Ancient arctic forests

0 CommentsPrint E-mail China.org.cn, December 17, 2010
Adjust font size:

In the Arctic, trees and forests just do not happen. However, long ago they did when the area was warmer and then turned cooler. As it turns out there are many such northern forests that have been preserved by mineralization and similar processes.

The northernmost mummified forest ever found in Canada is revealing how plants struggled to endure a long-ago global cooling. Researchers believe the trees -- buried by a landslide and exquisitely preserved 2 to 8 million years ago -- will help them predict how today’s Arctic will respond to global warming.

Axel Heiberg Island is an island in the Qikiqtaaluk Region, Nunavut, Canada. Located in the Arctic Ocean, it is the 31st largest island in the world and Canada's seventh largest island. According to Statistics Canada, it has an area of 16,671 square miles.

One of the larger members of the Canadian Arctic Archipelago, it is also a member of the Sverdrup Islands and Queen Elizabeth Islands. It is known for its unusual fossil forests, which date from the Eocene period. Owing to the lack of mineralization in many of the forest specimens, the traditional characterization of "fossilisation" fails for these forests and "mummification" may be a clearer description. It is clear that the Axel Heiberg forest was a high latitude wetland forest.

Joel Barker, a research scientist at Byrd Polar Research Center and the School of Earth Sciences at Ohio State University and leader of the team that is analyzing the remains, will describe early results at the American Geophysical Union meeting in San Francisco.

Over the summer of 2010, the researchers retrieved samples from broken tree trunks, branches, roots, and even leaves -- all perfectly preserved -- from Ellesmere Island National Park in Canada.

The fossil forest, which lies outside the borders of the new Quttinirpaaq National Park (formerly Ellesmere Island National Park) on Ellesmere Island, is unprotected from the damage that visitors can inflict.

"Mummified forests aren’t so uncommon, but what makes this one unique is that it’s so far north. When the climate began to cool 11 million years ago, these plants would have been the first to feel the effects," Barker said. "And because the trees organic material is preserved, we can get a high-resolution view of how quickly the climate changed and how the plants responded to that change."

Analysis of the remains has only just begun, but will include chemical and DNA testing.

For now, the researchers have identified the species of the most common trees at the site -- spruce and birch. The trees were at least 75 years old when they died, but spindly, with very narrow growth rings and under-sized leaves that suggest they were suffering a great deal of stress when they were alive.

"These trees lived at a particularly rough time in the Arctic”? Barker explained. "Ellesmere Island was quickly changing from a warm deciduous forest environment to an evergreen environment, on its way to the barren scrub we see today. The trees would have had to endure half of the year in darkness and in a cooling climate. That’s why the growth rings show that they grew so little, and so slowly."

"I want to be clear -- the carbon contained in the small deposit we’ve been studying is trivial compared to what you produce when you drive your car,”? he said. “But if you look at this find in the context of the whole Arctic, then that is a different issue."

Colleagues at the University of Minnesota identified the wood from the deposit, and pollen analysis at a commercial laboratory in Calgary, Alberta revealed that the trees lived approximately 2 to 8 million years ago, during the Neogene Period. The pollen came from only a handful of plant species, which suggests that Arctic biodiversity had begun to suffer during that time as well. The whole Neogene period lasted about 23 million years and saw the rise of early Man,

Now that the forest is exposed, it’s begun to rot, which means that it’s releasing carbon into the atmosphere, where it can contribute to global warming. How many such forests exist buried in the arctic ice waiting to be exposed is not known. The next effect on global climates is not yet known.

Examination of this ancient forest can reveal clues as to how plants adapt to a cooling environment.

Print E-mail Bookmark and Share

Go to Forum >>0 Comments

No comments.

Add your comments...

  • User Name Required
  • Your Comment
  • Racist, abusive and off-topic comments may be removed by the moderator.
Send your storiesGet more from China.org.cnMobileRSSNewsletter
主站蜘蛛池模板: 国产视频www| 扒开双腿疯狂进出爽爽爽动态图| 伺候情侣主vk| 舌头伸进去里面吃小豆豆| 国产欧美日韩一区二区三区在线 | 色窝窝亚洲av网| 在线日韩理论午夜中文电影| 一本大道香蕉视频在线观看| 日本69xxxx| 久久看免费视频| 柔佳呻吟乳峰喘息高耸入云| 亚洲欧洲自拍拍偷综合| 狠狠噜天天噜日日噜视频麻豆| 北条麻妃在线一区二区| 色老二精品视频在线观看| 国产国语对白露脸| 日本三级做a全过程在线观看| 国产精品男男视频一区二区三区| 97色伦图片7778久久| 天海翼被施爆两个小时| 一区二区三区免费视频播放器| 成人国产一区二区三区| 中文字幕网资源站永久资源| 日本24小时在线| 久久久久亚洲av成人无码| 日韩在线看片免费人成视频播放 | www久久精品| 打开腿我想亲亲你下面视频| 久久久久久久久久免免费精品| 日韩AV无码久久精品免费| 久久综合九色综合欧美就去吻 | 国产亚洲精品aa片在线观看网站| h视频在线观看免费| 国产精品国产三级在线专区 | 欧美亚洲综合另类在线观看| 亚洲综合色色图| 特级毛片a级毛片在线播放www| 佐藤遥希在线播放一二区| 男女猛烈xx00免费视频试看| 免费吃奶摸下激烈视频| 男人操女人的免费视频|