Effects of Mechanical and Chemical Methods of Bush Control

Most parts of arid and semi arid savanna rangelands are degraded and degradation poses a risk to the ecosystem integrity of these fragile dryland environments. One of the most visible forms of savanna degradation is bush encroachment, a term that describes the invasion of whole landscapes by few of several indigenous woody species, which flourish opportunistically under inappropriate management of rangelands. Bush encroachment results in an imbalance in the ratio of grasses to bush, a decrease in biodiversity and a decrease in the carrying capacity, which cause severe economic losses to ranchers. About 60% of Namibia's land surface and all its savanna rangelands are degraded by inappropriate rangeland management, such as over-utilization, prevention of fire and the elimination of mega-browsers. Total grass density was greatly higher in chemical and mechanical than in control treatment. Total woody density was significantly greater in the control than chemical and mechanical treatments. This book was written for ranchers, farm managers, ecologists, conservationists, policy makers and rangeland scientists.