California Lost 36 Million Trees to Drought Last Year

Dead and dying Ponderosa pine trees that have met their demise from bark beetles dot the landscape in Las Posadas State Forest in Angwin, Calif., on Tuesday, Sept. 20, 2022. Photo: Scott Strazzante/San Francisco Chronicle (AP)

Extreme drought and hot weather killed millions of trees in California’s forests last year, according to a new report from the U.S. Forest Service.

Aerial surveys conducted from July 2022 to October 2022 surveyed 39.6 million acres (over 61,000 square miles) of tree canopy across California. The Forest Service found about 2.6 million acres (over 3,100 square miles) of dead trees, or the equivalent of about 36.3 million dead trees.

The tens of millions of dead trees tell a story of how bad the dry and hot conditions were across the American West throughout much of 2022. The average mortality was a lot higher last year than in 2021, the report explained. The survey looked at a large variety of trees to assess which were the most affected. Douglas fir mortality especially increased in 2022 from 2021. In 2021, an estimated 170,000 Douglas firs died—that number jumped to around 3 million. This represents a 1,650% increase in mortality from one year to the next.

Lack of water, even for trees that don’t need all that much precipitation, has been a dire situation. Just this past November, large sections of Central and Northern California saw exceptional and extreme drought, according to the U.S. Drought Monitor. Prolonged drought doesn’t simply dry trees up; it makes them weaker, which makes them more susceptible to damage from insects that destroy the trees. Trees are usually attacked by bark beetles that lay their eggs in tree bark, and the larvae that hatch feed off the trees.

Ryan Tompkins, a forester and natural resources advisor at the University of California Cooperative Extension, told the LA Times that forest density in California makes things worse. “When these forests are really dense, trees are competing for a finite amount of water, particularly in a dry year,” he said. …


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