Robert Moor’s book *In Trees* explores the complex relationships between humans and trees across the globe, blending personal experience with scientific and cultural insight. Building on his 2016 bestseller *On Trails*, Moor offers an expansive view that moves beyond the biology of trees to consider how people engage with these natural giants.

Moor’s journey opens with memories of childhood tree climbing, emphasizing an instinctive human connection rooted in our evolutionary past as tree-dwelling primates. This connection is most evident in childhood but often fades with age. Moor, however, rekindles this bond as an adult through his own climbing experiences, starting in England’s Lake District where, guided by an arborist, he ascended a large sycamore barefoot. He describes achieving a heightened state of focus and a profound sense of being supported by a living organism, evoking a sensation he had not felt since childhood.

The narrative then shifts to the towering redwoods of California, where Moor climbs with specialized equipment to heights exceeding 200 feet. There, he witnesses the diversity of life thriving in the forest canopy, including soil layers and a variety of plant species—ferns, bushes, and small trees—as well as unexpected aquatic animals found hundreds of feet off the ground. The discoveries he recounts draw on research by botanist Steve Sillett, who documented the complexity and richness of these elevated ecosystems.

Moor also investigates human habitation in trees, visiting the Korowai people of Papua, Indonesia, who traditionally built tree houses. He notes, however, a modern disruption of this tradition as many such dwellings now incorporate synthetic materials. Additionally, he examines the nests constructed by chimpanzees in African forests, even spending a night in one, describing it as uncomfortable but eye-opening.

Environmental activism forms a significant thread in *In Trees*, particularly protests against logging old-growth forests in the western United States and Canada. Moor provides detailed accounts of tree-sitting campaigns, a method of direct action where protesters occupy trees to prevent felling. He highlights the tensions between Indigenous groups aiming to preserve forests for cultural heritage and environmental activists primarily focused on conservation, showcasing the complex dynamics within these movements.

While portions of Moor’s narrative occasionally digress into personal reflections, including forays into genealogical research, the overall work offers an engaging and thoughtful examination of humanity’s multifaceted relationship with trees. Through vivid storytelling and firsthand experiences, *In Trees* invites readers to reconsider the significance of trees in both natural ecosystems and human life.