 Research in Theme II concentrates on the physical and chemical properties of the environment, and how these affect the living organisms in an ecosystem.The spatial and temporal scale ranges from fluxes at the molecular level to the reconstruction of Quaternary climate change in different continents.Research related to human effects on ecosystems includes the fate of chemical pollutants in the system, CO2 sequestering, nutrient fluxes and soil fertility and the effects of land use on erosion and desertification.