Das Projekt "Modellierung der durch Umweltveraenderungen beeinflussten Walddynamik" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Departement Wald- und Holzforschung, Professur für Forstwissenschaften durchgeführt. The main goals of this project are first to evaluate the influence of biotic and anthropogenic factors on the development of forests in Central Europe and secondly to improve the accuracy of forest succession prognosis. Further objectives are the description of tree growth under optimal site conditions, the influence of human management on forest development and a sensitivity analyses of the driving factors of forest succession. A JABOWA/FORET-type model has been developed. Compared to other gap models the Forest Succession Model FORSUM is improved with a sophisticated hydrological approach. Verification and validation of this model will be made using field data from well-documented virgin forests and near natural forests in Central Europe. Sensitivity analyses shall help to understand the importance of different factors for tree competition, species composition, vegetation patterns and for long-term forest dynamics. FORSUM shall also help to evaluate the possible impacts of climatic changes on vegetation patterns and forest dynamics.