Phytophthora ramorum detection surveys for forests in the United States

Abstract

Diseases caused by Phytophthora ramorum in forest landscapes of North America are presently confined to areas of the Pacific coast in the states of CA and OR. However, the vulnerability of other ecosystems is suggested by the discovery in Europe and the U.K. of disease in hosts which are abundant in oak-dominated ecosystems of eastern North America; successful greenhouse inoculation trials of these and other potential eastern tree and shrub hosts; and brisk domestic and international trade in woody ornamental hosts. Overlay analysis was used to project low, moderate or high risk of P. ramorum diseases to U.S. forests using spatial estimates of overstory and understory host presence and density, climatic variables, and potential pathways of pathogen introduction (Smith and others 2002). The results showed a band of high risk along the length of the Pacific coast including WA, OR and CA, which included currently infested areas, but most of the high-risk area was in the East, centered in the Southern Appalachian Mountains.

Parent Publication

• Proceedings of the sudden oak death second science symposium: the state of our knowledge

Citation

Oak, S. W.; Smith, W. D.; Tkacz, B.M. 2006. Phytophthora ramorum detection surveys for forests in the United States. In: Frankel, Susan J.; Shea, Patrick J.; and Haverty, Michael I., tech. coords. Proceedings of the sudden oak death second science symposium: the state of our knowledge. Gen. Tech. Rep. PSW-GTR-196. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture: 365-366