Two-thirds of tropical forests ‘under threat in next decade’

[SÃO PAULO] Tropical forests can develop resistance to a warmer climate, but 71 per cent will come under threat in the next decade if global average temperatures reach two degrees Celsius above pre-industrial levels, a new study warns.

Forest-dependent communities and the global climate will be affected if tropical forests are further degraded, experts say.

Led by scientists at the University of Leeds and出版于科学, the study involved 226 researchers from around the world. The cohort analysed carbon stock data in 590 permanent forest plots in South America, Africa, Asia and Australia, with most in the Amazon region.

亚马逊雨林充当巨大的碳水槽，吸收和储存二氧化碳（CO₂）并帮助冷却全球温度。即使在高温下，树木也去除CO₂- 从大气中有助于全球变暖的温室气体。

However, the ability to store high levels of carbon drops dramatically if the forest is exposed to average temperatures above 32.2 degrees Celsius, the researchers found.

热带地区的可持续发展将直接影响if the biodiversity of tropical forests is altered by rising temperatures and they lose their ability to absorb carbon, says Luiz Aragão, head of the remote sensing division at Brazil’s National Institute for Space Research and a co-author of the study.

“Understanding how climate change impacts carbon absorption in tropical forests can help us identify the most vulnerable areas where biomass loss can interfere with local economies and human development,” he says.

Plínio Barbosa de Camargo, a researcher at the Centre of Nuclear Energy in Agriculture at University of São Paulo and a study co-author, has been monitoring permanent plots in Santarém, in Brazil’s Amazon, for 20 years. His team monitors the growth of about 20,000 trees and measures the forest's biomass and carbon balance.

“The region we monitor still has the capacity to absorb carbon and recover after prolonged periods of drought,” he says.

“This gives room for different societies to continue investing in the development of products and services from biodiversity.”

但是，只有通过适当的缓解气候变化以及用于保护和恢复本地植被的解决方案，森林的弹性潜力才能实现。

“The results suggest that intact forests can withstand heating to some extent,” but for this to happen it is vital that forests remain intact, agronomist and study co-author Simone Aparecida Vieira, from the Centre for Environmental Studies and Research at São Paulo’s University of Campinas (Unicamp), tellsSciDev.Net.

This requires reducing deforestation rates and the frequent fires associated with forest clearing, as well as mining, illegal logging and intensive low-productivity livestock farming.

“Understanding how climate change impacts carbon absorption in tropical forests can help us identify the most vulnerable areas where biomass loss can interfere with local economies and human development.”

路易斯·阿拉格（LuizAragão），巴西国家航天研究所。

Yet, it is unclear whether cooler forests in Asia and Africa will respond to global heating in the same way as those in South America or whether they can adapt in time, says Lara Kueppers, associate professor at the University of California, Berkeley’s energy and resources group, who did not take part in the study.

“I don’t have confidence that forests are going to be able to adjust on the time scale they will need to,” she says in a related科学commentary.

But, the research offers a good starting point to deepen knowledge about forests’ abilities to adapt to climate change, says biologist Ricardo Ribeiro Rodrigues from the Luiz de Queiroz School of Agriculture at the University of São Paulo, who was not involved in the study.