A strain of Sudden Oak Death previously undetected in the wild on the West Coast, has been discovered near Port Orford.
Before the recent discovery of infected tanoaks along Highway 101, just north of Port Orford, the NA2 strain had only been known to infect plants and trees in nurseries, according to a May 26 press release from the Oregon Department of Forestry.
Randy Weiss, Sudden Oak Death forester with the ODF, said he is not sure how the new strain was introduced, but he estimated it could be from plants transported from an infected nursery. Whatever the case may be, NA2’s presence here is cause for concern, especially for the tanoak he said.
“It’s such a widespread tree across the landscape. As far as acorn production for wildlife, it’s one of the main ones out here,” said Weiss.
Sudden Oak Death is caused by the invasive water mold Phythphtora ramorum, which spreads by spores, usually through the tree canopy. When the disease was first detected in Oregon in 2001, forest agencies attempted to eradicate it, but when that proved impossible Oregon’s SOD program shifted to slowing the spread of the disease.
The site is also sounding alarm bells because it was found 21 miles north of the 515 square mile quarantine zone, which is bounded by the state border to the south and the Rogue River to the north, including large portions of the Rogue River-Siskiyou National Forest and about a third of Curry County.
“That is a massive jump for us...It’s our most important site, being so far out of the quarantine,” said Weiss. “As the disease was moving north, we would expect it to jump the river, but not all the way to Port Orford with nothing in between.”
Another SOD site discovered outside the quarantine zone near Gold Beach recently finished treatment, as reported by the Pilot. However, the disease at that site was much closer to the existing quarantine zone than the Port Orford site. Additionally, it was a different strain of P. ramorum — EU1.
The Port Orford site faces additional challenges because it is located near private property. Since the discovery, forest officials have reached out to at least 15 landowners who may be affected by treatment or surveys. Weiss said many of the landowners have been cooperative and concerned about the spread of SOD.
Weiss said treatment of the immediate infected area will begin within weeks. Treatment includes falling all of the tanoaks within a reasonable radius of an infected tree, then piling and eventual burning. After the initial treatment, several arial and land surveys will occur in search of more infection in the area.