Integrating ecosystem services into spatial planning-A spatial decision support tool

Urbanization is viewed as endangering more critical habitats of global value and is more ubiquitous than any other human activity affecting biodiversity, climate, water and nutrient cycles at multiple scales. Spatial and landscape planning can help create alternative urban patterns protecting ecosystems and thus supporting the provision of needed services they provide. While many approaches exist to make the values of nature explicit, new tools are needed to interpret the vast quantity of information in an integrated assessment to support planning. In this study, we present a new spatial decision support tool PALM (“Potential Allocation of urban development areas for sustainable Land Management”) aimed at supporting the allocation of urban development zones. A GIS-based MCDA approach was integrated into a web-based platform that allows distributing a requested amount of urban development areas within a selected perimeter based on ecosystem services and locational factors. The short running time of different user-defined scenarios allows exploring consequences and tradeoffs between decisions in an interactive way, thus making it a useful tool to support discussions in participatory planning processes. The results of the application of PALM in a case study region in Switzerland show that integrating ecosystem services when distributing urban development areas is particularly effective in urban peripheries, where building zones are shifted towards urban centers securing the productive soils located around cities. This shift of building zones from the urban peripheries to the urban centers when considering ecosystem services is less pronounced in rural areas, as they provide fewer ecosystem services. However, the results also show that integrating ecosystem services in spatial planning needs to be embedded in the right policy context: Ecosystem services can only be traded-off for locational factors if the perimeter of the case study ranges across municipalities. Whereas this transparent and flexible platform offers a suitable tool at the beginning of a planning process, we also discuss further development needs.