RONALD, Wash. — The sound of wildfire prevention isn’t a fire engine siren. It’s chainsaws, wood chippers and heavy machinery chewing through brush. Across Kittitas County, crews are removing smaller trees, trimming limbs and clearing brush in an effort to reshape forests before the next wildfire season arrives. But the work underway here is also challenging one of the most deeply held ideas many people have about forests: That more trees always means a healthier forest. “Green is good,” said Katie Zander, the North Service Forestry coordinator for the Washington Department of Natural Resources (DNR) Southeast Region. “But out here historically we did not have this dense of forest stands.” According to Zander, eastern Washington forests evolved with regular low-intensity fires that naturally cleared out brush and smaller trees. But decades of aggressive wildfire suppression changed that pattern.