Mosses contribute significantly to ecosystem productivity in pristine ecosystems like arctic tundra and tropical cloud forests, and most mosses are colonized by cyanobacteria that fix atmospheric nitrogen, thereby transforming it into a plant available form. Together, they can contribute more than half to total ecosystem N input in these pristine ecosystems. But to date, we do not know how nitrogen fixation in mosses will be affected by climate change, and thus, how the nutrient budgets of pristine ecosystems will be altered. In our new project funded by the Independent Research Fund Denmark ( and in collaboration with the Metcalfe Lab at Lund University, my lab will link biogeochemistry with ecology in contrasting ecosystems (Arctic vs. Tropics). We will assess nitrogen fixation under climate change scenarios in mosses collected along our arctic and tropical field sites. Hence, our data will allow to predict climate change effects on this crucial ecosystem function. For more details and contact information, please visit my homepage ( or follow me on twitter (@kathrin_rousk) for the latest research updates.