Some of my oldest experimental plantations are now over 30 years old.  有一些我最早进行实验的种植园，到现在已经超过30年了。

You can check them out. That's how forest science works. 你可以去看看它们。这才是搞林业学应该做的事。

So now I want to talk about the science.  那么现在我想谈一谈科学本身了。

How were paper birch and Douglas fir communicating?  纸皮桦和花旗松到底是怎么交流的呢？

Well, it turns out they were conversing not only in the language of carbon but also nitrogen and phosphorus 实际上，它们不仅仅使用碳元素作为它们交流的语言，其实还有氮元素和磷元素，

and water and defense signals and allele chemicals and hormones -- information. 还有水、防卫信号、等位基因化学物和激素--这些都是信息。

And you know, I have to tell you, before me, scientists had thought  你知道吗，我得告诉你们，在我之前的科学家们都认为

that this belowground mutualistic symbiosis called a mycorrhiza was involved. 这种地下的互惠共生现象是因为一种菌根介入其中的。

Mycorrhiza literally means "fungus root."  菌根的字面意思就是“真菌的根部”。

You see their reproductive organs when you walk through the forest. They're the mushrooms. 当你穿行在森林中时，你经常都能看到它们的繁殖器官。它们就是蘑菇。

The mushrooms, though, are just the tip of the iceberg,  而其实那些蘑菇仅仅是冰山一角，

because coming out of those stems are fungal threads that form a mycelium,  因为从那些树干里冒出来的菌丝生成了菌丝体，

and that mycelium infects and colonizes the roots of all the trees and plants. 菌丝体会感染和占领树木和植物的根。

And where the fungal cells interact with the root cells, there's a trade of carbon for nutrients, 在真菌细胞和根细胞交流的地方，时时刻刻都发生着为了获取营养的碳交易，

and that fungus gets those nutrients by growing through the soil and coating every soil particle. 真菌靠着在土地里生长，并且覆盖住所有的土壤颗粒来获取养分。

The web is so dense that there can be hundreds of kilometers of mycelium under a single footstep. 这个网络无比密集以至于在你每走过一步脚下的菌丝连起来可以有几百公里长。

And not only that, that mycelium connects different individuals in the forest,  不仅如此，菌丝跟森林中其它的个体也都有联系，

individuals not only of the same species but between species, like birch and fir, and it works kind of like the Internet. 这种联系不仅仅在单一的种类中存在，在不同种类之间也存在，比如纸皮桦和花旗松，而且它的工作原理就像是互联网一样。