自然的运作（2012）

地球上有一千万个物种
10 million species live on planet earth.
但没有哪个物种 可以单独存活下来
But none can survive alone.
一切生命都有赖于 与其他物种的联♥系♥
All life depends on connections.
数百万种动植物间 有着始料未及的复杂联♥系♥
Unexpected and complex relationships between millions of plants and animals.
这次...
This time...
在热带雨林中
the tropical rainforest
高大的巴西坚果树...
Where the mighty brazil nut tree...
要依靠刺鼠生存
owes its life to the tiny agouti.
独特的联♥系♥使这里孕育出的物种 比地球其他地方都多
And extraordinary relationships have created more creatures than anywhere else on earth.
（大自然法则）
（丛林）
巴拿马
Panama.
以北部联♥通♥ 加勒比海...
Famous for its canal that connects the Caribbean sea in the north...
...南部融入太平洋的运河著称
...to the great ocean of the Pacific in the south.
运河侧面 有一片特殊的茂盛雨林
Flanking the canal a very special area of rainforest thrives.
管道之路
Pipeline Road.
道路沿着第二次世界大战时 一条旧管道分布
It runs next to an old pipeline from World War ll
这条贯穿原始雨林的管道 曾用来运油
that carried oil and carves through pristine rainforest.
和各地的雨林一样 这里拥有大量的动植物
Like rainforests everywhere it has an enormous number of plants and animals.
而鸟类尤其繁盛
Birds particularly flourish here.
志愿者们在这里创下了 新的世界纪录
Volunteers set a new world record in the area,
仅24小时内 就看到了357种不同的鸟类
spotting 357 different types of bird in just 24 hours.
此处成为了鸟类观赏者的 朝圣地
Making it a Mecca for birdwatchers.
即使在同一类鸟中 也存在惊人的多样性
Even within one group of birds, an amazing amount of variety exists.
蜂鸟
Hummingbirds.
它们以花蜜为食 觉得这些糖汁难以拒绝
They feed on nectar and find these dishes of sugar solution irresistible.
仅就这个鸟类来讲 巴拿马就有59种不同的蜂鸟
Within this family alone Panama boasts 59 different species.
它们拍打翅膀的频率在 一秒50次
Their wings beat at 50 times a second.
杂技般的飞翔方式意味它们能在 花朵间迅速移♥动♥及空中悬停觅食
And their acrobatic flight means they can dart between flowers and hover while they feed.
实际上 它们是唯一一种 可以倒着飞的鸟
In fact, they're the only group of birds able to fly backwards.
它们需要这种精湛的飞行技艺
They need such good flying skills
是因为它们的腿部短小纤细 无法行走
because their legs are so small and weak, they can't walk.
但持续飞行也要付出代价 这些乌必须每10分钟进食一次
But constant flying has a cost, and these birds must eat every ten minutes to stay alive.
它们的不同之处在于 鸟喙的大小和形状
Some of the variety between them is bill size and shape.
不过它们都以花蜜为食
While they all feed on flowers
根据喙部的大小 它们会吃相应种类的花蜜
their different bills allow them to specialise in feeding on different shaped flowers.
雨林展现出了各个动植物种群 惊人的多样性
Jungles show amazing variety in all different animal and plant groups,
从蜂鸟到箭毒蛙
from hummingbirds to poison arrow frogs.
这叫做生物多样性 即各个物种的数量
It's called biodiversity - the number of different living things.
这种生物非凡的多样性 让雨林独一无二
This extraordinary amount of biodiversity makes jungles unique.
它们的所在地 就是生物多样性的关键
Their location holds the key.
热带
The tropics.
在亚洲 雨林覆盖了上百座鸟屿
In Asia, rainforests cover hundreds of islands.
其中包括地球上一些 最偏远的地区
They include some of the remotest places on Earth.
横跨印度洋 是非洲刚果盆地雨林
Across the Indian ocean: Africa and the rainforests of the Congo basin.
再往西 是美洲亚马逊雨林
Further west, the Americas and the Amazon rainforest,
生长着热带最大的 连贯树木带
harbouring the largest unbroken expanse of trees in the tropics.
这些丛林共同形成了一条 围饶地球的翠绿环带
Together these jungles form an emerald band, that circles our globe.
