科学美国人60秒 热带树木常遭雷击致死（在线收听）

[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?

人被闪电击中的几率是微乎其微的。但是如果你是热带的一棵大树呢?

“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.”

闪电发生在几毫秒内。我们无法预测它会在哪里，而且在发生后我们通常也无法找到，所以要研究闪电很难。”

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.

埃文·戈拉是路易斯维尔大学的生态学家。现在，多亏了卫星数据和地面传感器网络，戈拉和同事们第一次能够量化雷击对世界各地热带森林的影响。

“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.”

“我们发现，每年每公顷被雷击次数越多的森林，树木的数量就越少，大概是因为它们被雷击致死。每年都有更多的生物被死亡，所以，闪电似乎正在影响森林并导致树木死亡。这样一来，它们的总生物量就会减少。”

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.

在巴拿马进行的一次地面调查中，研究人员发现，一次雷击通常会破坏20多棵树。一年之内，五到六个死亡。科学家们将这一数据与世界各地的卫星数据结合起来，计算了每年有多少热带森林的树木死于闪电。

“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.”

“我们认为约有8.3亿棵树被闪电击中，其中约四分之一，约2亿棵树被雷击死亡。就像之前提到的，被雷击的树木并不是随机的:通常，它是最大的树。”

The study is in the journal Global Change Biology.

这项研究发表在《全球变化生物学》杂志上。