|
The
Amazon Rainforest
The
Amazon is a rainforest in South America. It encompasses 1.2
billion acres (7 million km²), with parts located within
nine nations: Brazil (with 60% of the rainforest), Colombia,
Peru, Venezuela, Ecuador, Bolivia, Guyana, Suriname and
French Guiana. This forest represents over half of the
planet's remaining rainforests. States or departments in
four nations bear the name Amazonas for the Amazon.
The
forest lies in a basin drained largely by the Amazon River,
with 1100 tributaries. This basin was formed in the
Palaeozoic period, between 500 and 200 million years ago.
Biodiversity
The
region is home to ~2.5 million insect species, tens of
thousands of plants, and some 2000 birds and mammals. The
diversity of plant species is the highest on earth with some
experts estimating that one square kilometer may contain
over 75,000 types of trees and 150,000 species of higher
plants. One square kilometer of Amazon rainforest can
contain about 90,000 tons of living plants. This constitutes
the largest collection of living plants and animal species
in the world. One in five of all the birds in the world live
in the rainforests of the Amazon. To date, an estimated
438,000 species of plants of economic and social interest
have been registered in the region with many more remaining
to be discovered or cataloged. (Note: Brazil has one of the
most advanced laws to avoid biopiracy, but enforcing it is a
problem.)
Environmentalism
There
has been concern among environmentalists for many years,
regarding the deforestation of the region, stemming mainly
from the fact that more than one fifth of the Amazon
Rainforest has already been destroyed; and much more is
threatened. Not only are environmentalists concerned about
the loss of biodiversity which will result from the forest's
destruction, they are also concerned about the release of
the carbon which is held within the trees -- this carbon
will accelerate global warming.
The
deforestation of this area in the 1980s was largely
considered catastrophic. Yet, in 1996, the Amazon was
reported to have shown a 34 per cent increase in
deforestation since 1992. A new report by a congressional
committee says the Amazon is vanishing at a rate of 52,000
square kilometers (20,000 miles²) a year, over three times
the rate for which the last official figures were reported,
in 1994.
Environmentalists
commonly stress the fact that there is not only a biological
incentive to protecting the rainforest, but also an economic
one. One square kilometer in the Peruvian Amazon has been
calculated to have a value of $682,000 if intact forest is
sustainably harvested for fruits, latex, and timber;
$100,000 if clear-cut for commercial timber (not sustainably
harvested); or $14,800 if used as cattle pasture.
The
Força Aérea Brasileira has been using EMBRAER R-99
surveillance aircraft, as part of the SIVAM program, in an
attempt to halt rainforest molestation. At a conference in
July 2004, scientists warned that the rainforest will no
longer be able to absorb the millions of tons of greenhouse
gases annually, as it usually does, because of the increased
pace of rainforest destruction. The large-scale cutting of
trees begins a cycle in which farmers burn leftover jungle
scrub to replenish the soil, which releases huge amounts of
carbon dioxide (200 to 300 million tons in 2003) into the
atmosphere, that are in turn absorbed by the rainforest.
9,169
square miles of rain forest were cut down in 2003 alone.
|