自然的运作（2012）

And the importance of wetlands to the planet is huge.
一方面 从山上流下来的水速减慢
At one end, the water from mountain streams slows down
而数以万计的植物像海绵 那样拼命吸收水分
and millions of plants soak it up like a sponge.
另一方面 不断流
At the other end, water is released as a steady flow.
从而保证了河流、河中的生物 以及更远的下游
Ensuring that the rivers and their inhabitants further downstream
全年都得到充足的水资源
get a reliable supply of life-giving water, all year round.
但是当河水到达海岸的时候
But as the river reaches the coast...
这里的环境如此恶劣
Here it creates an environment so inhospitable that in order to survive
所以为了生存那里的动植物 必须有惊人的应对方法
animals and plants have had to evolve some spectacular solutions.
浩瀚的恒河河口
The end of the mighty river Ganges.
这是地球上最大的沼泽地
This is one of the biggest swamps on earth,
孟加拉海岸上的孙德尔本斯
the Sundarbans on the coast of Bangladesh.
生命在这里面临的最大挑战 就是不断变化的环境
The biggest challenge life here faces is the constantly changing environment.
一天两次 潮涨潮退
Twice a day, with the rise and fall of the tide,
整个地方都被洪水淹没
the whole place floods.
珍贵的养分 如这些树叶 都被冲出了大海
Precious nutrients like these leaves wash out to sea.
更糟糕的是 这里充斥着咸水 和对大多数植物有害的毒素
And worst of all, salty water, toxic to most plants, drenches everything.
退潮后 留下的是厚实的泥土 连空气都不能穿透它们
The tide retreats leaving behind thick mud, so thick that not even air can penetrate it.
硫细菌可就找到乐土了
Sulphur breathing bacteria thrive here.
它们不断释放有毒的硫化氢
They're pumping out toxic hydrogen sulphide
以致于空气中 充斥着臭鸡蛋的味道
making the air thick with the stench of rotten eggs.
但是孙德尔本斯并非人间地狱 尽管环境的确很恶劣
But the Sundarbans is not the Hell on Earth that it might seem.
泥土中有很多长相奇怪的鱼在挪动 它们叫弹跳鱼
The mud ripples with the movement of strange looking fish, air-breathing mudskippers.
这里有250多种鸟
250 species of bird flourish here.
黑头翠鸟
Black-capped kingfisher,
条纹鹭
striated heron,
印度鸢
brahmany kite.
捕鱼的人也在这里找到了天堂
And a large fishing industry finds plenty to catch.
成群的哺乳动物在树林中漫步
Herds of large mammals roam the forests,
3万只白斑鹿
30 thousand chital deer
还有几千只狝猴
and thousands of macaque monkeys.
这些动物 让泥泞的沼泽地充满生气
All these animals bring this muddy swamp to life.
也为世界上最难以捉摸 最危险的动物提供充足食物
And provide enough prey for one of the world's most elusive and dangerous predators.
它就是孟加拉虎
The Royal Bengal Tiger.
科学家发现 目前这里的老虎 数量占了世界的五分之一
Scientists are only now discovering that as many as one fifth of the worlds tiger population live here.
孙德尔本斯要维持那么多 肉食动物和植物的生命
For the Sundarbans to support so many predators the plants and animals that live here
就必须有独特的策略来解决 沼泽地的生存问题
have some unique solutions to the problems of living in a swamp.
这全依赖于一种非常独特的树
It all starts with a very strange tree.
海榄雌
The mangrove.
在这么厚的泥土中 大多数植物都会迅速窒息死亡
In this thick mud most plants would quickly suffocate,
但是海榄雌却有 与众不同的应对方法
but the mangrove has a spectacular solution.
这些奇丑无比的长须其实就是 它的通气管
All these vicious looking spikes are actually snorkels
这些通气管可以把氧气输送到 埋在泥土深处的树根
allowing oxygen to reach the roots deep in the thick mud.
但是空气只能维持它的生存
But this air supply only keeps the tree from dying.
要茁壮成长 还需要一种动物的援助
For the mangrove to really flourish it needs the helping hand of an animal.
它只出现在低潮中
That only appears at low tide.
这片沼泽地是螃蟹的天堂
This swamp is home to millions of crabs.
吃叶子的螃蟹和招潮蟹
Leaf eating crabs and fiddler crabs.
