中級 美國腔 15388 分類 收藏
開始影片後,點擊或框選字幕可以立即查詢單字
字庫載入中…
回報字幕錯誤
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.
提示:點選文章或是影片下面的字幕單字,可以直接快速翻譯喔!

載入中…

載入中…

【TED-Ed】為什麼生物多樣性如此重要? (Why is biodiversity so important? - Kim Preshoff)

15388 分類 收藏
稲葉白兎 發佈於 2015 年 6 月 10 日
看更多推薦影片
  1. 1. 單字查詢

    在字幕上選取單字即可即時查詢單字喔!

  2. 2. 單句重複播放

    可重複聽取一句單句,加強聽力!

  3. 3. 使用快速鍵

    使用影片快速鍵,讓學習更有效率!

  4. 4. 關閉語言字幕

    進階版練習可關閉字幕純聽英文哦!

  5. 5. 內嵌播放器

    可以將英文字幕學習播放器內嵌到部落格等地方喔

  6. 6. 展開播放器

    可隱藏右方全文及字典欄位,觀看影片更舒適!

  1. 英文聽力測驗

    挑戰字幕英文聽力測驗!

  1. 點擊展開筆記本讓你看的更舒服

  1. UrbanDictionary 俚語字典整合查詢。一般字典查詢不到你滿意的解譯,不妨使用「俚語字典」,或許會讓你有滿意的答案喔