评论
打印
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 relied on lightning to cause forest fires,
但是人类学家推论早期原始人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, and became central in many rituals and traditions.
他们用火来煮食和拓荒，火也成为许多传统仪式的核心。
So instead of seeing forest fires as an exclusively bad thing, ancient humans may have learned to appreciate them.
所以森林大火并非完全是件坏事，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，并不仅仅是人类受益于这一自然现象。
Even as they destroy trees, fires also help the forest themselves, however counterintuitive that seems.
虽然野火能摧毁树木，但它们也有助于森林的成长，这看来似乎有悖常理。
In fact, several forest species, such as select conifers, need fire to survive.
事实上，一些森林物种，如针叶树，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, lodgepole pines constantly seek the Sun.
北美的西部盛产茂密的针叶林，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 by growing straighter and faster than its neighbors.
它们的幼苗互相推挤以获得更多的阳光，长得又快又直才能在竞争中取胜。
Over time, generations of slender, lofty lodgepoles form an umbrella-like canopy that shades the forest floor below.
随着时间的推移，新一代的黑松变得又细又高，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, this signals a problem for the lodgepoles' future.
当成熟的松果在枝头绽放出摇摇欲坠的种子，它们面临着潜在的问题。
Very few of these seeds will germintate in the cool, sunless shade created by their towering parents.
极少数的种子能在荫冷的地面上发芽，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, and another type called serotinous cones,
一种松果每年定期自然释放种子，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, and are like waterproofed time capsules sealed with resinous pitch.
成千上万的晚熟松果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. Let's see that in action.
但是，当温度足够高，晚熟松果就会爆开来。让我们来看看是怎样进行的。
Once it's gotten started, a coniferous forest fire typically spreads something like this.
这个过程始于针叶林大火，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 under the canopy of lodgepole pines.
这是一种能在树荫下茁壮成长的树，它们长在黑松树的树荫下。
The fire uses these smaller trees as a step ladder to reach the higher canopy of old lodgepole pines.
火焰通过这些作为阶梯的小树蔓延到更高的黑松树冠。
That ignites a tremendous crown fire reaching temperatures of up to 2400 degrees Fahrenheit.
燃烧的树冠火焰可以达到2400华氏度。
That's well more than the 115-140 degrees that signal the moment when serotinous seeds can be freed.
这相当于115-140摄氏度，甚至更高，这是适合晚熟松果传播种子的温度。
At those temperatures, the cones burst open, releasing millions of seeds,
松果在这样的温度下爆开来，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 help lodgepole seeds germinate quickly and sprout in abundance.
大火过后，富含碳的土壤和充满的阳光地形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, and so would the many creatures that depend on them.
如果没有野火重整森林，许多树种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, that raises the risk of a catastrophic blaze,
如果一个有赖于火的森林太久没有燃烧，就有引发重大火灾的风险，
which could destroy a forest completely, not to mention people's homes and lives.
这就会完全毁灭整个森林，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 to the existence of healthy boreal forest ecosystems.
但它们对于维持健康的森林生态系统却有着重要的意义。
By coming to terms with that, we can protect ourselves from their more damaging effects
通过控制性地利用森林火，我们可以预防重大的火灾，
while enabling the forests, like the legendary phoenix, to rise reborn from their own ashes.
让我们的森林像传说中的火凤凰一样在烈焰中重生。
