Project Details
Projekt
Trees in space and time – effects of ESBC measures on the complexity-diversity relationship in the forest landscape and on individual tree stress level
Subject Area
Forestry
Term
since 2026
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 459717468
In this subproject, we want to investigate the effects of silvicultural measures aimed at enhancing structural heterogeneity in forest stands on biodiversity and tree vitality. The starting point is the finding that while structurally complex stands (high within-stand complexity, alpha level) may benefit certain animal species, diversity at the landscape level (beta and gamma diversity) is more strongly promoted by heterogeneity, i.e., variation of different structures side by side. However, it remains unclear at which spatial scales such positive effects occur and whether negative effects, such as increased stress for edge trees, arise simultaneously. A key aspect is the distinction between complexity and heterogeneity. Measures intended to promote species diversity, such as gap creation, can diversify habitats but also pose risks such as fragmentation or increased stress on edge trees due to exposure to higher light, heat and evaporative demand. With more frequent drought and heat events, tree vitality may become increasingly vulnerable. To address these questions, the project combines structural analysis at different spatial scales ranging from 0.25 ha plots to landscapes of 1,250 ha, deriving heterogeneity and complexity patterns and their scaling behavior. We also aim to analyze individual tree competition and how gap exposure affects the vitality of edge trees by dendrochronological and carbon isotope analyses (δ13C) in tree rings to address potential drought stress retrospectively. The subproject is guided by four hypotheses: (1) ESBC reduces structural complexity at the stand level, but (2) increases heterogeneity at the landscape (beta) level, (3) raises stress levels of trees directly adjacent to intervention areas, and (4) individual tree stress strongly depends on gap size and orientation. Overall, our subproject aims at providing an integrated understanding of trade-offs between biodiversity promotion and tree vitality, thereby offering guidance for sustainable and climate-resilient forest management.
DFG Programme
Research Units
