix A

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Limestone Pavement

Purple Moor‐Grass

Lowland Meadows

Calcareous Grassland

Dry Acid Grassland

Natural grasslands occur across all of Northern Ireland, commonly located on land with low agricultural value (NIEA, 2010). Lowland dry acid grasslands area rare and highly scattered, concentrated in County Down and Armagh (Cooper, McCann, & Rogers, 2009) and limestone pavement are restricted to west Fermanagh (CVNI, 2011). The remaining grassland habitats are located across County Down, Antrim, Derry and Tyrone, with the plains of Armagh and south Fermanagh dominated by commercial agriculture Figure 28 ‐ Northern Ireland's Grassland Habitats (Countryside Survey, 2008) land (Countryside Survey, 2008).

Rate of Habitat Loss Between 1998 and 2007 an extensive reduction in all natural grassland habitats was recorded, losing 12.5% of their area. The only exception is calcareous grasslands which seen a 2% increase (Cooper, McCann, & Rogers, 2009). Many types of grassland are reliant on the implementation of low‐intensity grazing to prevent the re‐colonisation of a region from shrubs and woodland (Corbett, 2003). Forestation and the loss of land to housing development and other building projects are cited as the leading causes of habitat loss for all grasslands. The table below presents the principle reason for grassland habitat loss in Northern Ireland (Northern Ireland Habitat Action Plan, 2005)

Causes of Habitat Loss

     Agricultural Improvement

  Airborne Pollutants

   Climate Change

   Forestation of Habitat

    Grazing

 Habitat Fragmentation

    Human Activities

  Land Development

 Land Infilling

  Natural Erosion

 Poaching

   Poor Habitat Management

 Quarrying

 Recreational Activities

Table 5 ‐ Leading Causes of Grassland Habitat Loss

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Ability to be recreated on a Green Roof Grass covered roofs have a long history of usage as a building treatment (Dunnett & Kingsbury, 2008), because of this the requirements for grasses to successfully occupy rooftops are comprehensively understood (Oberndorfer, et al., 2007). The following are the primary issue in regards to the simulating natural grassland habitats on rooftops.

Soil Requirements The variation in soil composition of natural grasslands is considerable, ranging from acidic gravels to lime‐rich soils (NIEA, 2010). However because of the experiences of the ecological roofing and the horticulture industry with creating grass dominated environments, the soil condition for all grassland habitats can be replicated within artificial roof ecosystems, provided the correct systems are implemented (Blythe & Merhaut, 2007).

Species Selection The most popular planting species for green roofs are variants of sedum, grasses, herbs and mosses (Emilsson, 2003). Commercial grass seeds are abundant on both the construction and landscaping markets (White & Snodgrass, 2003). As introduce of alien species to a is regarded as a leading degrading factor to natural grassland, recreated grassland habitats on rooftops must take measures to restrict the planting of unwanted flora (Dunnett & Kingsbury, 2008).

Habitat Management Requirements Because of the importance of low level grazing to maintain the diversity and health of a natural grassland (NIEA, 2010), a similar intensity of habitat maintenances will need to be replicated when a grassland ecosystem is relocated to roof level. Maintenance requirements, as described in chapter 1, will need to be considered when installing a grass roof (Frith & Gedge, 2000).

Micro‐climate, Exposure and Natural Plant Colonisation Numerous studies and built examples have shown that both flora and fauna species can readily colonise green roofs if the roof micro‐climate replicate there natural environment (Brenneisen S. , 2006). This factor in combination with the adaptability of urban vegetation (Larson, Matthes, Kelly, Lundholm, & Gerrath, 2004) can result in a grass roof being invaded by more resilient plant species (Landolt, 2001). This issue will be discussed further in chapter 3.

Grassland Habitats on Green Roofs Incompatible

36

Lowland Dry Acid Grassland

Calcareous Grassland

Lowland Meadow

Purple Moor & Rush Pasture

Limestone Pavement

Possible

Highly Suitable

The creation of grass environments on roofs is a mature building process (Dunnett & Kingsbury, 2008). And the establishment of habitats that replicate natural grasslands is limited only local conditions and design ability (White & Snodgrass, 2003).

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2‐06 Heathland Habitats The heaths of Northern Ireland have a wide habitat range; common to high mountain regions but also extend to lowland and coastal areas. The common characteristic of all heathlands is that that are based on nutrient‐poor, heavily mineralised soils and thin peat (NIEA, 2010). Heathlands are an internationally rare and threatened habitat, and the total UK habitat range represents a significant proportion of the global resource (Northern Ireland Habitat Action Plan, 2003).

Heaths provide opportunities for numerous mosses, mountain grasses and heathers which have evolved in wetland and blanket bog species, in addition to a verity of dwarf shrubs and conifer trees (Northern Ireland Habitat Action Plan, 2003). But are categorised as being lower in flora diversity other ecosystems described in this chapter, due to the underlying soil, however are commonly occupied by a diverse range of insects and other invertebrate species (NIEA, 2010). Endangered vertebrate species such as the Irish Hare and ground nesting birds like the Curlew, Chough, Red Grouse, Hen Harrier and Skylark all rely on heaths as are feed and breeding grounds (NIEA, 2010).

The principle habitats associated with heathland environments are: Lowland Heaths Lowland Heaths Upland Heaths Heathland that are situated below the upper altitude limit of cost effective agricultural practices, this is generally below 300m (Northern Ireland Habitat Action Plan, 2003) Figure 29 ‐ Murlough National Nature Reserve Figure 30 ‐ Bloody Bridge near Newcastle Upland Heaths Mountainous Heaths Reside above the altitude limit of the majority of Northern Ireland’s farms, typically between 300m and 600m, the habitat is based upon thin mineral or peat soil, usually with substrates layers less than 0.5m deep (NIEA, 2010) Figure 31 ‐ Mourne Mountains Mountainous Heaths Northern Ireland is the southern extreme of the natural range for montane or alpine heath habitats. These heaths occur widely in the Highlands of Scotland at altitudes over 600m, above the natural tree line (NIEA, 2010).

For more information on individual Heathland Habitats, please see Appendix A

Heathland habitats tend to be highly fragmented and restricted to small areas (NIEA, 2010). Lowland and Upland heaths have a largely confined range, occupying the slopes of the Mourne Mountains, the Ring of Gullion, Rathlin Island and narrow coastal strips in Down, Antrim and western Fermanagh (NIEA, 2010). The estimated 5,000ha of lowland heaths are general linked fens, dominating areas of Down and Armagh (Cooper, McCann, &

Figure 32 ‐ Northern Ireland's Heathland Habitats (Countryside Survey, 2008)

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37

Mountainous Heaths

Upland Heaths

Lowland Heaths

Rogers, 2009). Mountainous heaths are limited to the highest summits of the Mourne Mountains and the Sperrin Mountains, as Northern Ireland is the southernmost example of this habitat internationally (NIEA, 2010).

Rate of Habitat Loss Because of the high elevation, poor soils quality and harsh climate of Northern Ireland’s heaths, these habitats are not heavily threatened by encroaching farming land (Northern Ireland Habitat Action Plan, 2003). However heaths have been targeted as areas of building and infrastructure development, resulting in extensive habitat loss (CVNI, 2011). The development of forests on commercially low value heathland is another leading cause of habitat loss (NIEA, 2010). Also climate change is cited as a leading cause of mountainous heaths, this is exasperated by the habitat being at its southern extent in Northern Ireland (NIEA, 2010). The impact of climate change is Northern Ireland is predicted to be much smaller than in Britain and will have a less significant impact on local habitats (Coll, Maguire, & Sweeney, 2009).

The Northern Ireland Countryside Survey has estimated that lowland heaths have lost 11% of its total area between 1992 and 1998. Considerable losses in upland heaths areas have occurred during the same period, an estimated 20% of wet upland heaths, and 28% of dry upland heaths (Cooper, McCann, & Rogers, 2009). The below table lists the leading treats to heathland habitats in Northern Ireland (Northern Ireland Habitat Action Plan, 2003)

Causes of Habitat Loss

  Agricultural Improvement

  

Climate Change

  Fires

  Forestation of Habitat

   Grazing

  Land Development

  Natural Erosion

   Nutrient Enrichment

   Recreational Activities

   Species Invasion

Table 6 ‐ Leading Causes of Heathland Habitat Loss

Ability to be recreated on a Green Roof Heaths exhibit a number of attributes that are applicable to green roofs, due to their geographical and environmental requirements to develop (NIEA, 2010).The principle issues are:

Mixture of Waterlogged and Dry Soil Conditions Heather and mosses dominated areas have high water retention capabilities (NIEA, 2010), this ability to retain moisture and the variations in water levels across a small area has been shown to aid in creating a diverse range of flora and fauna species on green roofs (Brenneisen S. , 2006). As describe in chapter 1.

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38

Predominantly Monoculture Vegetation The exclusive use of a single plant species or group of related species is a hallmark of lightweight extensive green roofs (Dunnett & Kingsbury, 2008). A common planting method is to utilise vegetation mats, where dense groundcover species are combines with a non‐ organic fibres which mimics organic materials (Hitchmough, 1994), as discussed in chapter 1.

The most common commercial species are sedum; however the technology can easily be applies to moss and heather planting (Cooper & McCann, 2001), creating a cheap system of recreating heathland habitats.

Fragmented and High Altitude Locations The ability of heathland to thrive in exposed and isolated environments (Northern Ireland Habitat Action Plan, 2003) makes this habitat ideal for relocation to roof top environments.

The micro‐climate condition of the majority of rooftops in Northern Ireland (Dunnett N. , 2006) replicates the natural environmental conditions of natural heather habitats (Gates, 1980).

Heathland Habitats on Green Roofs Incompatible

Lowland Heaths

Upland Heaths

Mountainous Heaths

Possible

Highly Suitable

Heathland habitats support lightweight tolerant ground vegetation which is accustomed to shallow slightly acidic soils (NIEA, 2010).

The predominant form of green roofs construction in the UK, prefabricated vegetation mats (Emilsson, 2003); present an opportunity for an existing technology to be use for habitat recreation (Grant G. , 2006).

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2‐07 Peatland Habitats Peatlands are areas of waterlogged soil containing a high quantity of organic matter, which has accumulated over thousands of years. The laying down of peat is an ongoing process at approximately 1cm every 10 years (NIEA, 2010). The types of bog land which develops depend on a variety of local environmental and geographical conditions, such as climate, soil type and typology (NIEA, 2010). The climate of Northern Ireland provides the ideal climate conditions for peat formation, due to high rainfall, cool summers and high atmospheric humidity (Northern Ireland Habitat Action Plan, 2003). Blanket bogs in Ireland, represent 8% of the world’s total habitat area (CVNI, 2011).

Naturally peatlands support a variety of highly specialist plants, many of which are national priority species. The most abundant vegetation includes Sphagnum Bog Mosses and other plants adapted to waterlogged conditions (CVNI, 2011). Also the waterlogged conditions of peatland habitats are ideally situated for flora and fauna species which posses an aquatic phase in their life cycle, such as dragonflies. Invertebrates such as beetles, moths and dragonflies are better adapted to bog land environments, with few mammal species, apart from the Irish Hare, Red Deer, Foxes and the Pigmy Shrew, permanently residing within peatlands (NIEA, 2010). Additionally the lack of predators and human disturbance makes peatlands an idyllic environment for wading and nesting bird species such as the Skylark (Northern Ireland Habitat Action Plan, 2003).

The principle habitats associated with peatland environments are: Lowland Raised Bog Lowland Raised Bog Blanket Bog The gradually filling of shallow lakes to create peat based ecosystems, located primarily in altitudes below 150m and are characteristically are surrounded by mineral based soils (Northern Ireland Habitat Action Plan, Figure 33 ‐ Fairy Water Bogs, Tyrone Figure 34 ‐ Cuilcagh Mountain, Fermanagh 2003) Fens

Blanket Bog Bog lands which develop in response to the very slow rate at which plant material decomposes under waterlogged conditions, and have the ability to cover an Figure 35 ‐ Corbally Fen, Down entire landscape (Northern Ireland Habitat Action Plan, 2003) Fens Peatlands that receive the majority of their water and nutrients from ground water sources and naturally occur in river valleys and poorly drained basins. Are generally considered the starting form of lowing raised bogs (Northern Ireland Habitat Action Plan, 2005)

40

For more information on individual Peatland Habitats, please see Appendix A

40

Fens

Blanket Bog

Lowland Raised Bog

Bogs and fen occur throughout Northern Ireland (CVNI, 2011). Lowland raised bogs are concentrated around the drumlins of the Fermanagh lowlands and raised bogs more widespread in the northwest of Northern Ireland, around the Antrim Plateau (Northern Ireland Habitat Action Plan, 2003). Fens are similarly spread across Northern Ireland, typically associated with wetlands and lakes (CVNI, 2011).

Figure 36 ‐ Northern Ireland's Peatland Habitats (Countryside Survey, 2008) Rate of Habitat Loss Relatively few areas of peatland in Northern Ireland have remained unaffected by human activities, of the 160902ha (Cooper, McCann, & Rogers, 2009) of bog land only 15% has remained intact; with drainage for agriculture effecting 10% and 46% be cut for fuel (Northern Ireland Habitat Action Plan, 2003). Compared to the degradation of bogs the total loss of habitat is relatively small, with only a 2% reduction in area between 1998 and 2007 (Cooper, McCann, & Rogers, 2009). The peat industry is the principle cause of habitat loss, particularly in lowland raised bogs as they are more accessible than blanket bogs (Northern Ireland Habitat Action Plan, 2003).

Fens have similarly suffered with a decrease in territory of 18% (484ha) between 1988 and 1998 (Cooper, McCann, & Rogers, 2009), with forestation and invasion of shrubs being the leading causes of habitat loss (Northern Ireland Causes of Habitat Loss Habitat Action Plan, 2003).    Agricultural Improvement

   Climate Change The adjacent table lists the primary    Drainage contributor to peatland habitat   Fires

loss in Northern Ireland (Northern   Forestation of Habitat

Ireland Habitat Action Plan, 2003).  

Grazing



Illegal Dumping

  Land Development

 Land Infill

 Natural Erosion

   Nutrient Enrichment

   Peat Cutting

 Peat Milling

 Pollution

  Recreational Activities

 Shrub‐land Encroachment

 Soil Mineral Leaching

Table 7 ‐ Leading Causes of Peatland Habitat Loss

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Ability to be recreated on a Green Roof Peatland present a number of challenges in term of recreation, whether by traditional means or on green roofs, because of their unique geology and chemical makeup (NIEA, 2010).The principle issues are:

Waterlogged Environment Recreation of waterlogged environments which is dominated by reed beds flora is an existing roofing method, common in Germany (Earth Pledge, 2005) and will be further discussed in chapter 3. An acidic wetland ecosystem is possible with the appropriate water systems.

Invertebrate Dominated Fauna Bogs and Fens support a diverse array of insect species, several of which are extinct or threatened outside of Northern Ireland (CVNI, 2011). Invertebrates (in addition to birds) have been shown to highly adaptable to relocation and spontaneously colonising green roof that mirror their natural habitats (Dunnett & Kingsbury, 2008; Brenneisen S. , 2006), as described in the previous chapter and will be expanded upon in chapter 3. Green roofs are capable of support the majority of peatland fauna in addition to flora species (Brenneisen S. , 2006).

Soil Makeup Peat soil is an acid waterlogged substance, high in organic material (NIEA, 2010), both lowland raised bog and blanket bogs are commonly milling for peat as it is a common soil nutrient in the horticulture industry (Northern Ireland Habitat Action Plan, 2003).

It would be unsustainable to propose the creation of bog habitats, if natural peatland will be consumed in the production of commercial acidic soil (Gilbert & Anderson, 1998). While there are alternative methods of creating acidic substrates with high concentrations of organic materials using municipal solid waste (MSW) compost and dry sewage sludge, this a immature horticultural systems (Ingelmo, Canet, Ibañez, Pomares, & García, 1998).

Peatland Habitats on Green Roofs

Lowland Raised Bog

Blanket Bog

Fens

42

Incompatible

Possible

Highly Suitable

The inability to sustainably replicate the soil condition of peatlands will negate any benefits of producing bog and fen habitats on Northern Ireland’s roofs.

Again green roof can be considered as supporting habitats for bog species, such as the wetland habitat on created on the BMW Düsseldorf Office Building (GreenRoof, 2010) , which will be further discussed in chapter 3.

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2‐08 Rate of Habitat Change While the threat to individual habitat types has been discuss under each habitat segment.

The primary cause of habitat loss through Northern Ireland is human activities, principally due to converting land to agricultural use and the expansion of rural settlements (NIEA, 2002). The rate of new rural structure being constructed doubled between 1998 and 2007, with predominantly lowland habitats being consumed by such developments. These habitats where typically small semi‐natural grasslands which were part of larger habitat mosaics (Cooper, McCann, & Rogers, 2009).

Other common reasons of habitat loss or transition were the expansion of woodland and shrub habitats into open exposed lands, outcompeting local vegetation (Cooper, McCann, & Rogers, 2009).Climate change was universally sited as a future concern with the annual rainfall predicted to increase by 3‐5% by the 2050s and temperatures increase by 0.7OC to 2.6OC in Northern Ireland (NIEA, 2002).

The table below describes the rate of habitat loss/gain in Northern Ireland between 1998 and 2007 (Cooper, McCann, & Rogers, 2009)

Habitat Type Coastal Habitats Costal Rock Costal Sediment Freshwater and Wetland Habitats Standing Open Water Rivers & Streams Wetland, Marsh & Fen Woodland Habitats Broadleaved/Mixed & Yew Woods Coniferous Woodland Grassland Habitats Neutral Grassland Calcareous Grassland Acid Grassland Heathland Habitats Heath (Dwarf shrub) Bracken ‐ Dense Peatland Habitats Bog Agricultural Habitats Improved Grassland Arable and Horticulture Highland Habitats Mountainous Inland Rock Urban Habitats Urban/Built up Areas Roads / Tracks & Hard Embankments Total

ha

% of N.I.

Habitat Change Between 1998‐ 2007

1581 1995

0.11 0.14

61332 5495 47255

4.33 0.39 3.34

‐453 +105 ‐5680

81699 60617

5.77 4.28

+18193 ‐1518

231116 1802 10369

16.32 0.13 0.73

‐32786 +37 ‐2954

16751 2645

1.18 0.19

+2842 ‐439

160902

11.36

‐3314

573010 48917

40.47 3.46

+18028 ‐8295

735 5450

‐ 0.39

‐ ‐2520

74098 30951 1415986

5.23 2.19

+17251 +1503

ha

% Change

+18193 ‐1518

+28.65 ‐2.44

‐0.73 +1.96 ‐10.73 +28.65 ‐2.44 ‐12.42 +2.12 ‐22.18 +20.43 ‐14.25 ‐2.02 +3.25 ‐14.50 ‐ ‐31.62 +30.35 +5.10

Table 8 ‐ Rate of Habitat Change in Northern Ireland (Cooper, McCann, & Rogers, 2009)

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Northern Ireland and Green Roof Habitat Recreation

The following table illustrates the explored connections between the habitats capable of surviving on green roofs and the requirements of natural habitats in Northern Ireland.

