Study of adaptations to external influences and the affiliation to trophic levels regarding the orders Ephemeroptera and Trichoptera in tropical rivers (Costa Rica).

Tropical rainforests are not only habitats for animals, plants and indigenous peoples, but also perform important ecosystem services with regard to climate regulation. As a result of their high biomass stocks, they store 50 % more carbon than forests outside the rainforest. The COBIGA project, which focuses on expanding the La Gamba biological corridor by reforestation, aims to connect isolated forest fragments and thus expand the biological corridor. But how do changes in cover and carbon sequestration affect aquatic ecosystems? One way to address this question is to study aquatic invertebrates, which, as consumers due to their different diets, play an important role in the recycling of particulate organic matter and provide information on water quality and the structural condition of inland water bodies. In addition to biodiversity and abundance, which should show the difference between open land and reforested areas, Fabian Vassanelli and Dominik Gallenberger are primarily concerned with their food web in their Master's thesis. Fabian Vassanelli focuses on the order Ephemeroptera, whose larvae (nymphs) include detritus feeders, filter feeders, grazers, herbivores and preditors, and which has 9 families with a total of 44 genera in Costa Rica. Dominik Gallenberger deals with the two orders Coleoptera (20 families with 94 genera) and Trichoptera (15 families and 48 genera), which together have a large number of different feeding forms. By means of isotope analyses of the marrow gut content, an insight into the food chain of benthic invertebrates of tropical flowing waters will be created. The research results will show how changes in the food chain of aquatic organisms are feedback coupled with terrestrial processes.