Climate Induced Biotic Interactions
During the last ten years aquatic insects, and dragonflies in particular, have been used as model organisms describing climate change induced shifts in the distributions of aquatic biodiversity. These studies have shown tendencies towards southern species expanding northwards, while northern and specialist species are declining or stagnating near their southern distribution borders. In recent years a special emphasis has been given to changes in predator-prey relationships and the interaction between northern species and northward spreading predators/competitive species.
Even though a broad body of literature has described the possible reasons for climate induced changes on the distribution of aquatic insects, few studies have been able to demonstrate these effects in-situ. As to date, no field study has demonstrated how a climate-induced invasion of a predator might act as an extinction driver of northern distributed species.
Using range-expanding predacious diving beetles and closely related prey species, I try to test for interspecific differences on prey selection and predator effect between these species. This is done via metacommunity studies along the range expansion border of several aquatic beetles at the Baltic coast. These studies are combined with different ex-situ prey selection and predator avoidance experiments.