The Understory

Environmentalists have long paid attention to eye-catching creatures that people can easily care about, because championing such animals can help to protect entire ecosystems. Sparing bald eagles from the pesticide DDT — a cause adopted by many readers of Rachel Carson’s 1962 book, Silent Spring — benefited countless other organisms, for example. More recently, starving polar bears unable to pack on the pounds during shortened winter hunting seasons have served as one of the most prominent symbols of climate change. There’s even a name for these poster children of the environmental movement: charismatic megafauna.

Those who advocate for the protection of forests have often taken a similar approach, spotlighting what we might call charismatic megaflora. Even in the nineteenth century, as the race to cut down the sprawling forests of North America was accelerating, people could still be solicitous of astoundingly tall trees. When the United States government...