but they're actually vulnerable to collapse.

但是其實它們很容易崩解

Jungles can become deserts,

叢林可能變成沙漠

and reefs can become lifeless rocks,

珊瑚礁可能變成無生命的石頭

even without cataclysmic events, like volcanoes and asteroids.

甚至無需發生劇變 如火山爆發或隕石撞擊

What makes one ecosystem strong and another weak in the face of change?

在面對變化時是什麼造成 某種生態系變強，另一種生態系變弱呢？

The answer, to a large extent, is biodiversity.

從大範圍看 答案是生物多樣性

Biodiversity is built out of three intertwined features:

生物多樣性由三種交織的部分建構

ecosystem diversity,

生態系多樣性

species diversity,

物種多樣性 （種歧度）

and genetic diversity.

及基因多樣性

The more intertwining there is between these features,

這三部分交織愈緊密

the denser and more resilient the weave becomes.

所織出的網就愈密愈有韌性

Take the Amazon rainforest,

拿亞馬遜雨林為例

one of the most biodiverse regions on Earth

這是地球上極富多樣化的地區

due to its complex ecosystems,

因為它擁有複雜的生態系

huge mix of species,

大量雜交的物種

and the genetic variety within those species.

以及這些物種的基因變異

Here are tangled liana vines,

看看這些纏繞的藤蔓

which crawl up from the forest floor to the canopy,

從森林地表一直爬到林冠

intertwining with treetops

纏著樹梢

and growing thick wooden stems that support these towering trees.

長出粗大的木質莖 支持這些高聳的樹

Helped along by the vines,

藉由藤蔓的幫助

trees provide the seeds, fruits and leaves to herbivores,

草食動物可以順著藤蔓爬上樹 取食種子、果實及葉片

such as the tapir and the agouti,

例如貘及刺鼠

which disperse their seeds throughout the forest so they can grow.

牠們在森林內處處散播種子 讓樹得以生長

Leftovers are consumed by the millions of insects

殘存物則由數不清的昆蟲吃掉

that decompose and recycle nutrients to create rich soil.

分解、回收營養素 來產生肥沃的土壤

The rainforest is a huge system filled with many smaller systems, like this,

雨林是個很大的系統 充滿許多像這樣的小型系統

each packed with interconnected species.

每個小系統都塞滿相連的物種

Every link provides stability to the next,

每個環節都為緊鄰的環節提供穩定性

strengthening biodiversity's weave.

強化生物多樣性的網絡

That weave is further reinforced

這張網會進一步

by the genetic diversity within individual species,

因個別物種的基因多樣性而強化

which allows them to cope with changes.

使牠們能因應變化

Species that lack genetic diversity due to isolation

由於隔離而缺乏基因多樣性的物種

or low population numbers,

或族群數量少的物種

are much more vulnerable to fluctuations

就更容易因氣候變遷

caused by climate change, disease or habitat fragmentation.

疾病或棲地碎裂而產生波動

Whenever a species disappears because of its weakened gene pool,

無論何時只要有一種物種 因基因庫弱化而消失

a knot is untied and parts of the net disintegrate.

結就鬆了 部分的網子也就瓦解

So, what if we were to remove one species from the rainforest?

如果去除雨林中的 某物種會怎樣呢？

Would the system fall apart?

系統會不會隨之分崩離析？

Probably not.

大概不會

The volume of species,

物種的數量

their genetic diversity,

他們的基因多樣性

and the complexity of the ecosystems

及生態系本身的複雜度

form such rich biodiversity in this forest

在此森林中形成 如此豐富的生物多樣性

that one species gap in the weave won't cause it to unravel.

某物種消失造成的洞 並不會使這張網就此崩解

The forest can stay resilient and recover from change.

這座森林仍可維持韌性 並從變化中恢復

But that's not true in every case.

但這並非放諸天下皆準

In some environments, taking away just one important component

在某些環境下 就算只拿走一種重要的成分

can undermine the entire system.

都能破壞整個系統

Take coral reefs, for instance.

拿珊瑚礁為例

Many organisms in a reef are dependent on the coral.

在珊瑚礁中 有許多生物要靠珊瑚為生

It provides key microhabitats, shelter and breeding grounds

它提供關鍵的微棲所 遮蔽處及繁殖地

for thousand of species of fish, crustaceans and mollusks.

成千上萬的魚類、甲殼類 及軟體動物都以珊瑚為生

Corals also form interdependent relationships with fungi and bacteria.

珊瑚也與真菌類及細菌 形成相互依存的關係

The coral itself is a loom

珊瑚本身是織布機

that allows the tangled net of biodiversity to be woven.

織出生物多樣性的複雜網絡

That makes coral a keystone organism,

這使珊瑚成為關鍵生物

one that many others depend on for their suvival.

其他生物靠其存活

So what happens when destructive fishing practices,

所以當破壞性的捕撈行為

pollution and ocean acidification

汙染及海洋酸化

weaken coral or even kill it altogether?

使珊瑚弱化甚至死亡時 會發生什麼事？

Exactly what you might think.

就是你想的那樣

The loss of this keystone species leaves its dependents at a loss, too,

這種關鍵物種消失 會使依靠它的物種也無所適從

threatening the entire fabric of the reef.

威脅整個珊瑚礁的結構

Ecosystem, species and genetic diversity

生態系、物種及基因多樣性

together form the complex tangled weave of biodiversity

共同形成複雜交纏的 生物多樣性網絡

that is vital for the survival of organisms on Earth.

這對地球生物的生存極為重要

We humans are woven into this biodiversity, too.

我們人類也是生物多樣性 這團網絡的一部分

When just a few strands are lost,

就算只有少數幾股線消失

our own well-being is threatened.

我們自身的安康也受到威脅

Cut too many links, and we risk unraveling it all.

切斷太多環節 我們就面臨解體的風險

What the future brings is unpredictable,

未來如何不可預測

but biodiversity can give us an insurance policy,

但生物多樣性就是保險

Earth's own safety net to safeguard our survival.

是地球自身的安全網 保障我們的生存