When you walk through the woods, how much of the living matter there is animal, including bugs and birds and all? Two to three percent. Plants, trees, bushes, moss, grass, and flowers—most of what you see and think of when you think of a walk in the woods—make up 15 to 20 percent, depending. The rest is all a very quiet, nearly invisible world of fungi. The mushrooms you see aren’t so much the tip of the iceberg as dewdrops on top of the ocean.
