TheImprovement ofTropical and Subtropical Rangelands

OVERVIEW 9
of approaching this objective is to encourage herders to control their
grazing. However, herders are usually more sensitive to the management
of their grazing resources than are outsiders, and ifovergrazing
occurs, it is because other conditions make misuse of resources necessary
for survival.
Animals can be used to upgrade rangelands if their use is carefully
managed. Cattle, sheep, goats, and other livestock prefer somewhat
different forages, so they can be grazed together or selectively
in sequence. Grazing animals may encourage the dominance of unpalatable
species depending on how grazing occurs. This selectivity
is especially notable with some trees and shrubs. Improved grazing
management may not eliminate these unpalatable species; therefore,
other methods for removing them must be found.
Demands of the urban areas also generate pressures on rangelands.
For example, many countries encourage the development of
crop production in marginal areas to increase the amount of food
available to feed a burgeoning urban population. Ways should be
found to raise the efficiency of food and fodder production in areas
where high productivity is pOBBible, rather than expanding into
marginal areas where crop productivity is low but grazing is more
appropriate and dependable.
This report addresses issues of socioeconomic context, regional
&B8e8Bment and site evaluation, approaches to management, and criteria
for plant selection in intensive rehabilitative efforts. The case
studies provide further information regarding these issues, as well as
descriptions ofprojects that have succeeded as a result ofbroad-based
analysis and sensitivity to environmental and social context.
REFERENCES
Breman, H. and C.T. deWit. 1983. Rangeland productivity and exploitation in
the Sahel. Science 221:1341-1347.
National Relearch Council. 1981. EnWonmcntal D",.adoIion in MtJUritaniG. National
Academy Preu, Wuhincton, D.C., USA.
National Raearch Council. 1983a. AfI"O/oruby in tJac W.., A/riC4ft SoIW. National
Academy Preu, WuhinlkJn, D.C., USA.
National Relearch Council. 1983b. EnWonmcntal CMta,. in tJac W." A/riC4ft SWl.
National Academy Preu, WuhinlkJn, D.C., USA.