Changes in Small Mammal Trophic Interactions (SMaTI) in response to land-use intensity and biodiversity

• Applicant: Dr. Julia Tiede
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 433087393

Species interactions are the drivers of ecosystem processes and determinants of ecosystem functioning in multitrophic communities. However, studies concerning the influence of land-use intensity on biodiversity and species-mediated ecosystem processes have often measured the numerical response of species or ecosystem process rates instead of empirically assessing interactions. Recent advances in DNA-sequencing offer new possibilities to examine a large variety of interactions in detail. The SMaTI project aims to empirically assess changes in trophic interactions and ecosystem process rates by small mammals (Eulipotyphla, Rodentia) in response to season, land-use intensity and biodiversity in grassland and forest. Small mammals play important roles for ecosystem processes in managed or natural ecosystems, such as seed predation and herbivory. Despite the great ecological impact of small mammals on plant (herbivore Rodentia) and invertebrate communities (carnivore Eulipotyphla), it is largely unknown how land-use intensity affects their diet. Changes in trophic interactions along the land-use gradient will be analyzed by metabarcoding of plant and animal DNA in stomach contents of mice, voles, and shrews. This detailed snapshot of the diet will be completed by information on the long-term resource use and trophic position provided by stable isotope analysis of muscle tissue. Changes in the contribution of small mammals to seed and invertebrate predation under different land-use intensities and changing management regimes will be assessed by a combination of cafeteria experiments and camera observations. This method allows the identification of consumers and calculation of per capita consumption of seeds and sentinel prey by distinct consumer groups. The proposed study is the first that aims to track changes in the diet of small mammals along a gradient of land-use intensity. The highly detailed data on trophic interactions will provide valuable insights into mechanism underlying dynamics in species composition and ecological processes in complex real-world ecosystems.

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