Degradation of natural resources has become a serious challenge in rangelands, bearing negative impacts on the pastoral ecosystems, livestock production and livelihoods (Vetter 2005; Kassahun 2008). In Namibia, the driest country of sub-saharian Africa (Hutchinson 1995) 45 per cent of the national land area can only be used as rangeland (Mendelsohn 2003). Many Namibians are pastoralists, whose livelihoods mainly depend on natural rangeland vegetation and water resources. 43 per cent of Namibia’s land surface is used by 90 per cent of the population under communal land tenure (Dewdney 1996; Seely 1998). This socio-economic importance makes the sustainable use of the rangeland essential (Kassahun et al. 2008). Furthermore northern Namibia will be heavily affected by climate change (Beyer 2001). Integrating local and scientific environment perception, decision-making processes of the local land users and the impact of land use practices on vegetation dynamics into ecological research becomes increasingly important in today's complex web of social, ecological and political changes. This thesis develops an integrated approach focusing on ecological aspects in a social-ecological rangeland system in Northwestern Namibia.