PlanetArk 27 Jun 08;
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
Global warming causing plant migration in Europe: study
Yahoo News 26 Jun 08;
Global warming has caused numerous European plant species to migrate to higher elevations over the decades, according to new research published Thursday.
The research appears in the June 27 edition of the journal Science, and has potentially "important ecological and evolutionary consequences," the study's authors wrote.
A team of international scientists working in mountainous regions of Western Europe compared the natural elevation range of 171 forest plant species between 1905 and 1985, and again between 1986 and 2005.
"Along the entire elevation range, 0 to 2,600 meters (8,500 feet) above sea level ... we show that climate warming has resulted in a significant upward shift in species optimum elevation averaging 29 meters (95 feet) per decade," the researchers wrote.
The lead author of the study was Jonathan Lenoir of AgroParisTech in Nancy, France.
The report, compiled with data from the French National Climatic Network, was conducted in six mountainous regions throughout Europe.
They include the Northern Pyrenees, the Massif Central, the Western Jura, the Vosges, the Corsican range and the alpine regions, where average temperature increases have approached one degree Celsius since the start of the 1980s, researchers said.
Plants "Climbing" Mountains Due to Global Warming
Mason Inman, National Geographic News 26 Jun 08;
Like people vacationing in the mountains to escape summer heat, plants are "climbing" to higher elevations to cope with global warming, a new study shows.
Previous research has suggested that many plant and animal species have been shifting their ranges toward the Poles as the planet warms.
Now scientists have found evidence that plants have also been slowly moving into higher elevations to stay within ideal temperature zones.
Each year this "escalator effect" is pushing plants upward by about ten feet (three meters).
"When we started to look at this, I was not expecting such a strong message," said study leader Jonathan Lenoir, a forest ecologist at AgroParisTech, a research institute in France.
If global warming continues over the coming decades—as researchers predict it will—the plants will continue to climb.
But since some species move faster than others, this shift could tear established ecosystems apart, the researchers report in tomorrow's issue of the journal Science.
Moving on Up
For more than a century naturalists all over the world have been recording exactly where they found various plant species in the mountains.
"Botanists used to wander in mountain ecosystems … to look for and study specific mountain plant communities, to locate rare and endangered plant communities … or even simply to enjoy the landscape within mountains," Lenoir said.
In the mountains climate conditions change dramatically with altitude, making it is easier to detect when certain species shift to higher elevations.
"Mountains are [therefore] amazing places to observe vegetation changes in response to climate warming," Lenoir added.
The new study drew on nearly 8,000 historical surveys of the mountains in and around France, some stretching back to 1905.
Temperatures in these mountains—which include the Western Alps, Pyrenees, and Massif Central—crossed a threshold around 1985, the researchers say.
Before that year the region shows no clear trend in climate changes. But since then the mountains have been warming, and plants began moving in sync with rising temperatures.
The scientists looked at the movements of 171 species in forests on the lower slopes, from sea level up to 8,500 feet (2,600 meters).
While earlier studies had focused on plants in high altitudes that are known to be more sensitive to temperature changes, the new work found that even common plants at lower elevations are feeling the heat.
The team also discovered that different types of plants are moving at different rates.
"Long-lived plants like trees or shrubs did not show a significant shift, whereas short-lived species like herbs showed a strong upward shift in elevation," Lenoir said.
"This may imply profound changes in the composition and the structure of plant communities and on the animal species they interact with," he added. "It may disrupt ecosystems."
Out of Room
Steven Running is an ecologist at the University of Montana in Missoula who was not involved in the new study.
"Theory would predict that warming temperatures will allow plant distributions to expand into cooler, higher mountain elevations," he said.
"This paper confirms the theory. With a large population analysis, [it is] the best evidence published so far that plant distributions are rising [in altitude]."
The shifts in elevations of some plants and not others "shows very much that the ecosystems are already evolving away from the ecosystems as we know them," added Cynthia Rosenzweig of the NASA Goddard Institute for Space Studies in New York City.
With shorter-lived species, "we're seeing this rapid response" to warming, Rosenzweig said.
