男女羞羞视频在线观看,国产精品黄色免费,麻豆91在线视频,美女被羞羞免费软件下载,国产的一级片,亚洲熟色妇,天天操夜夜摸,一区二区三区在线电影
WORLD> Asia-Pacific
Australia's forests key to global warming fight
(China Daily)
Updated: 2009-06-17 09:03

CANBERRA: Ancient Australian forests are key to fighting climate change and contain the world's most dense carbon store, eclipsing tropical rainforests as efficient greenhouse gas absorbers, scientists said Tuesday.

Towering Mountain Ash forests covering Victoria state's cool highlands hold four times more carbon, or around 1,900 tons of carbon per hectare, than tropical forests, scientists at the Australian National University said.

"The trees in these forests can grow to a very old age, at least 350 years, and they can grow very large, very tall, and they grow very dense, heavy wood," said Brendan Mackey, a professor of environment science.

The researchers studied biomass data from 132 forests around the world to discover regions storing the most carbon, with results published in the Proceedings of the National Academy of Sciences.

The Australian forest was compared to old growth tracts on the United States Pacific Coast, Siberia, the central Amazon, Thailand and Cambodia, Venezuela, Finland and elsewhere.

The findings overturn conventional thinking about the carbon density of different forest types that until now held that tropical rainforests were the most carbon-dense, Mackey said.

The Victorian forest, part of the water catchment for Australia's second biggest city Melbourne, was a large store because the area had been protected from logging, highlighting the link between old growth forest felling and global warming.

"Part of the reason these trees store so much is that they have reached mature growth. You are just never going to store the same amount of carbon if you are turning the forest over every 40 years," Mackey said.

"This reinforces the point that we need to think about the carbon value of these forests, which we've just been thinking of until now as wood supply," he said.

A second reason for Mountain Ash's carbon efficiency was that plant growth rates were balanced by rates at which biomass decayed, with the cool Victorian forests conducive to high growth and slower rates of decomposition.

That placed Australia's living and dead biomass carbon among Mountain Ash forest at 1,900 tons per hectare against 650 tons per hectare in temperate US Pacific forests and between 140 and 250 tons in most rainforests globally.

The Victorian forests are in rugged mountains at the head of the Yarra River, which eventually flows through the center of Melbourne, and is surrounded by national park and state forest.

Mackey said the findings could be of real help in planning the fight against climate change in other parts of the world.

"If we were to have climate change policies that recognized the mitigation value of the carbon stocks in natural forest, then that would give a completely different set of values about forest resource management," he said.

Australia's Wilderness Society said the carbon stored in the native forests of Southeast Australia was equivalent to 460 million tons of greenhouse gas per year for the next 100 years, with 9.3 billion tons of carbon stored.

Reuters

主站蜘蛛池模板: 叙永县| 禹州市| 阿克苏市| 伊宁市| 登封市| 博野县| 伊宁市| 大丰市| 讷河市| 罗山县| 宿州市| 搜索| 普定县| 洪泽县| 南江县| 寿阳县| 资兴市| 克拉玛依市| 阿克陶县| 都安| 呼玛县| 方正县| 许昌县| 永新县| 华阴市| 林州市| 南和县| 邳州市| 利川市| 全椒县| 泾阳县| 武平县| 平凉市| 乾安县| 枣庄市| 囊谦县| 满城县| 广元市| 随州市| 江都市| 来宾市| 海口市| 怀宁县| 武威市| 华坪县| 贵港市| 沈丘县| 阿尔山市| 古田县| 万州区| 甘泉县| 山阳县| 冕宁县| 新闻| 阜南县| 海晏县| 琼结县| 平乐县| 丰城市| 方山县| 宁都县| 玉门市| 马山县| 涟源市| 通海县| 九龙县| 睢宁县| 右玉县| 鄄城县| 惠水县| 安溪县| 湘阴县| 遂昌县| 徐汇区| 怀来县| 贡觉县| 伊宁市| 浠水县| 武强县| 古田县| 宁海县| 肇州县|