FinalCut: Understanding the variability in deadwood decomposition and organismic diversity in the BELongDead deadwood logs after 17 years of decay

• Applicants: Professor Dr. Werner Borken; Professor Dr. Claus Bässler; Dr. Björn Hoppe; Dr. Harald Kellner; Professor Dr. Matthias Noll; Professor Dr. Sebastian Seibold; Professor Dr. Wolfgang W. Weisser
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 569059009

Deadwood is an important structural element of forest ecosystems, which contributes to forest biodiversity and impacts many ecosystem functions. Deadwood decays over time and decay rates depend on a number of factors, in particular size, temperature and tree species-specific wood traits, such as chemical composition and wood density. Key decomposer are fungi, but archaea, bacteria and various invertebrate groups also contribute to deadwood decomposition. In advanced decay stages, the physical structure and chemical composition of deadwood has changed considerably, which also alters the function of deadwood as a resource and habitat for many of these organisms. There is evidence of a relationship between organismic diversity and decay rates but it is still largely unclear how diversity and composition of deadwood-degrading communities is linked to decay rates of individual tree species. In addition, wood decay is patchy and varies both between as well as within deadwood logs of the same tree species. In this proposal, we will use logs of the old BELongDead (Biodiversity Exploratories Long-term Deadwood) experiment to study the variation in decay, within logs and between logs at different subplots and plots. The experiment was established in 2009 and logs are therefore in a late decay stage. We will focus on the variability in decay in four tree species that show great variation in mass loss among logs. Three wood sections of each of 108 logs in nine beech forest plots in the Hainich exploratory will be sampled and analyzed for chemical parameters, respiration (present microbial activity) and long-term mass loss, as well as for biodiversity, using molecular approaches coupled with the extraction of living animals. In addition, small-scale variability in environmental conditions will be assessed. FinalCut will disentangle drivers of heterogeneity within and among logs by using existing and new data covering variability within logs, and by linking variability in mass loss to variability in biodiversity (beta-diversity), chemical wood parameters and environmental conditions (e.g., moss coverage).

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1374: Biodiversity Exploratories