Area effects of point-shaped deadwood structures using the example of land molluscs

In many cases, forest owners in Germany are willing to incorporate biodiversity considerations into forestry concepts. From a forestry science perspective, however, the problem is that it is often not possible to provide enough practical information on how to implement concrete measures to preserve or promote biodiversity in forestry operations. Particularly with regard to the requirement for deadwood as a key structure important for biodiversity, there is already sound knowledge on quality requirements, e.g. with regard to diameter or tree species. Not least thanks to the work of Müller et al. (2005), significant progress has also been made in recent years with regard to the quantity of deadwood for selected indicator species of native fauna (e.g. land molluscs). In the course of efforts to achieve multifunctionality in forestry even on smaller areas through integrative forest management concepts, there is an increasing need to describe structural elements for forests to which a desired functionality is linked. Such structural elements are then referred to as "target structures". The aforementioned deadwood, for example, can be considered a target structure for the functionality "beetle and land mollusc diversity". Integrative concepts now envisage combining target structures with each other in such a way that functional diversity is achieved in a small area (stand). In order to be able to combine several target structure elements on a given area, the individual structure element may only cover a certain area. For such concepts, the question arises as to whether very small deadwood structures - referred to here as punctiform - can guarantee an area-wide effect at all. For practical consideration, statements are therefore needed on the distances at which these structures must be present in an area in order to have an area effect. The project applied for here is intended to provide information on how much deadwood must be present in an area and in what distribution it should be present in forests in order to develop habitat characteristics relevant to terrestrial molluscs. An example is thus being developed that provides concrete instructions for forestry operations for an animal group as part of integrative forest management concepts. The investigations will take place in the Bavarian Forest National Park.
Literature:
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