The Gunung Leuser ecosystem on Sumatra is one of the largest carbon sinks in Asia. It possesses a stunning amount of biodiversity and is also a vital water catchment area for millions of people. However, the region is currently being confronted by logging, agriculture, settlement construction and other threats. The project supports the sustainable management of the ecosystem, reconciling protection interests with the interests of the population. It provides infrastructure to the protected areas’ administrative bodies and advises them on how to set up new structures and improve existing ones. New geographic information systems (GIS) bolster the planning and monitoring ability of the regional planning authorities. The project works together with the municipalities to develop land use plans designed to improve the living conditions of the local population and avoid conflicts with the protected areas. Measures such as agroforestry and communal forests also create potential income for the population.