“Warmer and wetter weather is good for tree diseases, which is bad news for trees” Actually warmer and wetter is generally good for plant life. In this case though imported pathogens are harming the trees but really isn’t due to the weather, is it.
Climate change is likely to wreak havoc on California’s forests. Extreme weather, wildfires and insect outbreaks will all take a toll. Add to those another looming threat: disease. Forest diseases like Sudden Oak Death, which has infected trees in 14 counties in the state, stand to benefit from the effects of climate change, to the detriment, obviously, of the trees.
Trees are big and long-lived. Tree pathogens, mostly fungi and bacteria, are the opposite. They’re mobile, able to blow around on the wind. And they reproduce and evolve rapidly. That’s the crux of the problem, according to Susan Frankel, a plant pathologist with the Forest Service.
“When you look at forest health and the balance between forest trees and the pathogens that attack them, it does seem, given climate change, pathogens get the better end of the deal,” she told me.
Frankel is working with a group of ecologists, funded by the Forest Service’s Western Wildland Environmental Threat Assessment Center, to better understand how climate change will affect tree diseases. In a recent report, they outlined possible impacts:
Frankel is especially interested in Sudden Oak Death, which has killed more than a million trees in California. It needs moisture to spread and reproduce, and it thrives in warmer temperatures. “The pathogen blows in wind-blown rain,” Frankel explained. “It loves the weather we’re having right now.”