Tropical Forest Community Ecology

(Grace) #1
Tropical Rainforest Conservation 449

has resulted in endemism of more than 80%
in most groups of terrestrial organisms, while
extreme poverty and one of the highest popu-
lation growth rates on earth has put all forests
under pressure (Goodman and Benstead 2003).
The original broad band of rainforest along the
eastern side of the island has been largely cleared;
the surviving forest is fragmented and in many
places badly degraded (Dufils 2003, Du Puy and
Moat 2003). Although deforestation rates have
declined from their peak, the major threat con-
tinues to be clearing by poor farmers for rice
and cattle. Hunting and fuelwood collection are
also major problems, as is logging, although
the latter is not carried out on the scale seen
in other rainforest regions (Goodman and Ben-
stead 2003). Endemic reptiles and amphibians are
widely collected for the pet trade (Raselimanana
2003). Invasive plants and animals seem to be
a greater problem in Madagascar than in other
rainforest regions (e.g., Brown and Gurevitch
2004).


America

Half the world’s remaining tropical rainforests, as
well as the largest relatively intact forest blocks,
are in the Amazon basin. Although percentage
deforestation rates are lower than in Asia and
much of Africa, the absolute quantity of forest loss
is higher. The major problem is the advancement
of theagriculturalfrontierintotherainforest,both
from the margins in the southeast and west and
from hotspots in the interior (Fearnside 2005).
Forest is converted to crops and cattle pasture,
mostly by small farmers whose access to the
forest stems from the government’s road expan-
sion activities, which far outstri pthose in any
other major rainforest region (Lauranceet al.
2002, 2005; but see also the correspondence
on this issue inScience307, pp. 1043–1047).
Much of this infrastructure is justified by the
production of soybeans, an export crop grown
by wealthy agribusinesses that employ very few
people and displace small farmers to the forest
frontier (Fearnside 2002). Deforestation, logging,
and forest fires are all concentrated along the
new roads (Lauranceet al. 2005). As in other

regions, logging roads extend access beyond the
government road system and the total forest
area affected each year by logging and acciden-
tal fires is similar to the cleared area (Asner
et al. 2005). Environmental protection is improv-
ing in Amazonia, but the Brazilian government
does not currently have the capacity to control
illegal deforestation, logging, and mining across
this vast area (Fearnside 2005, Lauranceet al.
2005).
There were two other major rainforest blocks
in the Neotropics: the Brazilian Atlantic For-
est along the southeast coast of Brazil, and a
band of forest that extended from the Pacific
coast of northwest South America through Cen-
tral America to southern Mexico (Primack and
Corlett 2005). In both areas, the accessible forests
have been completely cleared or are highly frag-
mented, with the area of forest remaining being
inversely related to human population density
(Mastet al. 1999, Tabarelliet al. 2005). As in
the Amazon region, ranching and cash crops are
the major causes of deforestation. On the pos-
itive side, these two areas showcase innovative
conservation projects and conservation-related
research.

New Guinea

New Guinea, the largest tropical island, supports
the third largest contiguous block of rainforest
after the Amazon and Congo basins. The lowland
rainforest flora is generally similar at the family
and genus levels to that of Southeast Asia, but
the vertebrate fauna is very different (Primack
and Corlett 2005). The western half of the island
is the Indonesian province of Papua (previously
Irian Jaya). Papua has the lowest population
density of any Indonesian province, but as rain-
forest resources are depleted in western Indonesia,
Papua’s vast rainforests are increasingly exploited.
Clearing for cash crops such as oil palm, exploita-
tion of wildlife, and fires are all growing problems
in Papua, but the biggest threat is from a huge
(and technically illegal) logging industry (EIA
2005). The main target is merbau (Intsiaspp.).
A recent report documented a complex web of
operations, involving mostly Malaysian logging
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