Development of a quantitative 'bioassay' approach for ecosystem mapping

A map of ecosystem distribution is an essential reference for assessing ecosystem services. We suggest that a map of the natural distribution of species assemblages is an ecosystem map and that multiple ecological niche models can be used to create it. As the biogeographical context is understood to be a driving force of the character of a landscape, the need of using it as a key criterion for landscape classification is widely accepted. For example, the ‘Map of Biogeographical Regions’ (EEA 2008) is used as a fundamental framework for the European Commissions Habitats Directive 92/43/EEC and is being taken as a reference to assess the coherence of the European-wide nature protection system. Because of its large scale – Germany is divided into only three regions – it is of limited use for planning at the landscape level. Landscape planners need access to more detailed, sub-regional characteristics and environmental conditions to address local ecological and conservation issues. The biogeographical regionalisation approach proposed by the authors allows for zooming in to a more useful scale for planning purposes and is transparent, repeatable and transferable. The current article describes the conceptual thrust of the methodology and some examples of its application to a variety of landscapes in Germany. In conclusion, we discuss some of its limitations and potentials, including its potential to map probable spatial shifts of ecosystems induced by climate change.