title: Urban ponds as an aquatic biodiversity resource in modified landscapes.
abstract: Urbanization is a global process contributing to the loss and fragmentation of natural habitats. Many studies have focused on the biological response of terrestrial taxa and habitats to urbanization. However, little is known regarding the consequences of urbanization on freshwater habitats, especially small lentic systems. In this study, we examined aquatic macro-invertebrate diversity (family and species level) and variation in community composition between 240 urban and 782 nonurban ponds distributed across the United Kingdom. Contrary to predictions, urban ponds supported similar numbers of invertebrate species and families compared to nonurban ponds. Similar gamma diversity was found between the two groups at both family and species taxonomic levels. The biological communities of urban ponds were markedly different to those of nonurban ponds, and the variability in urban pond community composition was greater than that in nonurban ponds, contrary to previous work showing homogenization of communities in urban areas. Positive spatial autocorrelation was recorded for urban and nonurban ponds at 0-50 km (distance between pond study sites) and negative spatial autocorrelation was observed at 100-150 km and was stronger in urban ponds in both cases. Ponds do not follow the same ecological patterns as terrestrial and lotic habitats (reduced taxonomic richness) in urban environments; in contrast, they support high taxonomic richness and contribute significantly to regional faunal diversity. Individual cities are complex structural mosaics which evolve over long periods of time and are managed in diverse ways. This facilitates the development of a wide range of environmental conditions and habitat niches in urban ponds which can promote greater heterogeneity between pond communities at larger scales. Ponds provide an opportunity for managers and environmental regulators to conserve and enhance freshwater biodiversity in urbanized landscapes whilst also facilitating key ecosystem services including storm water storage and water treatment.
authors.affiliation: Institute of Science and the Environment, University of Worcester, Worcester, WR2 6AJ, UK.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Hill
authors.affiliation: Freshwater Habitats Trust, Bury Knowle House, Oxford, OX3 9HY, UK.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Biggs
authors.affiliation: University of Birmingham, Birmingham, B15 2TT, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Thornhill
authors.affiliation: School of Life, Sport and Social Sciences, Edinburgh Napier University, Edinburgh, EH11 4BN, UK.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Briers
authors.affiliation: Ecosystems & Environment Research Centre, School of Environment and Life Sciences, University of Salford, Peel Building, Salford, M5 4WT, UK.
authors.forename: David G
authors.initials: DG
authors.lastname: Gledhill
authors.affiliation: Centre for Hydrological and Ecosystem Science, Department of Geography, Loughborough University, Loughborough, LE11 3TU, UK.
authors.forename: James C
authors.initials: JC
authors.lastname: White
authors.affiliation: Centre for Hydrological and Ecosystem Science, Department of Geography, Loughborough University, Loughborough, LE11 3TU, UK.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Wood
authors.affiliation: School of Biology, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Hassall
mesh_terms: D000818:Animals; D044822:Biodiversity; D002947:Cities; D017753:Ecosystem; D061005:Ponds; D006113:United Kingdom
keywords: aquatic; biodiversity; biotic homogenization; city; conservation; ecology; freshwater; invertebrate; urban