In spring, hundreds of millions of birds make the annual trip to the arctic tundra.

春天里，数以亿计的鸟类像往年一样踏上了前往北极苔原的旅程。

But which places—Arctic tundra or Amazon rainforest—are most vulnerable to such climate change?

但是那些地方更容易受到气候变化影响呢？是北极苔原还是亚马逊热带雨林呢？

For lemmings, small fussy rodents, there is no place more comfortable than the Arctic tundra.

对于旅鼠这种小而挑剔的啮齿类动物来说，没有比北极苔原更舒适的地方了。

They report today that a white-spruce population has migrated surprisingly far north into the Arctic tundra.

他们今天报告说，令人出乎意料，一批白云杉向北迁移到了北极苔原。

They regularly take down bison six times their size. But here on the Arctic tundra, reindeer are their stable food.

它们经常制伏六倍于自己体型的北美野牛，但在这北极苔原上，驯鹿就是它们的主食。

Models predict that fires in the boreal forests and Arctic tundra will increase by up to four times by 2100.

多个模型预测，到2100年，寒带森林和北极苔原的火灾将增加4倍。

The arctic tundra is a vast treeless landscape that engulfs the earth between the North Pole and the coniferous forests of the Taiga.

北极苔原是一片广阔而没有树木的地带，它覆盖了北极与针叶泰加林带之间的整个地域。

It may seem strange to have herds of horses and cold-adapted sheep grazing the Arctic tundra. But then again, we're living in strange times.

让一大群马和适应寒冷的绵羊在北极冻原上吃草，这似乎有点奇怪。但话说回来，我们本来就生活在一个奇怪的时代。

Next up, a snowy owl normally found in the Arctic tundra shows up 3,000 miles away amid palm trees and beaches of sunny southern California.

接下来的新闻，一只雪鸮出现在了加利福尼亚州南部长满棕榈树的阳光沙滩上，但是雪鸮一般生活在距离加利福尼亚州3000英里以外的北极苔原带。

It may seem strange to have herds of horses and cold-adapted sheep grazing the Arctic tundra.

成群结队的马和适应寒冷的绵羊在北极苔原上放牧似乎很奇怪。

It's a head scratcher, all right, how did a snowy owl that normally lives in the Arctic tundra end up amid the palm trees of southern California?

真是百思不得其解。对吧？一只生活在北极苔原带的雪鸮到底是如何最后出现在加利福尼亚南部的沙滩上的呢？

The bear recently arrived from Louisville, Kentucky and is part of the Arctic tundra exhibit, which will teach the visitors about the impact of climate changes having on polar bears.

这只北极熊最近从肯塔基州的路易维尔来到这里，是北极苔原展览的一部分，旨在教给游客气候变化对北极熊的影响。

And once it thaws, that collapsing ground can drastically alter the vast expanse of the Arctic's tundra and boreal forest, and it can also threaten the homes and lifeways of Arctic residents.

一旦永久冻土开始融化，坍塌的土地会彻底改变北极地区大片的苔原和北部针叶林，这也威胁着北极地区居民的家园和生活方式。

For lemmings, small fussy rodents, there is no place more comfortable than the Arctic tundra.Their presence ensured their well-being of other tundra inhabitants that eat them: owls, Arctic foxes, weasels, eagles, gulls and cranes.

对于旅鼠这种小而挑剔的啮齿类动物来说，没有比北极苔原更舒适的地方了。它们的存在确保了其他苔原栖息者的福祉，猫头鹰、北极狐、黄鼠狼、鹰、海鸥和鹤都以它们为食。