招潮蟹因其巨大的钳而得名
A vastly enlarged front claw gives these fiddler crabs there name,
因为它们进食的时候 就像是拉小提琴
because when they're feeding it gives the impression that they're playing the fiddle.
它们也会向对手展示巨钳 以显示气势与力量
They also wave them at any adversaries in a show of size and strength.
用蟹钳来战斗 对它们而言轻而易举
But they come in particularly handy when engaging in claw-to-claw combat.
每一只螃蟹都要占据一个地盘
Each crab defends his claim to a valuable piece of land.
其中最重要的是地下的部分
The most precious part of which is underground.
这只招潮蟹正在挖洞 大概只有半米深
This fiddler is digging a burrow which could be over half a metre deep.
但是却很有用
But it's worth the effort
因为当肉食动物 如鹳来觅食 它们就有藏身之所了
because it gives the crab somewhere to hide when predators like this stork come feeding.
涨潮的时候 这里也就成了安全的港口
And when the tide moves in, it's a haven.
这些食叶螃蟹住在共同的洞穴中 洞穴间的隧♥道♥使之成为地下迷宫
These leaf eaters live in communal burrows and together their tunnels form an underground labyrinth.
这些螃蟹的洞穴对于海榄雌而言 十分重要
All of these crab burrows are vital for the mangrove.
潮水低的时候 它们挖土 建成了 一个提供空气的隧♥道♥ 直达树根
At low tide they channel an air supply through the mud, directly to the roots.
但不仅仅是氧气
And it's not just oxygen.
螃蟹还给海榄雌提供养分
The crabs supply nutrients to the mangrove.
这些招潮蟹在吃土壤中的细菌
These fiddlers are picking up particles of soil and eating all of the bacteria,
然后就剩下一堆干净的小沙球
leaving behind a scattering of cleaned balls of soil.
如果螃蟹不做这项工作 那么土壤 就会被一群有毒的硫细菌所占据
If the crabs didn't do this the soil would be choked by a layer of toxic sulphur breathing bacteria.
这只招潮蟹正在与潮水赛跑 把泥土带回洞穴
Racing against the tide, this fiddler is taking mud back to her burrow.
然后就继续进食 再用养分供给海榄雌的树根
Where she'll continue feeding and in turn release nutrients to nourish the roots of the mangrove.
当招潮蟹迅速收集泥土时
While the fiddlers quickly collect mud
吃叶子的螃蟹就会在落叶 被冲出大海前 把它们收集起来
the leaf-eaters gather up the fallen leaves before they wash out to sea.
它们可以收集孙德尔本斯 80%的落叶
They can collect up to 80 percent of the leaves that fall in Sundarbans,
然后把它们储存在洞穴的底部 从而滋养树木
and store them at the bottom of their burrows where they too will fertilise the trees.
这些螃蟹也司以帮助海榄雌 解决最致命的问题
The crabs also help to solve the mangroves deadliest problem,
盐
salt.
当潮水到达这些螃蟹的洞穴中 那新鲜地下水会与有毒海水混合
When the tide comes in all these crab burrows allow fresh groundwater to mix with the toxic seawater,
有毒的海水便得以稀释
diluting it.
这些洞穴组成的网路 延展了数千公里
This network of burrows extends for thousands of kilometres.
当科学家把螃蟹移出一个区域时 它们的重要性就显露出来
The importance of crabs is revealed when scientists remove them from a patch of mangrove.
该区域中的8棵树 死了7棵
7 out of 8 trees die.
正是这些螃蟹让孙德尔本斯 得以生存发展
Collectively crabs make the Sundarbans work.
如此重要、惊人的关系当然 不仅仅只产生这个作用
But this is not the only crucial and unexpected relationship.
螃蟹滋养了海榄雌 所以食草动物才有足够的食物
Thanks to the crabs gardening the mangrove, herbivores have plenty to eat.
这里有大量的猴子和鹿
These monkeys and deer gather in huge numbers.
它们的食量足以毁掉一个森林
Their appetites could destroy the forest.
这些猴子听到了不寻常的声音
But the monkeys sound a warning.
一只老虎
A tiger.
食草动物不断奔跑
Herbivores are kept on the move
肉食动物老虎阻止了 它们对树木的破坏
and through predation the tiger helps to limit the damage they cause to the trees.
