The Green Planet (Part Two)

◎万宇婧

上期我们了解了北极圈和赤道的不同生态风景，也领略了冰雪世界与热带雨林的极致反差，本期我们将走进水生植物与沙漠植物，带大家领略极端环境中的植物是如何绝地求生的。

剧情简介

植物在与动物建立互惠关系的同时，也展现了与其他生物一样的攻击性、竞争性。为争夺光照、空间、营养和繁殖的机会，它们与竞争对手展开激烈的生存斗争。这部纪录片透过全新科技呈现了二十多年来的新发现，深刻揭示了植物世界紧密相连的一面，将观众带入了一个超越人眼观察的深入角度，让人们从植物的角度看待地球。

Scene A

在含氧量极高的绿色水生世界，河床岩石上生长着一片粉色的水生植物——虹河苔，也被称作“瀑布兰花”。这片粉色羽毛般的丝状物，造就了卡诺克里斯塔莱斯河——地球上最美的河流之一。

Track 6

Plants cover much of the land surface of our planet.But there is another1)extraordinary green world, that is often hidden from us.It’s one where plants have2)overcome huge challenges in order to survive.At first sight, a lake like this would seem to have everything that life needs in order to3)thrive—clear,oxygen-rich water, plenty of dissolved nutrients and minerals and lots of sunlight.But in fact, life in fresh water presents plants with huge problems.To succeed, plants have had to abandon many of the adaptations that served them so well on land, and4)evolve something quite new.And in doing that, they have created some of the most beautiful and bizarre and important5)habitats on earth.

There are few places where it’s more difficult to make a6)permanent home than a freshwater7)torrent like this one.Violent currents8)rip across the riverbed, scouring it clean, ripping land plants from their9)margins and drowning them.How could any plant survive in a place like this? Yet, even here,some do manage to, quite literally, hold on! They can grasp the10)bare rock with remarkable strength.This ability allows plants to thrive in these otherwise11)hostile environments.

This is the Cano Cristales River in Columbia.These plants are Red Macarenia, sometimes called the “Orchid of the Falls”.They12)cling to the riverbed, not with their roots, but with their stems, blued to the rock surface by one of the most powerful adhesives in nature.The rock itself will break before these anchors lose their grip.These feathery filaments, are their modified leaves.And they do what roots normally do—gather the minerals and nutrients they need that are dissolved in the water.

With such13)spectacular colors,it’s hardly surprising that the Cano Cristales is sometimes called “the most beautiful river on earth”.

1) extraordinaryadj.非同寻常的

2) overcomev.克服；胜过

3) thrivev.茁壮成长；繁荣

4) evolvev.发展；进化

5) habitatn.栖息地

6) permanentadj.永久的；固定的

7) torrentn.急流

8) ripv.撕裂

9) marginn.边缘

10) bareadj.无遮蔽的；空的

11) hostileadj.敌对的

12) clingv.紧贴；附着

13) spectacularadj.壮观的；引人入胜的

植物覆盖了地球的大部分陆地表面，不过还有一个非凡的绿色世界往往会被我们忽视。在这个世界里，植物需要应对巨大的挑战才能获得一线生机。乍看起来，这样的湖泊似乎拥有生命繁衍生息所需要的一切条件——清澈而含氧量高的水、大量溶解于水的营养物质和矿物质，以及充足的阳光。然而事实上，淡水之中的植物，需要面对巨大的生存挑战。为了生存和繁衍，植物不得不放弃许多针对陆生环境的适应性改变，并发展出一些新的特征。在此过程中，它们也为地球创造了一些奇妙景致，一些发挥着关键作用的栖息地。

很难想象，像这样的淡水急流，能为一些植物创造出永久的栖息地。在激流之下，河床被冲刷得干干净净，就连长在河床边的植物也被冲刷下来，随波逐流。植物怎么可能在这样的环境中生存下来呢？然而，即便这里的环境如此恶劣，一些植物还是坚持了下来。它们能以惊人的力量，把自己固定在裸露的岩石上。这种能力使得一些植物可以在这些看似不可能的环境中生长。

