干旱区生态环境知识资源中心

A national-level land degradation risk monitoring system identified an important grazing area in central northern Namibia as an area at risk of environmental change. A time series analysis of primary indicators used for this monitoring system for the period 1971-2001 shows that increase in livestock pressure and high rainfall variability are potential threats. The study presented here compares these national-level results with those obtained by interviewing local farmers about their perceptions of past and present states of the environment in the grazing area. A majority of interviewees claim that grazing resources have decreased and deforestation has taken place since they first arrived. Increased livestock numbers and decreasing rainfall were thought to be major factors leading to perceived environmental changes. These perceptions support conclusions from national monitoring. The interviews reveal a more complex picture indicating that decreasing availability of grazing outside the study area, improved road access to the area, provision of permanent access to water, fencing of large areas of the commons, and prolonged dryness, in combination with non-adaptive land management, are major factors causing environmental changes. It is suggested that local knowledge contributes a sound basis for development and assessment of national monitoring initiatives. (c) 2006 Elsevier Ltd. All rights reserved.