Dead spruce stands of medium age - potentials of deadwood management (PoToMa)

The ongoing effects of climate change and the extreme weather conditions that are occurring are also placing an enormous strain on forest ecosystems in Germany. Regionally, the large-scale dieback of forest complexes is coming to the fore, especially if these are dominated by homogeneous pure spruce stands. According to the last forest condition survey in 2024, around 41% of spruce areas in the Free State of Thuringia showed significant loss of vitality or were in the process of disintegration. These developments are already causing high levels of deadwood in middle-aged stands. For forest enterprises and forest owners, this results in enormous timber losses and major economic losses, while the ecological effect of deadwood occurrences in these age classes is largely unclear.

The aim of the project is therefore to develop concepts and strategies based on ecosystem parameters for dealing with these deadwood occurrences. Due to increasing uncertainty, previous concepts usually favor clearing and artificial reforestation of the areas in order to minimize further economic damage.

The project will therefore

• Comprehensive site and vegetation ecology information will be collected and examined with regard to its dependence on the area-specific deadwood variants (cleared versus uncleared, lying and standing deadwood),
• experimentally investigated the potential of soil seed banks and their activation mechanisms,
• documented the temporal and spatial regeneration dynamics,
• evaluated the findings on the provision of ecosystem services on disturbed areas, taking into account the aforementioned deadwood variants.

By recording complex influencing factors that determine the regeneration success of the tree species and the competitive potential of the accompanying vegetation, a direct link can be established to the immediate effect of the different deadwood variants. By quantifying site-specific, climatic and vegetation-dependent parameters, silvicultural options can be derived that facilitate the integration of the disproportionate amount of deadwood into forestry practice. Ways can be shown which parameters can be controlled by silvicultural measures and which risks and opportunities exist for the regeneration of these areas.

The results of the project should make a significant contribution to the development of practice-oriented deadwood management on large, formerly spruce-covered disturbed areas.

The project is being carried out jointly by the Friedrich Schiller University Jena (Chair of Soil Science & Chair of Ecology), the TUD Dresden University of Technology (Chair of Silviculture) and ThüringenForst (Gotha Research and Competence Center).