Sudden Oak Death continues its steady slog north, the Oregon Department of Forestry announced this week.
Sudden Oak Death is caused by a pathogen called P. ramorum, which primarily attacks tanoaks.
In 2001, an estimated 9 square miles of land in Curry County was infected with SOD; since then, it has grown to more than 500 square miles, most of it in the south end of the county. The quarantine area now extends from Gold Beach and 13 miles east along the Rogue River, dog-legging south and east to the border at a point about two-thirds of the way to Josephine County line and west to the coast.
The pathogen infects primarily tanoak trees and has led to forestry officials treating hundreds of acres to keep it from spreading to other areas.
In 2018, the ODF found 40 new infestations at or beyond the “generally infested area,” which encompasses an area about an eighth the size of the county in and around Brookings to Carpenterville. Maps indicate, however, there are numerous infested spots outside that area, including about a dozen in the Chetco Bar Fire scar.
Officials at many levels — forestry, state and local — are working to keep SOD from spreading out of the county and infesting trees in other areas of the state. State Rep. David Brock Smith, R-Port Orford, often said during his tenure as a Curry County commissioner that if the pathogen spreads further, it could devastate the forestry industry in Oregon.
“The spread of Sudden Oak Death and EU1 could have devastating impacts on our local economy and environment,” said U.S. Sen. Jeff Merkley, who has worked to secure funding to fight SOD. “It has been enormously gratifying to see partners from a broad swath of governments and industries working together to address this crisis.”
If the entire county were to be placed in quarantine, the odds are dramatically increased that any plant product would not be purchased in other countries without an official declaration that the item if SOD-free.
“It has the potential of closing down the Port of Coos Bay,” Smith said in 2015, referring to countries that won’t accept logs and other items that originate in SOD-infected areas. “All the nursery industries, the lily bulbs, would be devastated.”
To further frustrate matters, a new strain — EU1, from Europe — was discovered here.
That strain attacks Douglas fir — the state tree — and other iconic state flora. Additionally, it is more aggressive and can cross-breed with the variant that attacks tanoak trees.
To locate new tree infestations, foresters “bait” streams to capture pathogens. If none are discovered, it is generally safe to assume there are no infested trees upstream. But if the test is positive, baits are placed farther upstream in an attempt to locate the tree from which the SOD pathogen originates.
According to Sarah Navarro, a forest pathologist with the ODF, 47 baits were deployed inside and outside the quarantine area this year, and 15 drainages tested positive — most of which had done so in past years.
One test near Carpenterville, however, indicates there might be another infestation upstream from a tree that tested positive in 2017.
Treatments this year
Treatment typically involves felling the infested tree and treating a 300-foot buffer around it by burning or chipping trees and brush.
The Forest Service treated three infestations on 58 acres, the state treated one infestation covering 16 acres and private landowners treated 337 acres to eradicate 24 infestations. There were 12 infestations of EU1 — mostly in the same areas as those found in 2017 — requiring treatment of 425 acres.
In 2018, there were 74 confirmed EU1 positive trees, Navarro said, and lineage testing is pending for 20 more. Most of those have been treated or prepared to be burned this month.
This year, the SOD Task Force hired Mason, Bruce and Girard, a natural resource consulting firm from Big Bear, California, to determine the cost of treatment, lost timber value due to that treatment, the cost to certify exports as being SOD-free, effects on tourism and impacts to landowners and cultural values of Indian tribes.
That firm is also working with researchers at North Carolina State University to develop a new model to determine the rate of SOD spread in Oregon. That report is due out this month, Navarro said.
Oregon State University’s Extension Service also recently published a new guide for homeowners; it can be found at https://catalog.extension.oregonstate.edu/em9216
Paying for it all
SOD eradication in itself has turned into its own industry, with efforts in 2018 costing about $2.375 million.
Until 2016, the state allocated $100,000 to treat SOD in Curry County. But when the EU1 strain struck, the governor convened a task force to aggressively address the problem.
Merkley was successful and brought back $1 million to fight the pathogen.
“That, combined with the $1 million dedicated from the Oregon State Legislature, is helping to have a significant impact on the spread of the SOD pathogens,” he said.
Federal funding has been used in the past, and this September, the state allocated $1 million from the state emergency fund to treat EU1 infested sites.
“I will continue to do everything I can at the federal level to fund research, education and mitigation, because we’ve made good progress, but the work to eradicate the NA1 and EU1 pathogens has a long way to go,” Merkley said. “We need to work collaboratively on more and better solutions to fight these pathogens.”