SUZANNE SIMARD says trees are "social creatures" that communicate with each other in cooperative ways that hold lessons for humans too. Simard grew up in Canadian forests as a descendant of loggers before becoming a forestry ecologist. She's now a professor of forest ecology at the University of British Columbia. She explains her research on cooperation and symbiosis in the forest, and shares her personal story in the new memoir Finding the Mother Tree: Discovering the Wisdom of the Forest.