在热带 温度湿度 全年居高不下
Here in the tropics, heat and moisture stay high all year round -
这种气候 便是生物多样性的关键
and this climate holds the key to biodiversity.
每年2500毫米降雨量
2% metres of rain falls every year.
湿度持续在80%左右
And humidity hovers at 80%.
植物通过混合二氧化碳与水 在光合作用中汲取养分
Plants get food by combining carbon dioxide and water, in the process of photosynthesis.
不缺水 就意昧着可以不断进行光合作用
No shortage of water means no shortage of photosynthesis.
阳光中的能量 为光合作用提供动力
Energy from the sun powers this reaction.
在赤道上 这些森林接收到的 阳光比其他纬度更强烈
Being on the equator, these forests receive more intense sunshine than anywhere else -
每天有12小时的稳定光照
a steady 12 hours of daylight every day.
雨林一年 所收到的阳光能量
The sun's energy captured by rainforests in one year alone
就够加州用2000多年
could power California for over a 2000 years.
所有这些能量促成了 这里独有的大规模光合作用
All this energy fuels photosynthesis on a scale unseen anywhere else.
茂盛的雨林植被给 食叶动物提供了丰盛的食物
Thriving rainforest plants provide an abundance of food for animals that can eat leaves.
切叶蚁是这些森林中的 主要食叶动物
Leaf cutter ants are the main herbivore in these forests.
大量食物使每个蚁巢里容纳了 多达700万只切叶蚁
Plentiful food allows each nest to contain as many as 7 million individuals.
雌工蚁整天收集树叶
Female workers collect leaves all clay long.
它们尖锐的颌部每秒震动 超过1000次以切碎树叶
Their sharp jaws vibrate at over a thousand times a second to slice off pieces of leaf.
但切叶蚁无法靠自身消化树叶
But leaf cutter ants can't digest leaves on their own.
它们现在需要运送超过 自身体重3倍的东西回巢
They now have to transport something over three times their bodyweight back to the nest.
它们将叶子碎片深埋在 巢穴里
They deposit the leaf fragments deep within the nest.
更小点的特殊工蚁 将树叶供给真菌
Specialised smaller ants feed the leaves to a fungus,
切叶蚁以真菌为食
which the ants then eat.
这座真菌农场生长得非常广袤
This fungal farm grows very large -
蚁巢可以发展到 一辆小卡车大小
the nest can become as big as a small truck.
体型巨大的切叶蚁蚁后 待在巢穴中♥央♥
The gigantic leaf cutter queen stays in the heart of the nest,
每天产下多达3万颗蛋
laying up to 30,000 eggs a day.
但这点燃了与植物之间的战火
But this starts a war with the plants.
这些蛋将孵化出更多工蚁 它们会整天切割树叶
These eggs will form more worker ants, which will spend all clay attacking leaves.
在这种气候下 雨林没有冬天 也就是说这些害虫不会冻死
The climate means rainforests don't have winters, so these pests are never killed off by cold.
对植物来说 这就意味着持续不断的攻击
For the plants, this means relentless attack.
仅这些切叶蚁就能毁掉它们 觅食地20%的树叶
These leaf cutter ants alone destroy 20% of the leaves in the area where they forage.
而且还有更多害虫 加入攻击行列
And many more plant pests join the assault.
有蚱蜢
Grasshoppers.
毛虫
Caterpillars.
蛞蝓和蜗牛
Slugs and snails.
几乎每片树叶 都有害虫攻击过的痕迹
Almost every leaf shows signs of pest attack.
为了一线生机 植物必须自我保护
To stand any chance of survival, plants have to defend themselves.
雨林中每棵植物 都配备起了武器
Every single plant in the rainforest has taken arms.
有些进化出了钩子 有些是毒刺
Some have evolved hooks, others vicious thorns.
有些采用了化学武器 在叶子中注满毒素
And some have taken to chemical weaponry, filling their leaves with poisons.
食叶动物不得不适应环境 找到一种方式规避这些抵御措施
Plant eaters have had to adapt to find a way around these defences.
比如这只雌性三趾树懒
Like this female three toed sloth.
她有又长又强壮的前腿 帮助她爬动觅食
She has long, strong front legs to help her climb around for food,
可以爬到20米高的树冠处
20 metres up in the canopy.
