绿色星球（2022）

这里的武伦柱长得非常粗壮
The cardones here can become so broad
可以为筑巢的鲣鸟提供阴凉
that they provide cooling shade for nesting birds.
雏鸟长大之后
As the booby chicks get older,
就会用它们的粪便...
they repay the cardones...
回报武伦柱
..with their droppings...
海鸟粪
..guano -
是鲣鸟消化大量鱼类之后的排泄物
the digestive remains of vast shoals of fish.
这些海鸟粪浓度很高而且含化学成分
This guano is of such strength and quantity
大多数植物都会因此被毒死
that most plants would be poisoned by it.
然而这些武伦柱已经进化出了独特的本领
These cardones, however, have evolved the ability
可以不受海鸟粪中的毒素成分影响 并吸收其中养分
to tolerate the toxins in the guano and digest the nutrients.
现在 武伦柱已经形成了茂密的丛林
As a result, the cacti now grow in a dense forest
数量超过100万株
over a million strong.
但是这种关系需要保持微妙的平衡
But such relationships are very finely balanced
一旦打破 将会造成严重的后果
and can only too easily tip into catastrophe...
津巴布韦北部就出现了这种情况
..as is now happening in northern Zimbabwe.
这里的热带大草原
For six months of the year,
每年有6个月时间经常下雨 这使它变得郁郁葱葱
the savannah here is kept lush and green by daily rains.
但当雨季结束后
But when the rainy season is over,
它就变得像荒漠一样干旱
it becomes as dry as any desert.
所以生长在这里的植物 就必须适应潮湿和干旱两种环境条件
So to survive here, trees must be able to tolerate both conditions.
而这些巨大的树木 就进化出了相应的能力
And these giants are adapted to do just that.
它们就是猴面包树
They are baobabs.
这棵树可能已经有1000多年的树龄了
This one might be over 1,000 years old.
它赖以生存的能力之一就是这个像海绵一样的树干
It survives here in part thanks to its ability
可以储存数千升水
to store thousands of litres of water
而它伤痕累累的外皮
within the spongy wood of its trunk.
有力地揭示了
But its battered surface is evidence
一种非常微妙的平衡关系
of a very finely-balanced relationship.
这些巨树
These huge trees
是所有动物关注的焦点
are a focus for animals of all kinds.
对大象而言 更是意义非凡
And they're particularly important for elephants.
在雨季 大象会吃猴面包树的果实
In the wet season, they eat the baobab's fruit
并通过粪便将种子散布各地
and disperse the seeds in their dung.
随着旱季的来临
Now as the dry season begins...
它们开始长途跋涉到有水源的区域
..they migrate to distant watering holes.
猴面包树的内部木质纤维比较潮湿
The baobabs have damp inner wood...
大象在迁移途中 就靠这些木质纤维来解渴
..and the elephants use it to quench their thirst on the journey.
这种关系之所以能够维持 是因为猴面包树
This relationship can only work because baobabs
具有惊人的自愈能力
have a remarkable ability to heal themselves.
每次受到攻击后
Between each damaging attack,
它们海绵一样的木质就会再生 并长出新的树皮
they expand their spongy wood and grow new skin.
几个世纪以来 它们不断重复这一过程
And they've done this time and time again over centuries.
但是现在 全球气候变化导致旱季持续的时间
Today, however, it's harder for the baobabs to recover
越来越长 越来越严重 猴面包树因此变得难以自愈
as dry seasons become longer and drier due to climate change.
不仅如此 大象也必须啃食更多的木质纤维
Not only that, but the elephants are forced to take ever more wood
才能生存
from the trees in order to survive.
在过去几十年来
In some parts of Africa,
非洲很多体型最大 最古老的猴面包树
many of the largest and oldest baobabs
已经倒下了
have fallen in the last decade.
像猴面包树这类重要物种的死亡
The loss of a vital species like the baobab
对荒漠中所有生物来说都是严重的打击
strikes a blow at all life in the desert.
在这样恶劣的自然条件下
In these hostile lands,
没有其他动植物的支持 很少有物种能够存活
few living organisms can survive without help from others.
亚利桑那州的仙人掌生长带
You can find an extraordinary illustration of this
就是这一问题的绝佳例证
in Arizona's saguaro country.
如果沿着这里的小路漫步
If you wander off the beaten track here,
你可能会见到这样的东西
you may be lucky enough to find one of these.
这看起来就像一只老旧的靴子
It might look like an old boot,
但实际上 它是仙人掌的一个枝杈
but in fact, it's part of a saguaro cactus.
几乎每个仙人掌都有这样的空壳枝杈
Almost every saguaro has one.
就像上面
There's one up there.
吉拉啄木鸟是造成这种空壳的间接原因
It has been produced indirectly by woodpeckers,
它们经常在粗壮的仙人掌枝干中为自己
which regularly dig homes for themselves in the bloated trunks
凿洞建巢
of the saguaros.
