TY - JOUR

T1 - Inconsistent short-term effects of enhanced structural complexity on soil microbial properties across German forests

AU - Schwarz, Rike

AU - Eisenhauer, Nico

AU - Ammer, Christian

AU - Bradler, Pia M.

AU - Decker, Orsi

AU - Delory, Benjamin M.

AU - Dietrich, Peter

AU - Fichtner, Andreas

AU - Huang, Yuanyuan

AU - Lettenmaier, Ludwig

AU - Junginger, Michael

AU - Mitesser, Oliver

AU - Müller, Jörg

AU - von Oheimb, Goddert

AU - Pierick, Kerstin

AU - Scherer-Lorenzen, Michael

AU - Cesarz, Simone

N1 - Publisher Copyright: © 2025 The Author(s)

PY - 2025/10

Y1 - 2025/10

N2 - 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.

AB - 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.

KW - BETA-FOR

KW - Forest soil

KW - Mechanistic context dependency

KW - Soil ecosystem functioning

KW - Sustainable forestry

KW - Biology

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=105011061110&partnerID=8YFLogxK

U2 - 10.1016/j.apsoil.2025.106335

DO - 10.1016/j.apsoil.2025.106335

M3 - Journal articles

AN - SCOPUS:105011061110

VL - 214

JO - Applied Soil Ecology

JF - Applied Soil Ecology

SN - 0929-1393

M1 - 106335

ER -