Highways for Wildlife - defending and extending the UK's road verge network for biodiversity

Mark Schofield Conservation Officer Lincolnshire Wildlife Trust

Highways for Wildlife - defending and extending the UK’s road verge network for biodiversity

Living Landscapes: Spaces for nature need to be ‘bigger, better, more and joined.’ Lawton Review 2011.

Field margins, hedgerows, agri-environment

Road verges, railways, watercourses

Living Landscapes: Spaces for nature need to be ‘bigger, better, more and joined.’ Lawton Review 2011.

Field margins, hedgerows, agri-environment

Road verges, railways, watercourses

Living Landscapes: Spaces for nature need to be ‘bigger, better, more and joined.’ Lawton Review 2011.

Field margins, hedgerows, agri-environment

Road verges, railways, watercourses

Living Landscapes: Spaces for nature need to be ‘bigger, better, more and joined.’ Lawton Review 2011.

Field margins, hedgerows, agri-environment

Road verges, railways, watercourses

Living Landscapes: Spaces for nature need to be ‘bigger, better, more and joined.’ Lawton Review 2011.

Field margins, hedgerows, agri-environment

Road verges, railways, watercourses

What’s out there?

Total road verge area in England, Scotland & Wales estimated to be over 200,000ha - roughly the size of Nottinghamshire, c.1% of mainland UK, >2x England’s NNRs William-Ellis, C. (1967). Roads in the Landscape. London, HMSO.

Total verge area for motorways today in the UK estimated at >11,000ha (5-6%) (about the size of Bristol UA) www.gov.uk/government/statistics Way, J.M. (1976) Grassed and planted areas by motorways Monks Wood Experimental Station Occasional Reports, No. 1, Abbots Ripton, Huntingdon.

Road classifications for England, Scotland and Wales Classification Rural C & U Rural B Rural A Trunk Rural A Urban C &U Urban B Trunk Urban A Motorway

Length (km) 188,540 24,719 27,574 8,092 126,313 5,498 10,671 3,641

% of Total 47.7 6.3 7 2 31.9 1.4 2.8 0.9

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Road classifications for Greater Lincolnshire Classification Rural C & U Rural B Rural A Trunk Rural A Urban C &U Urban B Principal Urban A Motorway

Length (km) 7,005.3 889.1 1,148.5 87.7 1,589.3 94.2 122.9 39.0

www.gov.uk/government/statistics

% of Total 63.8 8.1 10.5 0.8 14.5 0.9 1.1 0.3

Negative effects • • • • •

Habitat loss Pollution Disturbance Mortality by collisions Barrier effects

Positive Effects • Refuges • Corridors

Relatively speaking‌.

High biodiversity matrix

Low biodiversity matrix

e.g. National Parks

e.g. lowlands under intense arable cultivation

Ecosystem service provision of well-managed, biodiverse verges • Pollination of arable crops (worth £510 million UK DEFRA) • Continuity and diversity of nectar and pollen supply

• Improved road surface drainage • Penetration of compacted and impermeable soils by deeper root systems

• Improved safety of pull-over zone and visibility • Fertility buffering of adjacent field inputs e.g. by hedgerows and biomass removal ⇨ lower growth height at road edge

• Improved water quality • ⇩ Nitrates in drainage water through growth and removal of vegetation cuttings

• Mitigation of cross-winds and snow drifting • Roadside trees and hedgerows act as wind breaks in exposed areas

• Improvement of the urban environment • ⇧ oxygen, ⇩ temperature, ⇩ driver stress levels, ⇩ noise levels, ⇧ shade ⇧ air quality

Roadside habitat

Ditch, hedge and verge ownership and maintenance responsibilities

Hedgerow Management Cutting frequency ↓ every year → every 3 years Flower abundance x 2.1 Mass of berries x 3.4 Staley et al. (2012)

Moth abundance and diversity ↑ with ↓ in cutting frequency and cutting in winter rather than autumn Facey et al. (2014)

Most hedgerow berries are foraged by mid-January Croxton, P.J. & Sparks, T.H. (2004).

