http://www.commondreams.org/headlines02/1101-02.htm
Published on Friday,
November 1,2002 by the lndependent/UK
Half of the World's Species of Plants
are in Danger of Disappearing, Says Study
by Steve Connor
Up to half of the world's plants could become extinct this
century, according to a new analysis of the true number of
endangered species.
Existing studies suggest
that about 13 per cent of the known
plants in the world are threatened but the true figure could be
far higher, says a study published today in the journal Science.
Nigel Pitman of Duke
University in Durham, North Carolina, and
Peter Jorgensen, of the Missouri Botanical Garden in St Louis,
calculate that at least 22 per cent of species should be on
the Red List of the world's threatened plants.
The figure of 13 per
cent is a "serious underestimate" because
it was based largely on what is known about threatened species
in the temperate regions of the world - such as Europe and
North America - but it is in the Tropics where plant diversity
is at its richest and most vulnerable, they say.
"The results suggest
that as many as half of the world's plant
species may qualify as threatened with extinction under the
World Conservation Union classification scheme," the scientists
write. "Comprehensive Red Lists for plants are available
for
only a scattering of tropical countries, making it difficult
to assess the true scale of the global conservation crisis
for plants."
The two scientists
looked at the number of plants that are
endemic to nearly 200 countries and used this as a basis for
estimating how many are threatened by such things as habitat
loss and deforestation.
They say that the concentration
of endemic plants can be
directly linked to the proportion that would be expected
to be threatened with extinction. Globally, this means that
between 22 per cent and 47 per cent of plants could become
extinct in the foreseeable future. In some countries the
figure could be as high as 80 per cent or more of its endemic
plants.
There are thought to
be from 310,000 to 422,000 species
of plants in the world but Peter Crane, director of the
Royal Botanic Gardens at Kew, said fewer than one in 20
had been formally assessed for their conservation status.
"For some plant groups which have recently been studied
by specialists at Kew, at least 50 per cent of the
Brazilian species are considered to be threatened,"
he said.
© 2002 lndependent
Digital (UK) Ltd
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