Environmental Engineering Reference
In-Depth Information
and against other forms of land-use in Tanzania has enabled changes to
occur. Political discrimination against nomadic pastoralism and hunter-
gathering has led to the belief by many that this form of lifestyle is
backward, primitive and economically unproductive. Pastoralism and
hunter-gathering is predominantly seen as an inferior and unproductive
use of the land. That much of the land is common land enables those
engaged in formal agricultural practices that require privatized land,
greater economic status and political control over people involved in more
traditional land management practices. This gives the latter groups little or
no control over the land-use. In this context, and with the gathering body
of evidence that settled agriculture is an ecologically, and thus economi-
cally, unsustainable land-use option in semi-arid land, there is a clear need
for an accurate assessment of the full values of each form of production.
More precise estimation in monetary terms of the value of each system
in supporting production will allow a direct and fair comparison of each
form of land-use to be made.
Ecosystem values
In the past few decades, attention has been increasingly turning towards
recognizing the fact that natural ecosystems such as forest and savanna
provide a wide range of products that are highly valuable but may not
have an immediately apparent market value (Scoones et al., 1992). It
is realized that failure in the past to include these types of ecosystem
values in analyses of land-use has led to the undervaluing of ecosystems
(Swanson and Barbier, 1991). Scientists and to a certain extent policy-
makers are therefore now recognizing that if the total economic value of
an ecosystem is to be realized, a monetary value must be assigned to the
resources in question, enabling them to be 'counted' in an estimation of
the ecosystem's worth.
The lack of a market value, and thus underestimation or complete
absence of the resource's value, may be for one of two reasons. First,
the resource may not be one that is exchanged in the marketplace. For
example, hunting and gathering of wild products for subsistence living will
directly use many natural resources but these may be consumed directly
rather than sold (Campbell et al., 1997). In the case of livestock, animals
may be used for products other than meat that do not have a market value,
such as transport or labour (Scoones, 1992). Second, the value of the
resource may be in supporting the production of other goods rather than
through its own direct utilization.
The remainder of this section describes in detail the dif erences between
dif erent forms of ecosystem products. These products can be separated
into three categories, according to their type of use.
