Modelling aspects of forest decline in Germany: II. Application and validation of an integrated soil-plant-model

In 1993 the German Federal Environmental Agency initiated a project to evaluate the forest decline research of the period 1982–1992 in Germany. The soil-plant-model PLOT applied here was developed to integrate the research results. It consists of a soil module, BODEN, and a plant module. FICHTE, which both include several submodels. For validation of submodels, modules, and the whole model, a stepwise procedure was chosen and parts will be presented here. Focussing on soil processes and nutritional aspects, the model performance as well as the applicability range and limits are shown. The underlying cause-effect-relationships and the theoretical aspects of the modelling exercise are presented in a second paper [1, this volume].