摘要：We investigated vegetation dynamics in relation to livestock grazing as perceived by pastoral farmers in differentregions of Botswana. A structured questionnaire was used to collect farmers' understanding of vegetation changes and causeswithin three different grazing lands. The pastoral farmers' description of dominant vegetation differed significantly both at thelocal and district level, which suggests that rangelands consist of patches dominated by different grasses and woody vegetation.Most pastoralists indicated that grass composition has undergone changes, and unpalatable grasses such as Aristida congesta and Megaloprotachne albescens are increasing. The different factors perceived by pastoral farmers to cause changes in vegetationcomposition included rainfall, overgrazing, and fire. Bush encroachment is considered to be more common in communal grazingland than in ranches. According to pastoral farmers, the ranching system is less degrading to the environment and more sustainablefor livestock production than is communal grazing
