Eradication of the sudden oak death pathogen (Phytophthora ramorum) in southwest Oregon.
This photo the following excerpt are from Forest Health Highlights in Oregon 2004, located here:
www.fs.fed.us/foresthealth/docs/fhh/OR_FHH_2004.pdf "Since fall of 2001, state and federal agencies have
been attempting to eradicate P. ramorum from infested sites by cutting and burning all infected host plants and adjacent apparently uninfected plants, and treating the stumps to prevent sprouting. Any vegetation sprouting from stumps following the initial treatment is destroyed mechanically or with herbicides. As of the end of 2004, eradication was in progress on approximately 42 sites, totaling 70 acres.
P. ramorum has persisted on many infested sites despite eradication efforts. On approximately 50 percent of the sites the pathogen survived the initial treatment and was present in stump sprouts of host vegetation one or more years after treatment. Similarly, P. ramorum was recovered from soils at several eradication sites, but with very low frequency. P. ramorum also was detected in several streams associated with eradication sites, and almost never in streams not associated with known infestations. Repeated and extensive aerial surveys with 100 percent ground-verification and several ground surveys have failed to detect the pathogen in Oregon forests beyond the limited area near Brookings. Each year most new infected trees occurred within 0.1 mile of eradication sites, a pattern consistent with aerial spread via wind and rain. The number of new infected trees discovered each year has decreased since we first discovered the pathogen in Oregon. It appears that the eradication effort has reduced inoculum levels and slowed spread of the pathogen. As of the end of 2004 the area under federal and state quarantine remained at 11 square miles."
Photo by: Oregon Department of Forestry
Date: 2004
Credit: Oregon Department of Forestry
Source: Forest Health Highlights in Oregon - 2004;
www.fs.fed.us/foresthealth/docs/fhh/OR_FHH_2004.pdf Annual Forest Health Highlights for each state in the United States are available here:
www.fs.fed.us/foresthealth/protecting-forest/forest-healt... Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection:
www.fs.usda.gov/main/r6/forest-grasslandhealth
