Sudden Oak Death is Here to Stay

Ten years ago, dead tanoak trees were spotted during an aerial survey in the woods north of Brookings, Oregon. Sudden oak death (SOD), an invasive plant disease, had killed them. Immediately, four agencies (Oregon Department of Forestry, Oregon Department of Agriculture, US Forest Service, and Oregon State University) combined forces in an attempt to eradicate the infestation. For the past decade, they have tried everything they could think of, including cutting and burning hundreds of acres of trees, to stomp out the disease. This week they admitted defeat. Sudden oak death is here to stay.

Oregon’s SOD Task Force deserves huge credit for trying. It was a huge challenge and a courageous effort in a very remote area. Complicating matters from the start, this disease was new to science, and practically nothing was known about how it spread or how to control it. We know a lot more now. Too bad we can’t turn back the clock and try again. Oregon’s SOD busters are an outstanding team: Alan Kanaskie and Stacy Savona (Oregon Dept. of Forestry), Nancy Osterbauer (Oregon Dept. of Agriculture), Ellen Goheen (U.S. Forest Service), and Everett Hanson (Oregon State University). Thank you, it was a valiant effort, we salute you for dedicating a large part of your career to keeping keep SOD out of Oregon for as long as possible. Even though eradication didn’t work, your efforts kept the disease bottled up in a small area for 10 years. You bought us time. No one else anywhere in the world has ever eradicated a plant disease from a forest either. It was worth a try.

What happens now?  The Task Force met this week to discuss options. Unfortunately, there aren’t many good ones, especially given current budget realities.

Five options were discussed:

1.)    Continue the eradication treatments until the money runs out, then stop.

2.)    End the program entirely.

3.)    Treat only outlier sites to slow disease spread.

4.)    Create a host-free zone in an attempt to stop disease spread and continue to treat outliers outside the zone.

5.)    Treat with Agrifos (a phosphonate chemical that boosts tree immunity) to protect trees.

Option one would be like driving over a cliff. Number two would be the equivalent of giving up because it is hard. Options four and five would each cost millions of dollars that we don’t have with no guarantee of success. SOD jumped a host-free zone in Humbolt County, California recently. Wide-area treatment with Agrifos is being tried in Australia on a related disease. Here it would trigger an Environmental Impact Statement (a process that takes years) because federal land would be involved, and it can’t be sprayed over streams, making it impractical. That leaves option three: slow the spread by treating the outliers.

Sudden oak death, like a lot of diseases, doesn’t spread evenly along a continuous front. Spores blow in the wind like cinders coming out of a campfire. Every now and then those sparks start new infestations out in front of the generally-infested area. Stomping them out won’t stop the disease, but it should slow the overall rate of spread. Once again Oregon would be pioneering something that no one has ever tried.

Here is the recommendation from the Task Force:

1.)  Finish up all work-in-progress as of January 2010.

2.)  In the future treat only outlier sites on private land, and treat all sites on federal lands. Sites in the generally-infested core area would no longer be cut or burned by the State.

3.)  Landowners within the generally-infested core area would be encouraged to cut and burn infected and nearby tanoak (or other hosts) with possible assistance through a 50:50 cost share program with the Oregon Department of Forestry if funds are available. Landowner expenses to treat infested sites would qualify as non-federal matching dollars, freeing up US Forest Service money to support detection surveys, technical assistance to landowners, and treatment of high-priority outlier infestations.

4.)  Highest-priority outlier sites (furthest from the core) would be treated first. If resources allow, additional outlier sites could be treated working from the outside in.

5.)  Quarantine requirements should change. Cutting and burning in the generally-infested area would no longer be required, just encouraged. The quarantine boundary would be expanded as necessary if/when the disease spreads beyond the current line.

This is a big change, and right or wrong we’ll all have to live with the consequences. Before any of this happens, the Department wants to gather input from interested parties. The SOD Core Group, a loose network of stakeholders, will be briefed at their next meeting on Feb. 18 in Salem. A public information meeting will follow in Brookings, tentatively on March 2. Changes to the quarantine would trigger additional meetings. If you have thoughts, ideas, or comments, now is a good time to share them. I monitor comments to this blog, or you can send me an email at: dhilburn@oda.state.or.us. What do you think of this proposal?  Do you have a better idea?

Dan Hilburn