Ernst Zürcher listening the world of trees... in "Visages" on RCF.

Ernst Zürcher has been listening to the heartbeat of trees since his childhood. Having become a forestry engineer and a lecturer at the Swiss Federal Institute of Technology in Lausanne, he has become a leading expert in the study of tree life and their interactions. He is the author of "The Trees: Between the Visible and the Invisible," published by Actes Sud. An hour with him, and you'll never look at a tree the same way again.