Epidemic of dead trees

California’s forests, which cover a third of the state, are now choked with nearly 150 million dead trees.

Weakened by a prolonged drought, which scientists link to climate change, California’s ubiquitous pines and oaks are vulnerable to insect infestation and disease. Those giants crash to the forest floor and, unless they are removed, provide ready fodder for the next voracious fire. The die-off is catastrophic, beyond the reach of state foresters to remedy.

In many communities of the central and southern Sierra Nevada mountain range, “80 percent of trees are dead,” said Ken Pimlott, former director of Cal Fire.