所以老虎对孙德尔本斯 也是非常有价值的
And it's this that makes the tiger so valuable to the Sunderbans.
老虎需要螃蟹的帮助 形成树林
The tiger needs the crab to help build the forest,
而螃蟹需要老虎的帮助 保护树林
and the crab needs the tiger to help protect it.
这些无法取代的关系造就了 5000平方公里的海榄雌森林
All these unique relationships result in 5 thousand square kilometres of mangrove forest.
世界上最大的海榄雌森林
The largest in the world.
但是 这些关系并未就此结东
Surprisingly, these connections don't end here.
从全球范围来看 海岸线上的沼泽 如屏障般保护陆地免受暴雨影响
Across the planet, coastal wetlands act as barriers protecting the land from storms,
而且它们也为海洋中的鱼 提供养分
and they provide vital nurseries for ocean going fish.
但更重要的是它们以自己的方式 洁净水资源 防止养分的流失
But more importantly they help to clean the water on its way out to sea preventing the loss of nutrients.
而这对地球上海洋动物最多的 栖息地 有着深远的影响
And this has a profound effect on the survival of earth's richest marine habitats.
珊瑚礁
Coral reefs.
印度洋中的马尔地夫
The Maldives in the Indian Ocean
有着地球上最美丽的珊瑚礁
is where some of the finest coral reefs on earth can be found.
经过沼泽地和海榄雌后
Flowing through wetlands and mangroves,
大多数的泥沙都被滤掉 使这里的水几近洁净
most of the silt filters out, leaving the water here almost completely clear.
有四分之一的海洋动物 住在这个多彩的珊瑚城市中
Up to quarter of all marine species live in these vast colourful coral cities.
包括高级的肉食动物 如黑尖礁鲨
Including top predators like the black-tip reef shark.
这个海洋就好比热带雨林
It's like the ocean equivalent of a rainforest.
应该说更像沙漠
It should be more like a desert.
不仅沉积物少 养分也少
It's not just low in sediment it's low in nutrients.
但是这里的生物发展得还不错
But life flourishes here,
这得感谢地球上 最奇怪的生物之一
thanks to one of the strangest creatures on Earth.
不管这些奇怪的生物在哪里栖息 玳瑁都想要把它们吃掉
And wherever these strange creatures live a hawksbill turtle may be looking for one to eat.
这种龟的生命从岸上开始
This turtle starts life on the coast
但它大部分的时间都花在了 在珊瑚间寻找食物
but now it spends most of its time looking for food amongst the coral.
它的猎物也很奇怪 海绵 它是珊瑚礁中不摆架子的英雄
Its odd looking prey is a sponge, the unlikely hero of the reef.
海绵的身体非常坚硬 但是玳瑁可以咬破其皮肤
Sponges have tough flesh, but the beak of the hawksbill is able to bite through.
问题是如何在这些海洋的 水流中保持不动呢
The big challenge is keeping hold of it in these ocean currents.
水的流动和漩涡
These movements of the water and the swirling currents
对珊瑚礁而言 是最大的挑战之一
create one of the biggest challenges to all the reef.
但是海绵有应对策略
And the sponge has a solution.
作为地球上最奇特的动物之一
One of the most bizarre animals on the planet.
海绵有各种各样的形状和大小
Sponges come in all shapes and sizes.
它们没有心脏 神经系统和消化系统
They don't have a heart, a nervous or a digestive system.
关键是 它们藏身于珊瑚之间
Crucially they live embedded amongst the coral.
海绵和珊瑚之间的关系 是珊瑚礁形成的基础
The relationship between sponges and coral is the foundation of the reef.
珊瑚为礁石建立了基本的骨架
Coral provides the structural framework of the reef.
但事实上这是两个独♥立♥的生物体 一种动物和一种水藻
But it's actually two separate organisms, an animal and an algae.
这种动物叫珊瑚虫 只有几毫米长
The animal is called a polyp and it's just a few millimetres in length.
它有很多足 可以抓住洁净水中的微小颗粒
Using their many arms they constantly capture microscopic particles in the clear water.
但是它们90%的食物 来自珊瑚的小伙伴 水藻
But up to 90 percent of their food comes from their coral partners, algae.
水藻色彩斑斓 在珊瑚虫群体中安全地居住
Algae are the colourful specks that shelter within the safety of the polyps.
像植物一样 这些细小的水藻 经由光合作用得到大部分的养分