这是位于哥伦比亚的卡诺克里斯塔莱斯河。这些植物是虹河苔，它们有时候也被称为“瀑布兰花”。帮助它们附着在河床岩石上的，不是它们的根，而是它们的茎。它们可以分泌一种自然界中最强的黏合剂。在长时间的黏合腐蚀之下，岩石会发生分解。这些羽毛般的丝状物，是虹河苔发生形变的叶子。它们可以像普通植物的根系一样，收集溶解在水中的矿物质和营养物质。

因为有着如此绚烂的色彩，卡诺克里斯塔莱斯河有时也被称为“地球上最美的河流”。

考点解析

in order to 的用法

原文：It’s one where plants have overcome huge challenges in order to survive.

1.in order to do sth 是to do sth 的变体。用in order to do sth 表示目的时，它既可以用于句首，也可用于句末；用于句首时，其强调意味较浓。

【例】She arrived early in order to get a good seat.

她到得很早，只为占个好座位。

In order to get into a good school, I must study even harder.

为了考入一所好学校，我必须更加努力。

2.in order to do sth 的否定形式是in order not to do sth，意思是“为了不……;以免……”。

【例】Please reply at once in order not to lose this opportunity.

为了不失去这次机会，请立即回复。

3.in order to 和in order that 均可表示目的，区别是前者引出不定式短语，后者引导目的状语从句。与in order to do sth 表示目的的情形相似，in order that 引导的目的状语从句可以位于主句之前或之后。

【例】These men risk their lives in order that we live more safely.

这些人甘冒生命危险，为的是让我们的生活更安全。

4.so as to 和so that 也可表示目的，区别是前者引出不定式短语，后者引导目的状语从句。与用so as to do sth 表示目的的情形相似，so that 引导的目的状语从句通常位于主句之后。so that 有时可省略其中的that。

【例】They wrote the notices in several languages so that foreign tourists could understand them.

他们用几种语言写公告牌，以便让各国游客都能看得懂。

Leave the keys out so (that) I remember to take them with me.

把钥匙放在外面，我好记得带。

Scene B

你应该听说过藻类，但你见过篮球那么大的圆形湖球藻吗？在北海道的阿寒湖，不仅有美丽的天鹅，还有一种神奇的湖球藻。这种湖球藻是如何生存的呢？

Track 7

The frozen water world of Lake Akan, in northern Japan, home to one of the strangest and most14)primitive of plants.It’s an alga, like those that appear so15)mysteriously in our ponds.But this one is truly extraordinary.Each spring, the melting ice releases soft, velvety balls of16)interwoven threads, called Marimos.

This one is small, no bigger than a walnut.But there are lots of them here.They attract the attention of visiting whooper swans.But there is one way for the Marimos to escape from the danger, and it depends on a change in the weather.Fortunately in the spring, winds sweep across the lake,creating currents that carry some of the Marimos beyond the reach of hungry swans.

It’s a start of a remarkable journey.They are gently carried back and forth by the currents, so that the Marimos become more and more17)spherical.And slowly, they travel into deeper water.Here there are great numbers of them, certainly many millions! Some are the size of basketballs.They are safe from swans and the water is stil18)shallow enough for some sunlight to reach them.It seems a perfect home.And so it is, almost.

The snag is that these waters also carry a fine sediment that can clog the Marimos’ surface, cutting off the all-important light.But the Marimos are not entirely19)immobile.The winds blowing over the lake’s surface create currents beneath that are sufficiently strong to move the Marimos.They rub against each other, and in just a couple of hours of gentle movement, they’re all clean once more.As they spin, every part of their surface gets enough time in the sunlight to keep growing.

