TheImprovement ofTropical and Subtropical Rangelands

can be restored to the world's rangelands. The areas are vast, and
measures that could improve them are characteristically costly in
terms of labor or capital. Rehabilitation efforts are further affected
by social and political considerations.
This report takes a broad perspective. It focuses on the principles
of range management by describing various indigenous adaptations
to specific Old World ecosystems, and by discussing how
experience elsewhere can complement indigenous knowledge. It also
outlines techniques for assessing the condition of rangeland vegetation.
Although the report to some extent draws upon North American
experience, its authors fully acknowledge the limitations of this
experience in addressing degradation problems in the tropics and
subtropics. Nevertheless, this experience can usefully illustrate the
application of basic principles, which the panel hopes will stimulate
local research. What is needed is a basic appreciation of indigenous
adaptations, a knowledge of local socioeconomic and environmental
change over time, and innovation solidly based on an understanding
of ecological principles.
Rangelands that are "common property" are particularly difficult
to manage because of the frequent breakdown of organizations
and institutions responsible for their welfare. Successfully managed
rangelands characteristically benefit from some form of local control.
Therefore, case studies that describe successful approaches are also
provided.
This report complements More Water lor Arid Lands, published
by the National Academy of Sciences in 1974, which describes littleknown,
but promising, small-scale technologies for the use and conservation
of scarce water supplies in arid areas. The ImprotJement
0/ Tropical and Subtropical Rangelands is the third report to appear
in the series Resource Management for Arid and Semiarid Regions.
Other titles include Enwronmental Change in the West A/rican Sahel
and Agr%restr,l in the West A/rican Sahel.
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