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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research » Research » Publications at this Location » Publication #361432

Research Project: Integrated Disease Management of Exotic and Emerging Plant Diseases of Horticultural Crops

Location: Horticultural Crops Research

Title: Slowing spread of sudden oak death in Oregon forests, 2001-2015

item Kanaskie, Alan - Oregon Department Of Forestry
item Wiese, Randy - Oregon Department Of Forestry
item Norlander, Danny - Oregon Department Of Forestry
item Laine, Jon - Oregon Department Of Forestry
item Navarro, Sarah - Oregon Department Of Forestry
item Goheen, Ellen - Us Forest Service (FS)
item Rhatigan, Ron - Us Forest Service (FS)
item Hansen, Everett - Oregon State University
item Sutton, Wendy - Oregon State University
item Reeser, Paul - Oregon State University
item Grunwald, Niklaus - Nik
item Kamvar, Zhian - Oregon State University
item Osterbauer, Nancy - Oregon Department Of Agriculture

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/15/2016
Publication Date: 3/1/2017
Citation: Kanaskie, A., Wiese, R., Norlander, D., Laine, J., Navarro, S., Goheen, E.M., Rhatigan, R., Hansen, E., Sutton, W., Reeser, P., Grunwald, N.J., Kamvar, Z., Osterbauer, N. 2017. Slowing spread of sudden oak death in Oregon forests, 2001-2015. In: Proceedings of the Sudden Oak Death Sixth Science Symposium; 6/20/16-6/23/16; San Francisco, CA. Available: 1 p.

Interpretive Summary:

Technical Abstract: Sudden oak death, caused by Phytophthora ramorum, is lethal to tanoak (Notholithocarpus densiflorus) and threatens this species throughout its range in Oregon. The disease was first discovered in coastal southwest Oregon forests in July 2001. An interagency team attempted to eradicate the pathogen through a program of early detection and mandatory destruction of infected and nearby host plants. Eradication treatments eliminated disease from most infested sites, but the disease continued to spread slowly, mostly in a northward direction. Following a sharp increase in disease in 2010 and 2011, a result of leaving many infestations untreated, the program shifted goals from complete eradication to slowing spread. In 2012 the quarantine regulations were changed by establishing a Generally Infested Area (GIA) in which eradication on was no longer required by law. Since then, eradication treatments (cutting and burning host plants) have been focused on new infestations that occur outside of the GIA. All new infestations outside the GIA are cut and burned, but the size of the treatment area varies with available funds and location of the site. Since 2001 the area under quarantine has expanded seven times: from 22 km2 (9 mi2) in 2001 to 1,333 km2 (515 mi2) in 2015, which is approximately 31% of the total area of Curry County. The GIA has expanded four times and currently stands at 151 km2 (58 mi2). Within this area, hundreds of thousands of tanoaks have died in the since 2012, creating a high risk for wildfire and damage from falling trees. From the initial infestations of 2001, the disease has been found a maximum distance of 28 km (17.5 mi) to the north, 12 km (7.5 mi) to the northeast along the Chetco River, and 11 km (7 mi) to the southeast along the Winchuck River.