The ecology and management of urban pondscapes
Small water bodies provide valuable ‘blue space’ in urban environments, creating a network of semi-natural habitat patches for wildlife as well as providing a wide range of ecosystem services. However, the diverse and interacting anthropogenic stressors imposed by the urban environment pose considerable challenges for the effective management of these habitats. We outline some of the key factors that appear to influence urban pond biodiversity: land use with the local (and often small-scale) catchment, the connectivity of ponds through the landscape, and the nature of emergent and riparian vegetation. We argue that all three factors can be incorporated into a landscape-scale planning framework that can target particular areas for creation and amelioration of pond habitats. Such a joined-up approach is currently lacking from most urban planning frameworks, but could provide an opportunity to maximise services provided by urban wetlands at the landscape scale. We emphasise the application of recent ecological advances in our understanding of urban ponds to management guidelines, which have largely come in the form of gardening guides. This management will be required not only to enhance the biodiversity value of urban ponds, but also to control the less desirable elements of aquatic biodiversity such as invasive species and disease vectors that may pose a particular risk in urban environments. Finally, we note the lack of a comprehensive conservation strategy for ponds and highlight key legislation and guidance that can help to fill the gap. The fact that pond value lies in the aggregation of multiple habitats distributed through the landscape challenges our existing approach to habitat protection. However, contemporary approaches to pond creation for mitigation through planning processes and programmes of pond creation provide an opportunity to implement truly large-scale strategic habitat management. It is imperative that ecologists and conservationists are involved in the future planning process and its implementation.