Travel Reference
In-Depth Information
Flora and fauna
Over six thousand species of
plants
have been reported from one square kilometre tract
of Amazon forest, and there are close to a thousand species of birds spread about the
region. The rainforest has enormous structural diversity, with layers of vegetation from
the forest floor to the canopy 30m above providing a vast number of habitats. With the
rainforest being more stable over longer periods of time than temperate areas (there was
no Ice Age here, nor any prolonged period of drought), the fauna has also had freedom
to evolve, and to adapt to often very specialized local conditions. This is the foundation
of the Amazon's biodiversity.
Most of the
trees
found in the Amazon flood plain are tropical palms, scattered
between which are the various species of larger, emergent trees. Those plants which are
found growing on the forest floor are mostly tree
saplings
,
herbs
(frequently with
medicinal applications) and
woody shrubs
. The best-known of all Amazon trees are
concentrated on the upland
terra firme
, which never floods; here you can find the
rubber
tree
(
Hevea brasiliensis
), known as
seringueira
in Brazil, and the
Brazil nut tree
(
Bertholletia
excelsa
), which grows to 30m and takes over ten years to reach nut-bearing maturity; once
this is reached, a single specimen can produce over 450kg of nuts every year.
Deforestation
he amount
deforested
in the Amazon varies from year to year because of a number
of factors, especially climate. In
El Niño
years, such as 1998, the Amazon is much drier
than usual and fires start more easily; this in turn means bigger areas are denuded of
forest, allowing farmers to move in. Thus many models of climate change over the next
few decades, which suggest longer dry seasons and a drier forest in many parts of the
Amazon, are a cause for concern. What matters is not a deforestation spike in one year
or another, but general trends over time. These show deforestation increased alarmingly
in the 1970s and 1980s, fell back in the 1990s, and then rose again in the early
twenty-first century. Much deforested land is abandoned and regrows over time;
although it usually does not return to the level of ecological complexity it had,
deforested land can reacquire some of its biodiversity value.
In other words, all is not lost; the bulk of the Amazon is intact, and even the
damaged areas need not be written off. The other thing to remember is that the
frontier
period
of Amazonian development is largely over. The Amazon's population is stable,
and rapidly urbanizing; almost seventy percent of the Amazon's population lives in
cities. There are no longer waves of migrants flooding to the region, or a growing rural
population putting pressure on the forest. Policy makers and Amazonians themselves
are realizing it makes more sense to concentrate development efforts into degraded
areas, where there are already roads and people living, intensifying development instead
of extending it. This is unfortunate for the environmental integrity of the twenty-five
percent or so of the Amazon in this position, but it offers the real prospect that pressure
on the remaining 75 percent will diminish.
Threats to the forest
Forest clearance generally follows
road building
. When a road reached into new
territories in the glory days of highway building into the Amazon in the 1970s and
1980s, it brought with it the financial backing and interests of big agricultural and
industrial companies, plus an onslaught of land-seeking settlers. Historically, the
great villain in the deforestation piece has been
ranching
- the latest research suggests
that around eighty percent of forest cleared was turned into pasture, dwarfing the
deforestation caused by smallholders, commercial agriculture and logging. Although
much has been written recently about
soy farming
as a cause of deforestation, most soy
planting takes place on land that has already been cleared, and it remains a very minor
cause of deforestation. Forest
fires
are a major threat, generally caused by colonizing
