The social-ecological system of the Lake Manyara basin (Northern Tanzania), a UNESCO Biosphere reserve (BR) suffers from social-economic and environmental problems due to decreasing water levels, erosion and land and water use conflicts. We propose an integrated assessment of the social-ecological interactions of the area to support future sustainable management. Within the Drivers-Pressures-State-Impact-Response (DPSIR) framework an integrated literature review and several methods of knowledge collection were combined to identify future management priorities and challenges. During focus groups with farmers and pastoralists, stakeholders confirmed the role played by land use changes as driver and pressure in the landscape, e.g. through increased erosion rates and siltation of the lake. Moreover, economic and social issues were identified as prominent factors being influenced by, or influencing these processes. These statements match the scientific literature. During participatory mapping exercises different spatial and resource allocation perceptions appeared amongst pastoralists and farmers. The multidisciplinary approach proved to be useful to acquire an integrated and comprehensive understanding of the state, challenges and opportunities of Lake Manyara BR, to feed into a decision support system in service of an integrated management plan. Our assessment suggests that improved water governance in a multi-actor approach (with a focus on distribution of benefits, rights, and a specific role of the water authorities) should be a priority for future integrated management strategies. Also, awareness raising amongst decision makers, scientists and local communities is needed to demonstrate the advantages of an integrated approach. And finally, visible and fair mechanisms to share conservation revenues should be designed in a way that local benefits can be obtained together with incentive mechanisms for co-management and conservation.

Department of Earth Sciences University of the Western Cape Private Bag X17 Bellville 7535 South Africa

KU Leuven Ecology Evolution and Biodiversity Conservation Charles Deberiotstraat 32 box 2439 3000 Leuven Belgium

Nelson Mandela African Institution of Science and Technology PO Box 447 Arusha Tanzania

Royal Belgian Institute of Natural Sciences OD Nature CEBioS Programme Vautier Straat 29 1000 Brussels Belgium

Royal Belgian Institute of Natural Sciences OD Nature CEBioS Programme Vautier Straat 29 1000 Brussels Belgium; KU Leuven Ecology Evolution and Biodiversity Conservation Charles Deberiotstraat 32 box 2439 3000 Leuven Belgium; Hasselt University Centre for Environmental Sciences Research Group Zoology Biodiversity and Toxicology Agoralaan Gebouw D B 3590 Diepenbeek Belgium; Zoology Unit Finnish Museum of Natural History P O Box 17 FI 00014 University of Helsinki Helsinki Finland; Department of Botany and Zoology Faculty of Science Masaryk University Kotlářská 2 611 37 Brno Czech Republic

School of Geography Earth and Environmental Sciences University of Plymouth UK

TANAPA P O Box 3134 Arusha Tanzania

Trias P O Box 12005 Arusha Tanzania

Université Libre de Bruxelles Département de Biologie des Organismes Écologie des Systèmes et Gestion des Ressources Campus du Solbosch CP 169 Avenue Franklin D Roosevelt 50 B 1050 Brussels Belgium; Vrije Universiteit Brussel Biology Department Pleinlaan 2 1050 Brussels Belgium; Open University of the Netherlands Valkenburgerweg 177 6419 AT Heerlen the Netherlands; Hasselt University Centre for Environmental Sciences Research Group Environmental Biology Agoralaan Gebouw D B 3590 Diepenbeek Belgium

University of Zimbabwe Lake Kariba Research Station P O Box 78 Kariba Zimbabwe

References provided by Crossref.org