(单词翻译:单击)
听力文本
This is Scientific American's 60-second Science, I'm Scott Hershberger.
(CLIP: Thunder sound)
The chance that a human being like you will be struck by lightning is minuscule. But what if you're a tall tree in the tropics?
"Lightning happens in milliseconds. We can't predict where it's going to be, and we generally can't find it after it's happened, so what a hard thing to study."
Evan Gora, an ecologist at the University of Louisville. Now, for the first time, Gora and his colleagues were able to quantify the effects of lightning strikes in tropical forests around the world—thanks to satellite data and a network of ground sensors.
"We saw that forests that have more lightning strikes hitting per hectare per year have fewer large trees per hectare, presumably because they're killed by lightning. More biomass turns over every year, so basically, the lightning seems to be affecting the forests and causing trees to die. And then they have less total biomass."
In a ground survey in Panama, the researchers found that a single lightning strike typically damages more than 20 trees. And within a year, five or six of them die. The scientists combined this figure with their satellite data from around the world to estimate how many trees in tropical forests die each year due to lightning.
"We think around 830 million trees are struck by lightning, and about a quarter of those, around 200 million, are killed. So that's a lot. And as I mentioned before, we know that it's not just a random tree in the forest: typically, it's the largest trees."
The study is in the journal Global Change Biology.
Gora says the findings reveal that that lightning is one of the most important natural factors killing trees in the tropics. How climate change will affect lightning patterns is not well-understood. But some models predict more frequent lightning as the planet continues to warm—which could mean even more carbon-storing trees would disappear.
"Tropical forests basically function as our planet's, you know, main terrestrial air conditioner. So if we're decreasing the carbon stored in them, that's going to have a big effect on their ability to continue, you know, conditioning our planet and taking up all that carbon that we're producing."
Gora's work is just the beginning of this research. He hopes that future technological advances and fieldwork will help scientists better understand lightning's role in ecosystems across the planet. The findings should be illuminating.
Thanks for listening for Scientific American's 60-second Science. I'm Scott Hershberger.
参考译文
这里是科学美国人——60秒科学系列，我是斯科特·赫什伯格。
（音频片段：雷声）
像你这样的人类被闪电击中的几率微乎其微。但如果你是热带的一棵大树呢？
“闪电发生在几毫秒之内。我们无法预测它的位置，而且在它发生后我们通常也找不到它，因此闪电是很难研究的东西。”
路易斯威尔大学的生态学家埃文·戈拉说到。现在，得益于卫星数据和地面传感器网络，戈拉及其同事首次能够量化全球热带森林中雷击的影响。
“我们发现，每年每公顷遭受雷击次数较多的森林，其每公顷的大树数量较少，这可能是因为大树被雷击致死。每年都有更多的生物量翻转，因此基本上，闪电似乎正在影响森林，导致树木死亡。之后总生物量也会减少。”
在巴拿马的一次地面调查中，研究人员发现一次雷击通常会毁坏20多棵树。一年之内，其中五六棵树会死掉。科学家将这一数字与来自世界各地的卫星数据结合起来，以估计每年热带森林中有多少棵树死于闪电。
“我们认为约有8.3亿棵树被闪电击中，其中约有四分之一（即2亿棵左右）死亡。这相当多了。正如我之前提到的，我们知道被击中的不是森林中随便一棵树：通常是最大的树。”
这项研究发表在《全球变化生物学》期刊上。
戈拉表示，研究结果表明，闪电是热带地区致树木死亡的最重要的自然因素之一。气候变化会如何影响闪电模式尚不清楚。但一些模型预测，随着地球持续变暖，闪电活动将更加频繁，这可能意味着更多的储存碳树木将消失。
“热带森林基本上是地球的主要陆地空调。因此，如果我们减少森林的碳储存量，这将对森林继续调节我们的星球并吸收我们产生的所有碳的能力产生重大影响。”
戈拉的工作只是这项研究的开始。他希望未来的技术进步和实地考查将帮助科学家更好地了解闪电在整个地球生态系统中的作用。这些发现应该具有启发性。
谢谢大家收听科学美国人——60秒科学。我是斯科特·赫什伯格。
译文为可可英语翻译，未经授权请勿转载！
重点讲解
重点讲解：
1. what if (用于疑问句句首，尤用于询问不希望看到的事发生时的结果)如果…怎么办；
What if this doesn't work out?
如果这个不行怎么办？
2. thanks to 幸亏；归因于；
It is thanks to this committee that many new sponsors have come forward.
又有许多赞助商找上门来，这要归功于这个委员会。
3. function as 发挥功能；起作用；行使职责；
On weekdays, one third of the room functions as workspace.
在工作日，房间的1/3用作办公区域。
4. take up 接受；
Breeding or genetic modification could increase the efficiency with which animals and plants take up nitrogen.
育种或基因改造可以增加动植物吸收氮的效率。
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