New research has found that older Douglas-fir trees in Oregon are just as susceptible to Swiss needle cast as younger ones, suffering the same needle loss and in some cases almost stop growing. Photo from OSU.
Oregon’s state tree, the Douglas Fir, is under attack from a disease that’s spreading and intensifying through the Coast Range.
It’s called Swiss needle cast, a fungus that causes the tree to lose its needles and stunts its growth. Researchers with Oregon State University say the disease has gotten so bad, it’s damaging forests to the tune of $200 million per year.
They suspect global warming may be a cause.
