在西欧的一项关于171种森林物种的研究表明，这些树木正在移向海拔更高、更冷的区域。
来自AgroParisTech的研究人员Jonathan Benoir表示，这是第一次发现物种随海拔变化的"气候变化指纹"，并且这一现象是普遍存在的，而不仅仅发生在一些特定的敏感的生态系统。
他的课题组发现物种会向高海拔移动，这些物种最易被发现的区域的海拔，大多都高于它们所生存的全部区域的海拔的平均值以上。
Lenoir 等人发表在周五的Science上的文章表明，比较了1905-1985和1986-2005年间物种的分布，显示出每十年植物变会向高海拔移动95英尺（28.96m）。这一课题组的研究涵盖了法国的六个区域从海平面到海拔8500英尺（2.59km）间的不同物种，AgroParisTech是巴黎理工的农业分部。
来自智利的天主教大学的合作者Pablo Marquet认为，调查中发现，在不同的区域都显示出了温度的变化产生的影响，而不仅仅发生在山顶和极地区域。
当然，植物与动物不同，它们不能自由的移动并寻找一个更好的居住场所。但是作为一个物种的植物确实可以移动，这是因为种子离开母体后会在更适宜的区域生长发芽――在调查中，高海拔区域比低海拔区域更为适宜。
毫无疑问的，这种变化在那些生命周期短，繁殖迅速的植物――如草本植物、蕨类和苔藓类――中体现的更为明显。而那些生命周期长的生物的位置变化则非常缓慢。Lenoir表示，生命周期长的植物由于繁殖的慢，它们反而更易受到气候变化的影响。
对植物的调查研究涵盖了法国境内的绝大多数物种，在研究的171中物种中，有118中向上移动，另外53中则在向下移动的边缘。
在一封通过e-mail的采访中，Lenoir表示，"不同的物种有不同的表现，但是整体上来讲，我们的研究清楚的表明物种对于气候变化有着明显的响应，并且导致了它们向高海拔区域移动。"
对那些向低海拔移动的物种，确实存在有特定的因素，但是他们的研究并不针对某些特定的物种，而是要从全部物种中得到一个趋势。Lenoir表示，"通过研究的171种物种，我们得到的最重要的一点就是，大多数物种都向高海拔迁移。"
通过比较1993和1971年各物种的最佳适应海拔，研究组认为每十年植物会向高海拔迁移95英尺。1971年的数据反映了植物在1905-1985年间的平均海拔，而1993年的数据反映了1986-2005年间的平均海拔。
美国国家气象研究中心的资深科学家Linda Mearnes认为这项研究"为气候变迁对生物带来的影响这一课题提供可重要的数据"。她表示，"这项研究主要针对了物种生长的核心区域的变迁，而不是物种生长的边界区域的变化，这使得这项研究极为有意义。"
罗德岛大学的Jeremy Collie在另一项独立的研究中表示，在过去的50年中，那拉干系特湾和罗德岛海峡的海域的鱼类种群有着明显的变化，"我们现在可以捕捉到更多的鱼，我们也捕捉到了体型更小的鱼，这显示出温度的变化对鱼类的影响。跟我们最初的研究相比，目前这里占优势地位的鱼类种群是更适于温水的鱼类。"始于1959年的记录显示，这一海域的温度上升了3华氏度，并且由于优势种群的变化，在这一海域利用拖网捕捉的鱼类数量也有所增多。Collie认为"这事最为明显的全球变暖的证据，否则这种现象难以解释。"他的这一研究发表在Canadian Journal of Fisheries and Aquatic Sciences的七月号上。
原文：
WASHINGTON (AP) -- Faced with global warming, plants are heading for the hills.
A study of forest species in France, like these in the Alps, shows most are migrating to higher, cooler locations.
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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