Biodiversity More Complex Than Thought
12/31/97
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Headline: Biodiversity More Complex Than Thought
Source: United Press International
Date: 12/31/97
Byline: Elizabeth Manning
Copyright: 1997 by United Press International
UPI Science News
WASHINGTON, Dec. 31 (UPI) -- The broadest study yet of the effects of
a disturbed forest on its inhabitants reveals that biodiversity is a
more intricate, demanding issue than scientists previously believed.
British biologists report in today's journal Nature that no one
animal group can serve as a yardstick for environmental disturbance.
Researchers have often used birds, butterflies, and other so-called
``indicator species'' both to signal and broadly measure the impact of
habitat loss on biodiversity.
To obtain their findings, John Lawton of London's Imperial College
and his colleagues logged over 10,000 hours in a tropical forest reserve
of Cameroon, on the west coast of central Africa. They cataloged eight
animal groups, including birds, butterflies, beetles, and ants.
Among their other conclusions:
-- The actual richness of species may remain the same after humans
alter or destroy a forest. But birds that require an old-growth forest,
for example, still disappear. Their numbers are simply replaced by bird
species that can live in meadows.
-- While undisturbed tropical forests are still critical, some managed
forests do seem to help maintain biodiversity.
-- A detailed inventory that truly measures the impact in even one
tropical forest, Lawton says, ``will require a huge scientific effort,
far exceeding anything attempted so far anywhere in the world.''
Biologists chose to study the Cameroon forest because of its wide
environmental range. The Mbalmayo (``muh-bahl-MAH-yo'') reserve varies
from near-undisturbed forest to managed tree plantations to completely
cleared farmland.