Environmental Engineering Reference
In-Depth Information
according to its tangible outputs (direct-use values), for example, the value
of the crop harvested, and where no indirect-use value of the ecosystem
exists, this valuation is perfectly acceptable. A production function can
then be developed to quantify the components of an ecosystem that con-
tribute towards the production of a good. In doing this, an estimate can be
made of the relative values of each of the inputs into production.
If a comparison is being made of the relative values of dif erent forms of
ecosystem use, it is imperative that all components of the production func-
tion are included in the analysis. For example, the production of livestock
and/or game in a particular area (
Q
), will require inputs of labour (
L
) and
forage (
F
). However, as was shown by Scoones (1992), the productivity of
livestock may also be dependent on factors such as the physical conditions
of the environment. Thus, in the case of Scoones' research, livestock pro-
ductivity was also af ected by soil type. If this latter factor is overlooked and
excluded from the livestock production function, the result will be an under-
valuation of the soil value (
S
), giving it the incorrect production function:
Q
5
f
(
L
,
F
)
rather than:
Q
5
f
(
L
,
F
,
S
)
.
If this production function were dei ned incorrectly in this way, no value
would be attributed to the presence of a specii c type of soil cover.
In addition, Scoones (1992) showed that the output of livestock
amounted to much more than simply its meat production. Included in the
values of livestock in his study were milk production, manure production
and the provision of labour. By including these output variables the value
of livestock signii cantly increased. It can therefore be seen that care must
be taken to ensure that all inputs into production are incorporated in a
production function, and that all the outputs from an activity are also
included, if an accurate valuation of the input resources is to be obtained.
Indirect- use values
In agriculture and forestry, which involve the primary production of
goods, in addition to providing direct-use goods, in many cases the eco-
system may provide an ecological function that has an indirect value in
supporting the production of marketable goods. The ecological function
is then a 'factor input' in the production process. As already discussed, the
ecological function may have an important input for activities that are far
removed, either spatially or temporally, from the production process, and