14) primitiveadj.原始的

15) mysteriouslyadv.神秘地；不可思议地

16) interweavev.交织

17) sphericaladj.球状的

18) shallowadj.浅的

19) immobileadj.固定的；不动的

在日本北方阿寒湖的冰水世界中，生长着一种非常奇特而原始的植物。这是一种藻类，就像平时池塘里的那些隐秘藻类一样。不过，这种藻类有着非同寻常之处。每年春天，融化的冰水都会释放出天鹅绒般柔软的“线团”。它们被称为“湖球藻”。

这个湖球藻非常小，并不比核桃大多少。不过它们的数量非常惊人。来此逗留的天鹅，难免会对湖球藻产生兴趣。不过有一种方法可以让湖球藻脱离险境，而这取决于天气的变化。幸运的是，在春天，微风拂过湖面，湖水荡漾，一些湖球藻会被带到饥饿的天鹅无法触及的深水域中。

它们开始了一场非凡的旅行。在水流的裹挟下，湖球藻来回翻滚，变得越来越圆。它们慢慢地进入了更深的水域。大量的湖球藻在这里聚集，数量有百万之多！一些湖球藻甚至有篮球般大小。在这里，它们不会受到天鹅的伤害，而且水也不太深，所以阳光可以照射到它们。这里似乎是一个理想的家园。总体来说，确实不错。

因为湖水中也存在一些细小的沉积物，它们可能覆盖湖球藻的表面，阻隔其迫切需要的阳光。好在湖球藻并不是完全静止的。微风拂过湖面时，会在水下形成水流变化，这足以让湖球藻滚动起来。湖球藻相互摩擦推搡，经过几个小时的轻柔互动，它们又变得干干净净了。在转动过程中，湖球藻表面的所有部分都可以得到足够的阳光照射，并且能够不断地生长。

Know More

阿寒湖

阿寒湖位于日本北海道东部，是周长26 千米、海拔420 米、水深44.8 米的火山口湖，也是湖球藻生长的神秘之湖。在阿寒湖岸边，有多家温泉旅店。在阿寒湖的周边地区，也有一些很有特色的室外温泉，游客可以边泡温泉，边欣赏湖景。湖面上偶尔有结伴的天鹅在悠闲游动，冬天还可以看到白雪覆盖的层层远山。冬季的阿寒湖会结出厚厚的冰层，不仅可以徒步、冰钓，也可以承载雪地摩托。

Scene C

在一片荒漠世界中，能够存活下来的植物并不多。仙人掌是荒漠中最坚强的植物，也是荒漠中最危险的植物。一起来看看仙人掌是如何生长且自我保护的吧。

Track 8

Temperatures that20)swing from minus 20 to more than 40 degrees Centigrade.And most21)critically, almost entirely without rain.In every desert across the planet, plants have found ways to not only survive, but flourish.

In the Sonoran Desert of North America, the huge saguaro cacti have a different strategy.They store water in22)quantity and can live to a great age.But in their early years, they are extremely23)vulnerable.The young saguaro is protected by the mesquite’s branches.They24)halve the amount of scorching sunlight reaching the cactus, and so keep it cool.And the mesquite’s extremely long roots draw up water, bringing it within reach of the young saguaro.

No matter how old a desert plant is, water is always precious.Whether gathered from the melting snow, or a shower of rain.So cacti have developed extraordinary adaptations that enable them to not only collect water, but to25)retain it.Instead of leaves which would lose precious moisture through evaporation, they have spines.Each spine has a tiny padded-in space where the water is absorbed, and then stored in the great swollen trunk.A large saguaro could hold 5,000 liters of water.And it’s able to do so because it has another special adaptation.The ridges on its surface are like the pleats on an accordion; they allow the saguaro to change its shape.After rain has fallen, the pleats expand and the saguaro fills up its water tank.In the dry times, it uses its water to grow,produce flowers, and eventually, seeds.Fully loaded with thousands of liters of water, the saguaro won’t need to drink a single drop for another year.

But such valuable stores of water attract thieves.Now the spines function changes from collection to guarding.The spines of some species are a quarter of a meter long.Others are needle-like barbs that grow in clusters and easily break off in the skin of any animal that touches them.But perhaps the most vicious cacti belong to a group called “the chollas”.

This is called “a teddy bear cholla”, because the thick coating of spines on it.But don’t be deceived by the name.There is nothing cuddly about this particular teddy bear.In fact, it’s the most dangerous plant in the desert.And I wouldn’t dream of putting my hand anywhere near it without proper protection.Look closely at a spine, and you can see very clearly why they are so dangerous.Each is like a splinter of glass,sharp enough to pierce flesh.And they are covered with backward pointing barbs.

