Environmental Engineering Reference
In-Depth Information
value of
Q
with a change in the environmental input,
A
,
cannot be directly
obtained. This is often the case in developing countries where the use of
the environment is to support a subsistence lifestyle. Since the products do
not pass through a market, the benei ts accrued do not have a monetary
value. In these cases, an accurate comparison in economic terms between
dif erent forms of the land-use is dii cult to make, given the absence of
comparable systems. To overcome this problem, the output of the ecosys-
tem under dif erent uses must be considered in common terms. The stand-
ard approach to the valuation of products is in monetary terms and so if
goods produced by an ecosystem do not have a monetary value, a proxy
must be found for this value. In the case of land-use in Tanzania, land-
users include nomads who utilize the natural resources (
Q
), such as vegeta-
tion and game, for their own consumption to sustain a subsistence-level
lifestyle, and who do not generally trade goods in the marketplace. Many
of these products may have no market value, so to obtain an approxima-
tion of their 'worth', an estimate can be made of the market value of an
'equivalent' good.
In general terms, if this solution is unfeasible, the alternative is to i nd a
substitute or complementary resource between
S
and one of the marketed
inputs
x
1
. . .x
n
. Both this and the previous solution require a detailed
knowledge of the ecological interactions between inputs and outputs of
goods. It can be realized however, that in a system such as nomadism, this
latter solution is implausible since there are no marketed inputs into the
production of the goods.
The following section will illustrate, through the use of examples, the
employment of the production function approach in estimating resource
values for forest and/or savanna ecosystems.
Worked examples
Direct-use values: calculating the direct-use value of agricultural cover
The direct-use value assessed here is the amount of land available for live-
stock production and for wild fruit production. A hypothetical situation is
set up whereby a i xed area of land can either be used to produce livestock
(if it is deforested) or wild fruit (if it is forested). A production function is
estimated for both products based partially on the area of land available
for their production, and the optimal level of land cover of both types of
land is identii ed, in terms of proi t maximization.
Step 1: Identifying the production function for livestock
The amount of
livestock produced is (partially) dependent on the amount of land avail-
able for grazing. It will also be dependent on other factors such as the
