Land-use intensity mediated effects of microclimate on insect diversity

• Applicants: Professor Dr. Fabian Fassnacht; Professor Dr. Michael Staab
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; Ecology of Land Use
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 568815509

Intensive land use is contributing to habitat loss and ecosystem degradation, which threaten global biodiversity, particularly in grasslands that are home to diverse plant and insect communities. Most past research has focused on the direct effects of land use on insects, but indirect effects, such as changes in microclimate, have not been fully explored. How land use affects microclimatic niche space, and how this relationship moderates the negative impact of land-use intensity on insect diversity, is unknown. We will combine spatially highly-resolved microclimate data measured by thermal remote sensing with insect sampling and the measurement of thermal tolerances of insects to understand how land-use driven changes in microclimate relate to insect diversity and community assembly. We hypothesize that intensively-used grasslands will provide more narrow microclimatic niches and that different land-use components (mowing, fertilization, grazing), relate differently to microclimate. To comprehensively test this hypothesis, we will quantify the occurrence and diversity of insects in all 150 grassland plots with suction sampling (biocoenometer). At the same time, we will repeatedly survey surface temperatures at a high spatial resolution with drone flights to characterize microclimatic niches and to match insect samples with precise microclimate data. Using these surface temperatures and a range of covariates (e.g. plant cover, meteorological conditions) we aim to spatially characterize microclimate within and below the grassland canopy, as perceived by insects. To link thermal tolerance and resilience of insects to the microclimatic conditions they are exposed to, we will measure critical thermal maxima for a subset of insect species. These comprehensive and complementary data from remote sensing and insect ecology will help to disentangle the relationship between land use, microclimate and insect biodiversity in managed grasslands. Hence, the proposed research will considerably advance the understanding how different forms and intensities of land use affect biodiversity, which is one of the central questions of the entire Biodiversity Exploratories programme.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1374: Biodiversity Exploratories