An invasive, tree-killing pest has made its way to Portland, spelling trouble for the many native ash trees that cool residential neighborhoods on hot summer days.
On Wednesday, Oregon forestry officials announced the discovery of an emerald ash borer infestation in the Hazelwood neighborhood in Northeast Portland, in the parking lot of the David Douglas Aquatic Center. The affected trees will likely have to be removed.
The emerald ash borer is an iridescent green beetle that made its way to the U.S. from Asia in 2002, first decimating ash trees across the Midwest. Many tree experts say it’s not a matter of if, but when Oregon’s ash trees endure a similar fate.
Oregon ash trees not only provide critical shade to residential neighborhoods — they also line many of the creeks, streams and rivers that cities rely on for drinking water. These waterways are also critical habitat to struggling fish species.
Biologists worry that losing Oregon ash trees will make waterways more vulnerable in the face of climate change. Higher temperatures can degrade water quality in many ways — including increasing bacterial and algal growth, decreasing oxygen levels, and changing overall chemical profiles. That could make drinking water treatment more expensive, and it could kill fish.
The emerald ash borer was first discovered in Oregon’s Willamette Valley in 2022. It has so far targeted Washington, Marion, Yamhill and Clackamas counties.
This story comes to you from the Northwest News Network, a collaboration between public media organizations in Oregon and Washington.
