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The
forests carry out a fundamental
roll in the protection and
evolution of grounds.
In addition, they constitute
an important factor of climatic
control. |
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Through the centuries
it had accumulated tests about how
the human intervention can produce
innumerable Earth damages.
One of the forms
that that intervention assumes, the
deforestation, has seriously affected
the forests of the planet. About 10,000
years ago - before the beginning of
agriculture - that type of biome extended
on about 4,200 million hectares, the
two third parts of the terrestrial
surface. Today, in extensive regions
of Asia, Europe and North America
the natural forests had disappear,
and the deforestation threatens to
one of the most extensive forest,
the amazonian.
The deforestation,
which consists on the destruction
of forests by burning or cutting them,
goes accompanied by the technological
progress, that creates new and more
serious problems as well.
The fire and the
necessity to qualify the ground for
agriculture and the pasturing, devastate
great forest spaces, but in the long
term the grounds are eroded and impoverished
by the absence of protective natural
vegetation.
In America there
were great wooded extensions to the
arrival of the Spaniards. The action
of more and more destructive technologies,
did that at the present time only
one small part of the territory is
covered by forests. The rest was destroyed
to obtain firewood and wood of construction
and for the manufacture of furniture,
or simply burned to disassemble the
grounds that could be used in the
agricultural production. That way,
complete populations of certain species
were considerably reduced.
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Other trees served
like fuel in furnaces of mineral smelting.
The quebracho of Chaco were destroyed
to take advantage of the tannin, substance
used in the leather tanning. At the
beginning of the XX century the south
zone of this region began to change
its wooded appearance, to become a
barren and depopulated place.
In these times,
the most serious danger is the one
than threatens the Amazonia. This
jungle region, bathed by the Amazon
river and its affluents, counts on
a river basin of more than seven million
of km2, in territories of Brazil,
Peru, Bolivia, Colombia, Ecuador and
the Guayanas.
From the irruption
of the European colonizers to 1970,
0.5% of the amazonian forest had been
deforested; from that year to 1991
it was arrived at 10% (about 700,000
km2). The grounds are destined, in
general, to the farming operation
or the petroleum search and the extraction
of minerals, and also the future construction
of the great transamazonian highway,
of 3,000 km in length. It is predicted
that for year 2020, 78 dams will have
been raised, that will flood 100,000
km2 of this territory.
In this true lung
of the planet 80,000 vegetal species
coexist; 30,000 animals: 50% of the
biodiversity (number of species that
lives in a certain region) which has
the Earth. Many of those forms of
life are in serious danger now, by
the increasing destruction of their
habitats.
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destinies that occur to
the wood extract of a forest
are innumerable: from its
use like firewood to hulls,
pipes or musical instruments
that, for their manufacture,
require certain species. |
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The deforestation
creates new deserts
The presence of
the forest determines a constant interchange
of dioxide of carbon and oxygen between
the alive organisms and the atmosphere.
The plants consume carbon dioxide
and release oxygen; when they die,
it happens the opposite.
The disappearance
of forests, on the other hand, affects
the cycle of water, which is a necessary
factor of balance of the climate and
the atmospheric changes.
The deforestation
modifies the processes of evaporation
and the rain regime, with immediate
climatic changes that affects the
possibilities of survival of great
amount of species, in appearance not
damaged in direct form.
13,500 Km2 of tropical
forest are annually burn, to transform
the land into farming or pasturing
areas, taking to the desertification.
It is called thus to the process by
which a territory that did not have
the climatic characteristics of the
natural deserts finishes acquiring
them, because of the destruction of
its vegetal cover.
As a result of it,
the grounds become impoverished and
the smallest particles fly by the
wind, or slip with rains.
The fertile and productive ground,
that needs hundreds of years to form,
is also unstable.
In order to maintain
the cohesion and firmness of his particles,
it requires especially of the plants
and their roots. And if the plants
are destroyed, the erosion due to
the water and the wind soon leaves
the open the rock that, only after
the passage of many years, will be
able to return to be taken advantage
of by vegetables.
In sum, as much
agriculture as the ways, the dams
and the slumses are necessary; and
in new territories, they cannot be
done without deforesting. But the
elimination of arboreal species does
not have to exceed certain limits;
if rational plans of reforestation
do not exist, that intervention on
the ecosystem will have serious consequences
for the food web and life in general.
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specialized breeding grounds provide
with small trees as much to the
forest activity like a the forestation
areas that the governments establish
to avoid the disappearance of
the forests. |
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