5個原因說明森林的重要性

5個原因說明森林的重要性

Forests cover nearly a third of all land on Earth, providing vital organic infrastructure for some of the planet's densest, most diverse collections of life. They support countless species, including our own, yet we often seem oblivious of that. Humans now clear millions of acres from natural forests every year, especially in the tropics, letting deforestation threaten some of Earth's most valuable ecosystems.

森林覆蓋了地球上近三分之一的土地，為地球上一些密度最大、種類最多的生命提供了重要的有機基礎設施。它們支持著無數的物種，包括我們自己的物種，但我們似乎常常忽略了這一點?，F在，人類每年從天然林中砍伐數百萬英畝的土地，特別是在熱帶地區(qū)，這使得森林砍伐威脅到了地球上一些最有價值的生態(tài)系統(tǒng)。

Sunlight filters through a forest in Union Wood near Ballygawley, Ireland. (Photo: Mark Carthy/Shutterstock)

We tend to take forests for granted, underestimating how indispensable they still are for everyone on the planet. That would quickly change if they all disappeared, but since humanity might not survive that scenario, the lesson wouldn't be very useful by then. As the Once-ler finally realizes in Dr. Seuss' "The Lorax," a crisis like deforestation depends on indifference. "UNLESS someone like you cares a whole awful lot," Seuss wrote, "nothing is going to get better."

我們往往認為森林是理所當然的，低估了它們對地球上每個人來說仍然是多么不可或缺。如果它們全部消失，這種情況將很快發(fā)生變化，但由于人類可能無法在這種情況下生存下來，到那時，這一教訓將不會非常有用。正如這位曾經的作家在蘇斯博士的《洛拉克斯》(the Lorax)中最終意識到的那樣，森林砍伐這樣的危機取決于人們的漠不關心。“除非像你這樣的人非常在乎，”蘇斯寫道，“否則一切都不會好起來。”

In hopes of shedding more light on what forests do for us, and how little we can afford to lose them, here are 5 reasons why forests are so important:

為了讓人們更多地了解森林對我們的作用，以及我們失去森林的代價有多大，我們列出了森林如此重要的5個原因:

Morning mist shrouds a tropical forest at Kaeng Krachan National Park in Thailand. (Photo: Stephane Bidouze/Shutterstock)

1. They help us breathe.

它們幫助我們呼吸。

Forests pump out oxygen we need to live and absorb the carbon dioxide we exhale (or emit). A single mature, leafy tree is estimated to produce a day's supply of oxygen for anywhere from two to 10 people. Phytoplankton in the ocean are more prolific, providing half of Earth's oxygen, but forests are still a key source of quality air.

森林為我們提供生存所需的氧氣，并吸收我們呼出(或排放)的二氧化碳。據估計，一棵成熟多葉的樹每天能為兩到十個人提供氧氣。海洋中的浮游植物數量更多，為地球提供了一半的氧氣，但森林仍然是優(yōu)質空氣的關鍵來源。

2. They're more than just trees.

它們不僅僅是樹。

Nearly half of Earth's known species live in forests, including 80% of biodiversity on land. That variety is especially rich in tropical rainforests, but forests teem with life around the planet: Insects and worms work nutrients into soil, bees and birds spread pollen and seeds, and keystone species like wolves and big cats keep hungry herbivores in check. Biodiversity is a big deal, both for ecosystems and human economies, yet it's increasingly threatened around the world by deforestation.

地球上近一半的已知物種生活在森林中，包括80%的陸地生物多樣性。這種物種在熱帶雨林中特別豐富，但在地球上，森林中充滿了生命:昆蟲和蠕蟲將營養(yǎng)物質輸送到土壤中，蜜蜂和鳥類傳播花粉和種子，而狼和大貓等關鍵物種則控制著饑餓的食草動物。生物多樣性對生態(tài)系統(tǒng)和人類經濟來說都是一件大事，但它在世界各地正日益受到森林砍伐的威脅。

3. People live there, too.

人們也住在那里。

Some 300 million people live in forests worldwide, including an estimated 60 million indigenous people whose survival depends almost entirely on native woodlands. Many millions more live along or near forest fringes, but even just a scattering of urban trees can raise property values and reduce crime, among other benefits.

全世界約有3億人生活在森林中，其中估計有6千萬土著人民的生存幾乎完全依賴于當地的林地。還有數百萬人生活在森林邊緣或附近，但即使只是城市樹木的零星分布，也能提高財產價值，減少犯罪，還有其他好處。

The canopy towers above a coastal-plain forest in Italy's Nazionale del Circeo. (Photo: Nicola [CC BY 2.0]/Flickr)

4. They keep us cool.

它們使我們保持涼爽。

By growing a canopy to hog sunlight, trees also create vital oases of shade on the ground. Urban trees help buildings stay cool, reducing the need for electric fans or air conditioners, while large forests can tackle daunting tasks like curbing a city's "heat island" effect or regulating regional temperatures.

通過種植樹冠來吸收陽光，樹木也在地面上創(chuàng)造了重要的遮蔭綠洲。城市樹木可以幫助建筑物保持涼爽，減少對電風扇或空調的需求，而大片森林可以解決令人生畏的任務，比如抑制城市的“熱島效應”或調節(jié)地區(qū)溫度。

5. They keep Earth cool.

它們使地球保持涼爽。

Erawan Falls flows through a rainforest in the Tenasserim Hills of western Thailand. (Photo: Shutterstock)

Trees also have another way to beat the heat: absorb CO2 that fuels global warming. Plants always need some CO2 for photosynthesis, but Earth's air is now so thick with extra emissions that forests fight global warming just by breathing. CO2 is stored in wood, leaves and soil, often for centuries.

樹木還有另一種降溫方法:吸收導致全球變暖的二氧化碳。植物進行光合作用總是需要一些二氧化碳，但現在地球的空氣中含有大量的額外排放，森林僅靠呼吸就能對抗全球變暖。二氧化碳儲存在木材、樹葉和土壤中，通?？梢员４鎺讉€世紀。