The session opens contributions from studies of relationships between living organisms, ecological stoichiometry and biogeochemical processes/cycling in freshwater ecosystems. These relationships and dynamics are all affected by changes in atmospheric deposition, climate warming, and land use such as forestry. Hence, large scale environmental stressors affect the quantity, quality, and temporal dynamics of dissolved organic matter (DOM) and nutrients exported from terrestrial to aquatic systems. Recent research has shown that leaching of both inorganic nitrogen (N) and DOM affect the productivity and structural properties of lake food webs, as well as production and emission of greenhouse gases to the atmosphere. In addition many biogeochemical processes in aquatic ecosystems can directly affect or be affected by the overlying food web and these processes can have significant contributions to the food web dynamics.

In this session we welcome contributions from scientists in the fields of biogeochemistry, hydrology, ecology, and limnology, sharing insights and research questions on nutrient cycling and ecosystem dynamics and functioning in freshwaters. We expect topics for presentations to include factors determining nutrient leaching from both undisturbed and disturbed catchments, the implications of run-off patterns for nutrient availability and elemental stoichiometry in streams and lakes, and mechanistic processes related to nutrient and DOM retention and turnover in these ecosystems. The topics may also concern theoretical advancements in applications of stable isotope analysis in food web and microbial studies, and drivers of ecosystem biodiversity, productivity, surface water quality, and emission of greenhouse gases in freshwaters. Talks can be related to the effects of atmospheric deposition, climate or land-use change, and interactions between these stressors. Presentations on experimental, synoptic and modeling studies are welcome.