20) swingv.摇摆

21) criticallyadv.危急地；严重地

22) quantityn.数量

23) vulnerableadj.脆弱的；敏感的

24) halvev.（使）减半

25) retainv.保持

这里的气温最低可达到零下20 摄氏度，最高能超过40 摄氏度。最为严酷的是，这里几乎没有降水。在全球各地的荒漠中，有一些植物不仅找到了生存之道，还能繁衍壮大。

北美洲索诺拉沙漠中的一种巨大的仙人掌——巨人柱，采用了另外一种生存策略。它们可以大量储存水分，而且寿命很长。但是巨人柱在成长初期非常脆弱。牧豆树分散的枝条，保护了年幼的巨人柱，使它避开了一半的烈日炙烤，为它创造出些许凉爽。牧豆树的根系发达，它在汲取水分的过程中，也能让巨人柱幼苗的根系分享便利。

无论荒漠植物的年龄大小，水资源永远是珍贵的。它们的水分来源可以是融雪，也可以是雨水。仙人掌已经进化出超强的适应能力。它们不仅可以收集水分，还能储存水分。为避免水分蒸发，它们的叶片已经退化成了尖刺。每根刺的根部都连接着可以吸水的刺座。这些水分会汇聚，然后储存到巨大的茎干中。一株体型较大的巨人柱，可以储存多达5000 升水。能做到这一点，是因为它们进化出了另外一种能力。巨人柱表面的棱，就像是手风琴的褶皱一样，可以伸缩、变形。降雨来临时，它们会将褶皱撑开，把水分储存在茎干中。荒漠重回干旱之后，它们就依靠茎干里面的水分，生长、开花并结籽。这株巨人柱已经储存了数千升的水，哪怕不再吸收一滴水，也可以存活一整年的时间。

但是，珍贵的水资源会引来窃贼。于是，尖刺开始发挥收集水分之外的另一项功能——防御。一些仙人掌的刺长度可超过25 厘米，另一些则像一簇簇的尖锐倒钩。如果有任何动物胆敢触碰仙人掌，就会被刮破皮肉。最危险的一种仙人掌，或许就是多刺仙人掌家族的成员。

这种仙人掌叫作“泰迪圆柱”，因其表面覆盖一层浓密的刺而得名。但是不要被它的名字误导。这种“泰迪熊”可不能抱在怀里。实际上，它是荒漠中最危险的植物。如果没有恰当的防护措施，我绝对不会用手去碰它。仔细观察其中的一根刺，我们就知道它为什么那么危险了。它的每一根刺都像是一块玻璃碎片，非常尖锐，足以穿透皮肤，而且上面布满了倒刺。

考点解析

instead 常见用法

原文：Instead of leaves which would lose precious moisture through evaporation, they have spines.

1.instead 为副词，相当于 rather than，只能修饰动词或是句子，它的位置比较灵活，可以放在句首或句尾，在口语中，经常放在句尾。

【例】Instead, let all of that teach you what it can do.

相反，让所有这些教会你它能做什么。

I’m going to drop yoga and do aerobics instead.

我要放弃瑜伽，改做有氧运动。

2.instead of 是介词短语，后面一般接名词、代词、动名词或介词短语作它的宾语，可以放在句首或句尾。

【例】I’ll have tea instead of coffee.

我要茶而不是咖啡。

Instead of complaining, why don’t we try to change things?

与其抱怨，我们不如试着改变一下？

3.instead 与instead of 表达的意义不同：instead 句中的动作是要去做的，instead of 句中的动作或对象是要被替代的。

【例】I’m too tired to play football today.I’m going to stay at home instead.

我今天太累了，不能踢足球。我要待在家里。（待在家里是要去做的动作）

Now I can walk to work instead of going by car.

现在我可以步行去上班，而不必开车了。（开车是要被替代的动作）

4.instead 与instead of 在一定情况下可互换。

【例】Yesterday she didn’t hang out.She read books at home instead.

=Yesterday she didn’t hang out.Instead, she read books at home.

= Yesterday she read books at home instead of hanging out.

昨天她在家读书，而不是出去闲逛。