Evolutionary Race
Against Warming in Costa
Rica, Study Shows
By Adam Satariano
Bloomberg - Costa Rican
ants, moths and plants
are migrating to higher,
cooler sites as part of
an evolutionary race
against rising
temperatures, a study
that goes against the
belief that tropical
species are unaffected
by climate change
showed.
Scientists collecting
data for 2,000 plants
and insects along a
forested slope of a
Costa Rican volcano
determined temperature
increases may be pushing
species to follow their
familiar climates about
600 meters (2,000 feet)
higher into new
territory.
The study, published
today in Science
magazine, is the first
to document the
migratory shift of
species in the tropics
as a result of climate
change. Earlier studies
in the U.S. and Europe
found that birds,
butterflies and plant
species have shifted to
higher elevations.
A separate study also
published today in
Science found that
warming in California's
Yosemite National Park
has led small mammals to
move to higher
elevations.
The researchers surveyed
the park and compared
their findings with data
collected in the early
20th century. What they
found is that the ranges
for some high-elevation
mammals such as the
alpine chipmunk have
become smaller. Animals
living at low
elevations, such as the
harvest mouse, expanded
their ranges to higher
sites.
``When we asked
ourselves what changed,
it hit us between the
eyes: The climate,''
lead author Craig
Moritz, director of the
University of
California, Berkeley's
Museum of Vertebrate
Zoology, said in a
statement.
In the Costa Rica study,
the scientists note that
temperatures have
increased 0.75 degrees
Celsius (1.4 degrees
Fahrenheit) since 1975.
According to climate
models, temperatures
could rise an additional
3 degrees Celsius by
2100 in Central and
South America.
As a result of the
warming and species
shifting to remain in
hospitable climates,
lowland tropical forests
could experience a
decline in biodiversity,
according to the
researchers, led by
University of
Connecticut ecologist
Robert K. Colwell.
"These considerations
suggest, on evolutionary
grounds, that many
lowland tropical species
may be in for trouble if
they do not shift to
higher elevations or to
cooler, wetter
microhabitats in coming
decades -- and trouble
may already be at hand
for some,'' the study
said.
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