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- ST. LOUIS, MO
- A compilation of the latest data on extinction rates of plant and animal
life around the world reports that humanity's impact on the earth has increased
extinction rates to levels rivaling the five mass extinctions of past geologic
history. The paper was released today by the President of the International
Botanical Congress, Peter Raven, PhD, who is a world leader in plant conservation.
It predicts that between one-third and two-thirds of all plant and animal
species, most in the tropics, will be lost during the second half of the
next century. The paper calls for an eight-point plan to arrest species
loss within plant ecosystems.
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- "Human efforts have been notable for their lack
of attention to the living world that supports us all," said Raven,
who is also Director of the Missouri Botanical Garden. "In the face
of the worldwide extinction crisis, we should redouble our efforts to learn
about life on Earth while it is still relatively well represented."
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- More than 4,000 scientists from 100 countries are meeting
at the International Botanical Congress this week to discuss the latest
results of research on plants for human survival and improved quality of
life. Raven's remarks were made at a press briefing held prior to the "Millennium
Symposium," where the paper, "Plants in Peril: What Should We
Do?" will be formally presented to the Congress.
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- Over the past several centuries, the documented extinction
rates of a wide range of well-known groups of organisms are several times
higher than the background rate or rate at which species have been becoming
extinct for the past 65 million years, since the major extinction event
that closed the Cretaceous Period and the Mesozoic Era, which coincided
with the loss of the last surviving dinosaurs. This was the fifth major
extinction event in Earth history, a time when two-thirds of all terrestrial
organisms that lived at that time disappeared and the character of life
changed permanently. The current extinction rate is now approaching 1,000
times the background rate and may climb to 10,000 times the background
rate during the next century, if present trends continue.
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- According to the paper, species loss can be estimated
even when the members of many groups of organisms are relatively poorly
known because of the logarithmic relationship between species number and
the area in which they live. On the average, a tenfold increase in area
is correlated with a doubling in species number, and a tenfold decrease
with a halving of the original number. Given the relationship between species
number and area, one can determine the number of species that will survive
in a given area. Fragments of a given habitat that have been reduced in
size lose half of the species they are going to lose in about 50 years;
three-quarters of them in a century.
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- The paper states that if current trends continue, and
we retain just five percent of tropical forests in protected areas, which
will be true within 50 years at present rates of destruction (and sooner
if these rates are accelerated), then extinction rates will be three or
four orders of magnitude higher than those prevailing between mass extinctions.
At this rate, one-third to two-thirds of all species of plants, animals,
and other organisms would be lost during the second half of the next century,
a loss that would easily equal those of past extinctions.
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- The paper states that vast numbers of unknown plants,
animals, and other organisms are currently being lost before they've been
recognized. Only about 1.6 million organisms out of a conservative estimate
of between seven and 10 million have been recognized scientifically. A
great majority of these are poorly known, often from a single specimen,
a brief description, a locality, nothing more, according to the paper.
Some 250,000 of 300,000 species of plants have been identified, leaving
some 50,000 completely unknown.
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- The extreme depletion of genetic variation in individual
plant species causes them to become more vulnerable to extinction, according
to the paper. Genetically diverse traits in plants can often enable them
to grow in harsher environments, for example, or survive the competition
with weedy species. About 30 percent of the world's 300,000 plant species
are in cultivation now, "which provides a good start for conservation,"
according to Raven.
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- The paper outlines an seven-point plan to slow the extinction
rates of plants around the world. It suggests that a major United Nations-sponsored
conference on this topic could move these steps into country-by-country
actions.
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- "All plants are important in one way or another
and this comprehensive plan seeks to save them all -- a priceless gift
to future generations," said Raven.
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- 1. Establish a new coordinating body -- presumably connected
with the United Nations directly or through one of its constituent organizations
-- to monitor the status of plants throughout the world, detect those most
in danger, and take steps to conserve them.
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- "There are a number of organizations working effectively
in plant conservation now that could benefit greatly from the kind of overall
international coordination that such a global body could provide,"
said Raven. "These organizations include, but are not limited to,
Botanic Gardens Conservation International and the Plant Conservation Program
of the World Conservation Union's Species Survival Commission."
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- 2. Increase financial support for the study of plants
throughout the world both by strengthening the major museums and other
institutions that have holdings of specimens and literature on plants and
by capacity building in developing countries with scarce resources. Currently,
80 percent of the world's scientists live in industrialized countries,
which have about 20 percent of the world's population and only 20 percent
of the world's biodiversity.
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- "Nations will only preserve biodiversity if they
have their own institutions and their own scientists to make recommendations
about what's best for them," said Raven.
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- The paper calls for the Convention on Biological Diversity
(CBD) and the Global Environment Facility (GEF) to step their efforts train
scientists.
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- 3. Make information on plants -- now only available
in herbarium, arboreta, seed banks, universities, and botanical gardens
-- accessible on the Internet to people throughout the world, especially
to the poor "who truly need it."
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- "Although this expenditure may seem high, we are
living in an era when our great-grandchildren may live in a world in which
more than half of the plant species that exist now will be known only as
specimens," said Raven.
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- 4. Place more emphasis on alien-introduced plants and
animals as a major cause of biodiversity losses. Studies of aliens and
of the ways of controlling them should be taken into account in evaluating
the status of species in nature.
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- 5. At the national level in every country around the
world, maintain an active census of the condition of the country's plants,
so that it will always be obvious which are well protected in nature --
or so abundant so as not to cause concern -- and those that are rare and
endangered.
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- 6. Place special attention on conserving medicinal plants,
important for the livelihood of a great majority of the world's population.
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- 7. Internationally fund an ongoing program of research
on plant population biology and reproductive characteristics, generally,
so that these areas can be understood properly and used as part of the
world's overall preservation scheme.
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- "Recently, we have begun to realize how important
the survival of pollinators is to the survival of healthy plant populations,"
said Raven.
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- Held only once every six years, the International Botanical
congress last met in the United States in 1969, when it was convened in
Seattle, Washington. The XVI International Botanical Congress is being
hosted by the Missouri Botanical Garden in St. Louis.
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