We focus on the analysis of agroecosystems, the understanding of their functioning and the development of sustainable land use in the tropics and subtropics. A major goal is the optimisation of matter cycles, whereby we consider plant-animal interactions, the mobilisation of soil-borne nutrients, the prevention of wind and water erosion, and the preservation of biodiversity. Current research projects in West Africa and South Asia address the transformation of agricultural practices under the influence of climate change and urbanisation, with a strong emphasis on inter- and transdisciplinary approaches.