Environmental Engineering Reference
In-Depth Information
Total (forestry)
4184
Intensive cattle ranching on
ideal pasture
148
<2960
Not sustainable
Total (ranching)
<2960
Source
: After Peters et al. (1989).
Notes
:
a
After labour and transport.
b
Twenty-year discounted.
Efforts have been made to develop the idea of ecotourism to provide additional income
for forested areas. Tourists are encouraged to visit an area to view the beauty of virgin
tropical rain forest (Plate 28.4). Although still on a small scale in countries such as Costa
Rica, Belize and Ecuador, and not without its own problems, it does represent an
additional source of hard currency if correctly operated. The benefit here is that income is
generated at the local level through guides, transport and accommodation, with no major
disturbance of the forest.
CONCLUSION
The humid tropics are a sensitive environment. They occupy the hotter parts of the world
where solar energy is absorbed and transferred towards deficit parts of the globe.
Precipitation is generally high, with a dry season of variable length. Most of the soils
forming under rain forest conditions are relatively poor, with nutrients rapidly recycled
and being stored in the biomass rather than in the soil. The natural vegetation of the area
is a biologically rich forest with characteristic layers of growth, from the upper canopy of
the tallest trees down to the dense vegetation of the forest floor. These conditions provide
a variety of habitats for plants and animals. The number of species found in the average
rain forest is far greater than anywhere else on Earth.
For a variety of reasons, these forests have suffered major clearance, especially in west
Africa, southern India and parts of eastern Asia. The surviving areas, dominated by Latin
America and central Africa, are still experiencing great pressures for land clearance,
leading to dramatic losses of biodiversity and habitat.
In theory it should be possible to maintain forest cover, given sufficient investment in
agriculture and forest management and a well enforced network of protected areas.
Inevitably there will be some further losses of forested areas due to social and economic
difficulties, international disputes and problems of education. What needs to be stressed
is that such a valuable global resource must not be destroyed. A practical form of
sustainable management and control is needed.