接下来的六个月里
In the next six months,
仙人掌的伤口逐渐愈合
the cactus heals the wound
形成了一个安全、干燥、防水的巢穴
and so creates a safe, cool, and watertight nest hole.
里面质地紧密的肉层可以保持很多年
Its tough lining will persist for years,
即使在仙人掌已经死亡、腐烂之后 依然保持原样
even after the cactus itself has died and rotted away.
一株仙人掌可能有好几个这种舒适的鸟巢
A single saguaro may hold several of these extraordinary homes.
所以在它的一生中 可以为大约3000只雏鸟或不同的物种
So over its lifetime, it may provide accommodation for some 3,000 chicks
提供住所
of several different species.
但从长远来看 仙人掌可以从中受益
But in the long term, the saguaro benefits,
因为这些住客能帮它完成
as their lodgers repay the cactus
花朵的授粉
by pollinating its flowers...
并散播它的种子
..and dispersing its seeds.
就是这样的依存关系
It's relationships like these
让各种不同的生物
that enable life to flourish
能在地球上环境最恶劣的地区繁衍生息
in some of the world's harshest landscapes.
经过几百万年的演化
Over millions of years,
植物已经完全适应了
plants have become superbly adapted
荒漠贫瘠的环境
to hostile desert conditions.
这是一种非常微妙的平衡关系
But it's a very finely-balanced existence
因此也很容易被打破
and one that makes them uniquely vulnerable.
不过 人类现在越来越了解荒漠动植物之间
However, our growing understanding of the complex ways
这种相互依存的复杂关系
by which desert animals and plants rely on one another
也设计出了更加有效的保护措施来保护它们
is now helping us to understand how best we can protect them.
90年前 一位摄影师就在这个地方拍了一张照片
90 years ago, a photograph was taken from this very spot
照片中的仙人掌数量
that shows a population of saguaro cactus
与我们现在看到的有很大的差别
that was very different from what it is today.
在过去的50年里
In the last 50 years,
这里的仙人掌数量已经大大减少
the population of saguaros here has greatly diminished,
不仅是仙人掌遭受的直接伤害
not because of a direct assault on the cactus,
还有许多能遮荫的“护士树”数量减少
but because many of the shade-giving nurse trees
被砍伐当作柴火 留下仙人掌幼苗在阳光下干枯死去
were harvested for firewood, leaving young saguaro to die in the sun.
现在人们理解了这种依存关系
Now that this relationship is understood
于是开始保护“护士树”
and the nurse trees are protected,
已经有迹象表明 仙人掌正在逐渐恢复
there are already signs that the saguaro are recovering.
只要有荒漠存在的地方 植物都会进化不同能力以应对挑战
Wherever there's a desert, plants have evolved to meet its challenge.
但无论在哪里 它们都需要我们的帮助
But everywhere, they need our help.
现在我们越来越了解这些植物
As we understand more about them
还有它们之间亲密而又复杂的共生关系
and their intimate and complex relationships...
人类未来需要更好地保护好这些植物
..we will be better able to protect them and all life
以及共同生活在美丽 但日益脆弱的地球各种生物
in these beautiful but increasingly fragile worlds.
绿 色 星 球 幕 后 花 絮
荒漠摄影团队最偏远的取景地
The most remote shoot for the deserts team
是墨西哥的科尔特斯海的
is to the island of San Pedro Martir
圣佩德罗马尔蒂尔小岛上
in the Sea of Cortez, Mexico.
摄制组要去那里拍摄一种
They are to film the giant cacti
生存方式极为独特的巨大仙人掌
that have found a unique way to thrive here.
在波涛汹涌的海面上 乘船历经了48小时
It takes 48 hours to travel the 260 miles...
并行驶了260英里
..over unpleasantly choppy seas.
有些队员很不舒服
It's not made some of us feel very well.
我们其中一个人晕船很严重
I think one of us is quite seasick.
周围只能看到蓝色的大海
It's nothing but big blue out there,
那个岛屿大概在那个方向
and the island is somewhere in that direction.
现在还看不到
Can't see it yet.
在他们逐渐靠近小岛时
As they draw close to the island,
大海中出现了壮观的一幕 展现出海洋生命的丰富多彩
there's a spectacular reminder of how rich life in the sea is here.
哦 快看前面！有一大群！
Oh, look in front of us! Look at that for a pod!
啊 到处是这种鸟
Oh! They're everywhere!
它给我们指路呢
Show us the way.
在岛上迎接他们的 是荒漠专家本杰明·怀尔德
Meeting them here is desert scientist Ben Wilder.
摄制组最初就是通过他的研究
It's through his research that the team first heard
了解到岛上这种特殊的植物的
about the island's peculiar residents.
我永远忘不了刚来这里的情况
I'll never forget the first time I came
实际上 当时我就站在这儿
to, actually, exactly where we're standing right now.
那是2006年4月
It was April of 2006,
并看到了这个景象
and saw this view.
我整个头脑和心灵都沉醉不已