Habitats favoured

by Green Roofs

Coastal Vegetation

Northern Ireland habitats capable of addapting to Green Roofs

Habitats Commonly Recreated on Green Roofs

Habitats Promoted

by Ease of Construction and Financing

Tidal Marine Habitats Saline Lagoon

Coastal Habitats Sand Dunes Vegetated Shingles Banks Cliffs and Slopes

Arid Vegetation Wetland Habitats Reed Beds Floodplain Grazing Marsh

Reed Bed Vegetation

Woodland Habitats Wet Woodlands Mixed Ashwood Oakwood

Mountainous Vegetation

Grassland Habitats Lowland Dry Acid Grassland Calcareous Grassland Lowland Meadow Purple Moor & Rush Pasture Limestone Pavement

Limestone Vegetation

Heathland Habitats Lowland Heaths Upland Heaths Mountainous Heaths

Shrub & Heath Vegetation

Peatland Habitats Lowland Raised Bog Blanket Bog Fens

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44

Chapter 3

Green Roofs and Created Habitats

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45

A wealth of research data exists that supports the perception that green roofs in heavily built up areas can support a relatively diverse level of flora and fauna species (Köhler, 2006). The purpose of this chapter is to present examples of completed green roofs, which demonstrates the scope of habitat that have been created on green roofs and illustrate the value a successful green roof can have on the surrounding ecology.

Figure 1 ‐ Chicago City Hall The specific construction details of green roofing systems and whether they complement or clash with the equivalent natural environment shall be discussed. The table below show the range of natural habitats in Northern Ireland that have the potential to be replicated on green roofs.

Northern Ireland Habitats which can be readily adapted to Green Roofs Coastal Habitats Grassland Habitats  Sand Dunes  Lowland Dry Acid Grassland  Vegetated Shingles Banks  Calcareous Grassland  Cliffs and Slopes  Lowland Meadow

 Purple Moor & Rush Pasture Wetland Habitats  Limestone Pavement  Reed Beds

 Floodplain Grazing Marsh Heathland Habitats

 Lowland Heaths  Upland Heaths  Mountainous Heaths Northern Ireland Habitats that can be created on Green Roofs with additional Considerations Marine Habitats Peatland Habitats  Saline Lagoon  Lowland Raised Bog

 Blanket Bog Woodland Habitats  Fens  Wet Woodlands

 Mixed Ashwood Table 1 ‐ Habitats Capable of Existing on Green Roofs (Author)

Each section of this chapter will examine existing attempts to recreate a specify habitat, these examples will be assessed on their cost, structural makeup and ecological impact.

The aim of this undertaking is to refine the list of Northern Ireland habitats which can exist on a rooftop to those which are practical to replicate on green roofs. The finding of this chapter, in addition to previous chapters will provide material for the discussion of whether green roofs can play a role in habitat preservation in chapter 4.

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3‐01 Sand Dunes / Shingles Banks Habitat Case Studies Flat gravel roofs are a common roof typology within many urban centres; the material makeup of such roof already shows some similarities with many coastal environments. The free‐draining sandy and gravel covering presents environmental conditions, such as periods of drought and heavy wind exposure (Grant, 2006), which are common to sand dunes and shingles banks (CVNI, 2011).

As mentioned in section 1‐12, the stress tolerance Sand Dunes vegetation associated with coastal locations is ideal for rooftop occupation (Dunnett & Kingsbury, 2008). The lack of complex soil layer in sand and shingle beach heads (National Museums Northern Ireland, 2010) also means that it is possible to construct artificial soil which have the capability of mimicking organic beach material (Hitchmough,

1994). This presents opportunities to reduce the need for Figure 2 ‐ Murlough Dunes, Dundrum Bay the removal of natural sand or gravel soils in habitat Vegetated Shingles recreation projects.

Recent field research into how plant species spontaneously colonized urban areas and habitats (such as pavements, walls, roofs, lawns and roofs) originate disproportionately from coastal and rocky habitats (Lundholm & Marlin, 2006).

Figure 3‐ Kearney, Down

An important example of a green roof working to support coastal dunes and beach heads is the National Trust Visitor Centre at Portstewart Strand. A building designed by Donnelly O’Neill Architects is located next to a two mile stretch of protected beach and sand dunes. The green roof is a 400m2 extensive sedum roof, which is expected to be colonised by local dune grass in the future (GreenRoof, 2010).This project is one of the few attempts of habitat recreation at roof level in Northern Ireland.

Figure 4 ‐ National Trust Visitor Centre, Portstewart Strand

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Sechelt Justice Services Centre

The Sechelt Justice Services Centre is located Location Sechelt, Canada 2003 adjacent to the Pacific Ocean in British Completion Date District of Sechelt Columbia and is an example of a low‐impact, Client Architect Johnston Davidson site‐specific roof design. The roof was Landscape Architect Sharp & Diamond New developed to replace the coastal dune meadow New Build/Retrofit Extensive that was consumed during the building process, Green Roof Type 2 Roof Size 465m mimicking the local soil conditions and optimise Roof Coverage 40% Soil Medium 60% Black Pumice the exposure to sunlight and prevailing winds. and 40% Soil

Amendment The roof is populated by native costal grass Soil Depth 75mm 2 £46/m species and selected non‐native plants such as Cost 2 Weight 73.2kg/m sedum, mosses and herbs (Earth Pledge, 2005).

Significance to Northern Ireland Habitat Replication The construction method utilised by the Sechelt Justice Services Centre shows promise for the recreation of sand dunes / shingles banks habitats here in Northern Ireland.  The roofing systems use a lightweight structure that is within the structural tolerances of the majority of Northern Irelands buildings (Adler, 1999).  An artificial soil substrate supports coastal grasses, using pumice rock and plant nutrient supplements.  A mixture of native grasses and alien mosses and herbs are planted on the rooftop.

The mixture of native/non‐native species on Northern Ireland rooftops will have to be done in conjunction with the appropriate Northern Ireland Habitat Action Plan and the national Biodiversity Action Plan (Northern Ireland Habitat Action Plan, 2005).

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University Hospital of Basel

While every building in Basel hospital complex Location Basal, Switzerland has a green roof, only the roof of Clinic One was Completion Date 1999 University Hospital specially designed as a test site for urban bird Client of Basel habitat creation. The roof is covered with sandy Architect n/a loam and gravel from the nearby riverbank, Landscape Architect Stephan Brenneisen New shaped into small hills and perches that are the New Build/Retrofit Green Roof Type Extensive preferred train of insect‐hunting birds (Earth 2 Roof Size 1,860m Pledge, 2005).

Roof Coverage 60% Soil Medium 60% sand and

gravel; 40% topsoil The green roof has become frequented by an with stones and unexpected range of bird species; Black humus 90mm Redstarts, Wagtails, Rock Doves and House Soil Depth 2 £10/m Sparrows (typically mountainous, rural species) Cost 2 Weight 146.5kg/m dominate the roofscape, with common urban species rarely observed. Studies has have proposed that in dense urban areas where vegetation and food is scarce; migratory birds select rooftops which resemble their natural feeding and nesting habitats (Brenneisen S. , 2006).

A number of native grasses were planted during the construction of the roof; however the majority of vegetation has grown from seeds deposited by birds (Earth Pledge, 2005).

Significance to Northern Ireland Habitat Replication The Clinic One building illustrates the following points for habitat recreation  There exists a readiness by both flora and fauna species to habitat rooftop habitats, when the roof provides resources similar to their natural habitats.  The University Hospital of Basel represents a successful recreated habitat, which required a low financial investment.  The ability of plant species to colonise green roofs through seed dispersal by birds, highlights the natural transition of rooftops vegetation in response to the residing fauna species. This makes the Clinic One building an example of an artificial habitat roof reaching a level of symbiosis with local wildlife.

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Laban Dance Centre

The brown roof on the Laban Dance Centre was Location London, England constructed using debris found onsite during Completion Date 2002 Laban Dance Centre the construction process. Brick and Concrete Client Herzog & de were crushed and stacked unevenly across the Architect Meuron roof to simulate a waterfront gravel/shingle Landscape Architect Vogt Landscape Architects bank supported by local dry grassland New Build/Retrofit New vegetation, which was once common to the Green Roof Type Intensive Rubble Thames (Earth Pledge, 2005). The building won Roof 2 400m the RIBA 'building of the year' award, and Roof Size 33% Herzog & de Meuron won the Stirling Prize for Roof Coverage Soil Medium Rubble the Laban Dance Centre building in 2003 Soil Depth 120‐150mm 2 Cost £22/m (GreenRoof, 2010).

Weight Not available

The rooftop at the Laban Dance Centre has been designed to support the endangered Black Redstart bird species, one of the most endangered birds in the UK (Earth Pledge, 2005). The success of the roof in providing a nesting ground for the Black Redstart has encouraged the adoption of ecological green roofs by neighbouring buildings (Frith & Gedge, 2000); the issues of ecological roof in London will be expanded upon in chapter 4.

Significance to Northern Ireland Habitat Replication The Laban Dance Centre illustrates the following points for habitat recreation  The Laban Dance Centre is another example of a successful habitat roof project.  The nesting of the Black Redstart and use of the building as a part of their feeding area, demonstrates that green roofs can play an important role in aiding in conservation methods.  A use of recycled construction material (crushed brick and concrete) within the artificial soil substrate showcases a more sustainable approach to green roof planting. Crush building material used in the aggregate layer of green roofs is not wide utilised within the UK construction sector (Graceson, Hare, Hall, & Monaghan, 2011).

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3‐02 Cliffs and Slopes Habitat Case Studies An estimated 528 hectares of coastal cliffs and slopes surround Northern Ireland (Cooper, McCann, & Rogers, 2009), a diverse array of flora and fauna species inhabit these environments, dominating areas of high exposure and limited soil (CVNI, 2011).

The widespread presence of hard‐surfaced environments Cliffs and Slopes within built‐up areas and their colonisation by species adapted to rocky habitats has lead to the emergence of the ‘Urban Cliff Hypothesis’. This planning ecology concept states that development of urban areas is more complex than a simply destruction of natural habitat; rather original habitats are replacement by artificial habitats that function, both structurally and biologically, like rocky outcrop and cliff tops

Figure 5 ‐ Carrick‐a‐Rede Cliffs, Antrim (Larson, Matthes, Kelly, Lundholm, & Gerrath, 2004).

The combination of resilient plant species and a natural affiliation between cliff habitats and urban structure, creates a wide number of both flora and fauna species that can readily be applied to many rooftops (Dunnett & Kingsbury, 2008; Lundholm & Marlin, 2006).

An example of an interesting combination of cliff habitats and green roof environments is the Gallie Craig Coffee Shop at Drummore, Stranraer, in Scotland. The tourist building was designed by IB MacFadzean Architects whose green roof is integrated into the cliff face. A turf roof allows the building to blend into the contours of the land, reducing any detrimental visual effect on the landscape (GreenRoof, 2010).

While this is a very direct representation of the combination of cliff and rooftop habitats, the examples does showcase that a direct comparison between the two habitats on ecological terms can be made.

Figure 6 ‐ Gallie Craig Coffee Shop, Drummore, Scotland

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ACROS Fukuoka

The Asian Crossroads over the Sea (ACROS) Location Fukuoka, Japan building is a public/private development in the Completion Date 1995 Client Dal‐lchi Mutual Life centre of Fukuoka city, adjacent to the Tenjin Mitsui Real Estate Central Park. The aim of the design was to Architect Emilio Ambasz create public space equal to the land lost due to Landscape Architect Nihon Sekkei Takenaka the buildings footprint. 15 vegetated terraces Corporation dominated the structures south façade, with New Build/Retrofit New access to the building’s interior at each floor.

Green Roof Type Intensive 2 Roof Size 930m

Roof Coverage 80% The majority of the planting species are Soil Medium Rubble indigenous to Japan, mostly hardy grasses and Soil Depth 300‐600mm Not available perennial flowers, with some non‐native Cost Not available annuals and perennials used for their aesthetics Weight (Earth Pledge, 2005).

Significance to Northern Ireland Habitat Replication The construction method implemented by the ACROS Building presents the following points for habitat recreation.  A high percentage of the land consumed by the buildings footprint has been replaced by rooftop vegetation, however this was a design requirement as the structure is located in a dense urban area with few open spaces or public greenery (GreenRoof, 2010).  The design of the ACROS Building showcases its rooftop vegetation as a prominent part of its primary façade.  The soils substrate layer of the ACROS Building uses a rubble soil system similar to the Laban Dance Centre; however this report was unable to find out if any recycled material was used in the construction process.

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3‐03 Wetland Habitat Case Studies A growing market for organic water filtration systems (such as reed beds and willow) has encouraged the emergence of wetland habitats on many rooftops (Oberndorfer, et al., 2007). There is over an estimated 5,000 constructed wetlands in Germany, used primarily to treat residential and municipal wastewater in areas where a connection to the central sewage treatment system is too costly. The adoption of wetland rooftops has followed suit.

(Earth Pledge, 2005), the issues of green roof adoption in Germany will be further discussed in chapter 4. This report was unable to establish if a wetland roof has ever been attempted in Northern Ireland.

Wetland plants clean and filter water naturally; Reed Beds microorganisms in the root systems and in wetland soil absorb and breakdown contaminants, metabolising them into nutrients (Earth Pledge, 2005). Additionally the minimal soil requirements and the ability to recycle nutrients in water runoff, results in the ability of flora and fauna that requires a permanent waterlogged environment that can exist on green

roofs with appropriately designed drainage layers and Figure 7 ‐ Castle Espie, Down irrigation systems (Coffman & Davis, 2005).

Floodplain Marsh

The ability of rooftops to contain large bodies of water is limited. Partly due to the additional need for waterproofing any underling structure, but also the weight a substantial volume of water imposes.

Figure 8 ‐ Insh Marshes, Scotland The largest example of a body of water within an artificial roof wetland habitat recreation; is the 120m2 miniature lake around a penthouse suite of the BMW Düsseldorf Office Building. The rooftop habitat created by leading green roof manufacture ZinCo GmbH, is an intensive roof garden and large pond located 20 metres above ground on the roof of the BMW office building in Düsseldorf (GreenRoof, 2010).

While the ability of static bodies of water to exist at roof level is limited (Dunnett & Kingsbury, 2008), however the capacity to apply wetland grasses and reed species is a more applicable and mature roofing approach (Coffman & Davis, 2005).

Figure 9 ‐ BMW Düsseldorf Office Building

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KPMG Building

During a programme of building renovations, a Location Dusseldorf, wetland environment was created on the roof of Germany 2003 the parking complex in KPMG Dusseldorf. The Completion Date Client KPMG wetland was a renovation of a previous Architect Eckhard Gardenier ornamental pool which would regularly become Landscape Architect Ulrich Zens New choked with algae due to the high phosphate New Build/Retrofit Green Roof Type Intensive level of the tap water used to feed the habitat.

2 Roof Size 4,100m

Roof Coverage 67% topsoil for grasses; The wetland uses a mixture of plant species that Soil Medium lava mixed with are current marketed with organic rainwater zeolite for wetlands filtration systems and expanded into a larger Soil Depth 300‐ 400mm 2 £660/m natural system. The roof contains a well, grass Cost Not available landscaped area, an artificial swamp plus stream Weight and the original pond. The well collects rainwater, which is pumped to an irrigation system for the landscaped area and the stream which feeds the swamp which drain into the pond.

The water bodies are lined with volcanic rocks, which further filter the water and anchor reed species.

The habitat has shown to support a complex array of insect and bird species. In addition to this, the roofing treatment has saved the building occupiers money through reduction in storm water fees and heat/cool costs (Earth Pledge, 2005).

Significance to Northern Ireland Habitat Replication The KPMG building illustrates the following points for habitat recreation  A mosque of habitat condition has been created on the KPMG roof, which has been proven that a mix of habitats types on a single roof increases overall biodiversity (Brenneisen S. , 2006).  The water pumping system used by the KPMG buildings is complex and will have an impact of the maintenance and operation cost of the roof.  The construction costs and structural weight of the wetland roof is considerable

when compared to other grassland habitat roofs.

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Possmann Cider Company

During a series of schemes to modernise its Location Frankfurt, Germany 1993 factory, the Possmann Cider Company required Completion Date Client Possmann Company an alternative system to cool its fermentation Architect Siegfried Ziepke tanks because of Germany’s high water charges. Landscape Architect Not available

New Build/Retrofit Retrofit Green Roof Type Intensive In 1993, the company installed a similar wetland 2 Roof Size 3,000m green wetland roof as the system use at KPMG, Roof Coverage 100% creating a closed loop cooling system. Rainwater Soil Medium None ‐ hydroponic n/a collected by the wetland is directed to the Soil Depth Not available fermentation tanks and circulated back to the Cost Weight Not available roof. Plants thrive in the warmer water and the dense shaded root systems quickly cool the water.

The wetland has become populated by local bird species and a 1999 study showed that 20 new plant species had established themselves on the roof (Earth Pledge, 2005).

Significance to Northern Ireland Habitat Replication The Possmann Cider Company illustrates the following points for habitat recreation  The company states that the wetland roof treatment has an annual saving of £3,6501 in the buildings cooling cost (Earth Pledge, 2005). Displaying wetland green roof as a means of sustainable building cooling.  This roof type combines sustainable technologies, namely a grey water rainwater storage system to reduce the need for mains water to feed the roof environment.  The adaption of hydroponic plant feeding methods has completely removed the need for an artificial soil substrate.  The Possmann Cider Company is an example of a habitat roof naturally colonised by a local bird species.

1

Figure converted from stated value ($6,000)

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John Deere Works

The manufacturing and assembly process at the Location Mannheim, John Deere factory in Mannheim, Germany Germany 2003 produces an extensive volume of wastewater Completion Date Client John Deere due to its metal cutting systems. Previously all Architect John Deere wastewater in the factor was sent to a Landscape Architect John Deere Retrofit treatment plant and discharged to the New Build/Retrofit Green Roof Type Intensive municipal sewer system at a significant fee.

2 Roof Size 42m

Roof Coverage 65% None ‐ hydroponic The company did not have the require ground Soil Medium Soil Depth 50mm level land to support a natural treatment 2 Cost £330/m 2 system, so rooftop system were explored. The Weight 341.8kg/m roofing technique employed by the John Deere factory, does not utilise a soil base in order to limit the weight on the pre‐existing structure.

The plant life receives nutrient from a 50mm deep hydroponic system. The designers of the roof system have found that a combination of Sedges, Rushes and Irises species are the most effective in the breakdown of carbon and nitrogen compounds in discharge water and can accumulate and remove suspended phosphates and heavy metals particles through their root systems (Earth Pledge, 2005). Green roofs can remove over 95% of cadmium, copper and lead in retained water they also remove 16% of zinc and dramatic reduce the level of water soluble Nitrogen (Schmidt, 1990).

Significance to Northern Ireland Habitat Replication The John Deere factory illustrates the following points for habitat recreation  Again the John Deere factory uses a hydroponic plant feeding system  A wetland habitat roof system was used in the John Deere factory to reduce the water discharge of the metal works, unlike the Possmann Cider Company which was driven by the reduction of cooling costs.  Both the wetland roofs systems of the Possmann Cider Company and John Deere factory were designed as energy saving habitats, dedicated purely to their relationship with their connected buildings. This may present conflicting design drives; between building sustainability and habitat recreation.

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3‐04 Woodland Habitat Case Studies While it is unexpected to have woodland habitats at roof level many examples exist (Peck & Kuhn, 2000). Trees and large bushes are exclusive to intensive green roofs and have the highest visual impact of any planting; however a number of factors need to be considered when creating woodland habitats

Native Woodlands Wet Woodlands The weight of any planted tree must be calculated, as they induce a considerable concentrated load which can greatly increase during high winds due to the addition of tipping momentum under wind Figure 11 ‐ Bonds Glen, Derry Figure 10 ‐ Belvoir Park Forest, Belfast pressure (Francis & Lorimer, Mixed Ashwood Oakwood 2011). Trees with smaller leaves and a relatively small crown offer the best wind resistance, and the minimum soil depth for small trees is approximately 500mm.

