Invading Beavers Turn Tundra to Ponds

入侵的海狸把冻土地带变成了池塘

New beaver ponds in the Arctic may contribute to the destruction of the permafrost that holds that landscape together.

北极新出现的海狸池塘可能会破坏永久冻土层。而永久冻土是将北极各种地貌维系在一起的关键。

撰文/播音：艾米莉··施温（Emily Schwing）

翻译：张艺箫

审校：潘磊

When you look at satellite images it’s easy to pick out hurricanes, deserts, and the work of a certain semiaquatic rodent:

当你在看卫星图像时，很容易辨别出飓风，荒漠，和一种半水栖啮齿动物的工程痕迹

“And the reason you can see beaver activity from space is because they leave a mark on the landscape.”  

“你能在外太空中看出海狸活动是因为它们对地貌造成影响”

Ken Tape is an Arctic Ecologist at the University of Alaska Fairbanks.  

Ken Tape 是阿拉斯加费尔班克斯大学的一位北极生态学者

“So they make these ponds, and when a pond forms my idea was that we could infer, if it was a certain kind of pond and we could see a beaver dam, then we could infer that beavers had moved into that area, or moved out of that area if it’s a beaver pond that’s drained.”  

“所以他们创造了这些池塘，当有一个现成的池塘，我想我们可以进行推断。如果在这类池塘中我们可以找到一个海狸筑的水坝，我们可以知道，海狸已经进入该地区；如果水坝已经被毁掉，我们可以推断海狸已经搬走。”

Tape and a team of other scientists used Landsat satellite images that cover more than 19,000 square kilometers of in Alaska.

“We saw lots of new beaver ponds, I think we saw 56 new beaver ponds formed between 1999 and 2014.”

Tape和一支科学家团队参考了陆地卫星（Landsat）图像。拍摄范围覆盖了阿拉斯加州超过19000平方千米的冻原地带。

“我们看到了许多新形成的海狸池塘。我想我们看到了56个池塘在1999到2004年期间形成。

Beavers are considered keystone species, which have an outsized effect on their ecosystem. 

海狸被认为是对其周围生态系统有重大影响的物种

“And I think it’s particularly true in the Arctic because it’s underlain by all this frozen ground.”  

“我认为这一点在北极尤为明显，因为那里被冻结的地面完全覆盖。”

He’s talking about permafrost.

他所说的正是永久冻土层

“And what happens is when you start flooding permafrost areas, permafrost starts to deteriorate. And really the glue that’s binding the soil together, that’s holding the landscape together starts to thaw.”  

当你用水淹没冻土地区会导致冻土土质开始恶化。真正将土壤黏合到一起，维持着地貌的“胶水”开始融化。

Tape and colleagues presented their findings December 11th at the annual conference of the American Geophysical Union. He says the implications of beavers’ northward expansion are big.

Tape和他的同事们在12月11日召开的美国地球物理联盟年度会议上展示了他们的发现。他表示，海狸向北迁移的影响是巨大的。

“Imagine that you just dropped 56 groundwater springs into Arctic stream environments. A groundwater spring in the Arctic is a rare thing in the Arctic and it’s an oasis of biologic activity for fish spawning and things like that.”  

“想象一下，你把56个地下泉水源土壤突然放到了北极的河流环境中。地下泉水源在北极是一种罕见的东西，它是一片生命活动的绿洲，鱼类产卵等等行为在这里发生。

Beavers may be following the northward expansion of vegetation onto the tundra.

海狸也许会随着冻土地带植被区域的向北扩张而呈同样的趋势。

“But the other possible driver is rebound from heavy trapping a century ago.”  

“但另一个可能的驱动力是海狸正在收复一个世纪之前被严重缩减的栖息地。

If they contribute to the deterioration of the permafrost, you could call it coming back with a vengeance.

如果它们会导致冻土层的退化，你可以称之为复仇。