Landscape forming processes and diversity of forested landscapes : description and application of the model FORSPACE

In the project "Landschapsvormende processen en biodiversiteit" ("Landscape forming processes and bioversity") the spatial interactions between autonomous development of a vegetation and landscape forming processes were investigated and their implications for (bio)diversity at the landscape level were evaluated. For this purpose the model FORSPACE was developed which is a spatial explicit process model that describes vegetation dynamics and the impacts of landscape forming processes. In this study emphasis was paid to the effects of grazing by large herbivores and fire on the vegetation. Two approaches to analyse diversity at the landscape scale were developed: 1) a spatial analysis evaluating the time-evolution of dominant vegetation types, and 2) a metapopulation approach that describes the population dynamics of indicator species at the landscape scale depending on the availability of habitat. This report focuses on the methodological aspects of the study and thus acts as a reference for future applied studies. The model structure is described in detail, as well as the approach of spatial analysis and of the metapopulation dynamics of an indicator species. Much emphasis is paid on the validation of the driving processes for trees, herbs and grasses by evaluating controlled simulation experiments. In a case-study on the 200 ha of the Imbos, an area in the centre of the Netherlands, the impacts of grazing by herbivores and its interaction with different fire frequencies were evaluated.