'The Hidden Life of Trees': How they communicate, nurture and even show tribal loyalty They're probably the biggest symbol of the importance of protecting the planet, and they also play a huge role in stopping climate change. But trees are more than just a tool to help the human species survive. They're living beings themselves, with some even arguing they're capable of communicating, nurturing, learning and maybe even showing tribal loyalties. Peter Wohlleben, forester and author of "The Hidden Life of Trees", joined us on Perspective to tell us more.