http://story.news.yahoo.com/news?tmpl=story2&cid=570&ncid=570&e=2&u=/nm/20021031/sc_nm/science_plants_dc_1
[ Study
referenced below: 11/1/02 Issue of Journal, "Science",
Pg 989... ]
[ Study
referenced below: 11/1/02 Issue of Journal, "Science",
Pg 989, Data Table... ]
[ "Science",
is the journal of the American Association of the Advancement
of Science (AAAS)... ]
World Plants Near Extinction Close to 50 Pct.-Study
Thu Oct 31, 2002, 2:21 PM ET
By Christopher Doering
WASHINGTON (Reuters)
- The percentage of the world's plants
threatened with extinction is much larger than commonly
believed, and could be as high as 47 percent if tropical
species are included, researchers said on Thursday.
The study, published
in the November
issue of Science,
challenges earlier research that estimated the number of
species in danger of extinction was about 13 percent.
Previous studies of
extinct plants underestimated the
numbers because they failed to include many plants growing
in tropical countries such as Ecuador and Colombia.
Plants are becoming
extinct for many reasons, including
global warming and human encroachment into area habitats,
said Peter Jorgensen, a researcher at the Missouri Botanical
Gardens in St. Louis who coauthored the new study.
For example, scientists
discovered a single collection of
the passion flower, a light purple flower found only in
southern Ecuador, during the 1970s, Jorgensen said.
But recent trips to the region have found the species
has since disappeared.
Jorgensen reviewed
data from 189 countries and territories
and determined that between
310,000 and 422,000 plants
-- or 22 to 47 percent -- could be threatened.
In previous studies
"if you can't evaluate a species you
basically don't include it," Jorgensen said in a telephone
interview.
"Still, we don't
know enough ... to go out and do something
active on the ground to save them," he said. "Just because
there are more of them doesn't mean it's easier."
Identifying threatened
species is a crucial step toward
developing better management plans to protect them,
but Jorgensen conceded it will take a large amount of
money to develop such projects.
Maintaining a global
database of threatened plants
would cost an estimated $12.1 million annually,
the researchers said.
The vast majority of
plants that are threatened in
tropical areas are those located with a wide variety
of plant life or where habitat loss is rapidly occurring.
As a model for their
research, Jorgensen and his coauthor,
Nigel Pitman from Duke University, analyzed more than
4,000 species that are native to Ecuador.
After sifting through
data and determining those that
could be on the verge of extinction -- such as plants
with small populations or which are located only in a
small geographical area -- they determined that 83 percent
of all plants in the country are threatened.
The findings for Ecuador
are important, Jorgensen said,
because the country has one of the most complete databases
of plant species. Such results also can be applied to
neighboring countries such as Peru and Colombia where
data are scarce.
"We know so little
about plants in tropical regions,"
said Jorgensen. "And what really bothers me is we have
to guess so much because we don't have enough manpower
to go through all the countries."
