Lakes characterize the Arctic landscape accounting for up to 90% of the total land surface area. Collectively they may influence biogeochemical dynamics at regional and global scale and provide a variety of key ecosystem services, being critical habitats for unique species, atmospheric C sources/sinks and links of nutrients between terrestrial and marine systems. Nutrient inputs in Arctic lakes may be affected by changes in snow and vegetation cover and guano of migratory birds associated with climate warming, with implications on biodiversity, food web structure and functioning. Thus through field experiments and satellite data, the aim of this project is to test the hypothesis that the seasonal snow cover and abundance of migratory birds have a crucial role in determining C and N availability and fate in high Arctic lakes. Nutrient burial in sediments and soil, transfer along the food web and/or recycling into the atmosphere will be assessed. Samples for C and N stable isotope analysis and high-resolution satellite and field images for bird abundance, snow and vegetation cover will be collected in the area of Ny-Alesund, Svalbard. In addition short- and long-term decomposition experiments will be performed to evaluate the rate of nutrient release in water column. The project will develop a novel interdisciplinary approach applicable across the whole Arctic. Results will add valuable information to international research actions, including the European iCUPE and Terrestrial Ecology flagship NySMAC. They will provide important contribution for hydrological and ecological studies of the Arctic ecotone between terrestrial-freshwater habitats, and a necessary baseline of future monitoring and conservation plans. Datasets, maps and technical reports on methodologies developed during the project will be made available to the scientific community, being of interest for studies carried out in these extreme environments, which are also the most vulnerable to climate change.
