Meta Berghauser Pont. Green accessibility and green connectivity.

GREEN ACCESSIBILITY AND GREEN CONNECTIVITY C/O City Research project BEE CONNECTED*

PRESENTATION 2nd SEMINAR ON SOCIAL ECOLOGICAL URBANISM Meta Berghauser Pont 18 June 2019

* Research project by: META BERGHAUSER PONT Chalmers University of Technology, Department of Architecture and Civil Engineering KARIN AHRNÉ Swedish University of Agricultural Sciences, The Swedish Species Information Centre, Uppsala, Sweden ÅSA GREN The Royal Swedish Academy of Sciences, The Beijer Institute of Ecological Economics, Stockholm, Sweden ANNA KACZOROWSKA Chalmers University of Technology, Department of Architecture and Civil Engineering LARS MARCUS Chalmers University of Technology, Department of Architecture and Civil Engineering

GREEN ACCESSIBILITY AND GREEN CONNECTIVITY C/O City Research project BEE CONNECTED

GREEN ACCESIBILITY - health & well-being - Negatively affected by densification if green space dissapears - Positively affected as more services are feasible in high density, inlcuding green - Positively affecting green areas outside the densification zone (Ahlfedlt et al. 2017; Gren et al. 2018)

GREEN CONNECTIVITY - biodiversity - Negatively effected by densification because of fragmentation of the landscape within cities - Positively affecting green connected areas outside cities (Ahlfedlt et al. 2017; Gren et al. 2018)

Slutrapport C/O City, Research project financed by Vinnova

GREEN ACCESSIBILITY AND GREEN CONNECTIVITY C/O City Research project BEE CONNECTED

Biotope Area Factor (BAF) BAF =

Eco Effective Area Plan Area

Slutrapport C/O City, Research project financed by Vinnova

SPATIAL COMPONENTS

Streets Centrality

System perspective – spatial configuration Space Syntax (eg. Hillier and Hanson 1984)

FSI

GSI

Buildings Density

Density and spatial form Spacematrix (eg. Berghauser Pont and Haupt, 2009, 2010)

Plots

Configuration

Movement

Attraction = density

Theory of Natural movement Hillier et al. (1993)

SPATIAL COMPONENTS

Buildings Density

Movement

Density or FSI

Streets Centrality

Centrality or Integration Combination of Space Syntax, Spacematrix* and MXI index (Nes, Berghauser Pont and Mashhoodi, 2012).

Plots

SPATIAL COMPONENTS

Streets Centrality

Buildings Density Impact on pedestrian movement (Berghauser Pont, Stavroulaki and Marcus, 2019).

Plots

SPATIAL COMPONENTS

Streets Centrality

Buildings Density

Plots

Patches -Biotopes

Kaczorowska and Berghauser Pont (in review); Marcus, Berghauser Pont and Barthel (in review)

SPATIAL COMPONENTS Green Connectivity

Streets Centrality

Green Accessibility

Biotope Area Factor (BAF) Buildings Density

Plots

BAF =

Eco Effective Area Plan Area

Patches -Biotopes

Kaczorowska and Berghauser Pont (in review); Marcus, Berghauser Pont and Barthel (in review)

Dela(d) Stad projekt, Gรถteborg (Ann Legeby, Meta Berghauser Pont, Lars Marcus, KTH/Mistra Urban Futures)

URBAN MORPHOLOGY - LANDSCAPE ECOLOGY Urban Morphology Landscape ecology

Streets Plots Buildings

Distance Differentiation Density

Elements of urban form (Analysis Venice, Maretto 1960)

Corridor Patch Matrix

Connecting biotopes Habitable biotopes Non habitable biotopes

Elements of landscape ecology, Forman and Gordon, 1986

TEST ECOSYSTEM SERVICE POLLINATION Bumble bees

ES pollination is chosen for two reasons: Firstly, pollination is highly dependent on the connectivity of green areas, especially where habitat comprises less than 30% of the total land cover, which is often the case in cities (Andren, 1994; Fahrig, 2001).

