Why certain naturally occurring wildfires are necessary - Jim Schulz

翻译人员: Lyn Beaumont 校对人员: Tianchang Luo

There was a time before our ancestors smashed flint and steel together,

在我们的祖先学会用打火石取火以前，

when they felt the cold lack of fire in their lives.

他们经受这严冬的寒冷。

But anthropologists theorize that early hominids

但是人类学家推论早期原始人

relied on lightning to cause forest fires,

依赖闪电引起森林大火，

from which they could collect coals and burning sticks.

从而收取煤和燃烧的枝干。

Fire gave them the ability to cook food and clear land,

他们用火来煮食和拓荒。

and became central in many rituals and traditions.

火也成为许多传统仪式的核心。

So instead of seeing forest fires as an exclusively bad thing,

所以森林大火并非完全是件坏事。

ancient humans may have learned to appreciate them.

古人类可能早已学会了珍稀这些野火。

Yet, it wasn't just humans who benefitted from these natural phenomena.

然而，并不仅仅是人类收益于这一自然现象。

Even as they destroy trees, fires also help the forest themselves,

虽然野火能摧毁树木 但它们也有助于森林的成长，

however counterintuitive that seems.

这看来似乎有悖常理。

In fact, several forest species, such as select conifers,

事实上，一些森林物种， 如针叶树，

need fire to survive.

需要火来生存。

But how can fire possibly create life in addition to destroying it?

但火究竟是如何在摧毁生命的同时又创造生命？

The answer lies in the way that certain forests grow.

答案归结于某些森林的成长方式。

In the conifer-rich forests of western North America,

北美的西部盛产茂密的针叶林。

lodgepole pines constantly seek the Sun.

黑松树需要阳光的照耀。

Their seeds prefer to grow on open sunny ground,

它们的种子适合在阳光充沛的地面上成长，

which pits saplings against each other as each tries to get more light

它门的幼苗互相推挤以获得更多的阳光，

by growing straighter and faster than its neighbors.

长得又快又直才能在竞争中取胜。

Over time, generations of slender, lofty lodgepoles

随着时间的推移，新一代的黑松变得又细又高，

form an umbrella-like canopy that shades the forest floor below.

伞状的树枝遮蔽了下面的土地。

But as the trees' pine cones mature to release their twirling seeds,

当成熟的松果在枝头绽放出摇摇欲坠的种子，

this signals a problem for the lodgepoles' future.

它们面临着潜在的问题。

Very few of these seeds will germintate in the cool, sunless shade

极少数的种子能在荫冷的地面上发芽，

created by their towering parents.

这都归咎于那如高塔般的密林。

These trees have adapted to this problem by growing two types of cones.

为了适应了这个环境这些树产生了两种松果。

There are the regular annual cones that release seeds spontaneously,

一种松果每年定期自然释放种子，

and another type called serotinous cones,

而另一种则为晚熟松果，

which need an environmental trigger to free their seeds.

它们需要一个环境来触发释放他们的种子。

Serotinous cones are produced in thousands,

成千上万的晚熟松果

and are like waterproofed time capsules sealed with resinous pitch.

犹如被树胶密封的防水胶囊。

Many are able to stay undamaged on the tree for decades.

许多晚熟松果能完好地挂在树上几十年。

Cones that fall to the ground can be viable for several years, as well.

掉在地上的晚熟松果也能完好地保存很多年。

But when temperatures get high enough, the cones pop open.

但是，当温度足够高，晚熟松果就会爆开来。

Let's see that in action.

让我们来看看是怎样进行的。

Once it's gotten started, a coniferous forest fire

这个过程始于针叶林大火，

typically spreads something like this.

尤其是像这样蔓延性的森林火。

Flames ravage the thick understory provided by species like douglas fir,

火焰燃烧着底层茂密灌木，如花旗松，

a shade-tolerant tree that's able to thrive

这是一种能在树荫下茁壮成长的树，

under the canopy of lodgepole pines.

它们长在黑松树的树荫下。

The fire uses these smaller trees as a step ladder

火焰通过这些作为阶梯的小树

to reach the higher canopy of old lodgepole pines.

蔓延到更高的黑松树冠。

That ignites a tremendous crown fire

燃烧的树冠火焰

reaching temperatures of up to 2400 degrees Fahrenheit.

可以达到2400华氏度。

That's well more than the 115-140 degrees

这相当于115-140摄氏度，甚至更高。

that signal the moment when serotinous seeds can be freed.

这是适合晚熟松果传播种子的温度。

At those temperatures, the cones burst open,

松果在这样的温度下爆开来，

releasing millions of seeds,

撒出百万颗种子。

which are carried by the hot air to form new forests.

热空气把它们带到新的地方，长成新的森林。

After the fire, carbon-rich soils and an open sunlit landscape

大火过后，富含碳的土壤和充满的阳光地形

help lodgepole seeds germinate quickly and sprout in abundance.

有助于黑松种子快速发芽和茁壮成长。

From the death of the old forest comes the birth of the new.

死去的森林获得了新生。

Fires are also important for the wider ecosystem as a whole.

火对于整个生态系统也很重要。

Without wildfires to rejuvenate trees, key forest species would disappear,

如果没有野火重整森林，许多树种

and so would the many creatures that depend on them.

以及有赖于它们的动物就会灭绝。

And if a fire-dependent forest goes too long without burning,

如果一个有赖于火的森林太久没有燃烧，

that raises the risk of a catastrophic blaze,

就有引发重大火灾的风险，

which could destroy a forest completely,

这就会完全毁灭整个森林，

not to mention people's homes and lives.

更不用说人们的住房和生命。

That's why forest rangers sometimes intentionally start controlled burns

这就是为什么护林员有时进行控制性的烧林

to reduce fuels in order to keep the more dangerous wildfires at bay.

来减少易燃的树木和重大火灾的可能性。

They may be frightening and destructive forces of nature,

野火可能有点可怕， 并对大自然有破坏力，

but wildfires are also vital

但它们对于维持健康的森林生态系统

to the existence of healthy boreal forest ecosystems.

却有着重要的意义。

By coming to terms with that,

通过控制性地利用森林火，

we can protect ourselves from their more damaging effects

我们可以预防重大的火灾，

while enabling the forests, like the legendary phoenix,

让我们的森林像传说中的

to rise reborn from their own ashes.

火凤凰一样在烈焰中重生。