“Trees are horribly intermingled,” Fisher says. He points to the example of cottonwood trees. “Below ground, they’re connected by a network of large roots that make them one genetic individual. You can think of a trunk as really fingertips on a buried hand.” So what looks like a whole forest is really just one single, sprawling organism.

“Trees are horribly intermingled,” Fisher says. He points to the example of cottonwood trees. “Below ground, they’re connected by a network of large roots that make them one genetic individual. You can think of a trunk as really fingertips on a buried hand.” So what looks like a whole forest is really just one single, sprawling organism.