The Oregon Department of Agriculture has struggled with Curry County's outbreak of sudden oak death (SOD) fungus (previous blog here). The following chart shows that the ODA has had to grow the quarantine area multiple times...and it's now up to 26 square miles.
Counting the number of new SOD trees is nice, but the fungus can infect a number of trees and shrubs, only some of which it kills (like tanoaks and coast live oaks). Many common species like azaleas, rhododendrons, and evergreen huckleberries suffer damage but usually survive to provide a natural reservoir for the fungus. The ODA has obviously never gotten the reservoir under control.
This past August, the ODA found 14 infected trees in Azalea Park, which is in Brookings and thus outside of the quarantine area (previous blog here). That former state park, which has a number of tanoaks, is famous for its rhodies and azaleas...footstomp. Nearly three months later...
The state wants to expand the current Sudden Oak Death quarantine area around Brookings to 166 square miles in its ongoing attack on a disease that has already infected trees at Azalea Park and nearby private property.
The expansion, proposed by the Oregon Department of Agriculture (ODA), would impact two local lumber mills, about a dozen nurseries, five state parks and additional private landowners.
"The reason we are proposing such a large expansion, is because two of the most recent infested sites we found are at least three miles outside the existing quarantined area, meaning the pathogen is able to jump three miles from site to site," Nancy Osterbauer, plant health program manager for the ODA, said.
"We need to actively eradicate this disease before it spreads further, and that's why we are proposing to extend the quarantined area."
Since SOD readily spreads via rain and wind, waiting on this decision until the rainy season wasn't exactly a brilliant move.
In an effort to stop the spread of the tree-killing pathogen Phytophthora ramorum (P. ramorum)--responsible for for infecting more than 100 different plant species, specifically tanoak trees--the ODA is proposing to expand the existing 26-square-mile quarantine area directly outside Brookings to cover 12 miles inland from Pistol River down to the California State border.
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In an attempt to halt the spread of the disease, the ODA established a quarantine boundary and the Oregon Department of Forestry (ODF) began cutting and burning infected tanoaks. Even with the removal of more than 150 tanoak trees in Azalea Park in the past few weeks, the pathogen continues to gain a foothold in Curry County.
According to Dan Hilburn, ODA state plant regulatory official, the proposed quarantine site will restrict people and business from removing certain tree species out of the area, while the infested sites will be completely off limits.
"The quarantined zone will include sites where the pathogen has not been found, so the entire area won't be treated – just the five newly discovered sites," Hilburn said. "In those sites, we have already started cutting and burning host material, which includes tanoaks, less susceptible trees like myrtle, and bushes such as huckleberry and rhododendron. Within uninfected areas, people just need to be careful not to remove tanoak and other host material out of the quarantined area."
Just treating the areas discovered to be infected has certainly been a failed strategy thus far. Thus, we have no reason to expect that it will work this time. More drastic measures are needed, but the ODF still isn't being very aggressive.
"We needed to accommodate the increasing number of infested trees and sites that were discovered over the years," (ODF forest pathologist) Kanaskie said. "But after the Oregon Department of Forestry found five new sudden oak death-infested sites in 2007, we realized we need to expand the quarantined area to include everything and restrict the movement of the pathogen."
Osterbauer said the extension will include a 3-mile buffer of forest land between the infested sites and the quarantine boundary line--sort of like a safety net.
According to Kanaskie, if the proposed quarantined zone is approved by the ODA hearings officer, anyone who uses the forest--for pleasure or for business--will be affected.
"If you are a timber company and want to harvest tanoak or myrtle within the quarantined area, you can't ship it outside the boundary line," Kanaskie said. "For instance, South Coast Lumber in Brookings has been affected since infested sites have been discovered on their land, and the quarantined area will restrict their movement of lumber. But they are being very cooperative, and in most cases, we are contracting different companies to help them and others with the eradication effort."
That's it, a buffer zone? I'm underwhelmed.
According to Hilburn, all private landowners who own property within the five new infested sites, have already been notified by mail that the ODF found diseased trees on their land.
"We are working with the Oregon Department of Forestry to eradicate every infected tree, and most of the removal has not been done at the owner's expense," Hilburn said. "Thousands and thousands of trees have already been killed by sudden oak death in California – that's why we can't turn our backs on this, or else the pathogen will spread like ripples in a pond."
Osterbauer said the worst-case scenario would be if Curry County ended up with a situation similar to Humboldt County, Calif. where approximately 5,000 acres of forest land is infected with sudden oak death.
"The quarantined area is onerous for land owners, but the impact for the region is tremendously worse if we don't eradicate this disease," she said. "If we don't start showing some improvement and go through with this expansion, the United States Department of Agriculture (USDA) can quarantine the entire county–-which would affect a lot more people."
Humboldt County is nowhere near the worst case. Try more than a million trees killed between Mendocino and Monterrey in SOD's recent resurgence there.
At least the ODF's efforts have kept the spread of SOD slow. But if this is all the ODF is going to do, they ought to stop using the word eradication.
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