如何與其他動物分享地球

如何與其他動物分享地球

Earth is a big place, but size isn't everything. The planet's richest ecosystems are in rapid decline, forcing us to acknowledge the elephant in the room: Elephants, along with countless other creatures worldwide, are running out of room.

地球是一個很大的地方，但大小并不是一切。地球上最豐富的生態(tài)系統(tǒng)正在迅速衰落，這迫使我們認識到一個顯而易見而又被忽略的事實:大象，以及世界上無數(shù)其他生物，正在耗盡空間。

A young lion looks toward the Nairobi skyline from Nairobi National Park in Kenya. (Photo: Tony Karumba/AFP/Getty Images)

Like climate change, mass extinction is a global problem. It threatens wildlife all over the world, from iconic rhinos, lions and pandas to obscure amphibians, shellfish and songbirds. And while it will take lots of local efforts to save those animals, it will also take a bigger, more ambitious approach than we've used in the past.

與氣候變化一樣，大規(guī)模滅絕也是一個全球性問題。它威脅著世界各地的野生動物，從標志性的犀牛、獅子和熊貓，到鮮為人知的兩棲動物、貝類和鳴禽。雖然拯救這些動物需要很多當?shù)氐呐?，但它也將采取比我們過去使用的更好、更有野心的方法。

According to many scientists and conservationists, our best strategy is surprisingly simple — at least in theory. To avoid a catastrophic loss of biodiversity, we need to set aside half of Earth's surface area for wildlife. That might sound like a big sacrifice at first, but upon closer inspection, it's still an incredibly sweet deal for us: One species gets half the planet, and all other species must share the other half.

根據(jù)許多科學(xué)家和環(huán)保人士的說法，我們最好的策略出奇地簡單——至少在理論上是這樣。為了避免生物多樣性的災(zāi)難性損失，我們需要留出地球表面一半的面積給野生動物。一開始，這聽起來像是一個巨大的犧牲，但仔細觀察，這對我們來說仍然是一個令人難以置信的甜蜜交易:一個物種得到了地球的一半，而所有其他物種必須分享另一半。

The Amazon rainforest spans 40% of South America and hosts one in 10 of Earth's known species. (Photo: Shutterstock)

Half an Earth is better than none

半個地球總比沒有好

Today, protected areas cover about 15% of Earth's land area and 3% of its oceans, according to the U.N. Environment Program. Raising that to 50% would be no small feat, but it's not like we'd need to start from scratch. We would, however, need to move a little more quickly than we have so far.

根據(jù)聯(lián)合國環(huán)境規(guī)劃署(U.N. Environment Program)的數(shù)據(jù)，如今，保護區(qū)覆蓋了地球陸地面積的15%，海洋面積的3%。將這一比例提高到50%將是一個不小的成就，但我們并不需要從零開始。然而，我們需要比目前更快地采取行動。

A gray heron wades through reeds at a 100-acre urban wetland in London. (Photo: Dan Kitwood/Getty Images)

Missing forests for trees

為樹木而失去森林

About 60% of the U.S. Southeast was once longleaf pine forest, for example, which spanned 90 million acres from modern-day Virginia to Texas. After 300 years of land change for timber, agriculture and urban development, less than 3% of the region's signature ecosystem is left. A lot of biodiversity still persists in its remaining pockets — including up to 140 plant species per square kilometer — but large animals like Florida panthers and black bears are frequently killed by road traffic as they try to improvise their own makeshift wildlife corridors.

例如，美國東南部約60%的地區(qū)曾經(jīng)是長葉松林，從現(xiàn)在的弗吉尼亞到德克薩斯州，這片松林占地9000萬英畝。經(jīng)過300年為木材、農(nóng)業(yè)和城市發(fā)展而改變的土地，該地區(qū)標志性的生態(tài)系統(tǒng)只剩下不到3%。許多生物多樣性仍然存在于其剩余的區(qū)域——包括每平方公里多達140種植物——但是像佛羅里達黑豹和黑熊這樣的大型動物在試圖臨時搭建自己的野生動物走廊時經(jīng)常被公路交通撞死。

A sign in Everglades National Park warns motorists to watch for Florida panthers. (Photo: Everglades NPS)

Because ecosystems are so interwoven, the loss of one species can start a horrible chain reaction. When the American chestnut tree was driven to near extinction 100 years ago by an invasive Asian fungus, Wilson notes, "seven moth species whose caterpillars depended on its vegetation vanished, and the last of the passenger pigeons plunged to extinction." Similarly, the modern decline of monarch butterflies is largely linked to the decline of milkweed, on which their larvae rely for food.

由于生態(tài)系統(tǒng)是如此的相互交織，一個物種的消失可能會引發(fā)可怕的連鎖反應(yīng)。威爾遜指出，100年前，一種入侵的亞洲真菌將美洲栗樹逼到了瀕臨滅絕的境地，“七種依賴栗樹生長的毛蟲的蛾子消失了，最后一種信鴿也瀕臨滅絕。”同樣，帝王蝶數(shù)量的減少在很大程度上與馬利筋數(shù)量的減少有關(guān)，馬利筋是帝王蝶幼蟲的食物來源。

Even for urban-adapted birds, air pollution and climate change can pose grave threats. (Photo: Frederic Brown/Getty Images)

How the other half lives

另一半是如何生活的

Although we need to think bigger about habitat conservation, preserving tracts of wilderness is still a local struggle. If we set aside enough half-yards, half-towns, half-nations and half-regions for nature, Half-Earth should start to take care of itself.

盡管我們需要從更大的角度來考慮棲息地保護問題，但保護大片荒野仍然是一場地方性的斗爭。如果我們留出足夠的半碼，半城鎮(zhèn)，半民族和半地區(qū)的自然，半地球應(yīng)該開始照顧自己。

Half-Earth, therefore, isn't so different from today's Earth. We're already doing many of the right things, as Wilson recently told the University of California-Berkeley's "Breakthroughs" magazine. We still have a few big biodiversity zones left, and others that could still recover. We just need to protect as many wilderness areas as we can, fill in gaps wherever possible and do no further harm.

因此，半地球與今天的地球并沒有太大的不同。正如威爾遜最近對加州大學(xué)伯克利分校的《突破》雜志所說，我們已經(jīng)在做許多正確的事情。我們?nèi)匀挥幸恍┐蟮纳锒鄻有詤^(qū)域，其他的仍然可以恢復(fù)。我們只需要保護盡可能多的荒野地區(qū)，盡可能地填補空白，不再造成進一步的傷害。