California bark beetles may cause ecological change

Pine trees in California forests will die out and give way to brush and chaparral, forestry experts warn, unless agencies undertake what one analyst called a “massive effort” to reduce fuels and replant trees. Otherwise, the conversion to chaparral could further increase risk of wildfires and affect the state’s water supply.

A U.S. Forest Service survey, released in June, revealed that 66 million trees—mostly pine species—have died in the southern Sierra alone, due to bark beetle infestations, drought, wildfire and climate change. One question now, experts say, is what will replace those dead trees.

“We know in the Sierra and Sequoia national forests east of Fresno, the beetles have killed at least 85 percent of the entire pine vegetative type and at least 20 percent of the mixed conifer type, which is pine and fir,” said Steve Brink, California Forestry Association vice president of public resources. “By the end of this summer, essentially 100 percent of the pine type will be dead in the Sierra and Sequoia national forests, and you are going to have a massive conversion to chaparral.”

Source: Forestry experts say tree mortality brings added risk