Rising Temperatures Force Many Plants Higher - Study
UK: June 27, 2008
LONDON - Rising temperatures have forced many plants to creep to higher
elevations to survive, researchers reported on Thursday.
More than two-thirds of the plants studied along six West European mountain
ranges climbed an average of 29 metres in altitude in each decade since 1905
to better conditions on higher ground, the researchers reported in the
journal Science.
"This is the first time it is shown that climate change has applied a
significant effect on a large set of forest plant species," said Jonathan
Lenoir, a forest ecologist at AgroParisTech in France, who led the study.
"It helps us understand how ecosystems respond to temperature changes."
Earlier this week, US researchers warned warming temperatures could turn
many of California's native plants into "plant refugees" looking for more
suitable habitats.
They concluded that a warming climate and rainfall changes would force many
of the US state's native plants to range north or to higher elevations or
possibly even go extinct in the next 100 years.
The French team's findings suggest plants at high altitudes face the same or
greater impacts from rising temperatures, Lenoir said in a telephone
interview.
"Plant species move where it is optimal for them to grow," Lenoir said. "If
you change these optimal conditions, species will move to recover the same
conditions."
Using database on plant species found at specific locations and elevations
stretching back to 1905, the researchers showed many plants have steadily
crept higher to conditions best suited for survival and growth.
Plants move higher by dispersing their seeds in the wind, which blows them
to higher elevations and cooler temperatures similar to their former
location, Lenoir said.
The researchers tracked 171 forest plant species during two periods --
between 1905 and 1985, and from 1986 to 2005 -- along the entire elevation
range from sea level to 2,600 metres.
They found that two-thirds of the plants responded to warming temperatures
over that time by shifting to higher altitudes.
Plants at higher altitudes also appear most sensitive to warmer conditions
because slight temperature changes at higher altitudes have a bigger impact,
he added. (Reporting by Michael Kahn; Editing by Maggie Fox and Ibon
Villelabeitia)
Story by Michael Kahn
REUTERS NEWS SERVICE
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