The trailblazing scientist who pioneered the once-radical—and now broadly accepted—concept of sophisticated communication between trees returns with a book that blends rigorous science and neglected Indigenous wisdom in service of a powerful vision for the future of our forests. With her bestselling book Finding the Mother Tree, forest ecologist Suzanne Simard advanced a revelatory new paradigm for the profound intelligence of trees and their relationships with each other. Now, with When the Forest Breathes, she examines the forces that threaten forest ecosystems and, with years of research at her back, offers a pragmatic and hopeful vision for a responsible relationship with the forests that sustain us. Raised in a family of loggers committed to sensible forest stewardship, Simard has watched timber companies ignore the complexity of nature’s self-regulation and Indigenous communities’ finely honed knowledge of the natural world. Plundering the forests for profit, they leave in their wake heightened risk of wildfire, drought, water crises, and endangerment of plant and animal life. But Simard’s research, which recognizes forests as complex, adaptive systems, has the potential to reverse this pattern. Here, in accessible and impassioned prose, she shares the findings of one of the most ambitious climate research projects ever conceived. In her native British Columbia, Simard and her colleagues study innovative logging patterns that reflect an array of attempts at conservation, plant a mixture of tree species to identify the combinations most resilient to the stresses wrought by climate change, and introduce trees from other climates to increase the adaptivity of the forest. Simard also opens our eyes to the sophisticated knowledge systems of Indigenous peoples, who have stewarded the forests and waters for centuries. Their wisdom offers a valuable bridge from the past, a set of principles grounded in respect for the land. Powered by rigorous science but infused with authenticity and warmth, When the Forest Breathes is an emboldening declaration that when we take responsible steps, reversing the effects of climate change is within reach. In elegant prose teeming with reverence for the natural world and all it offers us, Simard shares with all of us the gift of her ingenuity, commitment, and optimism.