While it shows these plants are adapting to the changes, she noted, "they're going to have to keep moving up and up—and eventually run out of room."
And the longer-lived species that aren't moving may also be headed for trouble, she said.
"There's concern that they aren't adapting and may not have spread their seeds far enough" to shift their ranges to cope with continued warming.
Study: Global warming chases plants uphill
Randolph E. Schmid, Associated Press Yahoo News 27 Jun 08;
Faced with global warming, plants are heading for the hills. A study of 171 forest species in Western Europe shows that most of them are shifting their favored locations to higher, cooler spots.
For the first time, research can show the "fingerprints of climate change" in the distribution of plants by altitude, and not only in sensitive ecosystems, said Jonathan Lenoir of AgroParisTech in Nancy, France.
His team found "a significant upward shift of species optimum elevation, the altitude where species are the most likely to be found over their whole elevation range."
Indeed, comparing the distribution of species between 1905 and 1985 with their distribution between 1986 and 2005 showed a shift upward of 95 feet per decade, researchers led by Lenoir report in Friday's edition of the journal Science.
The team studied the preferred location of plants from sea level up to more than 8,500 feet in six regions in France. AgroParisTech is the agricultural branch of the Paris Institute of Technology.
This shows that the effects of climate change are being felt in all areas, not just mountain summits and polar regions, explained co-author Pablo Marquet of the Pontifical Catholic University of Chile.
Unlike animals, of course, plants can't just pick up and move in search of a better home.
But plant species do move, as seeds that are spread tend to grow better in one place than another — in this case at higher elevations in preference to lower ones.
Quickest to relocate, not surprisingly, were plants such as herbs, ferns and mosses with shorter life spans and faster reproduction cycles, the researchers said. Not so fleet were large woody plants that reproduce more slowly.
In fact, long-lived plants like trees that reproduce slowly are more threatened by climate change because they can't quickly relocate, Lenoir said.
Herbs, by having a short life cycle, have had several generations while trees have had just one, noted co-author Jean-Claude Gegout of AgroParisTech.
The plants studied tended to be the most common ones in the mountain forests of France, Lenoir said, allowing the researchers to collect the largest possible amount of information.
Of the 171 species studied, 118 moved uphill and 53 edged downward, the researchers said.
"Individual species behave differently, but as a whole the set of species we studied shows a clear and significant response associated to a shift in their distribution upwards," Lenoir said in an interview via e-mail.
There are a number of possible local reasons for some plants to shift downhill, he said, but the aim of the study was to look at large-scale change and not specific plant species.
"The most important result of our study is that among our 171 species, most are shifting upward," Lenoir said.
To calculate the upward advance of 95 feet per decade the team compared optimum plant locations in 1993 and 1971. The average location of plants from 1905 to 1985 occurred in 1971, while 1993 marked the average locations between 1986 and 2005.
Linda Mearns, a senior scientist at the U.S. National Center for Atmospheric Research, called the study "an important contribution to the growing literature documenting the effects of climate change."
"The fact that the authors are looking at the shift in the spatial core of the range, and not only the shifts at the boundaries of the ranges, makes the research particularly valuable," said Mearns, who was not part of the research team.
In a separate paper, Jeremy Collie of the University of Rhode Island reports that there has been a shift over nearly 50 years in the fish present in Narragansett Bay and Rhode Island Sound.
"While we're catching more fish now, we're also catching smaller fish," said Collie, "and that corresponds with how the preferred temperatures of the fish here have changed. The fish community now is dominated by warm-water adapted species compared with what we started with."
Water temperature in the bay is up about three degrees Fahrenheit since 1959, and the preferred temperature of the fish caught in the trawls has also increased by that amount, he said.
"That seems to be direct evidence of global warming," he said. "It's hard to explain any other way."
His findings appear in the July issue of the Canadian Journal of Fisheries and Aquatic Sciences.
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On the Net:
Science: http://www.sciencemag.org
Canadian Journal of Fisheries and Aquatic Sciences:
http://pubs.nrc-cnrc.gc.ca/rp-ps/journalDetail.jsp?jcodecjfas&langeng
