FORSUM, a forest succession model of the jabowa/foret type, was applied to the Solling spruce site. Reconstruction of the forest development for the last 100 years showed good agreement with real forest development for that site. One model experiment performed on the site was designed to explore the long-term effects of the management stop in 1966 on the spruce site. The invasion of other species takes place some 300 years from now and the vegetation slowly develops towards a beech-dominated forest. Finally, potential development of species composition was evaluated using the IPCC-‘business-as-usual’ climate scenario with a an increase of the mean annual temperature by 0.3°C/decade until the end of the 21st century. According to the model predictions Picea abies would disappear from the Solling site and be replaced by a Luzulo Fagetum forest type with Acer platanoides, Quercus petraea and Fagus sylvatica.
forsum successfully combines long-term (e.g., succession) and short-term (e.g., hydrology) processes, giving the opportunity to simulate forest ecosystem processes more adequately. Forest succession models can be used to evaluate climate change impacts on forest ecosystems, even though some parameters are highly uncertain or are even unknown. Further research efforts are needed to fill the knowledge gaps and to improve model accuracy and reliability, especially plant physiological aspects with respect to a changed and a changing environment.