纪录片《我们的地球》 第08期 从南极到北极(8)

This vast forest circling the globe contains a third of all the trees on Earth

这片环绕着地球的广大森林容纳了地球上1/3的树木

and produces so much oxygen it changes the composition of the atmosphere.

产生了大量氧气，从而改变了大气成分

As we travel south so the sun's influence grows stronger

随着我们向南行进，太阳的影响力逐渐增强

and at 50 degrees of latitude¹ a radical² transformation³ begins.

北纬50°的地方是一场重大变革的起点

Summers here are long enough for broadleaf trees to replace conifers.

由于有足够长的夏季，阔叶林得以取代针叶林

Broadleaves are much easier to eat and digest

阔叶树的树叶更容易食用和消化

so now animals can collect their share of the energy that has come from the sun.

因此动物们也能获得太阳馈赠给它们的那部分能量

It's summer and these forests are bustling⁴ with life.

现在是夏天，森林中一片生机勃勃的景象

But the good times will not last.

可是好景不长

Broad leaves must be shed in winter for their damage by frost.

由于严寒的原因，阔叶树得在冬天落叶

As they disappear, so the land becomes barren with little for animals to eat.

树叶消失之后，大地一片荒凉，动物们的食物日益稀少

The inhabitants must migrate, hibernate⁵, or face months of near starvation.

居民们只得迁往他处，或者冬眠，或者忍受几个月的饥荒

1 latitude   

n.纬度，行动或言论的自由(范围)，(pl.)地区

参考例句：

• The latitude of the island is 20 degrees south.该岛的纬度是南纬20度。
• The two cities are at approximately the same latitude.这两个城市差不多位于同一纬度上。

2 radical   

n.激进份子，原子团，根号；adj.根本的，激进的，彻底的

参考例句：

• The patient got a radical cure in the hospital.病人在医院得到了根治。
• She is radical in her demands.她的要求十分偏激。

3 transformation   

n.变化；改造；转变

参考例句：

• Going to college brought about a dramatic transformation in her outlook.上大学使她的观念发生了巨大的变化。
• He was struggling to make the transformation from single man to responsible husband.他正在努力使自己由单身汉变为可靠的丈夫。

4 bustling   

adj.喧闹的

参考例句：

• The market was bustling with life. 市场上生机勃勃。
• This district is getting more and more prosperous and bustling. 这一带越来越繁华了。

5 hibernate   

v.冬眠，蛰伏

参考例句：

• Bears often hibernate in caves.熊常在山洞里冬眠。
• Some warm-blooded animals do not need to hibernate.一些温血动物不需要冬眠。