TheImprovement ofTropical and Subtropical Rangelands

78 IMPROVEMENT OF TROPICAL AND SUBTROPICAL RANGELANDS
For example, highly saline rangelands may have been irrigated at
one time and later abandoned because of salt accumulation. Thus,
a general description of previous land uses, land use practices, and
their locations may be useful in understanding current problems.
Moreover, the successes and failures of the past may provide good
evidence ofwhat might be expected and how changes in management
alternatives might be developed during the project.
Livestock and WUdllfe
At the resource assessment level, it is necessary to produce a general
census of animal herds within the region. Information gathered
might include herd location, size, composition, general condition,
and seasonal movement. In addition, the forage preferences and consumption
patterns of the largest groups and their place in the local
economy should be noted. With this information, range resources
can be described in terms of forage demand, and the general economic
and social impacts of alternative animal management plans
can be projected.
INFORMATION ACQUISITION
Decisions concerning how the survey and other informationgathering
activities will be performed should be made at the outset
of the resource assessment. Although this will not affect the type
of information that is collected, it will determine, in part, how it is
collected and organized.
S1I1"Vey Approaches
Resource assessment might be approached in two ways: the
component approach, in which each land characteristic is mapped
individually, and the landscape or land systems approach, in which
land is viewed as an integrated whole and the units that are mapped
are more or less homogeneous. In both approaches, land characteristics
are analyzed together to derive an estimate of land capability.
Component Approach
In much of the world, including the United States, agencies have
been established to study individual resources (for example, climate
and soils) within the country, or have been assigned to manage