Dan Dagget believes that humanity can have a positive effect on the land. He demonstrates case after case of positive human engagement in the environment and of managed ecosystems and restored areas that are richer, more diverse, and healthier than unmanaged ones. Much of pre-Columbian America, he contends, was not a pristine wilderness but an ancient garden managed over millennia by native peoples who shaped the plant and animal communities around them to the mutual benefit of all.

Dagget recommends a new kind of environmentalism based on management, science, evolution, and holism, and...