Secondly, it is an essential ES for the majority of food production in the world (Allen-Wardell et al., 1998; Klein et al., 2007) and therefore also representing a tremendous monetary value (Ricketts et al., 2004; Gallai et al., 2008).

pollination

food production

pollination

biodiversity

health

TEST ECOSYSTEM SERVICE POLLINATION Bumble bees

EARLIER FINDINGS

COMPARING THREE MODELS

For the amount of bumble bees, local quality of sites, such as flower diversity, is most important (Ahrné et al. 2009).

1.

For the diversity of bumble bees, the amount of impervious surface in the direct surroundings of the observation sites is decisive; has a negative effect (ibid.).

2.

3.

Straight-line Euclidean distance to measure green accessibility as was used in the study of Ahrné et al.

(2009).

LCP accumulated-cost model using metapatches.

LCP accumulated-cost model using visibility graph analysis (VGA).

TEST ECOSYSTEM SERVICE POLLINATION Bumble bees

Berghauser Pont, Ahrné, Gren, Kaczorowska and Marcus (2017)

TEST ECOSYSTEM SERVICE POLLINATION Bumble bees

Berghauser Pont, Ahrné, Gren, Kaczorowska and Marcus (2017)

TEST ECOSYSTEM SERVICE POLLINATION Bumble bees COMPARING THREE MODELS 1.

2.

3.

Straight-line Euclidean distance to measure green accessibility as was used in the study of Ahrné et al. (2009).

LCP accumulated-cost model using metapatches.

LCP accumulated-cost model using visibility graph analysis (VGA).

1km

1,9

p12 2,6

p11 p5 p2 p7 p3 p4 p6

p1

3,1

p13 p8

1,0 1,0 1,5 1,7 1,1 1,2

0

p9

n

0

p10

p9

n

Σ A(p)

Σ (A(p) / S(p))

A = Area p = habitable patch

S = visual steps A = Area p = habitable patch

p=1

p=1

p10

TEST ECOSYSTEM SERVICE POLLINATION Bumble bees RESULTS GSI and the total amount of impervious surface within a 1 km radius show high correlation with bee species diversity (R2=0,79). GSI gives better results than accessibility to green areas (all methods).

Diversity Low Medium High

TEST ECOSYSTEM SERVICE POLLINATION Bumble bees RESULTS GSI and the total amount of impervious surface within a 1 km radius show high correlation with bee species diversity (R2=0,79). GSI gives better results than accessibility to green areas (all methods).

When looking into areas with similar GSI, proximity to green, tree-rich areas is important and the visual step depth distance measure gives slightly higher results than Euclidean distance and metapatch analysis (R2=0,70).

We expect this trend to be even stronger when studying more dense areas.

TEST ECOSYSTEM SERVICE POLLINATION Bumble bees RESULTS GSI and the total amount of impervious surface within a 1 km radius show high correlation with bee species diversity (R2=0,79). GSI gives better results than accessibility to green areas (all methods).

When looking into areas with similar GSI, proximity to green, tree-rich areas is important and the visual step depth distance measure gives slightly higher results than Euclidean distance and metapatch analysis (R2=0,70).

We expect this trend to be even stronger when studying more dense areas.

High traffic roads seem to be barriers as well. An intensity of AADT 120.000 seems to be negative for bee species diversity. (correlation increases to R2=0,82)

6 E4 with 120.000 AADT (Annual average daily traffic)

NEXT STEPS Integrating the green structure in the models of urban form

• • •

The way we weighted the green areas using the results of the VGA could be done in several ways and should be elaborated more on.

More case studies in highly urbanized areas.

Look into the impact of high traffic roads on bee mobility.

Further, it would of course be interesting to discuss the applicability of the method for other species that might be impacted by visual impedances when moving through the urban landscape.

And lastly, look into synergies and conflicts with other ES and of course, human needs in terms of green accessibility and the quality of green areas.

Jan Sahlberg, SMoG master thesis 2019 (work in progress)

Jan Sahlberg, SMoG master thesis 2019 (work in progress)