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 c.hassall@leeds.ac.uk

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

17. Hypothesis 3: Urban biodiversity 1-1 0-0..88 0-0..66 0-0..44 0-0..22 00 0 0 0.2 0.2 0.4 0.4 0.6 0.6 0.8 0.8 1 1 Dytiscidae Corixidae Asellidae Limnephilidae Coenagrionidae Gerridae Haliplidae Aeshnidae Erpobdellidae Sphaeriidae Gammaridae Physidae Hydrometridae Hydraenidae Pisidiidae Noteridae Gyrinidae Polycentropodidae Naucoridae Crambidae Dugesidae Nemouridae Tipulidae Acroloxidae Pyralidae Pleidae Hirudidae Ostracoda Dryopidae Culicidae Psychodidae Limacidae Helodidae Dixidae Cladocera Viviparidae Stratiomyidae Simuliidae Paguroidea Leuctridae Hydroptilidae Glossosomatiidae Ephemeridae Ceratopogonidae Astacidae Ancylidae Tortricoidea Sericostomatidae Potamanthidae Perlodidae Niphargidae Limnichidae Heteroceridae Hebridae Gastrodontidae Ephemerellidae Dreissenidae Calopterygidae Bibionidae Argulidae Anthribidae W = 10835, p = 0.886 103 taxa 91 taxa

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