To counteract the debilitating factors of high winds and shallow

Figure 12 ‐ Glenarm Woodlands, Antrim Figure 13 ‐ Breen Oakwood, Antrim soils it is necessary to anchor the root ball to the roof structure below (Dunnett & Kingsbury, 2008).

Irrigation systems are also crucial for the survival of tree on green roofs because of reduced root systems; they need a continuous flow of water to meet a tree’s nutrient and water requirements (White & Snodgrass, 2003). Additionally tree dominated rooftops are heavily affected by restricted size, due to a combination of the volume of single plants and the typical area of many roofs (Brenneisen & Hänggi, 2006).

Despite these restriction successful woodland habitats can exist within a green roof environment, all be it in a heavily managed format (Earth Pledge, 2005). An extreme example of the combination of tree habitat and building is the Hundertwasserhaus, an apartment block in Vienna, Austria by the artist Friedensreich Hundertwasser. The building possesses an earth covered roof supporting numerous grasses and large trees, many of which have sprouted from inside rooms with their trunks protruding through the roof structure and having limbs extending from windows. The structure supports a total of 250 trees and bushes (Earth Pledge, 2005).

While structures accommodating tree habitat do not go to such planting extremes as the Hundertwasserhaus, tree require care consideration before planting.

Figure 14 ‐ Hundertwasserhaus, Vienna

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The Patterson Garden

The rooftop garden of Glen Patterson at third Location Vancouver, Canada 2003 floor level in the Escala Tower in the Vancouver Completion Date Glen Patterson harbour district was designed to resemble a Client Architect K.M. Cheng costal wet forest. The roof supports a number of Architects Nakano Landscape transplanted mature trees, mostly Black and Landscape Architect Design White Pines and Maple, Cypress and evergreen New Build/Retrofit New Oak species (in addition a Gnarled Japanese Green Roof Type Intensive 2 185m Maple aged at over a 100years), an artificial Roof Size Roof Coverage 100% pond and stream and a number of species of Soil Medium black pumice dwarf rhododendrons and mountain hemlocks pebbles; graded sand; coconut as groundcover planting. fibres; zeolite

Soil Depth 300mm (600mm for Two years before the completion of the tree roots) Not available building, trees to be relocated to the roof were Cost Roof strengthened excavated and their roots cut back to 3‐foot Weight to load‐bearing of 2 diameter planting balls, to allow the plants time 1220kg/m to adapted to the compact environments of the roof. Additionally shortly before being replanted at roof level the root balls were bound tightly with plastic strapping, using bonsai9 techniques, to restrain root growth (GreenRoof, 2010).

Significance to Northern Ireland Habitat Replication The Patterson Garden illustrates the following points for habitat recreation  A 600mm substrate (a substantial soil depth for a roofing system) is needed to support tree species that have undergone induced stunted grown and dwarfism to adapt to roof conditions.  Special consideration was given during the roof’s construction to accommodate the additional weight imposed by the planted trees (Earth Pledge, 2005).  The roof has a purpose built automatic irrigation system to supply the water needs of the garden (Earth Pledge, 2005).  The rooftop was design as an ornamental garden not a natural habitat recreation with all trees species cloud pruned to a 900mm (Earth Pledge, 2005).

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Roppongi Hills

Roppongi Hills in the centre of Tokyo was Location Tokyo, Japan 2003 conceived as an experimental urban Completion Date Roppongi 6 Chrome development. In combination with a number of Client Redevelopment other schemes, the developments green spaces Association Cionran & Partners was envisaged as a way to revitalize the Architect Yohji Saski residences of downtown Tokyo, who were Landscape Architect & Dan Pearson categorised as have high levels of depressed.

New Build/Retrofit New Green Roof Type Extensive &

Intensive Presently Roppongi Hills represents 26% of 2 Roof Size 13,285m greens pace in central Tokyo. The scheme Roof Coverage 26% contains a number of green rooftops, with the Soil Medium Soil; Artificial aggregates; Keyakizaha building supporting a rice paddy with Sedum mats a parameter tree line (GreenRoof, 2010).

Soil Depth 30‐1200mm Cost Not available

2 Weight 97.6kg/m

Significance to Northern Ireland Habitat Replication The Roppongi Hills illustrates the following points for habitat recreation  A requirement for additional structural props was needed to be installed in order to stabilise the planted tree species (Earth Pledge, 2005).  Rainwater storage in combination with a drib irrigation system was developed to provide water and nutrients for the roof habitat (Earth Pledge, 2005).  Again the Roppongi Hills was designed as an ornamental garden rather than a natural habitat, the majority of the Roppongi Hills is a combination of traditional Japanese and Japanese‐British style gardens (Earth Pledge, 2005).

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3‐05 Grassland Habitat Case Studies Grasses are common on many green roofs; many roof designs state that mimicking natural meadows is their primary goal (Budge, 2009). The shallow roots systems and the pressures imposed by grazing (Northern Ireland Habitat Action Plan, 2005) have created a diverse range of stress‐tolerant vegetation that is capable of adapting to a green roof environment (White & Snodgrass, 2003).

While certain grassland habitats Lowland Acid Grasslands Calcareous Grasslands will require intensive soil layer to support their principle species (CVNI, 2011; White & Snodgrass, 2003), lightweight extensive green roofs are capable of providing for many grassland

Figure 16 ‐ Little Deer Park, Antrim Figure 15 ‐ Wangford Warren, Suffolk habitats (Larson, Matthes, Kelly, Lowland Meadows Rush Pastures Lundholm, & Gerrath, 2004).

Many of the grasslands in Northern Ireland rely on a variation of a shallow mineral soil (NIEA, 2010) these conditions are

Figure 17 ‐ Tees Valley, Middlesbrough Figure 18 ‐ Slievenacloy, Belfast Hills replicable within the substrate of Limestone Pavements extensive green roofs (Dunnett N. , 2006).

Grass roof habitats are a mature green roofing treatment, with a number of examples of grass covered green roofs which have

Figure 19 ‐ Knockmore, Fermanagh been proven to provide for surrounding wildlife or support rare species (Dunnett & Kingsbury, 2008).

An example of the statement is the Ducks Unlimited National Headquarters and Conservation Centre in Winnipeg, Canada which contains a grass roof, this example has been previously mention in the freshwater habitats conclusions of chapter 3. This is an example of habitat recreation that provides resources for nesting birds from the adjacent Oak Hammond Marsh which has many parallels to Lough Neagh (GreenRoof, 2010).

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Figure 20 ‐ Ducks Unlimited National Headquarters, Winnipeg, Canada

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Hill House

To comply with strict planning requirement for Location La Honda, California 1979 building within a ‘scenic corridor’, a buried Completion Date George & Adele dwelling was designed for the Norton family. Client Norton The house used a system of concrete/ fieldstone Architect Jersey Devil Design/Build retaining walls and sod covered roof to create to Landscape Architect Jersey Devil minimal impact building.

Design/Build

New Build/Retrofit New Extensive The roof was cover with Winter Rye and local Green Roof Type 2 232m wildflowers with boundary of the sloped roof Roof Size Roof Coverage 100% landscaped with Honeysuckle vines and Oak Soil Medium 50% road base and 50% topsoil trees (GreenRoof, 2010).

Soil Depth 200mm

2 Cost £650/m 2

Weight 439.4kg/m

Significance to Northern Ireland Habitat Replication The Norton Hill House illustrates the following points for habitat recreation  The Hill House is an example of a semi‐buried structure; while his will allow for the colonisation of additional fauna species it will not affect the rate of flora and invertebrate species (Dunnett & Kingsbury, 2008).  A mixture of commercially available road aggregate and natural topsoil was used in the development of this roof system; a sustainably questionable material mixture.  The direct connection between the building roof and surrounding natural environment was an imposed design feature.

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Heinz 57 Centre

The green roof on the Heinz 57 Centre was part Location Pittsburgh, Pennsylvania of the refurbishment of the long abandonment 2001 building located on the fringe of Pittsburgh Completion Date Client 623 Smithfield historic quarter (Earth Pledge, 2005).

Associates Architect Burt Hill Koser

Rittlemann The high masonry walls that surround the Associates garden have created a sheltered micro‐climate Landscape Architect Burt Hill Koser Rittlemann which has led to a more diverse range of Associates vegetation. The roof is populated by a number New Build/Retrofit Retrofit of flowering wildflowers and sedum species, Green Roof Type Extensive 2 1,115m with an all year round blooming cycle (Earth Roof Size Roof Coverage 33% Pledge, 2005). The plant list includes 35 Soil Medium 90% mineral; separate plant species, which ranges from low‐ 10% organic 120mm growing groundcover plants like sedum to taller Soil Depth 2 £105.50/m vegetation such as Anthemis and Carex Cost 2 Weight 146.5kg/m (GreenRoof, 2010).

Significance to Northern Ireland Habitat Replication The Heinz 57 Centre illustrates the following points for habitat recreation  No irrigation system is use on the Heinz 57 Centre; instead the roof drainage layer can hold 30% of its volume in rainwater (representing 55% of predicted annual rainwater). This water retention rate is in line with German FLL standards (Earth Pledge, 2005).  The roof structural systems is an example of what can be achieve at the low building costs and roof loading scale for grass roof habitats.  The high masonry walls of the Heinz 57 Centre shows that through appropriate building design it is possible mitigate the effects of exposed rooftops or even alter the conditions of a green roof through the creation of microclimates

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Chicago City Hall

In conjunction with an Environmental Location Chicago. Illinois 2001 Protection Agency programme to negate the Completion Date City of Chicago urban heat island effect and to improve city air Client Architect William McDonough quality, Mayor Richard M. Daley and the City of + Partners Chicago began construction of an exhibition Landscape Architect Conservation Design Forum semi‐extensive green roof on The Chicago City New Build/Retrofit Retrofit Hall in April 2000 (GreenRoof, 2010).

Green Roof Type Extensive &

Intensive 2 2,045m The garden was a retrofit development on the Roof Size Roof Coverage 56% century old city Hall and is not accessible to Soil Medium Commercial growth members of the public. The roof supports both media 100mm native and non‐native plant species, with has Soil Depth 150mm been organised in a number of colour related 450mm 2 planting beds (Earth Pledge, 2005).

Cost £300/m 2 Weight 100mm=146.5kg/m

2 150mm=293kg/m 2 The City Hall rooftop garden has over 150 450mm=439.5kg/m species, in addition to 100 woody shrubs, 40 vines and 2 trees, Cockspur Hawthorn and Prairie Crab‐apple (GreenRoof, 2010).

Significance to Northern Ireland Habitat Replication  The Chicago City Hall illustrates the following points for habitat recreation  It is stated that the city hall has an annual saving of £3,0502 in general utility cost due to the cooling effect and rainwater retention provided by the grass roof (Earth Pledge, 2005).  Supplemental irrigation systems has been added to the roofs systems to aid in the establishment of plants as well as provide supplemental water during extreme periods of drought (GreenRoof, 2010).  The research into the reduction of heat island effect and green roofs is still ongoing; however published figures state that there is a 15oC difference between the green roof and neighbouring black tar roofs in the height of summer (City of Chicago, 2010).

2

Figure converted from stated value ($5,000)

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Moos Water Filtration Plant

The Moos Water Filtration Plant near Zurich Location Zurich, Switzerland 1914 built in 1914 (one of the first reinforce concrete Completion Date Client City of Zurich structures in the region) supports nine‐acres of Architect Not available species rich rooftop meadows. These roofs were Landscape Architect Not available Retrofit not designed as a green roof, but as a New Build/Retrofit Intensive sand/gravel/soil roof to add in the cooling of the Green Roof Type 2 Roof Size 9,290m building and plants have naturally colonised the Roof Coverage 100% space over the buildings lifetime.

Soil Medium Topsoil and humus Soil Depth 200mm

Cost Not available The three oldest roofscapes cover Weight 2 488.2kg/m approximately 3 hectares and provide habitat for 175 different plant species, including 9 species of orchids (GreenRoof, 2010), including 6,000 specimens of Orchis Morio, an orchid species thought to be extinct in the area (Earth Pledge, 2005).

The roofs are currently under consideration to be granted environment protection orders by the regional government (Earth Pledge, 2005).

Significance to Northern Ireland Habitat Replication The Moos Water Plant illustrates the following points for habitat recreation  The roof’s structure presents excellent evidence for the longevity of green roofs (Dunnett & Kingsbury, 2008) and the ability of green roofs to be naturally colonised by unexpected species (Brenneisen, 2006).  The soil substrate consists of 5cm of sand and gravel as a drainage layer, with between 15cm and 20cm of topsoil. This again raises questions of sustainability and the sourcing of substrate material mixture.

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Vancouver Conference Centre

Also known as the Vancouver Convention Location Vancouver, Canada Centre West, this building includes a six‐acre Completion Date 2008 BC Pavilion green roof designed to replicate British Client Corporation Columbia costal grassland, which is currently the Architect LMN Architects largest in Canada and the largest non‐industrial Landscape Architect PWL Partnership New living roof in North America. The building was New Build/Retrofit Green Roof Type Intensive awarded an LEED Platinum rating on Roof Size 2 24,281m completion, the first conference centre in the Roof Coverage 58% Engineered Soil; world to achieve such a rating (GreenRoof, Soil Medium sand, organic 2010). medium, lava rock

Soil Depth 300mm Not available The green roof is landscaped with more than Cost Weight Not available 400,000 specimens of native plants and grasses from the Gulf Islands, including Sea Thrift and Beach Strawberry, which provides natural habitat to birds, insects and small mammals. An important design principle for the green roof was that no peat moss be use in the soil makeup (Budge, 2009), as such the roof medium is based on dredged dockland sands and recycled organic material (GreenRoof, 2010). This is because the client required that no existing habitats be damaged in the production of the soil layer for the new green roof (Budge, 2009).

Significance to Northern Ireland Habitat Replication The Vancouver Convention Centre illustrates the following points for habitat recreation  A design decision was made not to use peat moss in the development of the roof’s soil substrate. As such recycled aggregate and organic matter gathered from the building’s kitchen and landscaping activities (Budge, 2009).  The building is an example of the discovery that meadow wildflowers were more abundant on the north‐facing section, and annual species, although present, were less prevalent than on the south‐facing section (Grant G. , 2006).  The Vancouver Convention Centre is an example of a large scale green roof developed specifically for the purposes of habitat replacement within an urban area.

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3‐06 Heathland Habitat Case Studies The dominance of a limited number of species within a small area, the reliance on a nutrient‐poor, heavily mineralised soils in addition to an adaption for a fragmented and restricted habitat range (NIEA, 2010); presents numerous feature of heathland that make them a viable candidate for habitat recreation projects within Northern Ireland’s urban roofscape.

A continuous exposure to Lowland Heaths Upland Heaths environmental stresses has spawned an array of low dense vegetation, drought‐tolerant shrubs (Gates, 1980), and heaths (Cooper & McCann, 2001); all evolved to cope with

Figure 21 ‐ Murlough National Nature Reserve Figure 22 ‐ Bloody Bridge near Newcastle the condition that are present Mountainous Heaths on many rooftops.

There exists a growing industrial trend to use heath, mosses and sedum roofs are method of reducing rainwater runoff across the world (Earth Pledge,

Figure 23 ‐ Mourne Mountains 2005). And because of the thin soils requirements, heathland species can flourish on the substrate of lightweight extensive (Brenneisen, 2006). Additionally the natural tendency for heaths to be near mono‐culture plants in isolated locations (NIEA, 2010), a clear parallel exists between the natural conditions of heaths and the leading method of plant extensive green roof through sedum or moss vegetation mats (Dunnett & Kingsbury, 2008).

Many buildings already use heath and moss extensive roof on small isolated sections of roof, because of their ability to created at little structural or monetary cost and survive with relatively no maintenance (Dunnett & Kingsbury, 2008).

An example of this is the North German Bank (Nord LB0) in Hanover, Germany by Behnisch, Behnisch & Partner Architects.

The building supports 13 heath and moss extensive roofs and two larger intensive roofs. The generous use of heath roofs is cosmetic; creating a more visually pleasing environment for the buildings occupants looking out the structure exclusively glass facades (GreenRoof, 2010).

Figure 24 ‐ North German Bank, Hanover, Germany

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Life Expression Chiropractic Centre

The rooftops of the Life Expression Chiropractic Location Sugarloaf, Pennsylvania Centre was installed for its functional aspect of 2001 temperature regulation and runoff control, in Completion Date Client Life Expression addition to the visual quality of the roof Wellness Centre Van der Ryn vegetation to blend into the surrounding rural Architect Architects Appalachian Valley (Earth Pledge, 2005). The Landscape Architect Roofscapes Inc. unique roof design and planting allows New Build/Retrofit New rainwater runoff to discharge along the full Green Roof Type Extensive 2 557.5m length of the building’s eaves, creating a curtain Roof Size Roof Coverage 100% effect of falling water during heavy rain Soil Medium 90% mineral; 10% (GreenRoof, 2010). organic Soil Depth 120mm

2 Cost £46/m The roof is planted with a variety of native Weight 2 137kg/m mosses and sedum species (Earth Pledge, 2005).

Significance to Northern Ireland Habitat Replication The Life Expression Chiropractic Centre illustrates the following points for habitat recreation  The green roof demonstrates the ability of lightweight extensive roofs to support dense low‐growing groundcover on a sloped roof ranging from 14o to 30o, believed to be one of the steepest green roofs in North America (GreenRoof, 2010).  No irrigation system was installed on the roof; rather the growing medium was designed to retain an estimated 55% of the annual rainfall (Earth Pledge, 2005).  Any innovative approach was taken to protect the roof from wind erosion while the plant species established themselves. A medium surface with a photodegradable wind blanket mesh was installed to cover the sprouting vegetation, which has since degraded (Earth Pledge, 2005).

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Schiphol Plaza

Schiphol Plaza at Amsterdam airport has its Location The Vague, The Netherlands green roof designed to reflect the condition of Completion Date 1994 surrounding flat plains. The expanse of heath and Client Amsterdam Airport sedum species has a wide degree of seasonal Schiphol Benthem Crouwel colour change acting as visual aesthetic for Architect NACA traveller who utilise the underline train station Landscape Architect Andriaan Geuze, and airport terminal. The green roof also acts as West 8 New a measure to reduce water runoff in line with the New Build/Retrofit Green Roof Type Extensive airports environmental policies (Earth Pledge, 2 Roof Size 8,100m 2005).

Roof Coverage 90% Soil Medium Not available

30mm Construction of the green roof consisted of the Soil Depth 2 Cost £26/m 2 installation of pre‐vegetated mats of moss and Weight 45kg/m sedum bound together with coir fibre (made from the husks of coconuts), which absorb rainfall and contain a mineral‐based substrate that provides plant nutrients and eliminates the need for soil (GreenRoof, 2010).

Significance to Northern Ireland Habitat Replication The Schiphol Plaza illustrates the following points for habitat recreation  The Schiphol Plaza can showcase an example of a large scale green roof developed specifically to replicate a mountainous habitat that surrounds the built up area.  The planting choices and roof structure is extremely lightweight green roofing approach, being less than a third of the loading requirement of the UK’s domestic buildings, 45kg/m2 compared to 153 kg/m2 (Adler, 1999).

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Somoval Garbage Treatment Plant

The Somoval treatment plant in Monthyon is Location Monthyon, France 1997 located less than a mile from the Paris city limits Completion Date Somoval and contains a 4‐acre green roof to add in the Client Architect S’PACE minimal visual impact of the structure.

Landscape Architect Not available New Build/Retrofit New

Extensive The vibrant sedum and moss roof was designed Green Roof Type 2 Roof Size 15,329m to allow the building to better blend into the Roof Coverage Not available surrounding countryside after complaints by Soil Medium Commercial growing medium local residents. The roofs vegetation turns from Soil Depth 70mm red into summer to a green during winter and Cost 2 £14.50/m 2 provides an insulation effect for treatment the Weight 178kg/m plant (Earth Pledge, 2005).

