TheImprovement ofTropical and Subtropical Rangelands

INTRODUCTION 15
protein per hour of labor than does pastoralism. On the other hand,
ranching requires vastly greater inputs of energy, and expenses incurred
in connection with fencing, water development, brush control,
revegetation, grazing management, and selective breeding are substantial.
Pastoral systems represent the principal form of rangeland utilization
in Africa and Asia. They involve significant social adaptations
to the movement of livestock or wildlife from one location
to another in relation to the availability of forage and water. The
rangelands utilized are seldom privately owned, and mechanical and
chemical inputs are seldom prominent. The systems are labor intensive.
It has been estimated that livestock and wildlife support
some 30-40 million pastoralists, and the animals and animal products
associated with pastoral systems are critical to millions of other
individuals in settled communities (International Institute for Environment
and Development and the World Resources Institute, 1987).
The importance of livestock in pastoral systems exceeds their
value as sources of milk, meat, blood, and hides. Livestock often
represent a means of accumulating capital and, in some societies, are
associated with social status. They are assets that can reproduce
and that can be liquidated should cash be required. In addition to
supporting livestock, rangelands serve as sources of other significant
economic products: bushmeat, fruits, berries, nuts, leaves, flowers,
tubers, and other food for human populations, as well as medicinal
plants, building materials, thatch, fencing, gums, tannin, incense,
and other products important to the economies of rural populations
(Sale, 1981; National Research Council, 1983; Malhotra, Khomne,
and Gadgil, 1983).
The importance of rangelands as sources of bushmeat and vegetable
foods for human populations deserves special attention. These
foods are derived from species that are well adapted to the environmental
peculiarities of the regions in which they are found. Hence,
such foods are often available in the event of crop failure or substantial
losses of livestock. Even during periods with average rainfall,
satisfactory crop yields, and herd stability, such foods constituted a
significant part of local diets. Indeed, in many societies, the offtake
of wildlife from rangelands exceeds that of livestock in importance.
In 1959, for example, the sedentary and pastoral peoples of the
Senegal River Valley in West Africa relied upon fish and wildlife
for over 85 percent of the meat that they consumed (Cremoux,
1963); native plants were of equal or greater importance. Since