8-3: RESPONSES TO CLIMATE CHANGE IN INTERACTION WITH OTHER STRESSORS
State of research. In addition to direct effects of climate change (increased temperature, dry summers), indirect effects (e.g. through increased use of pesticides) may occur. During the first phase of BiK-F we could show that pesticides have different effects on key species, depending on the temperature. Therefore basal ecosystem functions are directly and indirectly affected by climate change and secondarily occurring anthropogenic stressors. It remains however unclear to what extent these multiple stressors affect biodiversity, and whether species or communities can adapt rapidly to multiple stressors.
Hypotheses. 1. Direct (e.g. changes in temperature, soil moisture) and indirect (e.g. land use change) consequences of climate change have interactive effects on ecosystems. 2. Multiple stress resulting from climate change affects biodiversity and ecosystem functions, which depend on biodiversity. 3. Anthropogenic effects can be compensated by adaptation of selected key species or on the community level.
Transfer reference. Predicting the future impact of presently considered safe concentrations of fungicides and insecticides on ecosystems has a high public relevance. To clarify what hazards or damages may occur, established approaches to environmental risk assessment (e.g. under chemicals legislation) as well as newer approaches (e.g. the acquisition of ecosystem services) have to be considered. The results of laboratory and mesocosm study will be incorporated into environmental models, which may significantly improve the risk assessment of plant protection products in the EU.
Work program. In terrestrial model ecosystems (TMEs), long-term tests are conducted in a factorial design. Thereby, the impact of a pesticide in interaction with increased salinity - as a parameter to the salinisation of agricultural soils in arid climates - on soil communities is examined. In the experiments, directly (temperature, soil moisture) and indirectly climate-dependent, especially biotic parameters (pathogens, root-associated fungal society, genetic modifications of key species) will be recorded. Those TME tests will be performed in parallel in Germany and Portugal. The aim of the terrestric research is to develop recommendations for the protection of soil quality under conditions of climate change.