Ecoseries for potential site mapping, an example from the Netherlands

Ecoseries are ecological land units which are classified by means of characteristics of soil and groundwater that can be regarded as conditioning site factors. These conditioning site factors control so-called operative site factors, such as moisture availability, nutrient availability, or acidity, which determine the species composition of the vegetation. Under undisturbed circumstances, each ecoseries type is characterized by a specific frequency distribution of operative abiotic site types. The latter may each carry vegetations in different stages of succession. Thanks to the relations between vegetation, operative site factors and conditioning site factors, an adequate ecoseries classification is a valuable tool for environmental policy analyses, for example in the context of predictive modelling or for assessing natureʹs recovery potential for physical planning, environmental management and nature conservation policy. In this paper, we explain how we achieved an ecoseries classification and nationwide 1 km2 database for the Netherlands, primarily intended for national water management questions. The database is derived from existing maps of soil and groundwater which were re-interpreted from an ecological point of view. We especially treat the use of the ecoseries classification for ‘potential site mapping’, where ‘site’ is used in the sense of abiotic conditions determining natural vegetation development. The occurrence probability of potential sites is calculated by applying site-diagrams which introduce a probabilistic element. The resulting maps are intended as an aid to focussing the national policyʹs financial means aimed at ‘nature development’ and restoration projects. The maps inspire confidence in the approach as they show a considerable overlap with actual sitesʹ occurrence as established from separately gathered floristic and vegetation data.