Institut für Waldschutz
Forest management practices alter belowground biodiversity and functioning. The cutting of forest gaps can act as a strong disturbance and impact soil fauna taxa in different, sometimes contrasting ways. The retention of deadwood in forest gaps can mitigate the negative effects of forest gaps and promote soil fauna density and diversity, but the relative importance of abiotic versus biotic factors for the effects of deadwood is not known. Here, we aim to trace long-term effects of forest gap creation and deadwood addition on soil communities and to quantify shifts in functioning and resilience across multiple taxa. In the framework of the DFG-funded Infrastructure Priority Programme SPP 1374 ‘Biodiversity Exploratories’ we will focus on the forest gap experiment (FOX), where we will record meso- and macrofauna species diversity, community composition and biomass in two-year sampling intervals, complementing our previous data from 2021, 2023 and 2025. Functional shifts due to forest gap creation and deadwood addition will be quantified by analyzing shifts in energy channeling through decomposer food webs, using state of the art techniques such as compound-specific isotope analysis of amino acids to reconstruct basal resources, energy fluxes and trophic positions, both at functional group and community level. To better understand the mechanisms driving the effects of deadwood on soil communities and how these are modulated by climatic differences, we will additionally take advantage of the new BEClimWood experiment, allowing to disentangle biotic and abiotic drivers. These goals will be achieved in three working packages (WPs), with WP1 focusing on long-term analysis of the impact of forest gap creation and deadwood addition on abundance, diversity and biomass of soil fauna and microbes in the FOX, WP2 tracing the temporal dynamics of energy fluxes and functions in soil in the FOX and WP3 disentangling effects of deadwood and climate on soil mesofauna and microbes in the BEClimWood experiment. In addition to analyzing soil animal communities at species level and quantifying energy fluxes within food webs, we will determine microbial biomass using substrate-induced respiration and microbial functional community composition using phospholipid fatty acid (PLFA) measurements. The quantification of microbial communities will provide valuable insights into biotic processes at the base of soil food webs and will therefore help to understand shifts in animal communities and energy channeling due to forest gap formation and deadwood addition.
German Research Foundation
