Source: Environment News Service (ENS) 2000. All Rights
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Status: Copyright 2000, contact source for permission to reprint
Date: May 30, 2000
WASHINGTON, DC, May 30, 2000 (ENS) - Many tropical forest fragments
are in immediate danger of collapse if new conservation measures are
not enacted quickly, according to a new study.
The study, published in this week's journal "Science," published by
the American Association for the Advancement of Science, shows that
the effects of logging and road construction are dividing much of what
remains of tropical forests into small, isolated fragments that are
unable to sustain their original biodiversity.
Authors Claude Gascon, G. Bruce Williamson and Gustavo A.B. da Fonseca
write that as forests are carved into smaller parcels because of human
activity, a series of ecological changes occurs on the fragment edges
which affects forest composition and the survival of biodiversity.
"In many places, these are the last remnants of primary tropical
forest," said Fonseca, who is vice president of the Washington, DC
based environmental group Conservation International (CI) and
executive director of the Center for Applied Biodiversity Science.
Conservation International applies innovations in science, economics,
policy and community participation to protect plant and animal
diversity in the most vulnerable tropical wilderness areas and key
marine ecosystems.
"With so much biodiversity at stake in these unconnected
islands of forests, long term conservation can only be achieved if
these fragments are connected across broad landscapes," said
Fonseca.
"What remains of much of the world's tropical forests are
mere fragments, and we now understand they face new risks,"
said Gascon, another CI vice president and lead author of the article.
"As tropical forests are continually reduced to small fragments they
are more susceptible than we imagined to the effects of human
disturbance."
In the Atlantic Forest hotspot of Brazil, for example, the
average size of restricted use protected areas is 9,210 hectares
(22,758 acres). These fragments exist among large expanses of
sugar cane and Eucalyptus plantations where burning and herbicide
application regularly occur.
The forest fragment edges are affected by these activities
which kill a diverse range plants in the remaining primary forest
interior, leaving the edge dominated by scrubby secondary
vegetation.
Zones where forest edges are affected easily reach up to
one kilometre (.62 mile) wide, and can impact forest species and
biological processes from 100 to 300 meters from the forest edge.
This means that forest fragments of up to 1,000 hectares (2,470 acres) can
easily be composed entirely of edge affected habitat.
The increase of human activity in the tropics has led to
the introduction of exotic species, and an increase in fires,
which compounds the effects of deforestation in places like the
Atlantic Forest, the Philippines and Madagascar, where the
landscape is already highly fragmented.
In Brazil, at least one timber company is working to
preserve as well as harvest the forests. In Itacoatiara, Brazil today,
during a meeting onboard Greenpeace's vessel, the Amazon Guardian, the
timber company Precious Woods Amazon presented a declaration which was
the outcome of negotiations and onsite forest inspections with Greenpeace
that lasted more than a year.
With its declaration, Precious Woods promised to make
frequent comparisons between a the logged tracts and a set aside
forest reserve which will serve as a standard for sustainable forest
management.
The timber company will set clear logging limits to
guarantee that 85 percent of standing tree volume always remain in the
forest.
There will be no application of pesticides, other
chemicals or alien organisms, in order to maintain the natural state of the
forest; and the company has agreed to minimize silviculture so that
the composition of native trees species will not be altered.
Precious Woods is the only logging operation in the Amazon
rainforest certified as sustainable by the Forest Stewardship
Council. "This forest management scheme should serve as a model for
logging in ancient forests," said Roberto Kishinami, Greenpeace
Brazil's executive director. "An approach such as this is the best
safeguard against destructive logging, and against illegal logging,
which the Brazilian government themselves admits is 80 percent of
all logging in the Amazon."
"Ecological logging, combined with other activities such
as rubber tapping, ecotourism, demarcation of indigenous lands, and
the extension of protected areas, will guarantee a secure and
diverse economic and ecological future for the Amazon," Kishinami said.
The Forest Stewardship Council is an international,
non-profit, non- governmental organisation that promotes independent, third
party certification of well managed forests and the labelling of
products from these forests for use by forest product consumers.