Environmental Engineering Reference
In-Depth Information
research has concentrated on the valuation of direct-use resources. Above
all, attention has also been placed on valuing tropical forest resources, and
although studies have been made across the globe, there has been a dispro-
portionate interest in Latin American forests (Godoy
et al., 1993).
Phillips et al. (1994) compared the usefulness to the indigenous popu-
lation of six l oristically distinct tropical forest types in south-east Peru.
They attempted to estimate the use values of each forest type through a
series of questionnaires to the local people about the relative importance
of the dif erent forest plant species. However, the results were produced as
a rating of dif erent values of the forest products and no monetary value
was placed on the products, thus making quantitative comparisons with
other forest values or uses impossible. In a very similar study, Toledo et
al. (1995) evaluated the usefulness of plant species in a Mexican tropical
forest. Through questioning and working with the local population, they
evaluated the number of non-timber products that were used from the
forest. Over 3000 products were identii ed, but as with Phillips et al.
(1994),
no attempt at placing an economic value on these products was made.
A number of studies have, however, attempted to put a monetary value
on the non-timber forest resources. Peters et al. (1989) estimated the
economic value of non-timber plant products of a small (1 hectare) area
of Peruvian tropical forest. Their calculations were based on empirical
i eldwork estimating the amount of standing vegetation in the forest, and
on the prices of the products in the local market. To arrive at a valua-
tion i gure, they multiplied the standing inventory of certain non-timber
forest products by the local market price, thus carrying out a very simple
cost-benei t analysis. A value of US$420 ha
1
year
1
for the products was
estimated, however, as was pointed out by Godoy
et al. (1993), Peters et
al. failed to take into account that the local market prices are a rel ection
of the supply of the produce. Supplying the market with all the forest
resources would result in a decrease in market prices. In addition, the
study did not provide an accurate value of the entire forest resources, since
only plant products were valued, with faunal products being completely
disregarded. Pinedo-Vasquez et al. (1992) estimated the potential value
of six fruits and derived a total value of the forest products of US$20 ha
1
year
1
. Hecht (1992) estimated the opportunity cost (that is, the value of
the other products lost from using the forest in this way) of using forests
for livestock-rearing in western Amazonia. The i nal value derived was
dependent on the size of the area over which the extraction was carried
out, and ranged from US$5-16 ha
1
year
1
. Nations (1992) considered the
value of only three plant products from a Guatemalan forest and derived
a value of US$10 ha
1
year
1
and Anderson and Ioris (1992) estimated a
1
year
1
for only three plant species in tropical Brazil.
value of US$79 ha