Significance to Northern Ireland Habitat Replication The Somoval Treatment Plant illustrates the following points for habitat recreation  The Somoval Treatment Plant is another example of a large green roof designed to replicate and blend in with a surrounding mountainous habitat.  The low construction cost of the Somoval Treatment Plant is noteworthy, being the second lowest costing of all the presented case studies.  Again the Somoval Treatment Plant is an example of a large roof at a scope with contains extensive planting.

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3‐07 Practical Implications of Rooftop Habitat Recreation The research undertaken in the development of this chapter has provided a number of values in regards to the physical and economical attributes associated with habitat recreation on building rooftops.

The following table details the type of environments capable of be recreated depending on the type of green roof installed.

Recreated Habitat Type Roof type

Coastal Extensive &

Intensive

Woodland Intensive only

Wetland Intensive only

Grassland Extensive &

Intensive

Heathland Extensive

Table 2 ‐ Required Roof Type for Habitat Recreation

The following table details the associated structural loading in regard to what form of habitat type has been developed on a building’s roof.

Recreated Habitat Type Weight/m2

Coastal 75 ‐ 145kg

Wetland 350kg

Woodland 1250kg

Grassland 150 ‐ 490kg

Heathland 45 ‐ 180kg

Table 3 – Imposed Roof Loading for Habitat Recreation

And finally the last table demonstrates a typical cost range to the construction and planting of an artificial habitat at roof level.

Recreated Habitat Type Cost/m2

Coastal £10‐£45

Wetland £300‐£600

Grassland £100‐£650

Heathland £15‐£45 Table 4 – Estimable Cost Range for Habitat Recreation

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Northern Ireland and Green Roof Habitat Recreation

The following table illustrates the explored connections between the habitats capable of surviving on green roofs and the requirements of natural habitats in Northern Ireland.

Habitats favoured

by Green Roofs

Coastal Vegetation

Northern Ireland habitats capable of addapting to Green Roofs

Tidal Marine Habitats Saline Lagoon

Habitats Commonly Recreated on Green Roofs

Habitats Promoted

by Ease of Construction and Financing

Coastal Habitats

Coastal Habitats Sand Dunes Vegetated Shingles Banks Cliffs and Slopes

Arid Vegetation Wetland Habitats Reed Beds

Wetland Habitats

Floodplain Grazing Marsh

Reed Bed Vegetation

Woodland Habitats Wet Woodlands Mixed Ashwood Oakwood

Mountainous Vegetation

Grassland Habitats

Woodland Habitats

Lowland Dry Acid Grassland Calcareous Grassland Lowland Meadow Purple Moor & Rush Pasture Limestone Pavement

Limestone Vegetation

Heathland Habitats

Grassland Habitats

Lowland Heaths Upland Heaths Mountainous Heaths

Shrub & Heath Vegetation

Peatland Habitats Lowland Raised Bog Blanket Bog

Heathland Habitats

Fens

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Chapter 4

Green Roof Habitat Creation for Northern Ireland

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The previous chapter focused on examples of environments created on green roofs to provide information on the practicality of habitat creation on green roofs. The final chapter of this report is designed to refine the number of viable green roof habitats to those which are most feasible to be applied to the existing urban areas in Northern Ireland. This task will utilise the information and findings revealed in previous chapters of this document, in order to gauge the consequences of Figure 1 ‐ Belfast City applying roof greening across Northern Ireland.

The combined endeavours of the previous chapters have generated information supporting the ability of green roofs to meet the habitat requirements of Coastal, Wetland, Woodland, Grassland and Heathland. This is further promoted by the environmental conditions of Northern Ireland which presents a preference for Cliff/Costal, Wetland, Grassland, and Heathland vegetation on our rooftops.

This chapter aims to examine the ability of Northern Ireland’s urban areas to support green roof habitats and briefly explore the physical, monetary and municipal influences over the development of rooftop habitats.

4‐01 Urban Resources in Northern Ireland Northern Ireland is a region dominated by agricultural land; with 44% of the national landmass consumed by improved grassland and horticulture plantations (Cooper, McCann, & Rogers, 2009). With a population density half that of the UK, 122people/km2 to the UK’s 255.6/km2 (Pointer, 2005), Northern Ireland is a relatively un‐urbanised country. The Northern Ireland Countryside Survey 2007 concluded that only 5% of Northern Ireland’s landmass consists of human settlements (Cooper, McCann, & Rogers, 2009).

Urban Habitats

Urban/Built up Areas Roads / Tracks & Hard Embankments

ha

% of N.I.

74098 30951

5.23 2.19

Habitat ha Change Between 1998‐ +17251 2007 +1503

% Change +30.35 +5.10

Table 1 ‐ Extent of Urban Area in Northern Ireland (Cooper, McCann, & Rogers, 2009)

The urban centres of Northern Ireland are primarily concentrated in the area surrounding Lough Neagh (Countryside Survey, 2008). The Belfast Metropolitan area is the largest urban centre, representing 22% of the total urbanised land in Northern Ireland (Pointer, 2005).

Growth in urban areas over the past number of decades throughout Northern Ireland has predominantly been at the expense of agricultural and natural grassland habitats (Cooper, McCann, & Rogers, 2009).

Figure 2 ‐ Northern Ireland's Urban Centres (Countryside Survey, 2008)

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While urbanised zones are a minority land use type, they are not without an ecological value (Wheater, 1999). Urban wildlife habitats consists of any ecological niches found within a built up area, such as buildings, hard surfaces, and any open brownfield or green spaces (NIEA, 2010).

Urban ecological habitats are based on managed green spaces (parks and gardens (Wheater, 1999)) and naturally seeded urban areas or industrial sites (demolition sites, railway lands or undeveloped Figure 3 ‐ Albert Bridge, Belfast industrial land (Harvey, 2001)). These habitats support a large number of plants, invertebrates and bird species, especially in the suburbs (National Archives, 1995). For example both Herring and Black‐backed Gulls are now commonly found nesting on the roofs of many buildings; flat roofs in particular are favoured as breeding grounds. Additionally the Albert Bridge in Belfast provides a safe roosting site for thousands of Starlings (NIEA, 2010).

The most important characteristic of urban areas is that they are compromised of a dense mosaic of habitats. This mixture of habitats within a limited location gives rare ground‐ nesting invertebrates and other fauna species a mixture of breeding site, foraging areas and shelter need to sustain their occupation (National Archives, 1995). Green roofs are a building treatment that will augment the existing ecological resources provided by urban habitats with a simulated natural environment, expanding the relationship between flora and fauna species and the built environment (Gedge & Kadas, 2005).

Estimated Rooftop Area in Northern Ireland Through a combination of information sources (the Northern Ireland Countryside Survey 2007, the Ordnance Survey NI and EU reports) and publish work by Lance Frazer; the following approximation of the total area of roof space in Northern Ireland has been made.

These figures will feature in further discussion on the implementation of green roofs within Northern Ireland.

Total Urban Area of Northern Ireland Estimated Roof space

741km2 (Cooper, McCann, & Rogers, 2009) 255km2 (Frazer, 2005)1

Estimated Rooftop Area of Northern Ireland Urban Centres

Belfast Metropolitan Area2 162km2 (Pointer, 2005)

Estimated Roof space 52km2 (Frazer, 2005)

2 Derry City Area 25km (Monaghan, 2011)

Estimated Roof space 8km2 (Frazer, 2005)

Newry City Area 9km2 (OSNI, 2011)

Estimated Roof space 2.9km2 (Frazer, 2005)

2 Armagh City Area 5km (OSNI, 2011)

2 Estimated Roof space 1.7km (Frazer, 2005)

Table 2 ‐ Size of Major Urban Centres in Northern Ireland

1 2

Based on the statistic that typically roof space represents up to 32% of the total surface areas in an urban area

Encompasses the Belfast Urban Area, Castlereagh Urban Area, Greenisland Urban Area, Holywood Urban Area, Lisburn Urban

Area, Newtownabbey Urban Area and Milltown (Lisburn LGD)

Additional Information

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Lisburn City Area: Estimated Roof space:

57km2 (Boyde, 2011) 18km2 (Frazer, 2005)

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4‐02 Re‐establishment of Natural Habitats As part of the Northern Ireland Habitat Action Plan, which has been discussed in chapter 2 and appendix A, a number of reports into individual habitat types were commissioned.

These documents described the condition of Northern Ireland’s natural habitats but also presented goals for the rehabilitation and future expansion of natural ecosystems.

While these documents discuss a number of factors effecting individual habits (such as key features, range and causes of habitat loss) which were utilised in previous chapters, they also detail requirements for future habitat conservation programmes proposed to be completed by 2015. These figures are detailed in the tables below.

Habitat to be restored by 2015

Habitat Type ha km2

Saltmarshes 100 1

Sand Dunes 1150 11.5

Vegetated Shingles Banks 25 0.25

Floodplain Grazing Marsh 50 0.5

Wet Woodlands 70 0.7

Mixed Ashwood 90 0.9

Oakwood 60 0.6

Limestone Pavement 220 2.2

Fens 50 0.5

Table 3 ‐ Northern Ireland Habitat Action Plan Required Restoration of Natural Habitats

While green roofs cannot play a direct role in the restoration of natural habitats, the case studies of chapter 3 have illustrated that green roof habitats can recreate the condition of a number of existing ecosystems. The multiple examples in chapter 3, showcases a type of environments possible and will be further discussed later on in this chapter.

Habitat to be re‐established by 2015

Habitat Type ha km2

Wet Woodlands 140 1.4

Mixed Ashwood 180 1.8

Oakwood 120 1.2

Lowland Dry Acid Grasslands 5 0.05

Calcareous Grasslands 10 0.1

Lowland Meadows 10 0.1

Lowland Heaths 130 1.3

Upland Heaths 100 1

Mountainous Heaths 25 0.25

Table 4 ‐ Northern Ireland Habitat Action Plan Required Re‐establishment of Natural Habitats

The figures stated above, describe a requirement for traditional methods of habitat recreation, and were not envisioned to be applied to urban habitat recreation projects, let

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alone rooftop environments. This stated the investigations undertaken by chapter 1 and 3, illustrate willingness by flora and fauna species to colonise rooftop habitats, when they provide resources similar to their natural habitats (Frith & Gedge, 2000).

Because of this fact, an argument can be made that rooftop habitats can have a place in the national recreation programs of certain natural habitats (Brenneisen S. , 2006).

4‐03 Structural Viability of Green Roof Habitats By combining the legal structural requirements for roofs under British Standards 6399 and the information gather on completed green roof habitat projects within chapter 3, a comparison can be made between typical building usage and the types of habitat roofs they can support.

UK Roof Structural Requirements (Adler, 1999)

BS6399 Category N/m2 kg/m2

Domestic 1.5 153

Offices 2.5 255

Retail 4.0 408

Warehousing 2.0 204

Factories, Workshops 5.0 510

Table 5 ‐ Required Roof Loading (Adler, 1999) These figures represent the general structural requirements for all new builds in the UK. While alternative values exist for buildings with specific usage, the above standards are the most common strength for the building category. These values are the legally required minimum for any construction system (Adler, 1999), so are reliable reflections of the strength of Northern Ireland’s buildings.

Range of Green Roof Weight Loads

Recreated Habitat Type Weight/m2

Coastal 75 ‐ 145kg

Wetland 350kg

Woodland 1250kg

Grassland 150 ‐ 490kg

Heathland 45 ‐ 180kg

Table 6 – Imposed Roof Loading for Habitat Recreation It is important to note that the above values are derived from completed examples of green roofs, a number of which are detailed in chapter 3. Green roof weight range are typically organised by the type of roofing structure (extensive, intensive, etc) and not ecological environments, however the weight of any green roof is calculated individually before installation commences and do not rely on generic or industry stated data.

An alternative body of data on the weight ranges of green roofs can be obtained from the German Landscape Research, Development and Construction Society guidelines (Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau [FLL]) and specific product guidelines.

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Heathland

Grassland

Woodland

Wetland

Coastal

Habitat

Types of Habitat Roofs capable of occupying Non‐Reinforced Structures

Building Type

  Domestic

   Offices

    Retail

   Warehousing

 

Factories, Workshops  

Table 7 – Building Types Capable of Carrying Habitat Roofs

Through cross‐comparison of the two above tables and an understanding of the range of habitats that are structurally viable on Northern Ireland’s building stock can be achieved.

Coastal, Grassland and Heaths are the most accommodating to a building’s structure as they are comprised of lightweight vegetation. Conversely woodland habitats, with their weighty planting are outside the structural norms of nearly all of Northern Ireland’s structures.

Wood roofs are considered to impose a load of 700‐1300kg/m² (Optigreen, 2011) placing them beyond the structural requirement of all typical structure, because of this woodland habitats are restricted to reinforced roofs only. Additionally the water retention rate of wood roofs is estimated at between 95‐99%, translating into a possible further 180‐320L/m² of rainwater to structurally accommodate (Optigreen, 2011).

The typical architecture of Northern Ireland’s is dominated by pitched roof structures. While green roofs can occupy the slopes common to most roofs, these systems require additional support and an associated weigh. Pitched lightweight sedum/moss/heather roofs weight 100‐130kg/m² (Optigreen, 2011) and grassed pitch roofs generally impose a loading of 160‐ 190kg/m² (Optigreen, 2011). These figures present Coastal and Heath habitats as structurally viable options on non‐strengthen domestic roof within Northern Ireland.

4‐04 Expense of Green Roof Habitat Recreation With the information gained during the third chapter, detailing examples of successfully developed green roof habitats. An approximation can be made for the general financial cost associated with any programme to facilitate rooftop habitat creation in Northern Ireland.

Green Roof Construction Costs

Recreated Habitat Type Cost/m2

Sand Dunes / Shingles Banks £10‐£45

Wetland £300‐£600

Grassland £100‐£650

Heathland £15‐£45

Table 8 – Estimable Cost Range for Habitat Recreation

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Because of the subjective nature of the building process, the above financial costing figures are to be considered representative prices only. These values are based on the information used in generating the datasets in chapter 3, and are all based on complete green roof projects.

Habitat to be re‐established by 2015

Habitat Type ha km2

Wet Woodlands 140 1.4

Mixed Ashwood 180 1.8

Oakwood 120 1.2

Lowland Dry Acid Grasslands 5 0.05

Calcareous Grasslands 10 0.1

Lowland Meadows 10 0.1

Lowland Heaths 130 1.3

Upland Heaths 100 1

Mountainous Heaths 25 0.25

Table 9 ‐ Northern Ireland Habitat Action Plan Required Re‐establishment of Natural Habitats

The Northern Ireland Habitat Action Plan proposes areas of habitat recreation to be achieved by 2015, which was discussed earlier in this chapter in section 4‐02. These government targets for natural habitat expansion are a fitting goal for a large scale programme for the adoption of habitat green roofs. The areas of proposed habitats re‐ established are negligible when compared to the total area of roof space throughout Northern Ireland, as shown in section 4‐01.

Rooftop Habitat Recreation Costs

Habitat Type km2 Cost

Lowland Dry Acid Grasslands 0.05 £5million ‐

£32.5million

Calcareous Grasslands 0.1 £10million ‐

£65million

Lowland Meadows 0.1 £10million ‐

£65million

Lowland Heaths 1.3 £19.5million ‐

£58.5million

Upland Heaths 1 £15million ‐

£45million

Mountainous Heaths 0.25 £375,000 ‐

£1.125million

Table 10 ‐ Estimated Costs of introducing wide scale Habitat Roofs to Northern Ireland

The above pricing is an estimated value of developing the corresponding natural habitats on rooftops in Northern Ireland to meeting the goals of the Northern Ireland Habitat Action Plan. These figure were arrive at by applying the expected cost per metre of green roofs to the require habitat expansion require under the Northern Ireland Habitat Action Plan.

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The initial costs related to the development of green roof habitats are significantly larger than those of traditional habitat recreation efforts, with the recreation of calcareous grasslands estimated at £40‐1500/ha (Gilbert & Anderson, 1998). However green roof typically exists the same length as their supporting building, with the green roofs at Moos Water Filtration Plant installed in 1914 (Brenneisen, 2006) and the ‘Derry and Toms’ department store in Kensington High Street, London installed in 1938 (Scrivens, 1980) being good examples. Whereas subsidising farmers to create natural habitats is licences in 5 year contracts under Northern Ireland’s Management of Sensitive Sites (MOSS) annual payment scheme (MOSS, 2002), the MOSS system is further expanded upon in Appendix B.

4‐05 Northern Ireland Accommodating Green Roof Habitats The ability of green roofs to promote habitat recreation and urban ecological diversity depends on factors associated with the local authority. A number of models exist to allow municipal authorities to develop green roofs within their area.

An example of the influence local government has over green roof adoption is Basel, Switzerland. The implementation of a course of ecological research projects into the biodiversity potential of green roofs in the city ultimately led to the amendment of the city’s building and construction laws (Nature and Landscape Conservation Act § 9; Building and Planning Act § 72). Currently as part of Basel's biodiversity strategy, green roofs are now mandatory on new buildings with flat roofs. (Brenneisen S. , 2006) And for green roofs over 500m2, the substrates must be composed of natural soils and come from the surrounding region (Brenneisen S. , 2005).

Northern Ireland can take note of the policies regarding green roof development in large cities around the world. Large international cities cope with similar urban scales and potential development programmes that would result in a national implementation plan if applied to Northern Ireland.

Berlin The city government of Berlin began to promote green roofs in order to reduce the city’s water consumption and as a response of a growing environmental consciousness among the city’s inhabitants (Earth Pledge, 2005), this was briefly mentioned in section 1‐10.

Green roofs first appeared in Germany in the 1880’s, during a period of rapid industrialisation when numerous tenement Figure 4 ‐ UFA Film Fabrik, Berlin blocks were built to house a growing work force. Inexpensive tar roofs were common but were highly flammable. To combat this risk, tar roofs were covered with layer of sand and gravel, accidentally creating an excellent growing medium allowing for the natural colonisation of the roof space (Earth Pledge, 2005). The modern move toward green roofs began in the 1970’s with the convergence of a growing environmentalism movement, urban renewal programs and the rediscovery of Berlin’s 19th century green roofs (Darius & Drepper, 1984).

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In 1975 the German Landscape Research, Development and Construction Society guidelines (Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau [FLL]) was developed providing universal standards for the construction and quality of green roofs. This has become a worldwide recognised standard for green roof construction (Gedge & Kadas, 2005).

During the 1980’s the West Berlin government began a grant program, following the successful completion of a demonstrator project which tested the aesthetic, environmental and public health benefits of greening an entire city block. The greening programme reimbursed residents for roughly half of the total cost of green roof installation, between3 £23/m2 and £47/m2. The grant subsidises succeeded in promoting the construction of 63,500m2 of extensive green roofs in Berlin between 1983 and end of the scheme in 1997 (Koehler & Schmidt, 1997).

In 1984, a federal court ruling introduced increased transparency in water utility billing, because of this base water levies were removed and freshwater consumption and storm water removal fees were introduced (Earth Pledge, 2005). Due to the water retention rate of green roofs and the delay in rainwater runoff (Graceson, Hare, Hall, & Monaghan, 2011; Keeley, 2003), green roofs were largely adopted in subsequent new developments (in conjunction with the grant system) as a means to reduce a buildings water costs (Keeley, 2003).

