GSTDTAP  > 气候变化
Amount of carbon stored in forests reduced as climate warms
admin
2019-05-15
发布年2019
语种英语
国家美国
领域气候变化
正文(英文)
IMAGE

IMAGE: Accelerated tree growth caused by a warming climate does not necessarily translate into enhanced carbon storage, an international study suggests. view more 

Credit: Ulf Buntgen

Accelerated tree growth caused by a warming climate does not necessarily translate into enhanced carbon storage, an international study suggests.

The team, led by the University of Cambridge, found that as temperatures increase, trees grow faster, but they also tend to die younger. When these fast-growing trees die, the carbon they store is returned to the carbon cycle.

The results, reported in the journal Nature Communications, have implications for global carbon cycle dynamics. As the Earth's climate continues to warm, tree growth will continue to accelerate, but the length of time that trees store carbon, the so-called carbon residence time, will diminish.

During photosynthesis, trees and other plants absorb carbon dioxide from the atmosphere and use it to build new cells. Long-lived trees, such as pines from high elevations and other conifers found across the high-northern latitude boreal forests, can store carbon for many centuries.

"As the planet warms, it causes plants to grow faster, so the thinking is that planting more trees will lead to more carbon getting removed from the atmosphere," said Professor Ulf Büntgen from Cambridge's Department of Geography, the study's lead author. "But that's only half of the story. The other half is one that hasn't been considered: that these fast-growing trees are holding carbon for shorter periods of time."

Büntgen uses the information contained in tree rings to study past climate conditions. Tree rings are as distinctive as fingerprints: the width, density and anatomy of each annual ring contains information about what the climate was like during that particular year. By taking core samples from living trees and disc samples of dead trees, researchers are able to reconstruct how the Earth's climate system behaved in the past and understand how ecosystems were, and are, responding to temperature variation.

For the current study, Büntgen and his collaborators from Germany, Spain, Switzerland and Russia, sampled more than 1100 living and dead mountain pines from the Spanish Pyrenees and 660 Siberian larch samples from the Russian Altai: both high-elevation forest sites that have been undisturbed for thousands of years. Using these samples, the researchers were able to reconstruct the total lifespan and juvenile growth rates of trees that were growing during both industrial and pre-industrial climate conditions.

The researchers found that harsh, cold conditions cause tree growth to slow, but they also make trees stronger, so that they can live to a great age. Conversely, trees growing faster during their first 25 years die much sooner than their slow-growing relatives. This negative relationship remained statistically significant for samples from both living and dead trees in both regions.

The idea of a carbon residence time was first hypothesised by co-author Christian Körner, Emeritus Professor at the University of Basel, but this is the first time that it has been confirmed by data.

The relationship between growth rate and lifespan is analogous to the relationship between heart rate and lifespan seen in the animal kingdom: animals with quicker heart rates tend to grow faster but have shorter lives on average.

"We wanted to test the 'live fast, die young' hypothesis, and we've found that for trees in cold climates, it appears to be true," said Büntgen. "We're challenging some long-held assumptions in this area, which have implications for large-scale carbon cycle dynamics."

###

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

URL查看原文
来源平台EurekAlert!
文献类型新闻
条目标识符http://119.78.100.173/C666/handle/2XK7JSWQ/129230
专题气候变化
推荐引用方式
GB/T 7714
admin. Amount of carbon stored in forests reduced as climate warms. 2019.
条目包含的文件
条目无相关文件。
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[admin]的文章
百度学术
百度学术中相似的文章
[admin]的文章
必应学术
必应学术中相似的文章
[admin]的文章
相关权益政策
暂无数据
收藏/分享
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。