Persistence of the Swiss Needle Cast Outbreak in Oregon Coastal Douglas-Fir and New Insights from Research and Monitoring.

Swiss needle cast (SNC), caused by , is a foliage disease of Douglas-fir (), that reduces growth in native stands and exotic plantations worldwide. An outbreak of SNC began in coastal Oregon in the mid-1990s and has persisted since that time. Here we review the current state of knowledge after 24 years of research and monitoring, with a focus on Oregon, although the disease is significant in coastal Washington and has recently emerged in southwestern British Columbia.

Repeated Emergence of Sudden Oak Death in Oregon: Chronology, Impact, and Management.

It has been two decades since the first detection of the sudden oak death pathogen in Oregon forests. Although the epidemic was managed since its first discovery in 2001, at least three invasions of three separate variants (clonal lineages), NA1, EU1, and NA2, are documented to have occurred to date. Control of this epidemic has cost over US$32 million from 2001 to 2020.

First report of the NA2 clonal lineage of the sudden oak death pathogen, , infecting tanoak in Oregon forests.

Werres, de Cock & Man in't Veld, causal agent of sudden oak death (SOD) and ramorum leaf blight, is comprised of four clonal lineages in its invasive ranges of North America and Europe (Grünwald et al. 2012, Van Poucke et al. 2012).

Local Eradication of Is Effective on Both NA1 and EU1 Lineages in Oregon Tanoak Forests.

Sudden oak death (SOD), caused by the oomycete , has been actively managed in Oregon since its discovery there in 2001. SOD is a devastating disease affecting an ecologically and culturally important tree species in southwestern Oregon. Initially infested with the NA1 lineage, the more virulent EU1 lineage was discovered in 2015.

Novel Introductions and Epidemic Dynamics of the Sudden Oak Death Pathogen in Oregon Forests.

Sudden oak death caused by has been actively managed in Oregon since the early 2000s. To date, this epidemic has been driven mostly by the NA1 clonal lineage of , but an outbreak of the EU1 lineage has recently emerged. Here, we contrast the population dynamics of the NA1 outbreak first reported in 2001 to the outbreak of the EU1 lineage first detected in 2015.