Presently Berlin implements a landscape master‐plan called the Biotope Area Factor (BAF). A plan which assigns targets for the amount of greenery that should exists on individual properties. The plan is non‐prescriptive about the form of urban greenery required, but property owners and developers must meet the target to be issued building permits (Earth Pledge, 2005). Green roofs have become a popular method of meeting a buildings BAF target and help progress the mainstreaming of green roofs within Germany (Dunnett & Kingsbury, 2008).

Tokyo The green roofs of Tokyo have been developed to take advantage of ability of green roofs to reduce the heat island effect (Skinner, 2006; Alexandri & Jones, 2008)as described in section 1‐10. Because of six decades of urban expansion, and that only 14% of Tokyo’s land area retains any greenery, the climate of Tokyo has become more tropical in the past 25 years; driven principally by a growing heat island effect due to the hard surfaces of the densely populated city (Earth Pledge, Figure 5 ‐ Atago Building, Tokyo 2005).

The temperature increase of Tokyo is five times faster than the global warming rate because of the local heat island effect4. The city’s biodiversity has changed as well, tropical species such as palm trees and wild parakeets have colonised parkland. Additionally, dengue fever

3

Converted for original value of 60DM/m2 and 120DM/m2 The mean annual temperature of downtown Tokyo increased by 3oC, compared to a 1.6oC rise in New York 4

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outbreaks began to occur after humid summers, due to the new tropical climate of central Tokyo (Brooke, 2002).

A 2001 Environment Ministry study found that the high percentage of impermeable surfaces in Tokyo was directly contributing to the city’s warming. The study recommended a widespread urban greening programme, including tree planting, park expansions and the proposed construction of 30km2 of green roofs (Morishita, 2002).

In order to address the need to add greenery to Tokyo, a subsidy programme began in 2002, which succeeded in greening 7,000m2 of Tokyo’s roofs, one‐fifth of which were retrofitted to existing buildings (MSNBC News, 2002). Furthermore amendments were made to building laws which mandated the installation of green roofs on all newly constructed building.

Private building larger than 1,000m2 and public buildings larger than 250m2 must cover 20% of rooftop with greenery or face an annual penalty of £1,6005 (Tokyo Metropolitan Government, 2002).

In the first year of its implementation, the net total of green roofs in Tokyo almost doubled, from 52,428m2 in 2001 to 104,412m2 at the end of 2002, achieved principally by private developments (Tokyo Metropolitan Government, 2002). Because of the success of this legislation; the requirement for 20% green roof coverage was extended to multiple‐dwelling housing schemes in 2003 (Earth Pledge, 2005).

Green roofs have become commonplace on new developments in Tokyo, partly due to government policy but and the realisation green roofs can improve property values.

Developers have begun to install elaborate roof gardens, which significantly increase the rents they can charge for their buildings (Earth Pledge, 2005).

London Docklands On a macro scale green roofs were advanced in London to reconcile biodiversity conservation with aspects of urban renewal along the Thames docklands, but more specifically they came to public attention because of birds (Frith & Gedge, 2000).

The brownfield sites around the Deptford Power Station and the Deptford Creek were areas that supported a number of endangered species, such as Linnets and the ‘Humble Bumble’ Bee whose primary habitat is urban brownfield site (Scholfield Figure 6 ‐ Canary Wharf, London & Waugh, 2003).

But it was the Black Redstart, one of Britain most endangered avian species, which brought the topic of urban habitat conservation to the public’s attention (Dunnett N. , 2006). A number of locations along the Thames are important nesting site for the Black Redstart and are legally protected.

However under UK conservation law at the time, these habitats were only protected while birds were nesting on the site. Due to this loophole developers were legally allowed to begin

5

Converted for original value of ¥200,000

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construction after breeding season (Grant, 2006). A number of developments within the Thames docklands proceeded against environmental protests, yet positively some early dockland projects engaged with local ecologists and the 1996 London Biodiversity Partnership, to create environmentally sensitive structures. Early examples are the Greenwich 2000 project, the Creekside Centre and the highly regarded Laban Dance Centre (Gedge D. , 2002). The success of reconciling building projects and local ecology within these projects at Deptford Creek became a feature of the 2002 England Biodiversity Strategy (DEFRA, 2003).

Thanks to the public interest in the Black Redstart and the success of dockland ecological roofing projects; the green roof movement in London is focused on biodiversity benefits. The dominance of biodiversity policy within the London docklands area differs from other UK legalisation regarding green roofs. However it is important to note that there is no overarching green roof policy in London, as in Berlin and Tokyo (Earth Pledge, 2005).

Interestingly green roofs have been more readily promoted by private developers, motivated by a combination of aesthetic and ecological concerns. The private developers of Canary Wharf have retrofit some of the areas skyscrapers green under the advisement of ecologist in addition to implementing a local green roof action plan. In 2001, 5,000m2 of green roofs were installed throughout Canary Wharf and the development possesses the highest green roof in Europe, at the 32 story Barclays HQ at One Churchill Place (Gedge, 2008).

A positive recent policy development comes in the form of the Biodiversity Action Plan for the London 2012 Olympics. The various stadiums and athletes village developments aim to construct at least 0.4ha (4,000m2) of green roofs (Olympic Delivery Authority, 2008).

London is an example of green roof policy which heavily promotes the ecological and biodiversity attributes of adopting green roofs. However the actual implementation of green roofing and building policy with London is not as robust as Berlin or Tokyo (Earth Pledge, 2005). But does showcase that private developers can promote green roofs independently for a local authority (Gedge, 2008).

Implication for Northern Ireland The principle similarity of the methods to promoting green roofs discussed is the combination of some form of government funding and a need to meet an environmental concern (Koehler & Schmidt, 1997; Tokyo Metropolitan Government, 2002).

Berlin shows the success in providing government grant and countering this with rising municipal rates to change building trends (Gedge & Kadas, 2005). The example of Tokyo illustrates an alternative to grants, by imposing building penalty fees and allowing private sector developer to adapt to a force change in the building market (Morishita, 2002).

Northern Ireland can take inspiration for both approaches to develop a system which suits the distinct requirement of the local building fabric.

The development of green roofs along the London docklands demonstrates a methodology where a local authority takes a secondary role in the development of ecological roofs (Earth Pledge, 2005). The installation of green roofs in the Deptford Creek area was due to pressures place on developers by local environmental activists. While green roofs are not as

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popular in London as Berlin and Tokyo (Gedge, 2008), it is possible for green roofs to gain favour without the backing of local government.

If green roof are to be promoted by national or local policies in Northern Ireland, they must be in keeping with the existing environmental and biodiversity strategies namely the Environment (Northern Ireland) Order 2002, the Northern Ireland Biodiversity Action Plan and the Northern Ireland Biodiversity Strategy (NIEA, 2010).

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Northern Ireland and Green Roof Habitat Recreation

The following table illustrates the explored connections between the habitats capable of surviving on green roofs and the requirements of natural habitats in Northern Ireland.

Habitats favoured

by Green Roofs

Coastal Vegetation

Northern Ireland habitats capable of addapting to Green Roofs

Tidal Marine Habitats Saline Lagoon

Habitats Commonly Recreated on Green Roofs

Habitats Promoted

by Ease of Construction and Financing

Coastal Habitats

Coastal Habitats Sand Dunes Vegetated Shingles Banks Cliffs and Slopes

Arid Vegetation Wetland Habitats Reed Beds

Wetland Habitats

Coastal Habitats

Floodplain Grazing Marsh

Reed Bed Vegetation

Woodland Habitats Wet Woodlands Mixed Ashwood Oakwood

Mountainous Vegetation

Grassland Habitats

Woodland Habitats

Grassland Habitats

Lowland Dry Acid Grassland Calcareous Grassland Lowland Meadow Purple Moor & Rush Pasture Limestone Pavement

Limestone Vegetation

Heathland Habitats

Grassland Habitats

Lowland Heaths Upland Heaths

Heathland Habitats

Mountainous Heaths

Shrub & Heath Vegetation

Peatland Habitats Lowland Raised Bog Blanket Bog

Heathland Habitats

Fens

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Conclusions

Are Green Roofs a Practical Ecological Recourse for Northern Ireland?

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The purpose of this report was to investigate the potential of green roofs to address habitat loss in Northern Ireland. By exploring the factors contributing to habitat loss, the characteristics that differentiates individual ecosystem and the ecological traits of Northern Ireland’s urban centres; this report intended to explore whether these attributes were compatible with the known biological qualities of green roofing systems.

The number of complete green roofs in Northern Ireland is low as a percentage of our overall building stock while habitats on rooftops are more common in other parts of the world, particularly central Europe (Dunnett & Kingsbury, 2008). The concept of using green roofs to reinforce local ecology has been tried and tested in numerous studies in multiple cities (Brenneisen S. , 2006; Frith & Gedge, 2000). Because of the case studies presented in chapter 3 and 4, it is has been established that green roofs, given the appropriate substrate and design (Köhler, 2006), can prove to be an invaluable resource to local flora and fauna (Grant, 2006).

Due to the wealth of precedence on artificial habitats created on green roof, some of which are discussed in chapter 1 and 3, this report has extensively addressed the issue of whether or not a green roof ‘can’ mimic a natural ecosystem. The examples of the Laban Dance Centre in London, ACROS Centre in Fukuoka Japan, and the Moos Water Filtration Plant near Zurich, discussed in sections 3‐01, 3‐02 and 3‐05 respectively, has shown the readiness for both native flora and fauna species to be both supported by and enhanced by green roofs though active colonization (Clement & Foster, 1994; Frith & Gedge, 2000). The remaining issue of how can Northern Ireland utilise green roofing methods to address the environmental requirements of its native environments shall now be discussed.

Figure 1 ‐ View of the David Kier Building and the greater Belfast area

Cn‐01 Habitat Green Roof for Northern Ireland The combined content of chapters 1, 2 and 3 generated a list of habitats that can occupy green roof environments while remaining ecologically viable. The analysis and discussion of chapter 4 further refined this list of possible habitats into ecosystems that are structurally feasible and cost effective to the majority of the built environment within Northern Ireland’s urban settings.

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The natural habitats associated with Coastal, Heathland and Grassland environments are the biological networks that present the most opportunity for the adoption to a rooftop situation in Northern Ireland.

Coastal Habitats

Figure 2 ‐ Costal Meadow grasses planted on the Nassau Icehouse Brewery

Grassland Habitats

Heathland Habitats

Figure 3 ‐ Grass sloped roof on the Vancouver Conference Centre

Figure 4 ‐ Heath Planting on Sloped Roof at Schiphol Plaza, Amsterdam Airport

The potential of these habitats to be adapted to existing roof structure throughout Northern Ireland is the primary reason that this report highlights them as possessing the greatest potential to meet the needs to counteract natural habitat loss or support existing ecosystems.

Coastal and Heather habitats are capable of existing on extremely lightweight structures and grassland habitats requiring lightweight to medium strength structure depending on the type of soil substrates required (Adler, 1999; Dunnett & Kingsbury, 2008). Similarly the financial costs of Coastal and Heather habitats are extremely low with grasslands being low to medium in the spectrum of building expenditures (Earth Pledge, 2005). The three habitat types described represent the most effective habitats to be implemented on the majority of green roof conversion projects in Northern Ireland.

The number of research projects (Snepa, Van Ierland, & Opdama, 2009; Grant, 2006), lessons from the building laws of Basil, Berlin and Tokyo and private developments such as Canary Wharf the planned Wood Wharf parks (Brenneisen S. , 2006; Earth Pledge, 2005) have shown that urban expansion can be integrated with ecologically considered greening mechanisms.

Additionally, studies have proven that adding extensive green roofs on industrial and commercial land on the outskirts of residential areas (briefly discussed in section In‐01) , can greatly improve the ecological resources in an urban area (Brenneisen S. , 2006), and this policy could be encouraged in Northern Ireland. The size restriction of habitat green roofs is one of their primary limiting factors (Brenneisen & Hänggi, 2006). The close proximity of Figure 5 ‐ Wood Wharf, London building and typically common ownership at some period in the developments construction, presents opportunities for a mosaic of habitat green roofs to be created on industrial parks (Snepa, Van Ierland, & Opdama, 2009). Previous research has shown that the combination of small green roofs to create habitat corridors will significantly contribution to wider environmental quality (Grant, Engleback, & Nicholson, 2003).

These factors further reinforce the ability of Coastal, Heathland and Grassland habitats to become a potential part of Northern Ireland’s urban environments.

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Cn‐02 Potential Benefits of Green Roof to Northern Ireland’s Bird Populations Many natural habitats in Northern Ireland are critical to a variety of avian species, nationally supporting over 200 bird species, not including rare and migratory species (Biodiversity NI, 2011). There has been widespread decline in the bird population of Northern Ireland, the common House Sparrow has declined 19% during 1994‐2006 and the Curlew, Snipe, Redneck and Lepwing species have declined by over 50% in the last 20 years (NIEA, 2010). It is estimated that the total number of birds in the UK has reduced by 6% in the last 30 years (Defra, March 2008), with the RSPB recording a decrease of 40% in farmland bird populations over the same period (RSPB, 2006).

Examples of completed projects in chapter 3 have shown the adaptability of bird species to green roof habitats.

Additionally, as mentioned in section Cn‐01, there is research supporting extensive green roofs in industrial estates and business parks as high value ecological resources for local bird populations (Brenneisen S. , 2006).

Many of Northern Ireland’s towns, which are in the breeding and feeding range of migratory and native birds, Figure 6 ‐ Wildwood Community College, Missouri, USA

can be retrofitted to support these populations. Buildings such as the Clinic One at University Hospital of Basel, Laban Dance Centre in London and the Ducks Unlimited National Headquarters and Conservation Centre in Winnipeg, described in section 3‐01, 3‐01 and 3‐05 respectively, illustrate the ability of birds to dominate roof spaces which resemble their natural habitat.

Green roofs have the potential to play an important role in Northern Ireland’s bird conservation schemes, especially in urban centre. The value of green roofs to bird populations is already recognised by the RSPB, who have issued guidelines for bird habitats on green roofs (RSPB, 2011).

Cn‐03 Envisioned Setback to Green Roof development in Northern Ireland While it is the opinion of the researcher that green roofs present a clear potential for the creation of natural habitats in the urban areas of Northern Ireland, there are a number of obstacles that are currently preventing any wide scale adoption of green roofing systems

Commercial Planting opposed to Natural Planting The most extensively used planting on green roofs in the northern hemisphere is sedum, due to their shallow rooting, tolerance to cold and drought (Snodgrass. & Snodgrass, 2006).

Even intensive roofing system use a selection of commercially available grass, mosses and herbs (Dunnett & Kingsbury, 2008).

Internationally there exist different policies on the importance of using native planning on green roofs. One school of thought is the use of local soil and vegetation will encourage the development of habitation of a rooftop (Brenneisen, 2006), with the opposing methodology stating that rooftops possess different micro‐climates to ground level habitats and should be treated as such (Dunnett N. , 2006). Regardless of this debate, the current commercial available planting Figure 7 ‐ Modular Green Roofing System systems produced by Northern Ireland’s horticultural industry are dominated by sedum 88

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species, with supplementary variants of wildflowers and meadow grass (Green Roofs Ireland, 2010).

Many ecological reports support the replacement of sedum roofs with local groundcover planting (Grant G. , 2006), however commercially Northern Ireland is not in a position to meet this request. The approach of National Trust Visitor Centre at Portstewart Strand, described in section 3‐01, illustrates a stop gap solution to the lack of native planting available for green roofing. The building uses a sedum roof which is expected to become colonised and hopefully dominated by the surrounding native sand dune grasses (GreenRoof, 2010). Until native species are introduced to commercial horticulture in Northern Ireland, green roofs will be dominated by alien vegetation.

Lack of Social Drivers for Green Roof Adoption The rapid adoption of green roofs in cities such as Berlin and Tokyo was made possible through the culmination of social, political and financial drivers (Earth Pledge, 2005). It is the view of the researcher that the current socio‐political climate of Northern Ireland does not support the possibility of any form of large scale adoption or favouring of green roofs.

The water saving qualities of greening roofs are irrelevant to Northern Ireland. Water charges in Northern Ireland are based around three models; a standing charge based on supply pipe size; a variable charge based on the volume of water used; or unmeasured and a fixed standing charge is issued (NI Water, 2011). So there is no financial incentive for build occupant to commission green roofs because there are no financial penalties for excessive rainwater runoff. Secondly the climate of Northern Ireland and the small scale, low height and low density of its urban areas does not produce excessive ‘heat islands’. The ‘heat islands’ of Northern Ireland are considered to be 1oC for small town, and Belfast is believed to have a 2oC heat island effect (Morris, 2007). This is softened by the temperature range of Northern Ireland and the future effects of climate change, which has been predicted as much smaller in Ireland than in Britain (Coll, Maguire, & Sweeney, 2009). Resulting in a low probability for green roofs to be widely implemented in Northern Ireland in order to combated excessive summer temperatures.

The only remaining socio‐political concern that can affect any future urban greening policy is one based on promoting biodiversity and urban wildlife. The current political landscape does not present any strong champions for this agenda. Because of these factors the political and social environment does not look likely to promote any urban greening methods in the near future.

Cn‐04 Concluding Statement The goal of this report was to ascertain if green roofs could play a role in addressing habitat loss in Northern Ireland. And the content of this report has provided adequate evidence that they are capable of supporting a range of habitats of Northern Ireland that are currently threatened in their natural settings.

While arguments can be made for the ability of green roofs to sustain replicant habitats of Woodland and Wetlands districts, the potential of Coastal, Heathland and Grassland environments to be applied to existing structures across Northern Ireland elevates these habitats as the principle candidates for habitat reconstruction in urban areas. Additionally the opportunity of green roofs in Northern Ireland to provide safe breeding ground for

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internationally important bird populations is a valid reason in itself to promote green roof adoption.

However, without some form of government support, either in the form of grants or favourable building policies, the wide scale implementation of a habitat focused green roofs will find a limited appeal about the Northern Ireland populace. A study commissioned by English Nature and published in 2003 concluded that “Although individual green roofs offer local environmental benefits, any significant contribution to wider environmental quality is only likely to become apparent once a more substantial area of town and city roof space has been greened. Such a programme will require political commitment and concerted action underpinned by science, technical expertise and good design. In order to refine the design of green roofs for biodiversity conservation, some further research and experimentation is required.” (Grant, Engleback, & Nicholson, 2003) This statement accurately describes the current status of green roofs in Northern Ireland.

Coastal Habitats Sand Dunes

Grassland Habitats Lowland Grasslands Calcareous Grasslands

Figure 9 ‐ Wangford Warren, Suffolk

Figure 10 ‐ Little Deer Park, Antrim

Figure 11 ‐ Murlough National Nature Reserve

Lowland Meadows

Rush Pastures

Upland Heaths

Figure 13 ‐ Tees Valley, Middlesbrough

Figure 14 ‐ Slievenacloy, Belfast Hills

Limestone Pavements

Figure 8 ‐ Murlough Dunes, Dundrum Bay

Vegetated Shingles

Cliffs and Slopes Figure 12‐ Kearney, Down

Figure 16 ‐ Carrick ‐a‐Rede Cliffs, Antrim

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Heather Habitats Lowland Heaths

Figure 17 ‐ Knockmore, Fermanagh

Figure 15 ‐ Bloody Bridge near Newcastle

Mountainous Heaths

Figure 18 ‐ Mourne Mountains

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Appendix A

Detailed Descriptions of Northern Ireland’s Natural Habitats

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Tidal Sandy, Shingle and Gravel Shores

Coastal sandy and gravel shores occur in a wide variety of environments and are common in Northern Ireland waters (Northern Ireland Habitat Action Plan, 2005). The habitat develops in a range of physical environments, from sheltered beaches to mobile sandbanks. The sediments layer may be very thick but in large areas of Northern Ireland, may only form small deposits covering the bedrock (Northern Ireland Habitat Action Plan, 2005).

