Our planet's diverse thriving ecosystems may seem like permanent fixtures, but they're actually vulnerable to collapse.
我们星球上多样又生机勃勃的生态系统也许看上去像固定的家具，但是实际上它们脆弱又容易崩溃。
Jungles can become deserts, and reefs can become lifeless rocks,
丛林可能变成沙漠，珊瑚礁可能变成死气沉沉的石头，
even without cataclysmic events, like volcanoes and asteroids.
就算没有像火山喷发或行星冲撞这样的毁灭性灾难。
What makes one ecosystem strong and another weak in the face of change?
在面对变化时，是什么决定了一个生态系统的优胜劣汰？
The answer, to a large extent, is biodiversity.
这个问题的答案，在很大程度上来说，是生物多样性。
Biodiversity is built out of three intertwined features: ecosystem diversity, species diversity, and genetic diversity.
生物多样性由三种息息相关的特征组成：生态系统多样性，物种多样性和基因多样性。
The more intertwining there is between these features, the denser and more resilient the weave becomes.
这三种特征之间联系的越紧密，生态网就越会越密集并且恢复能力越强。
Take the Amazon rainforest, one of the most biodiverse regions on Earth due to its complex ecosystems,
例如亚马逊雨林，这个地球上生物多样性最丰富的地区之一，它具有复杂的生态系统，
huge mix of species, and the genetic variety within those species.
大量混杂的物种，并且这些物种的遗传因子十分多样。
Here are tangled liana vines, which crawl up from the forest floor to the canopy,
这些是缠绕在树上的藤蔓，它们从丛林地面向树冠攀爬，
intertwining with treetops and growing thick wooden stems that support these towering trees.
与树梢和正在不断成长从而支撑耸立的大树的粗壮树干缠绕在一起。
Helped along by the vines, trees provide the seeds, fruits and leaves to herbivores,
在藤蔓的帮助下，树林为食草动物提供种子、水果和叶子作为食物，
such as the tapir and the agouti, which disperse their seeds throughout the forest so they can grow.
这些动物如貘和刺豚鼠，又将种子散播到丛林内外，这样丛林才会成长。
Leftovers are consumed by the millions of insects that decompose and recycle nutrients to create rich soil.
剩下的会被数不尽的昆虫吃掉，营养物质会被分解和循环，将土壤变得更肥沃。
The rainforest is a huge system filled with many smaller systems, like this, each packed with interconnected species.
雨林这个大系统包含了很多这样的小系统，每个小系统中不同物种紧密相连。
Every link provides stability to the next, strengthening biodiversity's weave.
这些联系一环扣一环，不断强化着生物多样性网络。
That weave is further reinforced by the genetic diversity within individual species, which allows them to cope with changes.
这个网也通过单个物种间的遗传多样性而进一步增强，这种多样性能让它们更好的应对改变。
Species that lack genetic diversity due to isolation or low population numbers,
由于被隔离、或者种群数量小而遗传多样性低的物种，
are much more vulnerable to fluctuations caused by climate change, disease or habitat fragmentation.
在面对由气候变化、疾病或栖息地破碎化导致的波动时会更加脆弱。

Whenever a species disappears because of its weakened gene pool, a knot is untied and parts of the net disintegrate.
每当一个物种由于它脆弱的基因池而消失时，联系网的一环解扣，某些部分的联系也随之分裂。
So, what if we were to remove one species from the rainforest?
那么，如果我们移除雨林中的一个物种呢？
Would the system fall apart? Probably not.
这个系统会崩溃吗？也许并不会。
The volume of species, their genetic diversity, and the complexity of the ecosystems
多样的物种、它们的遗传多样性和生态系统的复杂性
form such rich biodiversity in this forest that one species gap in the weave won't cause it to unravel.
形成了生态多样性如此丰富的雨林，单个物种的消失并不能使之瓦解。
The forest can stay resilient and recover from change.
自愈能力使丛林可以适应这种变化。
But that's not true in every case.
但是也有例外。
In some environments, taking away just one important component can undermine the entire system.
在某些环境中，一个重要部分的缺失可以破坏整个系统。
Take coral reefs, for instance. Many organisms in a reef are dependent on the coral.
以珊瑚礁为例，很多生物寄生在珊瑚上。
It provides key microhabitats, shelter and breeding grounds for thousand of species of fish, crustaceans and mollusks.
珊瑚为成千上万种鱼类、虾蟹和软体动物提供着重要的微生境、庇护所和繁殖地。
Corals also form interdependent relationships with fungi and bacteria.
珊瑚同时也和真菌和细菌互相依存。
The coral itself is a loom that allows the tangled net of biodiversity to be woven.
有了珊瑚这个织布机，生物多样性的网才细细的编织起来。
That makes coral a keystone organism, one that many others depend on for their suvival.
这就让珊瑚成为其它微生物赖以生存的基石。
So what happens when destructive fishing practices, pollution and ocean acidification weaken coral or even kill it altogether?
所以当破坏性捕鱼行为、污染和海洋酸化伤害或将珊瑚全部杀死的时候，会发生什么呢？
Exactly what you might think.
就像你想的那样。
The loss of this keystone species leaves its dependents at a loss, too, threatening the entire fabric of the reef.
这一基础物种的消失会让依靠它的生物岌岌可危，同时也威胁着礁石的整个生态网。
Ecosystem, species and genetic diversity together form the complex tangled weave of biodiversity
生态系统、物种多样性和遗传多样性一同组成了生态多样性这个复杂的网络，
that is vital for the survival of organisms on Earth.
这个网络是地球生物存活的关键。
We humans are woven into this biodiversity, too.
我们人类也在这个生物多样网络中。
When just a few strands are lost, our own well-being is threatened.
即使只少了网上的几根线，我们的安康也会受到威胁。
Cut too many links, and we risk unraveling it all.
切段太多的联系，将有全军覆没的风险。
What the future brings is unpredictable,
未来发生的事不可预见，
but biodiversity can give us an insurance policy, Earth's own safety net to safeguard our survival.
但是生物多样性可以给我们上个保险，地球的安全网保护着我们的平安。