A comparative analysis of biodiversity in urban ponds in the UK
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A comparative analysis of biodiversity in urban ponds in the UK Christopher Hassall 1 , David Gledhill 2 , Paul Wood 3 , Jeremy Biggs 4 1 Univ Leeds, 2 Univ Salford, 3 Univ Loughborough, 4 Freshwater Habitats Trust @katatrepsis [email protected]
A comparative analysis of biodiversity in urban ponds in the UK
Talk given at IALE UK meeting, 1-3 September 2014. I discuss how to define an urban pond (more difficult than you'd think) and some preliminary data characterising urban pond ecology across multiple published and unpublished studies.
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1. A comparative analysis of biodiversity in urban ponds in the
UK Christopher Hassall1, David Gledhill2, Paul Wood3, Jeremy Biggs4
1Univ Leeds, 2Univ Salford, 3Univ Loughborough, 4Freshwater
Habitats Trust @katatrepsis [email protected]
2. Acknowledgements Institutional support Funders Field
assistants Andrew Noble Nicole Barber Denny Moyers Surveyors
Jonathan Guest David Bentley
3. What is an urban pond? urban pond
4. What is an urban pond? Crown Copyright 2014. An Ordnance
Survey/EDINA supplied service.
5. What is an urban pond? Crown Copyright 2014. An Ordnance
Survey/EDINA supplied service.
6. What is an urban pond? Crown Copyright 2014. An Ordnance
Survey/EDINA supplied service. Run-off from dense residential Low
connectivity to other water bodies Industrial run-off Concrete
edge, poor vegetation 2014 Google
7. What is an urban pond? Different design Different context
Different management Different priorities JR P, CC-BY-NC 2.0,
http://bit.ly/1rzf3RX; Nick M, CC-BY 2.0, http://bit.ly/VQmQM9;
Reinhold Behringer, CC-BY-NC-SA 2.0, http://bit.ly/1ATkvjn; Loz
Pycock, CC-BY-SA 2.0, http://bit.ly/1wB04Jj Hassall C (2014) The
ecology and biodiversity of urban ponds. WIREs Water, 1,
187-206.
8. Management of urban ponds 2 5 3 2 1 3 2 2 1 2 1 1 1 1
Hassall C (2014) The ecology and biodiversity of urban ponds. WIREs
Water, 1, 187-206.
9. A comparative analysis of urban ponds Dataset N ponds Moyers
& Hassall (unpub) 11 Noble & Hassall (in review) 21 Barber
& Hassall (unpub) 10 Hassall et al. (2011) 425 Wood et al.
(2000) 36 Gledhill et al. (2008) 37 FHT (NPS) 153 FHT (TP) 76 FHT
(ROPA) 179 TOTAL 938 186 urban ponds 751 non-urban ponds Noble A,
Hassall C (in review) Urban Ecosystems; Hassall C, Hollinshead J,
Hull A (2011) Biodiversity and Conservation, 20, 3189-3222; Wood
PJ, Barker S (2000) Applied Geography, 20, 65-81; Gledhill DG,
James P, Davies DH (2008) Landscape Ecology, 23, 1219-1230;
Williams PJ, Biggs J, Barr CJ et al. (1998) Lowland Pond Survey,
London, DETR.
10. Urban vs non-urban ponds Three main hypotheses: 1. Urban
ponds exhibit biotic homogenisation PREDICTION: urban communities
are more similar than rural communities 2. Urban landscapes are
less permeable PREDICTION: urban communities show stronger spatial
structuring than rural communities 3. Urban stressors reduce
diversity PREDICTION: urban ponds contain lower family richness and
diversity than rural ponds
11. Hypothesis 1: Biotic homogenisation Urban Compare samples
of Mahalanobis distances between urban and non-urban Non-urban
12. Hypothesis 1: Biotic homogenisation Environment W = 16514,
p= 0.312 (Northing, altitude, shade, pH, emergent plants, area)
Biological community W = 50282, p= 0.008
13. Hypothesis 1: Biotic homogenisation
14. Hypothesis 2: Landscape permeability Urban Non-urban
Distance between sites Correlation between communities Expect high
autocorrelation at small spatial scales in urban sites due to low
permeability, with negligible correlation beyond that due to biotic
homogenisation Expect low-moderate autocorrelation across spatial
scales with non-urban ponds
15. Hypothesis 2: Landscape permeability Urban ponds show
greater fine-scale spatial autocorrelation, with negative
autocorrelation at intermediate (inter-city?) distances
16. Hypothesis 3: Urban biodiversity Prevalence in non-urban
Prevalence in urban Taxon 1 Taxon 2 Taxon 3 Taxon 4 Taxon 5 Taxon 6
Taxon 7 Taxon 8 Taxon 9 Taxon10 Taxon 11 Taxon 12 Taxon 13 Taxon 14
Taxon 15 Taxon 16 Rapid drop-off in prevalence as stress-tolerant
species are passed Stress-tolerant species are present, along with
other species with lower tolerance to disturbance
18. Summary of hypotheses Three main hypotheses: 1. Urban ponds
exhibit biotic homogenisation PREDICTION: urban communities are
more similar than rural communities 2. Urban landscapes are less
permeable PREDICTION: urban communities show stronger spatial
structuring than rural communities 3. Urban stressors reduce
diversity PREDICTION: urban ponds contain lower family richness and
diversity than rural ponds
19. Implications for management Regardless of function, urban
ponds promote aquatic biodiversity The diversity of urban pond
types may be key to this role, so diversity of types must also be
conserved Biodiversity may persist despite conflicting management
priorities Easy-wins could further enhance this resource
(revegetation, strategic pond creation, pollution reduction)
20. Take Home Messages 1. To find out what an urban site is,
compare with non urban 2. Synthetic approaches provide additional
insights (meta-analyses often not possible) 3. Ecological theories
about urban environments may not hold for ponds 4. Urban ponds may
have a high biodiversity value which justifies protection, but
might not need it!
21. A comparative analysis of urban ponds Crown Copyright 2014.
An Ordnance Survey/EDINA supplied service.
22. Three measures of urbanness In/out Distance to edge 1km
buffer