Woodwise Summer 2014

Ditch management • • • •

Slubbings and cut vegetation should not be left Amphibians least affected November to January Water voles least affected in October Plants and invertebrates least affected Sep - Feb

A final redoubt for our national wildflowers • Over 700 species of wild flowers grow on verges • nearly 45% of our total flora • 7 species rely on them • 87 threatened with extinction

1962 Atlas of the British Flora, Nature Conservancy, BSBI.

Road verges act as pollinator sanctuaries

• Study in Devon and Cornwall by Plymouth University 2014 • Bumblebee abundance >2x on roadsides than field margins • Species richness and abundance of flowers used by bumble bees higher on roadsides • Road verges could be used more for pollinator conservation Hanley, M. and Wilkins, J. 2014. On the verge? Preferential use of road-facing hedgerow margins by bumblebees in agro-ecosystems. Journal of Insect Conservation. 19, 1 (2014).

Lincolnshire’s losses and last stands Chalkhill Blue (Polyommatus coridon)

Lizard Orchid (Himantoglossum hircinum)

Bastard Toadflax Perennial Flax (Thesium humifusum) (Linum perenne subsp. anglicum)

Man Orchid (Orchis anthropophora)

Routes of invasion – proof of corridor effect

Scott and Davison Watsonia, 1982.

Distribution of Puccinellia distans on roadsides.

A striking correlation with the routes of the A1 and M1

Principal pressures on road verge grassland Cuts too frequent or too infrequent Too many cuts: diversity lost No cuts: tussocks – scrub – trees • >2 cuts per year / no cuts

Smothering mulch Only vigorous minority of species survive • No collection of cuttings

Accumulating fertility Tall growth of nettles, hogweed, thistles • Mulching cuts, farming inputs and vehicle emissions CS2000 (Lowland England, Scotland and Wales)

Roadside Nature Reserve Management in Lincs.

• Roadside Nature Reserves in Lincolnshire (80km) • Cut and collect hay with sub-contractors including local farmers • £25k/yr (>£150/km verge) – more needed for optimal management • £7k/yr CES agreements for SSSI verges (NE) • Hay making between mid-July and end of Sept with flail in autumn

Claxby RNR Lincolnshire Wolds

Lincolnshire Wildlife Trust owned single axle machines: (Aebi CC66 with attachments)

Single axle and compact tractor work rates Single axle machine 0.15ha/man day (e.g. 750m of 2m wide verge)

Compact tractor 0.3ha /man day (e.g. 1.5km of 2m wide verge)

Equipment storage

Pricing: RRPs (ÂŁ) excl. VAT Pedestrian and compact tractors Single Axle BCS

Aebi

Brielmaier

Compact Tractor

Power Unit

6,300

10,500

16,000

9,200

Flail

1,500

3,700

5,200

3,500

Cutter bar

1,500

2,700

4,600

Belt rake Drum mower Flail collector

1,500

1,500

1,500

Mini baler

7,000

1,200 1,800

2,300 7,000

7,000

5,000

BUT hay-making is expensive, labour-intensive, time-consuming and weather-dependent

Can we cut the ‘Gordian Knot’?

Potential solution: Biomass harvesting with anaerobic digestion of cuttings

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Cut and collection harvester systems 2005

Montgomeryshire

• 11t/ha fwt • Cuttings could be used for AD • Economics and logistics still to be investigated

Cut and collection harvester systems

2016

• • • •

Lincolnshire

Mastenbroek Herder LCC, Leeds Univ., London Business School, Peakhill Assoc.

PAHs / PTEs / C:N / pH / solubility all favourable for AD Harvest cost achievable below benchmark value for grass

Cut and collection harvester systems

2018

• • • •

Lincolnshire

JCB Fastrac 5.5m-reach Tifermec, 1.1m suction flail head with auger Improved efficiency - trailer with novel coupling >30t/day at 3-5km/hr

Avg mown verge width recorded in 1972 (m)

Accessible herbaceous biomass by region?

4.0 3.5 3.0 2.5 2.0 1.5

1.0 0.5 0.0

East

Midlands

South

South-west

Upland

Region NERC 1972

Harvestable verge in Lincolnshire?

• GIS analysis of 6 selected 10km radii • Using OS MasterMap® average rural verge area outside towns = 0.76ha/km i.e. average verge widths are approximately 3.8m • Assuming only 50% harvestable:

conservative estimate of 3,500ha (0.5% of the county’s area = LWT land) • Lincolnshire roadsides could produce enough biomass to provide electricity annually for up to 4,500 homes or gas for some 1,100 households.

