TheImprovement ofTropical and Subtropical Rangelands

THE NA.TURE OF TROP/OAL AND SUBTROPIOA.L RANGELANDS 35
this has destroyed the subsistence base that supported the coping
strategies of local populations, and has reduced the range of economic
options' available to them. Wildlife, honey and beeswax, gums
and resins, cordage, tannin, and medicinals are among the economic
products lost through the degradation of environmental systems in
Africa and Asia.
Characteristically more subtle, but equally important, impacts
on socioeconomic and environmental systems result from destructive
modifications of indigenous systems of values, ideology, knowledge,
and social organization. An unfortunate consequence of past efforts
in international development is that so much attention was directed
toward the transformation of what are now belatedly recognized to
be critically important social adaptations, without corresponding
effort being made to understand the context or consequences of the
changes promoted.
In addressing issues of range management in the tropics and
subtropics, many of the most important clues as to appropriate actions
for governments and development agencies reside in the analysis
of traditional adaptations to local environmental systems. Growing
awareness of the importance of traditional adaptations is contributing
to a shift of emphasis by governments and development agencies
from open-field cultivation and plantation forestry to more biologically
complex agroforestry or agro-sylvo-pastoral systems (National
Research Council, 1983a). The growing interest in camel husbandry
in the drylands of Africa and Asia similarly reflects pre-colonial
strategies of rangeland utilization. In West Mrica, for example,
camel-based livestock systems were commonly replaced by cattlebased
systems by colonial administrators unfamiliar with the characteristics
ofthe drylands of West Mrica in relation to the requirements
of cattle. By so doing, these administrators contributed greatly to
the current environmental emergency in Africa (National Research
Council, 1983a). An overview of selected Mrican and Asian pastoral
adaptations is contained in Douglas Johnson's The Nature 01
Nomadism (1969).
NOTES
1. In this report, the terms "tropics- and -tropical- are expanded to
include the sllbtropics (Tropical and Subtropical Steppe, Tropical and Subtropical
Desert, Mediterranean or Dry Summer Subtropical, and Humid Subtropical
climatic regions) as well.
2. Moisture indexes provide expressions of climate derived from monthly
rainfall and evaporation, with the estimate of evaporation baaed upon measures