Why is biodiversity so important Kim Preshoff

Our planet’s diverse thriving ecosystems
may seem like permanent fixtures,

but they’re actually
vulnerable to collapse.

Jungles can become deserts,

and reefs can become lifeless rocks,

even without cataclysmic events,
like volcanoes and asteroids.

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

The answer, to a large extent,
is biodiversity.

Biodiversity is built out
of three intertwined features:

ecosystem diversity,

species diversity,

and genetic diversity.

The more intertwining
there is between these features,

the denser and more resilient
the weave becomes.

Take the Amazon rainforest,

one of the most biodiverse
regions on Earth

due to its complex ecosystems,

huge mix of species,

and the genetic variety
within those species.

Here are tangled liana vines,

which crawl up from the forest floor
to the canopy,

intertwining with treetops

and growing thick wooden stems
that support these towering trees.

Helped along by the vines,

trees provide the seeds, fruits
and leaves to herbivores,

such as the tapir and the agouti,

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

Leftovers are consumed
by the millions of insects

that decompose and recycle nutrients
to create rich soil.

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

each packed with interconnected species.

Every link provides stability to the next,

strengthening biodiversity’s weave.

That weave is further reinforced

by the genetic diversity
within individual species,

which allows them to cope with changes.

Species that lack genetic diversity
due to isolation

or low population numbers,

are much more vulnerable
to fluctuations

caused by climate change, disease
or habitat fragmentation.

Whenever a species disappears
because of its weakened gene pool,

a knot is untied
and parts of the net disintegrate.

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

Would the system fall apart?

Probably not.

The volume of species,

their genetic diversity,

and the complexity of the ecosystems

form such rich biodiversity in this forest

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

The forest can stay resilient
and recover from change.

But that’s not true in every case.

In some environments, taking away
just one important component

can undermine the entire system.

Take coral reefs, for instance.

Many organisms in a reef
are dependent on the coral.

It provides key microhabitats,
shelter and breeding grounds

for thousand of species of fish,
crustaceans and mollusks.

Corals also form interdependent
relationships with fungi and bacteria.

The coral itself is a loom

that allows the tangled net
of biodiversity to be woven.

That makes coral a keystone organism,

one that many others depend on
for their suvival.

So what happens when destructive
fishing practices,

pollution and ocean acidification

weaken coral
or even kill it altogether?

Exactly what you might think.

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

threatening the entire fabric of the reef.

Ecosystem, species
and genetic diversity

together form the complex tangled weave
of biodiversity

that is vital for the survival
of organisms on Earth.

We humans are woven
into this biodiversity, too.

When just a few strands are lost,

our own well-being is threatened.

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

What the future brings is unpredictable,

but biodiversity can give
us an insurance policy,

Earth’s own safety net
to safeguard our survival.

我们星球上多样化的蓬勃发展的生态系统
可能看起来像是永久性的固定装置,

但它们实际上
很容易崩溃。

丛林可以变成沙漠

,珊瑚礁可以变成没有生命的岩石,

即使没有
火山和小行星等灾难性事件。 面对变化,是

什么让一个生态系统强
而另一个弱?

答案在很大程度上
是生物多样性。

生物多样性
由三个相互交织的特征构成:

生态系统多样性、

物种多样性

和遗传多样性。

这些特征之间

的交织越多
,编织就越致密和更有弹性。

以亚马逊雨林为例,

它是地球上生物多样性最丰富的地区之一,

因为它具有复杂的生态系统、

种类繁多的物种

以及这些物种中的遗传多样性

这里是缠结的藤本植物

,从森林地面
爬到树冠,

与树梢交织在一起

,长出粗壮的木茎
,支撑着这些参天大树。

在葡萄藤的帮助下,

树木为貘和刺鼠等食草动物提供种子、果实
和叶子

它们将种子散布在
整个森林中,以便它们能够生长。

数以百万计的昆虫消耗剩饭剩菜,这些

昆虫分解和回收养分
以创造肥沃的土壤。

雨林是一个巨大的系统,充满
了许多较小的系统,就像这样,

每个系统都充满了相互关联的物种。

每一个环节都为下一个环节提供稳定性,

加强生物多样性的编织。 个体物种内的遗传多样性

进一步加强了这种编织

使它们能够应对变化。

由于孤立

或人口

数量少而缺乏遗传多样性的物种更容易

受到气候变化、疾病
或栖息地破碎化引起的波动的影响。

每当一个物种
因其基因库减弱而消失时,

一个结就会解开
,网络的一部分就会解体。

那么,如果我们
要从热带雨林中移除一个物种呢?

系统会崩溃吗?

可能不是。

物种的数量、

它们的遗传多样性

和生态系统的复杂性

在这片森林中形成了如此丰富的生物多样性,

以至于编织中的一个物种间隙
不会导致它解开。

森林可以保持弹性
并从变化中恢复。

但并非在所有情况下都是如此。

在某些环境中,
仅移除一个重要组件

可能会破坏整个系统。

以珊瑚礁为例。

珊瑚礁
中的许多生物都依赖于珊瑚。

它为数千种鱼类、甲壳类动物和软体动物提供了关键的微生境、
庇护所和繁殖地

珊瑚还
与真菌和细菌形成相互依赖的关系。

珊瑚本身就是一台织布机


可以编织错综复杂的生物多样性之网。

这使得珊瑚成为一种重要的生物

,许多其他生物
赖以生存。

那么,当破坏性
捕捞活动、

污染和海洋酸化

削弱珊瑚
甚至完全杀死它时会发生什么呢?

正是你可能想的。

这种关键物种
的丧失也使其家属不知所措,

威胁着整个珊瑚礁结构。

生态系统、物种
和遗传多样性

共同构成了
生物多样性错综复杂的结构,

这对地球上生物的生存至关重要

我们人类也
融入了这种生物多样性。

当只有几根线丢失时,

我们自己的福祉就会受到威胁。

剪掉太多的链接
,我们就有可能把这一切都解开。

未来带来的是不可预测的,

但生物多样性可以为
我们提供保险单,

地球自身的安全网
来保障我们的生存。