Stricken sycamores, waning willows, ailing oaks – thanks to years of drought and invasive pests, tens of millions of trees are at imminent risk of a massive die-off.
While visions of sunny Southern California may conjure up thoughts of its iconic palm trees, anyone who has admired the region’s lush canopy knows there is so much more. Home to 71 million trees, the urban forest there is an exquisite thing – giant graceful sycamores, exuberant live oaks, swaying willows, myrtle, avocado, liquidamber … the list goes on and on.
But the outlook for this dense verdant treescape isn’t looking so good.
As Louis Sahagun writes in the Los Angeles Times:
The trees that shade, cool and feed people from Ventura County to the Mexican border are dying so fast that within a few years it’s possible the region will look, feel, sound and smell much less pleasant than it does now.
“We’re witnessing a transition to a post-oasis landscape in Southern California,” says Greg McPherson, U.S. Forest Service researcher who has been studying what many are calling an unprecedented die-off of the region’s precious trees.
The native sycamores may be the hardest hit so far, compliments of the polyphagous shot hole borer beetle, which McPherson says could kill 27 million of the trees in Los Angeles, Orange, Riverside and San Bernardino counties. That’s 38 percent of the region’s trees. This particular tiny menace is from the group of beetles known as ambrosia beetles and hails from South East Asia; pregnant females drill into the trees and lay eggs, along with a pathogenic fungus to feed the new babes, all of which can prove lethal to the host trees.
“Here’s the sad news about sycamores,” says plant pathologist Akif Eskalen from the University of California, Riverside. “If we cannot control the shot hole borer, it will kill all the sycamores in California. And when they’re done with sycamores, they’ll move to other trees.”
And that’s just one insect. There are plenty of others – the Kuroshio shot hole borer