Environmental Engineering Reference
In-Depth Information
Plate 28.3
Subsistence agriculture on
the banks of the Amazon near Iquitos,
Peru. Cattle are grazing near by.
Photo: Peter Smithson.
IMPACTS OF DEFORESTATION
When rain forests are cleared we are losing more than a collection of trees because of the
implications which total clearance would have on the world environment. Here we will
concentrate on the main impacts, which can be summarized as (1) loss of species
diversity; (2) loss of natural resources; (3) environmental consequences; (4) possible
changes of climate on a local, regional and global scale.
LOSS OF BIODIVERSITY
As we have seen, rain forests are incredibly diverse in terms of the number of species
which grow there and of those which are dependent upon the forest for their survival. As
habitats are removed through clearance, so the number of individuals will decline. There
will be greater pressure on the surviving habitats and the remaining species will be forced
to live in a smaller area. As we have no clear idea of the number of species in the rain
forest it is hard to be precise about the rate of species loss. Estimates range from one
species becoming extinct every half-hour as a result of the destruction of rain forest to
