rangelands represent the major land resource in most developing countries. Characterized by low and uncertain levels of rainfall, high desiccating factors, and periodic drought, these uncultivated lands can be grazed and browsed by both wild and domestic animals. In the developing countries of Africa, rangelands comprise over half the land area and support a large human population who are dependent, in one way or another, on grazing livestock. The livestock account for a significant percentage of the gross domestic product of these countries. These lands also produce forage for wildlife and are an important source of critical fuelwood, which provides the energy source for around 80 percent of the African population. In most African rangelands, livestock grazing and at times wildlife use represent the only existing possibilities for support of human populations. Most of the attention focused on the effects of human population increase in developing countries is directed to urban centers and farming areas. Yet demographic pressures affect rangeland areas with at least equal intensity, and in the rangelands the critical relationships among population increase, environmental degradation, and human welfare are much more dramatically evident. The growth of human populations affects arid and semiarid rangelands in two ways: The first involves increases in the size of the pastoral populations themselves-those who live on the rangelands and are directly dependent upon the grazing resource. The carrying capacity of these lands for people is directly related to their carrying capacity for livestock. Increased numbers of people lead to increased numbers of livestock, which, in turn, lead to overgrazing, degradation of the range resource, and ultimate reduction of the ability of these