南冰洋溫度上升一攝氏度，會(huì)有哪些變化？

研究者們?yōu)榱伺宄蜃兣瘜?duì)海洋生物的影響，實(shí)施了一項(xiàng)實(shí)驗(yàn)。他們發(fā)現(xiàn)海床溫度升高1℃，海洋原生動(dòng)物的繁殖速度加倍了，最終控制了這個(gè)種群，使得其他物種消失，從而減少了生物的多樣性。

After warming a natural seabed in the Antarctic Ocean by just 1℃ or 2℃,researchers observed massive impacts on a marine ecosystem,as growth rates nearly doubled. The results of what the researchers call“the most realistic ocean warming experiment to date”reported in Current Biology on August 31 show that the effects of future warming may far exceed expectations.

“I was quite surprised,”says Gail Ashton of the British Antarctic Survey and Smithsonian Environmental Research Center，“I wasn't expecting a significant observable difference in communities warmed by just 1°C in the Antarctic.I have spent most of my career working in temperate climates where communities experience much greater temperature fluctuations（波動(dòng)）and wasn’t expecting such a response to just 1°C of change.”

Predicting how organisms and whole communities will respond to climate change in the future remains a major challenge.So,Ashton and her colleagues decided to actually warm an area of seabed around the Rothera Research Station and watch what happened.They used heated settlement panels（面板）to warm a thin layer of water by 1°C or 2°C above the surrounding temperature.Those increases in global temperature are expected within the next 50 and 100 years,respectively.

The experiment showed that with a 1°C increase in temperature,a single pioneer species of protozoan（原生動(dòng)物）increased in number like crazy.That one species finally dominated（支配）the community,driving a reduction in overall species diversity and evenness within two months.

The responses of organisms to a 2°C rise in tem perature were much more variable.Growth-rate responses to warming differed among species,ages,and seasons.Species generally grew faster with warming through theAntarctic summer.However,different responses among species were observed in March,when both food availability forsuspension feeders and surrounding temperature declined,the researchers report.

The researchers said the findings suggest that climate change could have even greater effects on polar marine ecosystems than had been anticipated.As the planet warms,there will be winners and losers.

The researchers say they now plan to expand the use of this technology to investigate the response to warming in other locations and communities,including the Arctic.