usually known as nonuse values, which are benefits that are unrelated to any
form of use. To illustrate the meaning of these concepts for agroforestry, direct
use benefits include revenues to farmers from the sale of agricultural and for-
est products and things such as provision of shade and protection from the
wind. Indirect use benefits encompass most of the ecological services provided
by forests preserved under agroforestry, such as watershed protection that may
indirectly benefit others in society. Option value is the value of preserving bio-
diversity and forests through agroforestry for possible future benefit such as
the potential pharmaceutical use of a species or substance or the development
of new crop varieties.
In addition, various groups in society (including farmers) may also derive
a benefit from the simple knowledge that ecosystems, forests, and biodiversity
are being protected by agroforestry systems when compared with more dam-
aging land uses. Economists call this an existence value. Society may also value
the fact that these ecosystems, forests, and biodiversity are being protected for
the use of others (altruistic value) or for future generations (bequest value). As
noted earlier, these nonuse values are not selfishly motivated and reflect con-
cern for others, for future generations, and for the environment in general.
The question is, How can these values of an agroforestry system be meas-
ured in economic terms? It may seem like an impossible task given the multi-
ple dimensions involved. But a number of techniques can be used to place a
monetary value on the various components of Figure 4.1, with some tech-
niques being more appropriate to estimate use values and others being partic-
ularly suited to measure nonuse benefits. Although estimating the total value
is necessarily a complex and time-consuming process, possibly involving a
74 II. The Ecological Economics of Agroforestry
Figure 4.1. Components of the total economic value of agroforestry.