Use of local knowledge for assessing vegetation changes in the Southern Gadarif Region,Sudan

The vegetation cover in Gadarif Region, Sudan, underwent drastic changes within the last 60 years because of the combined effect of anthropogenic and climatic factors. As a consequence, a large number of plant species are threatened or even became extinct, and vast areas are now deforested. The purpose of this study is to use the local knowledge as a tool to identify and describe patterns of vegetation changes associated with the introduction of mechanized rain‐fed agriculture in the southern Gadarif Region. Data were collected by interviewing 10 key informants and 41 large‐scale farmers. The results provided rich ethnobotanical knowledge and a clear historical perspective of vegetation changes including plant species which have disappeared, decreased and increased in the area. The main factors leading to changes in plant species composition and abundance were vegetation clearance, charcoal and firewood production, wood cuttings, grazing and recently herbicides application. Respondents acknowledged that grazing, duration of abandonment, length of cultivation period, amount and variability of rainfall, fire events and weed composition are the major factors determining succession on fallow land. Farmers showed interest to preserve some multi‐purpose woody species (e.g. Acacia senegal, Balanites aegyptiaca) in their land. Such species should be given priority in rehabilitation activities.