California loses 36 million trees in ’22, mostly due to drought

About 36.3 million dead trees were counted across California last year, a dramatic increase from previous years that experts attribute to drought, insects and disease, according to a US Forest Service report.

The same survey last year counted 9.5 million dead trees in the state, but the impact of this year’s dramatic tree dieback is more severe and spans a broader spectrum, according to the report released Tuesday.

The aerial report paints a bleak picture of a state beset by drought, disease and insects feeding and nesting in thirsty trees. From mid-July to early October, the researchers surveyed nearly 40 million acres, including federal, state, and private land. They found dead trees spread across 2.6 million acres.

True firs were hardest hit, with 3 million Douglas firs counted dead across 190,000 acres, mostly in the central Sierra Nevada Range. Last year, just 170,000 dead trees were counted on 18,000 acres, with this year’s numbers representing a 1,650% increase, according to the report’s authors.

15 million dead spruces have been counted on 890,000 acres, and an additional 12 million silver firs have been counted on 1.5 million acres. Both represented a significant increase over the previous year’s results and were primarily focused on the Northern California city of Redding, including the Shasta-Trinity National Forest and surrounding areas.

Drought conditions have exacerbated disease and insect infestations. Overcrowded forests full of dead trees and unusually high temperatures have also played key roles in the increased mortality, according to forest officials.

In 2016, at the height of a historic drought in California, federal and state agencies counted nearly 62 million dead trees. The following year the number dropped to 27 million dead trees, and by 2019 surveyors counted 15 million dead trees.

The main cause is the state’s multi-year drought.

According to the US Drought Monitor, severe drought conditions hit about 80% of the state earlier in the year. Thanks to a series of winter rainstorms, the latest data shows that figure has dropped to just 32%.

But forest officials say that despite all the rain, the increase in dead trees will be a problem for years to come as rainfall levels remain low.

According to officials, forest management will play a key role in how the state responds to tree mortality.

“Forest health is a top priority for the forest service,” Jennifer Eberlein, regional forest ranger for the US Forest Service for the Pacific Southwest region, said in a statement.

The agency’s 10-year plan to address the problem includes removing dead and dying trees in areas where they pose the greatest risk to surrounding communities.

Northern California witnessed several deadly, fast-moving wildfires in 2022, including the Placer County mosquito fire and the Siskiyou County McKinney fire. Northern California also saw more dead trees than any other part of the state.

According to a study published earlier this month in the Proceedings of the National Academy of Science-Nexus, the number of burned homes and other buildings in the western United States has increased over the past 11 years compared to the previous decade. According to the results of the study, the number of homes and buildings destroyed has increased by almost 250%, while wildfires have become significantly more destructive over the past decade.

The key finding is that more homes and outbuildings were destroyed by man-made fires in California over a 22-year period.