GEO Brasil - UNEP

Deforestation and cattle raising for big landowners are
instruments of judicial property claims. For small
producers, cattle raising is the immediate alternative for the
appreciation of degraded soil that is incapable of recycling
soil nutrients after the first year of harvesting. The
substitution of forests with forage means increasing
phosphorous production in soil and causes larger erosion.
This is due to the fact that water drainage in forage is ten
times bigger than in forests. This facilitates more intense
floods during rainy seasons and reducing river flows during
dry seasons.
The search for wood, another factor of considerable pressure
on vegetation cover, is constantly increasing, specially in
the internal market. Major log producers still continue to
exist in States of Pará and Mato Grosso, followed by
Rondônia, and major consumption of this production –
37.4 %, is absorbed by the Southeast region, mainly by the
State of São Paulo (20.1%). The external market absorbs 14
% of the production (Egler,2001).
The introduction of investments in agriculture in the
Amazon is a historical innovation, having survived the
extraction activity. The trademark crops of this new model
are soybean, rice and maize. Until the mid-nineties, these
crops represented a small share but in 1999 they represented
occupation in new and significant portions of the Legal
Amazon.
In the Cerrado biome, expansion tendencies of the
urbanisation process were demonstrated in the formation
of the new and dynamic urban territorial complex of Goiânia,
Anápolis and Brasília. Goiânia, founded in 1942, and Brasília,
in 1960, are recent events in the history and geography of
Brazil. However, in conjunction, they have more than three
million inhabitants and a strong tendency to maintain this
quick pace of expansion. Located in areas of soft topography,
with no notable obstacles to the expansion of urban
constructions, its spatial standard tends towards the
proliferation of peripheral centres. These are mainly
populated with low-income populations that expand rapidly
into the Cerrado. As in the Amazon, some states in this
location maintain the tendency to extend the occupied area
to agriculture and cattle breeding establishments, specially
in the State of Mato Grosso, where a soybean complex has
been developed.
Intense occupations of this biome have caused
environmental problems on a larger scale due to rapid
expansion of the agriculture-pasture economy. Among
these impacts, we can stress the following: erosion and soil
compaction, water contamination and biota contamination
by chemical fertilisers, deforestation, reduction of availability
of subterranean water resources due to inadequate irrigation
of cultivated areas, reduction in vegetation and animal
diversity and soil degradation.
TThe use of improved processes for other surroundings,
like “central pivot” irrigation, demands energy and water
use intensity that are not available in the Cerrado reserves
today. Used in a controlled manner, this type of irrigation
provokes large losses of water accumulated in waterbeds,
thus compromising the future water supply. This includes
water for human consumption. Lowland irrigation that is
affected by gravity, although it has fewer negative affects
than the “central pivot” method, also presents problems
when used without planning. This can jeopardise river and
valley ecosystems. The drainage system used in this kind
of irrigation may provoke a lowering of the waterbed,
destroying riverside forests and areas with buriti palms,
causing future destruction of lowlands. This phenomenon
is easily found in the Cerrado area.
Deforestation and clearing and burning are used in the
formation of huge pasture areas for cattle breeding. The
installation of such pasture areas, with a single crop, Xuawa
considerable consumption of different products, like
correctives, fertilisers, herbicides, pesticides and extensive
use of heavy machinery. A depletion of the ecosystem is
observed immediately, with a loss of native vegetation
species that creates conditions for the appearance of
plagues, insects and damaging weeds.
environmental management
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