Bollmann K.,Eidgenossische Forschungsanstalt fur Wald |
Muller J.,Nationalpark Bayerischer Wald DE
Schweizerische Zeitschrift fur Forstwesen | Year: 2012
The question "How large should the total extent of strict natural forest reserves be?" dominates the current debate about the need of unmanaged forests for biodiversity conservation in Central Europe. However, within a system of close-to-nature forest management, the quality, location, composition and distribution of natural forest reserves might have higher impacts on the diversity of species, communities and natural processes than the reserves' extent alone. Strictly speaking, the correct answer about the minimal required surface is directly related to the superior conservation objectives. In addition, the required ratio of forest reserves in relation to the total forest area is influenced by other factors such as the abundance and distribution of forests pirmarily managed for conservation objective, protected forest biotopes and old-growth stands as well as the general standards for an integrative, close-to-nature silviculture. Since concrete, superior objectives for forest biodiversity conservation are still missing in Central Europe, we put the focus of this article on the criteria that influence the conservation-specific impact and quality of strict natural forest reserves. These are amongst others the extent and compactness of a reserve, its habitat continuity and connectivity, the representativeness of forest types, their species composition and biogeographic distribution, a reserve's site heterogeneity and naturalness of its vegetation as well as the abundance of key structures and target species.