Treesearch

Sudden oak death (SOD), caused by Phytophthora ramorum, was first discovered in Oregon forests by aerial survey in July 2001. Since then an interagency team has been working with landowners to eradicate the pathogen by cutting and burning all infected and nearby host plants. The Oregon SOD program now consists of the following elements: early detection; delimitation of infested areas; treatment; research and monitoring; and host reduction in areas of probable disease spread.

The Sudden Oak Death Fourth Science Symposium provided a forum for current research on sudden oak death, caused by the exotic, quarantine pathogen, Phytophthora ramorum. Ninety submissions describing papers or posters on the following sudden oak death/P. ramorum topics are included: biology, genetics, nursery and wildland management, monitoring, ecology, and diagnostics.

Since the first reports in Great Britain (GB) of Phytophthora ramorum (2002) and P. kernoviae (2003), the death of a small number of infected trees and of heathland Vaccinium has been recorded. Initial policy against these pathogens was one of containment, with a view to eradication based on recommendations arising from Pest Risk Analyses (PRAs), whilst more evidence was gathered on their likely impact. Both pathogens have continued to spread slowly, mainly in the southern and western part of GB. In 2008, a policy and science review, including a public consultation, was carried out in...

Discovering the origins of Phytophthora ramorum remains a challenge. To improve our chances of finding the origin of P. ramorum or any other introduced organism, we need to be sure of our motivation, because success will require persistence. We need to be able to distinguish indigenous from exotic organisms, to know what to look for and recognize when we have found it, and we need a practical "search image" to guide the discovery and sorting of candidate organisms. Perhaps the most frequently asked question about P. ramorum and sudden oak death is "Where did it come from?" Despite several...

In the United States, water and soil baiting have been part of the U.S. Department of Agriculture, Animal and Plant Health Inspection Service (USDA APHIS) Confirmed Nursery Protocol (CNP) to prevent the spread of Phytophthora ramorum from infected nursery stock since 2005. Additionally, the U.S. Department of Agriculture, Forest Service (USDA FS) has, since 2006, supported the national early detection stream baiting survey of forests and urban areas to monitor the potential spread of this pathogen from nurseries and other high-risk settings. These surveys have been conducted in cooperation...

In Alaska, an unprecedented dieback and mortality of Alnus incana ssp. tenuifolia has occurred which stimulated an effort to determine causal agents of the disease. In Europe, similar dieback and mortality of Alnus incana and Alnus glutinosa has been attributed to root rot by a spectrum of newly emergent strains in the hybrid species Phytophthora alni. The variable hybrids of P. alni were grouped into three subspecies: P. alni ssp. alni (PAA), P. alni ssp. multiformis (PAM), and P. alni ssp. uniformis (PAU). From 2007 to 2008, we conducted a survey of Phytophthora species at 30 locations...

A new needle blight disease was observed on Pinus radiata in Chile during 2004. The disease, known in Chile as Daño Foliar del Pino (DFP), stretches southward from the Arauco to Valdivia Provinces, and was present over an area of about 60 000 ha in 2006, with different levels of intensity. The disease is typified by needle infections and exudation of resin at the bases of the needle brachyblasts. Only P. radiata trees have been affected by DFP. Other Pinus species in the area, such as P. pinaster, remain healthy. Isolations from infected needles on selective media have consistently yielded...

A new threat to oaks (Quercus spp.) in California was identified in June 2008 following years of misdiagnosis. The goldspotted oak borer (GSOB), Agrilus coxalis auroguttatus Schaeffer (Coleoptera: Buprestidae), is aggressively attacking and killing three species of oaks in oak woodlands in San Diego County. About 20,000 coast live oaks (Quercus agrifolia), California black oaks (Q. kelloggii), and canyon live oaks (Q. chrysolepis) have died in a 4903 km² area centered on the Descanso Ranger District, Cleveland National Forest and Cuyamaca Rancho State Park. Oak mortality has been continuous...

Nursery plants are also important long-distance vectors of non-indigenous pathogens such as P. ramorum and P. kernoviae. Pre-shipment inspections have not been adequate to ensure that shipped plants are free from Phytophthora, nor has this method informed growers about sources of contamination in their nurseries. We applied an approach based on Hazard Analysis of Critical Control Points (HACCP) for systematically detecting sources of Phytophthora contamination in four Oregon nurseries. HACCP is an approach broadly applied in the food processing industry to prevent contamination of foods by...

This study examines perceptions of service quality on an ethnically diverse national forest adjacent to a large metropolitan area, specifically looking for differences among whites, Hispanics, and Asians. Published studies of recreation and ethnicity have focused primarily on activity participation rates and patterns. The literature contains few cross–cultural comparisons of perceived service quality in a forest recreation setting. Data from a purposive convenience sample of recreationists (n = 1,075) visited Angeles National Forest, California, US, includes 444 whites, 312 Hispanics, and...