Quantification of biodiversity loss and convergence of trait responses to pesticide exposure in agricultural areas

• Applicants: Dr. Jörn Buse; Professor Dr. Henner Hollert; Professor Dr. Ralf B. Schäfer
• Subject Area: Ecology of Land Use
• Term: from 2015 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 270296709

Pesticides represent an important stressor for ecosystems in agricultural landscapes. Despite their relevance, a comparatively low amount of studies has examined the effects of pesticides in real world ecosystems. Quantification of the effects of pesticides on biodiversity has been hampered by confounding factors such as sedimentation and nutrient input that co-occur with pesticides in areas with intensive agriculture. Areas with agriculture that has minimal pesticide use can be found in Eastern European countries, where traditional low-intensity agriculture persists in rural areas. Ecosystems adjacent to these fields receive inputs of suspended sediments and nutrients, but only minimal pesticide input. Moreover, past studies on pesticide effects on invertebrate communities were either restricted to the aquatic or the terrestrial ecosystem in the agricultural landscape. We will conduct a field study in a region of Romania with a gradient in pesticide use to determine a potential biodiversity loss and effects on sensitive species with reference to agricultural streams that receive no or minimal pesticide input. In addition, we will compare the responses of the aquatic invertebrate community to those of hygrophilic beetles in the riparian zone. We hypothesise a trait convergence of communities in streams and the riparian zone in response to pesticide exposure. We will sample stream invertebrates and the hygrophilic beetle community along a gradient of pesticide exposure. In addition, cholinesterase activity as a biomarker for pesticide exposure will be determined in widely occurring organisms. Given their well-known immunocompromising effects, parasites such as microsporidia will be analysed in amphipods and other dominant taxa collected at the sampling sites. Selected insecticides and fungicides will be analysed in water and sediment samples. Finally, the ecosystem function of organic matter breakdown will be measured in the aquatic and terrestrial habitat to assess the similarity in the functional response. Overall, this study will deliver important insights on the effects of pesticides in aquatic and terrestrial communities and will allow for the quantification of potential biodiversity losses.

• DFG Programme: Research Grants