韧带将她的脚趾头连接在一起 让她的爪子变成了大钩子
Ligaments bind her toes together, turning her claws into large hooks,
所以她能毫不费力地 吊在树枝上
so she hangs from a branch without spending much energy.
这种奇怪的身体结构是 为了适应一种特殊的饮食方式
This bizarre body has developed as one big adaptation to a specialised diet.
她吃好几种树木
She eats just a few kinds of tree.
这些坚硬树叶含有大多数动物 都无法消化的不可食用毒素
These tough leaves contain inedible toxins that most animals can't digest.
她的胄部进化出专门的袋状系统 能将不同消化阶段的食物分开
Her gut has developed a special system of pouches to separate food in various stages of digestion
而且里面含有特殊细菌 可以分解树叶
and it hosts specialised bacteria that break down the leaves.
但消化要用上好几个星期
But digesting can take weeks.
这表示她每天只能吃 一小点食物
This means she only has space to eat a very small helping of leaves a clay -
只有一个小鸡蛋那么重
the weight of a small egg.
她的进食方式只能汲取很少能量 因此她只好将运动量减到最小
She gets so little energy from this diet, that she must keep movement to a minimum.
这就解释了树懒 出了名的移♥动♥迟缓
This explains the famous slowness of sloths.
她几乎成了森林里的不动产
She has almost become part of the forest furniture
其他动物开始迁入
and other creatures have started to move in.
她成了一群树懒蛾 理想的家园
She has become the ideal home for a colony of sloth moths.
她看似无害但树懒吃树叶的习性 让她成为了植物反击的对象之一
She looks harmless but this sloth's leaf eating makes her part of the plant pest battle too.
她的外貌、移♥动♥方式 以及进食方式
The way she looks, the way she moves and the way she eats
都帮她克服了植物的抵抗
all help her overcome the plant's defences.
为了在这场战争中存活 食叶动物要有种特殊的进攻方式
To survive in this war, plant eaters need to have a specialised mode of attack.
每种植物和害虫都锁定在一场 不断进化的战争中 适者生存
Each plant and pest becomes locked in an ongoing battle, and all must adapt, or die.
持续的战争 让生物更加多样
The continuous warfare creates even more biodiversity.
这条西番莲藤用化学物质 进行反击 在叶子上涂氰化物
This passionflower vine uses chemicals to fight back - lacing its leaves with cyanide.
氰化物对昆虫 的威胁和对人类的威胁一样大
And cyanide poses just as much danger to insects as it does to humans.
但不是所有昆虫都怕氰化物
But not all insects.
这些毛毛虫有反♥攻♥的方法
These caterpillars have a counter attack.
它们来自毒蝶家族 名为海神毒蝶
They're from a Heliconius butterfly, called Heliconius Doris.
海神毒蝶进化出了特殊化学物质 能抵抗植物所产生致命氰化物
Doris has evolved a unique internal body chemistry that can counteract the plant's deadly cyanide.
作为战利品 它们能将氰化物 一生留存在体内
As an added bonus, they can keep this cyanide in their bodies throughout their lives,
也就是说它们将一直是有毒的 而且基本不会被吃
which means they stay toxic and largely safe from predation.
作为少数能吃这种藤的动物
Being one of the few animals that can eat this vine,
这些毛毛虫基本可以 独享这一食物来源
these caterpillars have this food source pretty much to themselves.
弊端是海神毒蝶必须 找到一种刺穿藤蔓外皮的方式
The downside is Doris must specialise to find a way through the vine's armour.
她吃不了森林中其他的东西 也只能把卵产在这种藤蔓上
She can't eat anything else in this forest, and will only lay her eggs on this vine.
因为长有不同外皮的植物 能够抵御她的进攻
Because plants with different armoury can resist her attack.
其他种类的西番莲藤 也长在这里
A different species of passionflower vine grows in the same patch of rainforest.
它所含有的氰化物质 稍微不同一些
It has a slightly different cocktail of cyanide.
这一微妙的变化 使它对海神毒蝶有着毒性作用
But these subtle changes make it toxic to Heliconius Doris.
可能...藤蔓获胜了?
A victory for the vine ...perhaps'?
只是这场战争从无终点
Except this battle never ends.