Review by Sid Perkins
It’s amazing that a small sackful of bark beetles, each no larger than a grain of rice, can in a matter of days kill a tree more than a century old. Yet maybe it’s not surprising, considering that these voracious pests descend upon forests in swarms that can easily weigh more than a pod of killer whales.
Nikiforuk, a Canadian journalist, chronicles the plague of bark beetles that in the last quarter-century has killed more than 30 billion pine and spruce trees from Alaska to New Mexico. No creatures except humans, he says, can change a landscape as dramatically and quickly.
Several factors have conspired to set the beetles free of their natural constraints. A century of fire suppression has nearly tripled the proportion of old trees, which don’t produce enough resin to create a gooey protective barrier against beetles. Climate change plays a role, too: Trees s