The course provides extended knowledge of processes across Arctic and Subarctic terrestrial ecosystems. It provides understanding of how ecosystem processes are regulated by abiotic and biotic factors, such as nutrient availability, the Arctic climate and plant-soil-organism interactions and its relationship to the ecosystem function. Particular focus will be on potential impacts of changes in climate on ecosystem processes and on feedback mechanisms from arctic ecosystems to the climate system. The course provides an overview of how controls and impacts on ecosystem processes depend on temporal and spatial scales. Excursions to various ecosystems and project work are included. The course is given by researchers at the Climate Impacts Research Centre and is located in Abisko, Lapland.