The pros and cons to biomass harvesting The ‘do nothing scenario’ • Continuing loss of road verge grassland diversity

Potential benefits • • • • • • •

Improved ecosystem service provision Restore and maintain favourable condition for roadside LWSs Local authorities offset carbon footprint by producing green energy New low input AD feedstock that does not impact food production NERC Act 2006 Biodiversity Duties Biodiversity Net Gain principle – Government’s intention to mandate 25 Year Environment Plan: 40% of 500,000ha restoration target

Risks of biomass harvesting and how to mitigate them Potential risks of biomass harvesting • • • • •

Damage to invertebrate populations Interruption of plant lifecycles and removal of seed Removal of shelter for wildlife Ground nesting birds, hedgehogs New market for AD feedstock drives intensive management of verges o Lose roadside grassland diversity o No resources in local authorities to regulate private sector

How could we mitigate that risk?

• Establish clear map of verge quality and biodiversity opportunity • Optimise management of the best • ‘Mainstream’ better management for the rest o Rotation, sanctuary stretches, sanctuary strips

Baseline surveys • Citizen Science • • • •

250 volunteers organised with online maps Field classes Basic survey form with H&S 6 survey seasons between 2009-2015

• Coverage • 1/3rd Lincolnshire (chalk and limestone) • 3,900km (2,400 miles) of road

• Designation • 159 new LWS on 250km/100ha • GIS reporting facility

Turning the unknown into useful baseline data‌

Verge ‘Quality Pyramid’

Life on the Verge 2009-16, Lincolnshire Wildlife Trust

When and how to mow a linear meadow?

Mowing parallel strips of vegetation at different times should deliver best long-term survival for grassland wildflowers.

Auestad, I. et al. 2010. Pimpinella saxifraga is maintained in road verges by mosaic management. Biological Conservation. 143, 4 (2010).

Partial mowing or ‘shoulder season’ mowing (May / Aug) impacts flower-feeding moths and butterflies least.

Valtonen et al., 2006. Effect of different mowing regimes on butterflies and diurnal moths on road verges. Animal Biodiversity and Conservation. 29.2 (2006).

No damage-free mowing technique; bar mowers less damaging than rotary mowers; silage conditioners and tractor wheels dramatically increased mortality.

Highlights importance of leaving refuges and minimising running wheels on verge.

Humbert, J. Y. et al. 2010. Impact of different meadow mowing techniques on field invertebrates.

Journal of Applied Entomology. 134, 7 (2010), 592–599.

Mowing twice per year with hay removal increased grassland plant species richness, numbers of flowers, insect abundance and pollinator visits. An early summer cut benefited insects as a result of re-flowering later in the season.

Noordijk J et al. Optimizing grassland management for flower-visiting insects in roadside verges.

Biol Conserv. 2009;142:2097–103.

Jakobsson 2018 - How does roadside vegetation management affect the diversity of vascular plants and invertebrates? A systematic review.

Reviewed 54 studies from Europe and North America and concluded that species richness of vascular plant increases if…

• if roadsides are mowed each year • if they are mowed twice rather than once a year • if hay is removed after each cutting Only few studies on invertebrates; showed effects that diverged across taxon groups; not enough data for quantitative analysis Jakobsson et al. Environ Evid (2018) 7:17

Our Conclusions: • • • • • • •

Combine management regimes in a linear mosaic & remove the cuttings.

Leave an interval between mows for regrowth and seed set (10-12 weeks).

Avoid June and early July - therefore cut in May and August/September.

Do not use a suction flail on designated verges (sanctuary stretches).

Only harvest 1 in 3 yrs from hedgerow base on wider verges (sanctuary strips).

Avoid running machinery along verges and ‘carry’ flail at back verge.

Avoid doing the same thing everywhere at once – rotate your programme.

Linear mosaic cutting and regrowth windows

Sanctuary strip mowing

The ‘2-cut sweet spot’ Study in Germany of energy recovery from grass of urban roadside verges: • Mean total annual yield greater from 2-cut versus 4-cut regimes • No difference in methane yield from 2-cut versus 4-cut regimes • Suggests a better return on energy invested for a 2-cut regime Piepenschneider et al. 2016

Jakobsson + Piepenschneider

2-cut sweet spot for biodiversity and energy recovery

Please take: Life on the Verge Wildflower ID Guide Get in touch: Survey forms project evaluation reports

mschofield@lincstrust.co.uk