Figure 1 ‐ Dundrum Bay, Down The habitat typical starts with gravel beds in coastal water deeper than 10m and continues towards boulder slopes and gravel plains inshore (Erwin, Picton, Connor, Howson, Gilleece, & Bogues, 1986). Extensive gravel shores are found in a number of areas around the Northern Ireland coast. They tend to occur in places where strong tidal currents or wave action prevent the deposition of finer material.

Sand and Gravel shore can support a number of marine animal species such as polychete worms, isopods, and crabs (CVNI, 2011). These shorelines may have a fairly diverse flora occupation above the high water mark. Below the high tide mark, disturbance to the shingle and the salinity of the ground will prevent any growth of significant plant life. (National Museums Northern Ireland, 2010).

The 2005 Habitat Action Plan for Northern Ireland’s sandy and gravel shores has set the following targets for the conservation of the habitat Maintain the extent of a representative range of sub‐littoral sands and gravel habitats and associated communities in Northern Ireland Maintain the condition of a representative range of sub‐littoral sands and gravel habitats and associated communities in Northern Ireland

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Seagrass Beds

Seagrasses are a type of submerged aquatic vegetation that have evolved from terrestrial plants and have become specialized to live in the marine environment. Seagrass beds develop in shallow, sheltered tidal sediments and in Northern Ireland are confined to sea loughs (Northern Ireland Habitat Action Plan, 2003), such as Strangford Lough, Lough Foyle and Belfast Lough (CVNI, 2011).

Seagrasses are a unique group of plant species, Figure 2 ‐ Eelgrass, North Strangford Lough they are the flowering plants that are fully adapted to a marine environment, there are approximately 60 species of seagrass existing today (Den Hartog, 1970). Five seagrass species are found in Northern Ireland; three species of eelgrass and two species of tassel weed (Northern Ireland Habitat Action Plan, 2003).

Seagrass beds are considered to be highly productive habitat as they support a wide variety of flora and fauna in addition to acting as a nursery for a many fish species. Seagrass beds can support an extensive volume of different animals, one hectare of seagrass may support up to 125 million small vertebrates and 10,000 fish (CVNI, 2011).

Seagrass beds are an important food resource for wintering wildfowl. This tidal seagrass zones represent an important resource in the diet of many nationally important species, such as Mute Swans, Whooper Swans, Light‐bellied Brent Geese and Wigeon (Northern Ireland Habitat Action Plan, 2003).

The 2003 Habitat Action Plan for Northern Ireland’s seagrass beds has set the following targets for the conservation of the habitat Maintain the extent of seagrass beds in Northern Ireland waters Maintain the quality of seagrass beds in Northern Ireland waters Maintain the distribution of seagrass beds in Northern Ireland waters Where feasible, restore lost, damaged or degraded seagrass beds These targets are reliant on surveys to be undertaken to ascertain the extent, quality and distribution of seagrass beds in Northern Ireland

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Mudflats

Figure 3 ‐ Millbay, Antrim

Mudflats are intertidal habitats created by sedimentary deposition in low energy coastal environments, such as mud silt and clay. These habitats are particularly found in estuaries and other sheltered areas such as sea loughs (Northern Ireland Habitat Action Plan, 2003).

Typically mudflats can cover a large area, often being several kilometres in width and often being located between the low tide water mark and vegetated saltmarshes. Mudflats play an important role in protecting saltmarshes as they absorbing wave energy (CVNI, 2011).

Mudflats are characterised as areas of high biological productivity and are capable of supporting a large volume of organisms. However this wealth of fauna is marked low species diversity with few rare species, particularly amongst microorganisms and lower food chain animals (Northern Ireland Habitat Action Plan, 2003). While mudflats may appear to be deficient in plant cover, they do possess extensive mats of microalgae which support numerous species (Northern Ireland Habitat Action Plan, 2003). And where the shore is made up of mud or fine silt, certain flowering plants adapted to growth in saline conditions can thrive between low and high water marks (National Museums Northern Ireland, 2010).

Mudflats in combination with other tidal habitats are of great national importance to large numbers of bird and fish species. These environments are crucial feeding, resting and breeding grounds for internationally important populations of waterfowl. The mudflats at Strangford Lough support over 70,000 birds annually, making it the most important sea lough in Northern Ireland for waterfowl (Northern Ireland Habitat Action Plan, 2003).

The 2003 Habitat Action Plan for Northern Ireland’s mudflats has set the following targets for the conservation of the habitat Maintain the extent of mudflats and associated plant and animal communities in Northern Ireland Maintain the condition of mudflats and associated plant and animal communities in Northern Ireland Where appropriate, enhance the extent and condition of mudflats in Northern Ireland

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Saltmarshes

Saltmarshes form when vegetation becomes established and thusly stabilises sheltered tidal mudflats, they typically occupy the areas between spring and neap tide on adjoining mudflats. Saltmarshes consist of a series of island of low‐growing plants separated by narrow channels (Northern Ireland Habitat Action Plan, 2005). They can be found at estuaries, saline lagoons or behind barrier islands.

Figure 4 ‐ Ballymacormick Point, Bangor Saltmarsh is a rare habitat in Northern Ireland; this may be due to smaller tidal ranges than the UK and Republic of Ireland. As a result there are fewer potential areas for saltmarshes to establish themselves, saltmarsh in Northern Ireland comprise only 0.5% of the total UK habitat area (Northern Ireland Habitat Action Plan, 2005) or 250ha (Northern Ireland Habitat Action Plan, 2005).

The largest areas of saltmarsh in Northern Ireland are the Roe Estuary in Lough Foyle, around Strangford Lough, at Ballycarry in Larne Lough, the Bann Estuary and Mill Bay in Carlingford Lough. These five sites account for 90% of the saltmarsh area of Northern Ireland (Northern Ireland Habitat Action Plan, 2005).

Saltmarshes provided for a range of organisms, in particular specialist plant communities and their associated animals. They provide a valuable resource for wading birds and wildfowl as they act as high tide refuges for birds feeding on adjacent mudflats. They also provide breeding sites for waders, gulls and terns, and are a source of food for passerine birds particularly in autumn and winter (Northern Ireland Habitat Action Plan, 2005).

Northern Ireland is one of the most important regions in the UK for wintering wildfowl, due to its mild winter climate and abundance of wetland. Strangford Lough is considered to be Northern Ireland’s major coastal site for migrant and wintering waterfowl with 20,000 birds migrating there every year. It also supports 25 national important waterfowl species, three of which are international protected (Northern Ireland Habitat Action Plan, 2005).

A number of specialist invertebrate species are associated with saltmarshes in Northern Ireland such as the Rove Beetle, a Priority Species (Northern Ireland Habitat Action Plan, 2005).

The 2005 Habitat Action Plan for Northern Ireland’s saltmarshes has set the following targets for the conservation of the habitat Maintain the current extent of saltmarsh at 250ha Maintain the area of saltmarsh in favourable condition at 135ha By 2015, restore to favourable condition an area of saltmarsh in unfavourable condition (100ha.)

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Saline Lagoon

Saline lagoons are bodies of seawater that have become disconnected from the sea. The environment of these lagoons where is neither marine nor freshwater but may vary from brackish to fully or hyper‐saline (Northern Ireland Habitat Action Plan, 2005).

Saline lagoons can be both naturally of artificially constructed. Natural lagoons occur when a barrier such as a sand or shingle bar separated a lagoon from the sea. Artificial lagoons are Figure 5 ‐ Strand Lough, Down frequently created when engineering works cut off part of an estuary or bay from direct tidal influences (Northern Ireland Habitat Action Plan, 2005).

Although small brackish pools are frequent around the coast in saltmarshes, larger bodies of brackish water are rare. There are only 30 reported saline lagoons in Northern Ireland (Bamber, Gilliland, & Shardlow, 2001). Strand Lough in Down, is an example of a large body of semi‐saline water (CVNI, 2011).

The variations in the salinity of individual lagoons entails distinctiveness in local their flora and fauna. Each pool represents a limited opportunity for vegetation and animals, and often has to be highly specialised to cope with the environmental conditions (National Museums Northern Ireland, 2010). Thus the presence of such a degree of specialist flora or fauna makes the conservation of saline lagoons important in maintaining biodiversity (Northern Ireland Habitat Action Plan, 2005).

Saline lagoons are often an important habitat for large numbers of wildfowl and waders, provide important locations for high tide roosts and offer habitats for migrating birds (Northern Ireland Habitat Action Plan, 2005).

The habitat is also favoured by a number specialised marine species but flora and fauna. The lagoon cockle, (a filter feeding bivalve), that is often found submerged in the soft sediments of the lagoon (Northern Ireland Habitat Action Plan, 2005). And for plant life, a mixture of freshwater and marine plant life occupies saline lagoons. The fringe vegetation of these bodies of water are similar to freshwater ponds and lakes, with additional marine species such as ‘beds’ of Tassel Weeds and the seagrass Spiral Tassel Weeds, both of which are protected by separate habitat action plans (CVNI, 2011).

The 2005 Habitat Action Plan for Northern Ireland’s saline lagoon has set the following targets for the conservation of the habitat Maintain the extent of saline lagoons and associated plant and animal communities in Northern Ireland Maintain the condition of saline lagoons and associated plant and animal communities in Northern Ireland Create lagoon habitat to offset losses. (Although it is not clear how much of this habitat has been lost, it is apparent that there has been a loss. An interim target of 2ha by 2010 has been set, initially based on the requirement of UK habitat action plan)

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Sand Dunes

Sand dunes occur when a beach is large enough or has the significant tidal power to allow sand to dry out complete between high tide points.

The dry sand is then blown landwards by the wind, where it accumulates into dunes. Dunes are then stabilised by plant life which grows through the hardened sand (CVNI, 2011). The largest dune systems are located along the north and south‐east coasts, namely in north Antrim and South Down. (Northern Ireland Habitat Action Plan, 2005) Figure 6 ‐ Murlough Sand Dunes at Dundrum Bay

Little to no new dunes are currently forming around Northern Ireland at present, the formation of sand dunes is not continuous and existing coastal dunes were formed thousands of years ago (Northern Ireland Habitat Action Plan, 2005). The area between Lough Foyle and the Bann Estuary has some of the oldest recorded dunes in Ireland, at over 5000 years.

Dune habitats are typically nutrient poor and have deficiencies in there supply of fresh water; however this has created a high diversity of specialised plants and fauna specials.

Murlough Dunes at Dundrum, Co. Down supports 55 species of bee, ant and wasp (which equates to 33% of Irish fauna), 213 species of moth (48% of Northern Irish fauna) and 21 species of butterfly, roughly 71% of Northern Irish butterfly fauna (Northern Ireland Habitat Action Plan, 2005).

The EHS estimated there is approximately 3000ha of sand dunes in Northern Ireland; however the area of vegetated sand dunes is estimated to be somewhere between 1300ha and 1500ha (Northern Ireland Habitat Action Plan, 2005).

The 2005 Habitat Action Plan for Northern Ireland’s sand dunes has set the following targets for the conservation of the habitat Maintain the current extent of sand dunes at 1500ha Maintain the area of sand dunes in favourable condition at 300ha By 2015, restore to favourable condition an area of sand dune in unfavourable condition (1150ha.)

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Vegetated Shingles Banks

Vegetable shingle banks occupy the landward side on coastal shores when local conditions suit there formation. Shingle banks are typically long strips that cover a small total area and while they occur throughout the costal, there is a concentration on the northeast shoreline, namely the Mournes Coast and Rathlin Island (National Museums Northern Ireland, 2010).

An estimated 50ha of vegetated shingle occurs in Northern Ireland (Northern Ireland Habitat Figure 7 ‐ Kearney, Down Action Plan, 2005). Of this, approximately 30ha are considered stable. These areas support a range of plant communities, including scrub and grassland, often rich in lichens. It is these areas of stable shingle that are the main focus of this habitat action plan. Currently 48ha of vegetated shingle habitat are protected by Areas of Special Scientific Interest (ASSI) notification in Northern Ireland.

Shingle banks are naturally broken up by sea action and are subject to occasional disturbance by storms. This disturbance prevents most land plants from effectively colonising them (NIEA, 2010). However above the high water mark a fairly diverse flora exists. Below high water mark tidal disturbance of the shingle and the salinity prevents any growth of vascular plants. Shingle banks are partially important for several species that are scarce in Northern Ireland, such as oyster plant and sea cabbage (National Museums Northern Ireland, 2010).

The 2005 Habitat Action Plan for Northern Ireland’s vegetable shingle banks has set the following targets for the conservation of the habitat Maintain the current extent of coastal vegetated shingle at 50ha Maintain the area of coastal vegetated shingle in favourable condition at 25ha By 2015, restore to favourable condition as much as is practical, of the remainder of the resource i.e.

25ha

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Cliffs and Slopes

It is estimated that the length of Northern Ireland’s coastline is 650km (Northern Ireland Habitat Action Plan, 2005), with 500km of this comprising of coastal cliffs and slopes. The Northern Ireland Countryside Survey 2000, give an approximation of the total area of the habitat to be 528 hectares (Cooper, McCann, & Rogers, 2009).

The vegetation on cliffs can vary vastly over short distances; this is due the soil composition Figure 8 ‐ Carrick ‐a‐Rede Cliffs, Antrim and local geography (Northern Ireland Habitat Action Plan, 2005). Northern Ireland’s cliffs are an important habitat for breeding seabirds which can reach numbers of international importance. There are seabird colonies on many stretches of the Down and Antrim coasts.

There is a wide range of coastal breeding birds associated with cliff habitats; these include the priority species such as the Chough and Twite. The cliffs on Rathlin Island provide nesting sites for nationally important colonies of Guillemot and Kittiwake and the internationally important Razorbill (CVNI, 2011).

Maritime cliff habitats have been in decline during the past century for much of Britain and Ireland (CVNI, 2011). However in Northern Ireland, no significant losses have been recorded between 1991‐1998 (Northern Ireland Habitat Action Plan, 2005), in fact the flora of sea cliffs is one of the few habitats largely undamaged by modern human activities (National Museums Northern Ireland, 2010).

The 2005 Habitat Action Plan for Northern Ireland’s maritime cliff and slope has set the following targets for the conservation of the habitat Maintain the current extent of all maritime cliff and slope at 500km Maintain the area of maritime cliff and slope in favourable condition at 250km By 2015, restore to favourable condition 225km of maritime cliff and slope in unfavourable condition

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Eutrophic Waters

Eutrophic standing water describes a body of water with a high nutrient content (nitrogen and phosphate). Most of Northern Ireland’s larger lakes such as Lough Neagh and Lough Beg and Lough Erne are regarded as eutrophic (Northern Ireland Habitat Action Plan, 2005). The Environment and Heritage Service (EHS) states that the area of eutrophic standing water in Northern Ireland is approximately 940 km2. This is comprised mainly of the five largest lakes in Northern Ireland, which represent less than 0.3% Figure 9 ‐ Eutrophic Water, Upper Lough Erne of the total lake numbers but contribute 89% of the total national water volume (Northern Ireland Habitat Action Plan, 2005).

The high nutrient levels make these bodies of water are very productive and have a high biodiversity. Plankton and algae are plentiful and together with the submerged vegetation they support a large variety of species, during summer it is common for a dense population of algae to accumulated, making the water green (CVNI, 2011).

Dragonflies, water beetles, stoneflies and mayflies are found in eutrophic standing water habitats. A number of fish and eel species are common and eutrophic water supports some of the few amphibians that reside in Northern Ireland for example frogs and newts (CVNI, 2011).

The areas surrounding eutrophic water are important for bird species, non‐migratory species such as Whooper Swan, Tufted Duck, Cormorant and Graylag Geese, in addition to migratory wader and wildfowl species all rely of these habitats for feeding and breeding (CVNI, 2011).

The 2005 Habitat Action Plan for Northern Ireland’s eutrophic standing water has set the following targets for the conservation of the habitat Restore to Good Ecological Status all eutrophic standing waters by 2015, in line with the WFD

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Mesotrophic Lakes

Mesotrophic and eutrophic lakes support an overlapping body of flora and fauna species. This is due to their similar chemical makeup (Northern Ireland Habitat Action Plan, 2005); eutrophic denotes a high level of nitrogen and phosphate, with mesotrophic showing a moderate level and finally oligotrophic lakes, which contain low levels of nutrients (NIEA, 2010).

According to the UK Habitat Action Plan mesotrophic lakes are relatively infrequent; Figure 10 ‐Tower Lake, Newtownstewart, Omagh however Northern Ireland contains a high proportion of the total UK resource. Mesotrophic lakes are generally represented by small body of water, the two largest mesotrophic lake sites in Northern Ireland are Lough Melvin (2100 ha) and Upper Lough Macnean, however the majority (72%) of Northern Ireland lakes have a surface area of less than 2ha (Northern Ireland Habitat Action Plan, 2005).

Mesotrophic lakes supports a higher diversity of submerged aquatic plants than any other type of standing water, countered by the characteristically clear waters of mesotrophic lakes giving rise to low levels of growth in planktonic and filamentous algae (Northern Ireland Habitat Action Plan, 2005).

This habitat type contains a variety of fish species, generally a mix of coarse and salmon species, but it is typical for several fish species to have been introduced and become established as part of the biodiversity associated with these lakes (CVNI, 2011).

Lough Melvin is the only recorded site to support the Arctic Char in Northern Ireland in addition to three distinct races of brown trout and the Atlantic salmon (CVNI, 2011).

It is important to note that mesotrophic lakes contain a high proportion of nationally rare aquatic plants, like the white water‐lily, the yellow water‐lily and several pondweeds species (CVNI, 2011). Other species supported by mesotrophic lakes include important groups of dragonflies, water beetles, stoneflies and mayflies, otters, Whiteclawed Crayfish, Globeflower, and Chaffweed.

The 2005 Habitat Action Plan for Northern Ireland’s mesotrophic lakes has set the following targets for the conservation of the habitat Restore to Good Ecological Status all mesotrophic lakes by 2015, in line with the WFD

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Marl Lakes

Figure 11 ‐ Knockballymore Lough, Fermanagh

Marl lakes are natural lakes which occur at low altitude (over 60% of Northern Ireland’s lakes occur at altitudes of less than 100m); they differ from other lakes by highly alkaline water (Northern Ireland Habitat Action Plan, 2005).

These lakes typical lie in drumlin basins receiving water as run‐off from the drumlin slopes; thusly the majority of marl lakes in Northern Ireland are mainly concentration in south east Fermanagh.

Northern Ireland marl lakes are relatively small, averaging about 2.5 ha in the marl lake; the largest is Lough Inver in Fermanagh at 13ha (Northern Ireland Habitat Action Plan, 2005).

Marl lake water bodies are characterised by very clear water but has a low nutrient status.

The high clarity of water creates excellent condition for aquatic plants, but the base‐rich chemistry of the water presents few nutrients to support phytoplankton and other fauna (Northern Ireland Habitat Action Plan, 2005).

Marl lakes sustain a similar range of flora and fauna as other lake types, with macro invertebrates being well represented, particularly groups like dragonflies, water beetles, stoneflies and mayflies (Northern Ireland Habitat Action Plan, 2005). Some inter‐drumlin marl lakes are regionally important for the diversity of their pondweeds including rare species like the fen pondweed (CVNI, 2011).

The 2005 Habitat Action Plan for Northern Ireland’s marl lakes has set the following targets for the conservation of the habitat Restore to Good Ecological Status all marl lakes by 2015, in line with the WFD

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Reed Beds

Reed beds describe wetland habitats that are dominated by the Common Reed and other tall flowering plants which are adapted to growing in wet conditions. There are two forms of reed beds; reed swamps which are permanently waterlogged and reed fen where the water level is below the ground surface in summer and are more botanically diversity (CVNI, 2011).

