Invasive insects are expected to cost the nation several billion dollars every year for dead tree removal – and jeopardize U.S. industries that rely on timber.
Scientists say forests from New England to the West Coast are at risk, with some tree species are being driven toward extinction.
In California, a prolonged drought has helped sudden oak death reach catastrophic levels.
“For native bark beetles in California, drought is the trigger. You can see some of the tunneling,” says U.S. Forest Service Entomologist Sheri Smith, pointing to the damage beetles have done to a sugar pine, lethally gutted by the infestation. It’s not just in the Sierra foothills. The beetles are clear-cutting their way through pine forest, all the way down to southern California.
As for the future – even some drought relief might make some problems worse. While a healthy rain season would slow the beetles, sudden oak death thrives in moisture, meaning normal rainfall could kick the disease into high gear.
Bugs like the Emerald Ash Borer and the Gypsy Moth are spreading in part due to global trade, the warming climate and drought.
Strategies for fighting the problem include the genetic alteration of trees to help the resist the pests and planting at risk tree species in more hospitable areas.