Biotope patterns and amphibian distribution as assessment tools in urban landscape planning

We investigated how information on biotope patterns over time and spatio-temporal distribution patterns of focal species (amphibians) in Stockholm, can assist in identifying landscape-ecological zones and give support to urban planning. Species data were combined with biotope patterns interpreted from aerial photographs (1998 and 1945/1950). These were then compared with information on roads with heavy traffic (1998 and 1950), with anticipated serious isolation effects. Spatial analyses were conducted using GIS (ArcView). We found that temporal distribution of amphibians is negatively related to increased fragmentation of valuable biotope configurations. Our use of context sensitive data on biotopes and species, provided insight into the ability of ecosystems to buffer land cover changes. We identified a time-lag of several decades between changes in urban land and road traffic intensity, and the response in species occurrence. This time-lag is not recognised in present-day planning and, therefore, the view of the status of wetland biodiversity in Stockholm’s natural and semi-natural areas remains too optimistic. To maintain the resilience of biotopes in urban areas, we argue that organisations responsible for implementing any active plan regarding biodiversity should more fully consider comprehensive reference data in their analysis programme, i.e. biotope and species data with a time-span that covers all land and waters in the given municipality. This is to develop a greater capacity to adapt physical planning work to the different risk of biodiversity loss in specifically chosen areas.