Reed beds are widely distributed along the margins of water bodies, streams, river and Figure 12 ‐ Castle Espie, Down other forms of wetlands and bogs. In Northern Ireland, they are especially associated with lowland areas around the large lakes and drumlin wetlands. Several large (over 10ha) reed beds occupy the catchment areas of Lough Neagh and Lough Erne, in addition to an estimated 40 sites, greater than 2ha, in Down and Armagh (Northern Ireland Habitat Action Plan, 2005).

UK wide, there has been a considerable loss in reed bed habitats, with a reduction in area of 40% between 1945 and 1990 (Hawke & José, 1996). It is believed that the habitat has diminished by a similar amount during the same period in Northern Ireland, the 2000 Northern Ireland Countryside Survey reported that the habitat range has remained stable between 1988 to 1998 (Cooper, McCann, & Meharg, 2002).

Reed beds in Northern Ireland are generally unmanaged with their coverage limited by water‐levels and nutrient supply. The habitat is defined as being a vegetation species‐poor environment, but support a rich array of fauna adapted to wetlands, notably breeding birds (Northern Ireland Habitat Action Plan, 2005).

A wide range of wetland fauna benefits from the resources provided by reed beds, especially where they are located near to fens or open water. UK wide reports state that at least 700 species of invertebrates can be associated with reed beds; with 64 insect species partially dependent on reed and some 40 species of insect feed solely on reed (Northern Ireland Habitat Action Plan, 2005).

A rapidly growing level of research and installation of reed beds is accruing as they are a natural filtration system for waste water. Currently there are a number of schemes looking at reed bed technology for a variety of purposes aimed at sewage and waste water treatment, industrial effluent, and agricultural run‐off (CVNI, 2011).

The 2005 Habitat Action Plan for Northern Ireland’s reed beds has set the following targets for the conservation of the habitat Maintain the total extent of reed bed in Northern Ireland at 3,200ha Where favourable, maintain the condition of reed bed in Northern Ireland Achieve favourable condition of 95% of reed bed which lies within designated sites, by 2015 For stands outside ASSIs, secure favourable condition over, as near as practicable, 100% of the reed bed resource in Northern Ireland, by 2015

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Floodplain Grazing Marsh

Grazing marshes are divided into two main categories; coastal and floodplain grazing marches. Coastal grazing marshes occur in flat coastal areas frequently behind natural barriers, typically sand dunes, and coastal defences (often resulting from reclaimed saltmarsh or mudflats).

Floodplain grazing marshes are connected to large slow‐moving rivers and lakes. Much of these habitats were formerly wet woodlands, fens or reed beds repurposed for agricultural use (Northern Ireland Habitat Action Plan, 2005).

Figure 13 ‐ Insh Marshes, Scotland

Grazing marshes are commonly residual habitats resulting from redundant agricultural practices that were more widespread in the past, with the hallmark features of this habitat type relying on some form of maintenance (Cooper, McCann, & Rogers, 2009).

Inland floodplain grazing marshes are more widespread in Northern Ireland than the rest of the UK. The habitat characteristically occurs in flat low‐lying areas in combination with other wetland habitats, for instance lakes and fens. Based on the Northern Ireland Countryside Survey 2000, the area of species‐rich wet grassland in Northern Ireland is believed to cover 1.0% of the country, estimated to be 13,808ha (Cooper, McCann, & Rogers, 2009).

Although much of Northern Ireland’s grazing marshes are inclined to be somewhat poor in the diversity of vegetation species, several notable flora species which have a restricted habitat range in Ireland do reside in grazing marshes. Notable species are the Whorled Caraway, Tubular Water‐Dropwort, Water Violet and Flowering Rush, Marsh Pea, and Irish Lady’s‐Tresses Orchid (Northern Ireland Habitat Action Plan, 2005).

The environment also provides resources for an array of important breeding and wintering waterfowl such as snipe, lapwing, redshank and curlew. Additionally the pools and ditches within the habitat are commonly rich with freshwater invertebrates and plants species (Northern Ireland Habitat Action Plan, 2005).

Because of its importance to breeding waterfowl, the habitat has been the subject to numerous surveys over the past few decades. These species have exhibited al long running population decline(Donaghy & Mellon, 1999), in line with a rapid area decline of 28% in grazing marshes between 1991 and 1998, due to drainage schemes and related agricultural improvement (Cooper, McCann, & Rogers, 2009).

The 2005 Habitat Action Plan for Northern Ireland’s coastal and floodplain grazing marshes has set the following targets for the conservation of the habitat Maintain the total extent of coastal and floodplain grazing marsh in Northern Ireland Where favourable, maintain the condition of coastal and floodplain grazing marsh in Northern Ireland Achieve favourable condition of 95% of coastal and floodplain grazing marsh which lies within designated sites, by 2015 For stands outside ASSIs, secure favourable condition over, as near as practicable, 100% of the coastal and floodplain grazing marsh resource in Northern Ireland by 2015 Restore 50ha of coastal and floodplain grazing marsh by 2015 Restore a further 50ha of coastal and floodplain grazing marsh by 2020

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Wet Woodlands

Wet woodlands describe an assortment of woodland and scrub forms that occupy on waterlogged or seasonally flooded land. The timber species that inhabitant wet woodlands is quite diverse, usually being dominated by Willow, Alder or Downy Birch, but also includes Ash or Oak on the drier margins of the habitat (Northern Ireland Habitat Action Plan, 2005).

Willow scrub woodlands are the most extensive wet woodland community in Northern Ireland, Figure 14 ‐ Bonds Glen, Derry they often occur as an initiate woodland colony prior to the development of a more mature habitat (Northern Ireland Habitat Action Plan, 2005).

Wet woodlands are not limited to one soil condition and are capable of developing on nutrient‐rich mineral, acid soils and nutrient‐poor peat soils. The common factor in there development is that they typical occupy the fringes of a primary water, a lake or bog for example and frequently occur in conjunction with other woodland habitats (Northern Ireland Habitat Action Plan, 2005).

The precise extent of wet woodland in the UK is unclear, but it is estimated to be between 50,000 ‐ 70,000ha (JNCC, 2001). Unfortunately with the extensive historic forest clearance in Northern Ireland has resulted in the current national wet woodland resource being of relatively recent origin (typically less than 100 years old). Wet woodlands are currently a scattered habitat, inclined to be small than 3‐5 ha in size (Northern Ireland Habitat Action Plan, 2005). Recent estimates place the extent of wet woodlands in Northern Ireland to occupy an area of 2,600ha. Positively the NICS 2000 has indicated a 9% range increase in the wet woodlands and shrubs between 1988 and 1998 (Cooper, McCann, & Rogers, 2009).

Generally wet woodlands are unmanaged and are often used for grazing and shelter by livestock. Nevertheless the habitat is noted as an excellent resource for insects and other invertebrates, like snails and spiders. Furthermore these wet environments support a very large number of species, providing cover and breeding sites for otters and are of value for bats and a number of breeding birds many of which are now rare in Northern Ireland (CVNI, 2011).

The 2005 Habitat Action Plan for Northern Ireland’s wet woodlands has set the following targets for the conservation of the habitat Maintain the area of all wet woodlands in Northern Ireland at least 2,600ha Maintain the current area of all ancient or long‐established semi‐natural wet woodlands Maintain condition, where favourable, of the existing resource Achieve favourable condition of 1650ha of wet woodland by 2015 Restore 60ha of former wet woodland on ancient and long‐established woodland sites by 2010 Restore a further 70ha of former wet woodland on ancient and long‐established woodland sites by 2015 Establish 120ha of wet woodland by 2010 Establish a further 140ha of wet woodland by 2015

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Mixed Ashwood

The categorisation of mixed ashwoods is applied to an expansive range of forests located on base‐ rich soils, in the case of Northern Ireland this is the basalts region of County Antrim and the limestone basins in County Fermanagh, with more periodical sites in the Sperrins and County Down and Armagh (Northern Ireland Habitat Action Plan, 2005).

Ash is generally the dominant species, although locally oak, downy birch and even hazel may be Figure 15 ‐ Glenarm Woodlands, Antrim the most abundant species (Northern Ireland Habitat Action Plan, 2005). Ashwood ground flora is particularly rich and varied because of fertility nature of the soils and a forest canopy which doesn’t cast dense shade, such as Wood Anemone, Bluebell, Primrose and Ramsons (wild garlic) (CVNI, 2011).

In general, mixed ashwoods are unmanaged in Northern Ireland often being utilised for grazing and shelter by livestock (Northern Ireland Habitat Action Plan, 2005).

It is estimated that the total area of ashwoods in the UK is 67,500ha, however this is only an estimate as there is no precise data (JNCC, 2001). Similarly the estimated area of mixed ashwoods in Northern Ireland is a minimal 3,430ha, with 3,300ha in private ownership and 130ha in public ownership (Northern Ireland Habitat Action Plan, 2005). The NICS 2000 survey present positive information on the extent of ashwoods, with a 9% increase between 1988 and 1998 (Cooper, McCann, & Rogers, 2009).

The 2005 Habitat Action Plan for Northern Ireland’s mixed ashwoods has set the following targets for the conservation of the habitat Maintain the total area of all mixed ashwoods in Northern Ireland at 3,430ha Maintain the current area of all ancient or long‐established semi‐natural mixed ashwoods Maintain condition, where favourable, of the existing resource Achieve favourable condition of 2000ha of mixed ashwoods by 2015 Restore 80ha of former mixed ashwoods which has been converted to plantation on ancient or long‐ established woodland sites by 2010 Restore a further 90ha of former mixed ashwoods which has been converted to plantation on ancient or long‐established woodland sites by 2015 Establish 160ha of mixed ashwoods by 2010 Establish a further 180ha of mixed ashwoods by 2015

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Oakwood

Oak forests were once common across Europe and Ireland (CVNI, 2011).These forests are characterised populated by native oaks like Sessile Oak and Pedunculate Oak and Downy Birch, the habitat normally contains smaller tree species, tree species such as Holly, Rowan and Hazel are common within the forest canopy (Northern Ireland Habitat Action Plan, 2005).

Northern Ireland’s oak woodlands are concentrated in the north east, on less base‐rich soils, in rocky and wet locations (CVNI, 2011).

Figure 16 ‐ Breen Oakwood, Antrim

Oak trees are an important commodity for the forest dwelling flora and fauna. A individual oak tree is recorded at be capable of supporting over 350 different species of insect, (much more than any other tree) as well as an abundance of lower plants such as fungi, ferns, mosses and lichens (CVNI, 2011). The range of plants living at ground level in oak woods varies according to the underlying soil type and degree of grazing; but Bluebell, Bramble and fern communities, through to grass, Bracken and moss dominated areas are common (Northern Ireland Habitat Action Plan, 2005).

Similar to other forest types, the exact are of oakwood forests in the UK is uncertain, but it is gauged at between 70,000 ‐ 100,000ha (JNCC, 2001). With the extrapolated Northern Ireland oak woods occupies an area of 2,350ha, with an approximate 2,000 ha in private ownership and 350 ha in public ownership (Northern Ireland Habitat Action Plan, 2005).The NICS 2000 has reported a 11% increase to the habitat range between 1988 and 1998 (Cooper, McCann, & Rogers, 2009).

Oaks can live more than 500 years, with the production of acorns taking up to 80 years (CVNI, 2011).

The 2005 Habitat Action Plan for Northern Ireland’s oak woods has set the following targets for the conservation of the habitat Maintain the total area of all oak woods in Northern Ireland at 2,350ha Maintain the current area of all ancient or long‐established semi‐natural oak woods Maintain condition, where favourable, of the existing resource Achieve favourable condition of 1600ha of oak woods by 2015 Restore 60ha of former oakwood which has been converted to non‐native plantation on ancient and long‐established woodland sites by 2010 Restore a further 60ha of former oakwood which has been converted to non‐native plantation on ancient and long‐established woodland sites by 2015 Establish 120ha of oakwood by 2010 Establish a further 120ha of oakwood by 2015

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Lowland Dry Acid Grasslands

Lowland dry acid grassland habitats generally occur on nutrient‐poor, free‐draining soils which are based on acid rocks or shallow deposits of sands and gravels (NIEA, 2010). When acid grasslands are located in highland locations they are often a species poor product of former heathland. However when correctly managed, lowland dry acid grasslands are generally species rich, with a wide range of grasses, herbs, dwarf shrubs, lichens and mosses (Northern Ireland Habitat Action Plan, 2005).

Figure 17 ‐ Wangford Warren, Suffolk

The most characteristic herb and grass species are Heath Bedstraw, Sheep’s Sorrel, Sheep’s Fescue, Common Bent, Pill Sedge and Tormentil. Dwarf shrubs, such as Heather and Bilberry can also be present, as are brightly coloured and unusual fungi, like the Wax‐Cap, Fairy‐Clubs and Earth‐Tongues (NIEA, 2010).

Lowland dry acid grasslands are rare in Ireland and the UK, with the total area of the habitat in Northern Ireland only estimated at 674ha with only small concentrations in Co. Down and Armagh. The territory of these grasslands is highly scattered, with examples tending to be small occupying on rocky knolls or as part of other more dominant grasslands (Northern Ireland Habitat Action Plan, 2005). Individual instances would seldom have an area exceeding 0.25ha (Corbett, 2003).

The habitat also occurs as lawns associated with old gardens, church yards and other amenity areas where regular cutting and absence of nutrient inputs has resulted in very leached and as a result, relatively acid soils (Northern Ireland Habitat Action Plan, 2005).

The habitat range has undergone substantial decline over much of the Britain and Ireland over the past century. The decline has been mostly due to agricultural intensification and forestation (Northern Ireland Habitat Action Plan, 2005). Approximately 7% of species‐rich dry grassland were lost to development projects in Northern Ireland between 1991 and 1998 (Cooper, McCann, & Rogers, 2009), although it is not clear how much of this, if any, was lowland dry acid grassland.

The 2005 Habitat Action Plan for Northern Ireland’s lowland dry acid grasslands has set the following targets for the conservation of the habitat Maintain the total extent of lowland dry acid grassland in Northern Ireland at 674ha Maintain condition, where favourable, of the existing resource Achieve favourable condition of all significant stands of lowland dry acid grassland within ASSIs by 2010 For stands outside ASSIs, achieve favourable condition over 75% of the resource by 2015 Re‐establish 5ha of lowland dry acid grassland at carefully targeted sites by 2010

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Calcareous Grasslands

Calcareous grasslands are species‐rich grassland occurring on shallow, lime ‐rich soils the majority of which derive from chalk and limestone rocks (Northern Ireland Habitat Action Plan, 2005).

These habitats were originally created when woodland was cleared and rely on grazing or other management to prevent shrubs from re‐ colonising the region (NIEA, 2010).

All calcareous grassland in Northern Ireland occur in highland location, where as lowland Figure 18 ‐ Little Deer Park, Antrim calcareous grasslands occur in the rest of the UK. The majority of calcareous grassland occurs in the limestone uplands of County Fermanagh, with most examples occur above 150m altitude with only small pockets o f the habitat found at lower elevations (Northern Ireland Habitat Action Plan, 2005).

Calcareous grasslands are a significant habitat for several species, particularly butterflies.

Numerous Northern Ireland priority species reside in these environments, namely Irish Hare, Skylark, the ‘Small Blue’ Butterfly, Dingy Skipper Butterfly, Irish Eyebright, Dense Flowered Orchid, the Hoverfly and a selection of mosses. Of these species, Irish Eyebright, Dense Flowered Orchid and Autumn Gentian are found nowhere else in the UK.

Calcareous grasslands in Northern Ireland typically occur as components of larger habitat ranges, which are generally managed as rough grazing land for domestic livestock. (CVNI, 2011) This results in the habitat being fragmented in areas such as Antrim. The NICS 2000 places an approximate value of 936ha for the extent of the habitat type (Northern Ireland Habitat Action Plan, 2005).

Like many other important habitats, calcareous grasslands has undergone significant decline in recent years, but there is very little data available to tell us exactly how much. This decline can be mainly attributed to scrub invasion or changes in management to more intensive practices (CVNI, 2011).

The 2005 Habitat Action Plan for Northern Ireland’s calcareous grasslands has set the following targets for the conservation of the habitat Maintain the total extent of calcareous grassland in Northern Ireland at 936 ha Maintain condition, where favourable, of the existing resource Achieve favourable condition of all significant stands of calcareous grassland within ASSIs and SACs by 2010 For stands outside ASSIs, achieve favourable condition over 75% of the resource by 2015 Re‐establish 10 ha of calcareous grassland at carefully targeted sites by 2010

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Lowland Meadows

Lowland meadows are areas of agricultural unimproved grassland which contains few high plant species, like trees and a minimal coverage by bushes (Northern Ireland Habitat Action Plan, 2005). The soil layers of these habitats are generally composed of well‐drained mineral soil, with the habitat characteristically supporting a rich variety of herb species.

There are no significant concentrations of Figure 19 ‐ Tees Valley, Middlesbrough lowland meadow in Northern Ireland, but often reside on relatively steep hill slopes. The habitat is typically fragmented and is often restricted to small parts of fields where agricultural operations are difficult (Northern Ireland Habitat Action Plan, 2005). A noteworthy number of lowland meadow sites in Northern Ireland survives as hay meadow and are a result of the traditional agricultural practices for hay production (CVNI, 2011).

There is a wealth of low lying vegetation inhabitant lowland meadows, concentration around herbs and fine‐leaved grasses. herb species such as Meadow Vetchling, Common Knapweed and different types of fine‐leaved grasses like the Common Bent, Red Fescue and a variety of scarce and declining plants such as the Butterfly‐Orchid (Northern Ireland Habitat Action Plan, 2005).

Important fauna, both vertebrates and invertebrates species, rely upon lowland meadows for example Skylarks, Corncrake and the Irish Hare, all of which are Northern Ireland priority species (CVNI, 2011).

In the UK the area of lowland meadows of conservation value has declined by 95% since the 1930 (Northern Ireland Habitat Action Plan, 2005). Areas of traditional species‐rich hay meadows in Northern Ireland may have declined by as much as 97% over the last 50 years, with the area covered decreased by 20% since 1991. Only a minority (13%) of lowland meadows are considered to be of a high ecological quality, which relates into an area estimate of 937ha of high quality habitat in Northern Ireland (Northern Ireland Habitat Action Plan, 2005).

The 2005 Habitat Action Plan for Northern Ireland’s lowland meadows has set the following targets for the conservation of the habitat Maintain the area of lowland meadow in Northern Ireland at 937ha Maintain condition, where favourable, of the existing resource Achieve favourable status of all significant stands of lowland meadow within ASSIs by 2010 For stands outside ASSIs, achieve favourable condition over 75% of the resource by 2015 Re‐establish 10ha of lowland meadow at carefully targeted sites by 2010

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Purple Moor‐grass & Rush Pastures

Purple moor‐grass and rush pastures are habitat types that occur on poorly drained, usually acidic soils in lowland areas of high rainfall in Western Europe (Northern Ireland Habitat Action Plan, 2005). Northern Ireland contains a large portion of the European resource and is estimated to contain a third (18,700ha) of the total UK area.

This habitat comprises approximately 1.2% of the total land area of Northern Ireland, with over half of this sum occurring within the Fermanagh Figure 20 ‐ Slievenacloy, Belfast Hills district (CVNI, 2011).

