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INTRODUCTION t 
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Identification of relevant descriptive populations (physiographic, 
climatic, and vegetative) is a necessary initial activity to establish a 
framework for operational program evaluations which may ultimately lead men 
to the implementation of management systems for efficient use of natural j an 
resource products and uses. Essentially, this activity is needed to "match" s ^ s 
management systems to inherent characteristics of wildland units potentially 
available for implementation of such systems. Then, if a management 
system warrants consideration as a means to increase the production and ^ ec 
use of a certain natural resource mix, but only limited wildland units a -^ 
can be "matched" for implementation, the system may be given low priority 
in future planning. 
The above-described activity is of particular importance in Arizona, 
where an assessment of potential management systems for achieving specified 
goals of increased water yield has been undertaken. This assessment 
involves the identification of "high potential" management systems, and, ^ 
once identified, a determination of the extent to which systems can be a ^ r 
imposed. The latter evaluation will decide, in part, the operational Q; p 
feasibility of such programs. me( ^ 
Specifically, considering the identification of vegetative populations, 
portions of wildland units that support forest density levels which may ^ol 
affect the yield of natural resource products and uses must be quantified g as 
to estimate the operational feasibility of a proposed management system. ^ ti 
Unfortunately, estimates of average parameters, as commonly derived, do 
not necessarily provide complete knowledge of vegetative characteristics, 
particularly with frequently "skewed" forest population parameters. In- ^ ma 
stead, another statistic, the portion of wildland units in a forest that Nat 
support arbitrarily defined minimum forest density levels that are associated 
with yields of natural resource products and uses would be useful to: y n ^. 
(a) set realistic limits for implementing systems, (b) judge the suit 
ability of wildland units for a management system, and (c) establish ^ n a 
priorities for operational programs among wildland units. Such a statistic 
can be obtained from solutions of forest stocking equations , which may be 
generated by applications of remote sensing techniques. 
by » 
A forest stocking equation describes the portion of a forest, ^ 
the dependent variable, that is stocked to an arbitrarily defined minimum 
forest density level, the independent variable (Ffolliott and Worley, 
1973). Forest density is a measure of the extent of crowding among 
individual trees on a forested tract of land. Expressions of forest t 
density include crown closure, basal area, number of stems, volume, etc. se ^ ( 
(Avery, 1967). lin , 
The development of forest stocking equations from source data obtained 
from conventional ground inventories has previously been reported (Ffolliott 
and Worley, 1973). In this paper, a study designed to develop forest ^ 
stocking equations describing the portions of wildland units in the forest