Californians can help protect urban and wildland trees this summer by buying firewood local to where they will be using it and not moving it from one place to another, according to officials.

“Time and time again we see invasive species spread long distances as a result of firewood movement. This is something we can all help stop. Keeping firewood local is such an easy way for all of us to help do our part to protect our trees and the forests we love,” Katie Harrell, California Firewood Task Force chair, said in a press release.

Invasive species such as the goldspotted oak borer, shot hole borers, sudden oak death, and pitch canker are killing millions of trees in California, and all can move on firewood. Over the past year alone, the goldspotted oak borer, Kuroshio shot hole borer, and polyphagous shot hole borer have spread to new counties in Southern California as a result of firewood and green waste movement, officials said.

For more information on invasive species in California’s forests or the risks of moving firewood, go online.