The essential idea in the book is that the forest is a community of trees whose members care for one another rather than compete for water and canopy space. Wohlleben states his case early on: “A tree is not a forest. On its own, a tree cannot establish a consistent local climate. It is at the mercy of wind and weather. But together, many trees create an ecosystem that moderates extremes of heat and cold, stores a great deal of water, and generates a great deal of humidity. And in this protected environment, trees can live to be very old.”