Examples of more‐grass and rush pastures in Northern Ireland are difficult to define as it encompass a wide range of species, determined locally by an assortment of factors including soil condition, aspect and management practices (Northern Ireland Habitat Action Plan, 2005). However, they play an important role in providing areas where different priority species can live, feed and breed; this includes birds such as the Skylark, Curlew, and the Reed Bunting. These territories provide for a series of UK priority flora (Blue‐Eyed Grass and the Irish Lady’s‐Tresses Orchid) and fauna species such as the Irish Hare, Marsh Fritillary Butterfly and the Common Ground Beetle (CVNI, 2011).

The 2005 Habitat Action Plan for Northern Ireland’s purple moor‐grass and rush pastures has set the following targets for the conservation of the habitat Maintain the total extent of purple moor‐grass and rush pastures in Northern Ireland at 18,919ha Maintain condition, where favourable, of the existing resource Achieve favourable condition of all significant stands of purple moor‐grass and rush pastures within ASSIs and SACs by 2010 For stands outside ASSIs, achieve favourable condition over 75% of the resource by 2015

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Limestone Pavements

In the UK there is less than 3,000 hectares of this rare landscape and in Northern Ireland limestone pavement is restricted to west Fermanagh. Where, limestone pavement occurs within 8 main localities the largest of which are Crossmurrin, Western Marlbank (70‐100ha) and Noon’s Hole Knockmore (100ha) (Northern Ireland Habitat Action Plan, 2005). However larger areas of Limestone Pavement occur within Southern Ireland in areas such as the Burren in Galway and Clare (CVNI, 2011).

Figure 21 ‐ Knockmore, Fermanagh

There are three broad types of limestone pavement described in the UK; open, wooded and scrubby, however, in Northern Ireland wooded limestone pavement is largely absent (Northern Ireland Habitat Action Plan, 2005).

The limestone surface typically supports grass species and plants adapted to rocky habitats or have no vegetation cover, mosses and liverworts are often prominent in exposed areas (CVNI, 2011). The shelter proved by the limestone grikes often support taller plants more lime and calcium based woodlands and include herbs, occasional shrubs such as Hazel and ferns such as Brittle Bladder and Hart’s Tongue (CVNI, 2011). The lack of good soil, space for root growth as well as grazing pressure often means that any trees or shrubs that are present are often stunted or dwarfed (Northern Ireland Habitat Action Plan, 2005).

The open pavement provides a habitat for upland grassland vertebrate species such as the Irish Hare and the Skylark (Northern Ireland Habitat Action Plan, 2005). Other fauna that occupy the open pavements areas are the Cuckoo, Wrens, Common Lizard and Stoats.

Invertebrate species include a range of less common insects, moths and butterfly species (CVNI, 2011).

The 2005 Habitat Action Plan for Northern Ireland’s limestone pavements has set the following targets for the conservation of the habitat Maintain the extent of limestone pavement in Northern Ireland at 220ha Where favourable, maintain the area of limestone pavement in favourable condition Achieve 200ha of limestone pavement in favourable condition by 2015 Achieve 220ha of limestone pavement in favourable condition by 2020

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Lowland Heaths

Lowland Heaths are defined as heathland that are situated below the upper altitude limit of cost effective agricultural practices, this is generally below 300m. Thusly these environments supports a range of flora and fauna not found in upland heaths. Lowland heathland is characterised by the dominating presence of dwarf shrubs such as Heather and Bell Heather. These heaths exist in both dry and wet environmental conditions, with most Figure 22 ‐ Murlough National Nature Reserve heathlands being 25‐90% of wet heaths species (Northern Ireland Habitat Action Plan, 2003).

High quality lowland heathlands are usually structurally diverse supporting plants such as the Cross‐leaved Heath and Purple Moor‐grass, and the Black Bog‐rush. Dwarf shrubs like heathers, Western Gorse and trees such as Scots Pine are common (CVNI, 2011). Lowland heathland is a very important habitat for invertebrates like the Keeled Skimmer Dragonfly and the water beetles and endangered species like Curlew, Irish Hare, Chough, Marsh Fritillary Butterfly and Skylark can also be spotted (CVNI, 2011).

Lowland heathlands are an internationally rare and threatened habitat, and the total UK habitat range represents a significant proportion (58,000ha correspond to about 20%) of the global total area (Northern Ireland Habitat Action Plan, 2003). The Northern Ireland Countryside Survey has estimated that the area of lowland heathland in Northern Ireland is in the range of 5,000ha, with no habitat loss to dry and an 11% loss of wet lowland heaths between 1992 and 1998 (Cooper, McCann, & Rogers, 2009).

Within Northern Ireland, lowland heathland is generally fragmented and restricted, largely confined to the lower slopes of the Mourne Mountains and the Ring of Gullion, Rathlin Island and narrow coastal strips in Down and Antrim. Small areas of lowland heaths are linked to a number of fens in Down and Armagh (NIEA, 2010).

The 2003 Habitat Action Plan for Northern Ireland’s lowland heathlands has set the following targets for the conservation of the habitat Maintain the current extent and overall distribution of all existing lowland heathland (5,000ha) Achieve appropriate management on all lowland heathland within ASSIs so that it is in or approaching favourable condition by 2010 Improve by management, all existing lowland heathland currently in unfavourable condition Encourage the re‐establishment by 2010 of a further 130 ha of lowland heathland

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Upland Heaths

Figure 23 ‐ Bloody Bridge near Newcastle

Upland heaths reside in the heathland zones above the upper altitude marker of the majority of Northern Ireland’s farms and the country’s mountainous regions, typically between 300m and 600m. The habitat is based upon thin mineral or peat soil, usually with substrates layers less than 0.5m deep (NIEA, 2010). In Northern Ireland, blanket bog covers much of the shallow upland landscape, relegating heathland habitats to steeper slopes where the fall of land is too sharp or soil too deep for peat accumulation (Northern Ireland Habitat Action Plan, 2003).

Upland heaths dominated with same dwarf shrubs as their lowland counterparts with the addition of a number of blanket bog plant species, as the two habitats occupy similar ranges (NIEA, 2010). Fauna species are also shared by all habitats providing feeding grounds and shelter to the rare priority species; Argent and Sable Moths, Sword‐Grass Moths, Red Grouse, Curlew, Hen Harrier and the Irish Hare (NIEA, 2010).

Upland heathland is particularly prevalent in the Antrim Hills, Sperrin Mountains, Mourne Mountains, Ring of Gullion and the scarp slopes of western Fermanagh, where some important heathland sites straddle the border with the Republic of Ireland (Northern Ireland Habitat Action Plan, 2003).

No comprehensive assessment in the extent, distribution or condition of the upland heathlands in Northern Ireland exists, but its extent is estimated at 58,500ha (Cooper, McCann, & Rogers, 2009), with the total upland heathland resource in the UK between 2 and 3 million hectares (Northern Ireland Habitat Action Plan, 2003).

Unfortunately there has been considerable upland heathland loss in recent times, an estimated 20% of wet heaths, and 28% of dry heath pastures have been lost in Northern Ireland between 1992 and 1998 (Cooper, McCann, & Rogers, 2009).

The 2003 Habitat Action Plan for Northern Ireland’s upland heathlands has set the following targets for the conservation of the habitat Maintain the current extent and overall distribution of upland heathland which is currently in favourable condition Achieve appropriate management on all upland heathland within ASSIs so that it is in or approaching favourable condition by 2010 Improve by management at least 50% of upland heathland currently in unfavourable condition outside ASSIs by 2010 Seek to increase dwarf shrubs to at least 25% cover where they have been reduced or eliminated due to inappropriate management. A target of 2,000 ha is proposed for such restoration by 2010 Initiate management to re‐create 100 ha of upland heathland by 2010 where heathland has been lost due to agricultural improvement or afforestation, with a particular emphasis on reducing fragmentation of existing heathland

Mountainous Heaths

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Seek to increase dwarf shrubs to at least 25% cover where they have been reduced or eliminated due to inappropriate management. A target of 2,000 ha is proposed for such restoration by 2010 Initiate management to re‐create 100 ha of upland heathland by 2010 where heathland has been lost due to agricultural improvement or afforestation, with a particular emphasis on reducing fragmentation of existing heathland

Mountainous Heaths

Northern Ireland is located at the southern extreme of the natural range for montane or

alpine heath habitats. These heaths occur widely in the Highlands of Scotland at altitudes over 600m, above the natural tree line (NIEA, 2010).

Over 90% of the total UK montane heaths (approximately 600,000 ha) occurring in Scotland (Northern Ireland Habitat Action Plan, 2003).

The distribution of montane heaths is influenced heavily by local environmental factors (climate, Figure 24 ‐ Mourne Mountains altitude, aspect, slope and maritime influences), and unlike Scotland where these habitats are largely undisturbed, the montane heaths in Northern Ireland are highly impacted by sheep grazing and hill walking, especially the Mourne Mountains (Northern Ireland Habitat Action Plan, 2003).

The vegetation is influenced by a cold and wet climate, thin soils and steep rocky ground (NIEA, 2010). Due to the strong winds at high altitudes, shrubs can only grow 5‐10cm in height and several arctic species (Stiff Sedge, Dwarf Willow and a number of Clubmosses) which are adapted to harsh climatic occupy these heathlands (NIEA, 2010).

In Northern Ireland, the flora of these areas is restricted to dwarf‐shrub heaths, moss heaths and montane grasses, however in Scotland where national latitude is more situated to montane heaths; there is a greater diversity in plant species (Northern Ireland Habitat Action Plan, 2003).

Invertebrates adapted to cold environments reside in montane heaths such as beetles and especially of the Linnaeus beetle, which are rare in the rest of Europe (NIEA, 2010)

The distribution of montane heathlands in Northern Ireland is limited to the highest summits of the Mourne Mountains, Dart Mountain and Sawel Mountain in the Sperrin Mountains and the summit of Cuilcagh Mountain in west Fermanagh (NIEA, 2010).

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The 2003 Habitat Action Plan for Northern Ireland’s mountainous heathlands has set the following targets for the conservation of the habitat Maintain the extent of all existing mountainous heath Achieve appropriate management on all mountainous habitats (150ha) so that it is in or approaching favourable condition by 2015 Encourage the restoration by 2010 of 25ha of degraded mountainous heath in the Mourne Mountains

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Lowland Raised Bog

Lowland raised bogs are peat based ecosystems, which develop primarily in altitudes below 150m and as a formation feature are surrounded by mineral based soils. The climate of Northern Ireland, the Republic of Ireland and north‐ western Britain possess ideal climate conditions for peat formation, due to high rainfall, cool summers and high atmospheric humidity (Northern Ireland Habitat Action Plan, 2003).

The lowland landscape of Northern Ireland is Figure 25 ‐ Fairy Water Bogs, Tyrone principally comprised of drumlins and glacial boulder clays, thus resulting in poorly drained soils along the major the national river basins.

Because of the levels of continuously waterlogged soil in Northern Ireland, a regular occurrence exists of the anaerobic conditions that are necessary for the formation of peat.

Thusly Northern Ireland contains a proportionally high quantity of lowland raised bogs (CVNI, 2011).

Lowland raised bogs support a variety of specialist plants and national priority species. The most abundant vegetation that exists in raised bogs includes Sphagnum Bog Mosses and other plants adapted to waterlogged conditions, such as the Cotton Grasses, Great Sundew, Cranberry and Bog Rosemary (CVNI, 2011). A distinctive range of rare and localised animals which are supported by raised bogs include breeding waders, Skylark and a variety of invertebrates, such as the Large Heath Butterfly (CVNI, 2011).

The area of lowland raised bog in the UK that has remained unaffected by human activities is remarkable small. An estimated 94 % of raised bogs in the UK have been spoilt by human activities (6,000ha out of 95,000ha), in Northern Ireland the figure is 2,000ha out of 25,000ha (Northern Ireland Habitat Action Plan, 2003).

The 2003 Habitat Action Plan for Northern Ireland’s lowland raised bogs has set the following targets for the conservation of the habitat.

Maintain the current extent and overall distribution of near natural intact lowland raised bog in Northern Ireland, estimated at 1,600ha Ensure that the condition of the current near natural intact lowland raised bog is maintained where favourable. Improve the condition of those areas that are unfavourable through the establishment of appropriate management regimes and hydrological conditions Establish where practicable, appropriate hydrological and management regimes for intact areas which are in a degraded state (< 10 % Sphagnum Cover), but still retain nature conservation interest (c400ha). By 2015, aim to achieve management conditions that are conducive to the restoration of degraded intact lowland raised bog towards favourable condition By 2005, identify areas, timescales and targets for the conservation, improvement or restoration of significantly altered lowland raised bog, including those areas formerly cutover for fuel, improved for agriculture or planted with trees By 2006, initiate restoration projects for priority sites according to the agreed timescales

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Blanket Bog

Blanket bogs are a restricted and endangered peatland habitat of global importance. Blanket bogs form in cool, wet, oceanic climate and currently are one of the most extensive habitats in the UK and Ireland. The blanket bog region in Ireland, represent 8% of the world’s total habitat area (CVNI, 2011).

Blanket bog peat accumulates in response to the very slow rate at which plant material decomposes under waterlogged conditions, with Figure 26 ‐ Cuilcagh Mountain, Fermanagh an ability to cover an entire landscape, even developing on slopes of up to 300m. Although most widespread in the wetter west and north regions of Northern Ireland, it also occurs in the Mourne Mountains (Northern Ireland Habitat Action Plan, 2003). The most extensive regions of blanket bog are inclined to occur at altitudes in excess of 200m and thusly are concentrated in the Antrim Plateau, the Sperrin Mountains and the Fermanagh drumlins (Northern Ireland Habitat Action Plan, 2003).

These bogs are capable of supporting a wide range of animals, insects and birds.

Invertebrates that are common to boglands include mayfly and stonefly larvae as well as dragonfly and damselfly larvae. Whirligig beetles, Pondskaters and Water Boatmen are common water insects. Raised bogs are not heavily populated by mammals, although the Irish Hare, Foxes and the Pigmy Shrew are occasional occupants (CVNI, 2011).

The total extent of blanket bogs in the UK amounts to just under 1.5 million hectares, with Northern Ireland contributing an estimated 140,000ha (Northern Ireland Habitat Action Plan, 2003). About 15% (22,000ha) of the Northern Ireland blanket bogs remains intact, with 10% (14,000ha) having been drained and 46% (64,400ha) hand‐cut for fuel. The remaining 29 % (40,600ha) of blanket bog vegetation is considered severely degraded and is considered too spoilt to merit restoration (Northern Ireland Habitat Action Plan, 2003).

The 2003 Habitat Action Plan for Northern Ireland’s blanket bogs has set the following targets for the conservation of the habitat.

Maintain the current extent and overall distribution of blanket bog currently in favourable condition Improve the condition of those areas of blanket bog which are degraded but readily restorable so that the total area in or approaching favourable condition by 2010 is 36,000ha Introduce management regimes to improve the condition of a further 38,000ha of degraded blanket mire by 2015, resulting in a total of 74,000ha (i.e. around 75% of the total extent of favourable or restorable blanket mire) in or approaching favourable condition. Blanket bog targeted for restoration or improvement will include extensive areas cutover for fuel and in some instances areas used for agriculture and forestry

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Fens

Fens are peatlands that receive the majority of their water and nutrients from rock and ground water sources. Naturally occur in river valleys, poorly drained basins, along lake margins and in river flood‐plains (Northern Ireland Habitat Action Plan, 2005). The water table in fens sits close to or above the ground surface and in which the water itself is more nutrient‐rich and base‐rich, than that of a bog (National Museums Northern Ireland, 2010).

Figure 27 ‐ Corbally Fen, Down

Fens are ecologically considered the begins of boglands, as fens are covered by mats of floating plants and moss which start to slowly decompose to form the basis of the layers of peat (CVNI, 2011). The term fen covers various ecosystems based on waterlogged peat soils that differ on several points. Based on each fens specific designation, a wide range of variations in water height, pH of the water or the nutrient status of the water, can occur (National Museums Northern Ireland, 2010).Fens facilitate more than two hundred different flora species, however the type of vegetation inhabiting a fen depend on whether a fen is classified as ‘poor’ or ‘rich’ (CVNI, 2011).

‘Poor‐fens’ arise in upland locales and have their water and nutrients feed from sandstone or granite rocks. These environments are dominated by Sphagnum Bog mosses, Purple Moor‐Grass, Bottle Sedge and the smaller sedges, such as Star Sedge and Common Sedge (CVNI, 2011).

‘Rich‐fens’ reside within a restricted range and mostly occur in lowland areas where they are fed by mineral enriched waters. The variety of vegetation is frequently much more diverse than ‘poor‐fens’; including Bog Pimpernel, Meadow Thistle, Saw Sedge, Marsh Helleborine, Blunt‐Flowered Rush, Grass‐of‐Parnassus, Common Butterwort, Black Bog‐Rush Sand Bladderworts (CVNI, 2011).

Northern Ireland’s fens play a particularly important role for invertebrates in the UK context, several species which are extinct or threatened in the rest of the UK occur here. These include dragonflies such as the Irish Damselfly, beetles such as the Whirligig beetle, the Water beetle, the Pond Skater and the Carabid beetle (CVNI, 2011).

The Northern Ireland Countryside Survey 2000 estimated that fens occupy an area of 2,950ha, with a decrease in territory of 18% (484ha) between 1988 and 1998 (Cooper, McCann, & Rogers, 2009).

The 2005 Habitat Action Plan for Northern Ireland’s fens has set the following targets for the conservation of the habitat Maintain the total extent of fen in Northern Ireland at 3,000ha Where favourable, maintain the condition of fen in Northern Ireland Achieve favourable condition of 95% of fen which lies within designated sites, by 2015 For stands outside ASSIs, secure favourable condition over, as near as practicable, 100% of the fen resource in Northern Ireland, by 2015 By 2015, restore 50ha of fen By 2020, restore a further 50ha of fen

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Appendix B

Description of Northern Ireland’s Management of Sensitive Sites (MOSS) Scheme

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MOSS is a voluntary scheme administered by Environment and. Heritage Service (EHS), which is designed to ensure the proper ecological management of land within Area of Special Scientific Interest (ASSI).

Farmers must agree to a programme of natural habitat recreation/restoration or to leave an ecological important area fallow minimum of 5 years. Participants in the scheme are required to works which adding the upkeep of their registered natural habitat. While keeping records of the work carried out, in addition to allowing access to the habitat to EHS staff at all reasonable times (MOSS, 2002).

For this, participants will receive an annual payment (after an EHS inspection) with additional bonus on each anniversary of the signing of the agreement. The EHS also comments to review the levels of payments for each habitat every three years and with contribute to assist with the initial capital costs of when establishing any new habitats (MOSS, 2002).

The following are the annual payments under the MOSS system

Habitat Type Payment/ha Payment/m2

Saltmarsh

£80 0.8p

Sand Dunes

£80 0.8p

Vegetated Shingle

£80 0.8p Maritime Cliff Slope

Reedbeds

Wet Woodland

Mixed Ash Woodland Oakwood

Parkland

Lowland Dry Acid Grassland Calcareous Grassland Lowland Meadow

Purple Moor Grass and Rush Pastures

Limestone Pavement

Dry Heath

Wet Heath

Mountainous Heath

Raised Bog

Blanket Bog

Fens

Buffer zone ‐ Wildlife Corridors 130

£80

£110 £95 £95 £95 £50

0.8p

1.1p 0.95p 0.95p 0.95p 0.5p

£140 £140 £140 £140

1.4p 1.4p 1.4p 1.4p

£110

1.1p

£50 for 1‐100ha £25>100ha £50 for 1‐100ha £25>100ha £50 £70 £50 £110 £345 ‐ £385

0.5p for 1‐100ha 0.25p>100ha 0.5p for 1‐100ha 0.25p>100ha 0.5p

0.7p 0.5p 1.1p

3.45p ‐ 3.85p

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