This study is part of the interdisciplinary project "Greifensee", which aims at developing economic, socially responsible and ecological land-use concepts. The region of Greifensee is a typical landscape in the Swiss Central Plateau and serves as a case study area. 19% of the region is covered by forests which provide several forest products and services required by society. Depending on a particular forest's characteristics, these products and services vary in quantity and quality. Most of them are public goods and come freely as by-products of timber production.
The most important forest products and services in this region are:
• recreational space,
• ecological aspects (considering as examples: nature and species conservation, air pollutant removal, water purification), and
• timber
To assess the effects of forest management on these products and services, the interrelationships between them and the forest's characteristics are first modeled, and then forest management is simulated with six management strategies. These are Business-as-usual, no intervention, mass production, continuous forest cover, recreational forest, and ground-water protection.
The simulation results show clearly that, depending on the main demand, different management strategies are more promising. Where more than one demand is of concern and the emphasis is on retaining the multifunctionality of a forest, the strategies Business-as-
usual, no intervention, or recreational forest are recommended. They fulfill all demands to a certain degree, but not necessarily ideally. Therefore, it seems reasonable to define primary functions for forest areas with high demands and to choose the correspondingly most promising management strategy for that specific area.
Combining forest-growth simulation and evaluation models seems to be a good way of assessing the effects of forest management on public products and services. However, the simulation results show clearly that a change in management strategy will only have visible effects after 15 to 20 years.