Applying ecological models to altered landscapes: Scenario-testing with GIS

Including ecological information within the planning process is problematic. Individual species response to landscape change will be complex and is often difficult to express in terms of cost or benefit. Pressure on land, particularly in densely populated countries such as the UK, means that land-use needs to be planned in all areas, urban and rural. Designing landscapes to conserve biodiversity is challenging, and a holistic perspective must be retained at all times. A Geographic Information System (GIS) is described which integrates ecological models of species occurrence with spatial data on known landscapes. The use of the tool is illustrated with a series of models of woodland birds within the fragmented landscape of East Anglia, England. Scenarios of woodland loss or gain can be visualised quickly through the creation of altered landscapes; the bird models can then be re-run and the predicted impact on species distributions displayed. The tool is generic, in that any species can be modelled at any scale if ecological models are available to describe its distribution in terms of landscape variables. It is argued that it remains the job of the ecologist to make knowledge about species distributions accessible to the planning process. The key to this is that mathematical models must be expressed spatially in a format suitable for scenario-testing.