Diseases caused by Phytophthora ramorum Werres, De Cock, & Man in’t Veld including ramorum canker (also known as sudden oak death), ramorum blight, and ramorum dieback were first detected in U.S. forest landscapes in Marin County, CA, in the mid-1990s. The range in the United States has expanded since then, but in 2007 it was still limited to 14 central coastal California counties and a small area in Curry County, OR (U.S. Department of Agriculture, Animal and Plant Health Inspection Service 2007). Despite the presently limited disease distribution in forests and measures to limit artificial movement of the pathogen by State and Federal regulatory agencies through quarantine and restrictions on the movement of plant materials, other areas are at risk. This is especially true for oak-dominated forest ecosystems in the Eastern United States
Oak, Steven. 2011. Phytophthora ramorum early detection surveys for forests. In: Conkling, Barbara L., ed. 2011. Forest health monitoring: 2007 national technical report. Gen. Tech. Rep. SRS-147. Asheville, NC: U.S. Department of Agriculture Forest Service, Southern Research Station.pages 143-153. 11 p.