Understanding the variability in deadwood decomposition and organismic diversity in the BELongDead deadwood logs after 17 years of decay
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 project, we use logs of the 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.
Specifically, we aim to disentangle drivers of heterogeneity within and among logs by using existing and new data at the log-scale and to link variability in decay to variability in biodiversity (beta-diversity). To avoid that potential drivers are confounded, we focus on the nine beech forest Experimental Plots (EPs) in Hainich, to obtain similar conditions in overall climate and soil conditions, and on effects of canopy cover associated with forest structure but not tree species composition. We focus on tree species where there is still sufficient variation in mass loss among logs. Based on this data, we will focus on Acer, Fraxinus, Pinus, and Larix. In addition, to finalize the long-term time series for mass loss, we measure mass loss for all logs across and all 30 plots.
- Heterogeneity in deadwood decay within and among logs (of the same tree species) is explained by differences in environmental conditions, such as cover of trees, herbs, shrubs or mosses, soil, leaf-litter contact and living roots.
- There is significant beta-diversity of organisms within logs that contributes to the beta-diversity of organisms among logs.
- Beta-diversity of organisms within and among logs is correlated with (small-scale) differences in exogeneous drivers, cover of trees, herbs, shrubs or mosses, soil, leaf-litter contact and living roots.
- Gamma-diversity of organisms across logs is more strongly driven by beta-diversity within and between logs than alpha diversity.
We assess diversity of various taxonomic groups of wood-inhabiting organisms (including fungi, prokaryotes, arthropods and nematodes) by applying metabarcoding. In addition, respiration rates, mass loss and wood chemical properties are analyzed and quantified and linked to biodiversity patterns to resolve the heterogeneity patterns of microbial mediated wood decay.
Scientific assistants
