Inconsistent short-term effects of enhanced structural complexity on soil microbial properties across German forests

Research output: Journal contributionsJournal articlesResearchpeer-review

Authors

  • Rike Schwarz
  • Nico Eisenhauer
  • Christian Ammer
  • Pia M. Bradler
  • Orsi Decker
  • Benjamin M. Delory
  • Peter Dietrich
  • Andreas Fichtner
  • Yuanyuan Huang
  • Ludwig Lettenmaier
  • Michael Junginger
  • Oliver Mitesser
  • Jörg Müller
  • Goddert von Oheimb
  • Kerstin Pierick
  • Michael Scherer-Lorenzen
  • Simone Cesarz

Structural and biotic homogenization can result from forestry practices lacking promotion of canopy gaps and deadwood. This can lead to biodiversity loss and impaired ecosystem functions. Enhancing structural complexity (ESC) has been proposed to counteract these effects, but its impact on soil properties remains insufficiently understood. Overall, we hypothesize that ESC enhances soil abiotic properties, their spatial variability, and microbial functioning, with effects modulated by environmental context and increasing over time. Data were collected from 148 patches (50 × 50 m) in eight beech forests across Germany. In half of the patches, structural complexity was enhanced by felling 30 % of the basal area of living trees through two spatial patterns—aggregated (one large gap) and distributed (small gaps)—combined with leaving or removing deadwood (stumps, logs, snags). The other half served as controls, representing managed, homogeneous production forests. Soil carbon (C) %, nitrogen (N) %, and C:N ratio increased near deadwood. Soil microbial biomass and activity were significantly affected in three of eight forest sites, effects ranging from −30 % to +62 %. Higher soil water content was associated with increased microbial biomass, and greater understorey biomass correlated with a lower microbial respiratory quotient. However, no temporal trends were observed over five years. Although soil properties showed resistance to structural interventions, site-specific effects underline the importance of soil moisture and the understorey vegetation for microbial functioning. Further research building on our results is needed to develop practical forest management strategies to clarify how structural complexity may support soil functioning and ecosystem resilience.

Original languageEnglish
Article number106335
JournalApplied Soil Ecology
Volume214
Number of pages13
ISSN0929-1393
DOIs
Publication statusPublished - 10.2025

Bibliographical note

Publisher Copyright:
© 2025 The Author(s)

    Research areas

  • BETA-FOR, Forest soil, Mechanistic context dependency, Soil ecosystem functioning, Sustainable forestry
  • Biology
  • Ecosystems Research