Alan Kanaskie

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Phytophthora ramorum, the causal agent of sudden oak death and ramorum blight, is known to exist as three distinct clonal lineages which can only be distinguished by performing molecular marker-based analyses. However, in the recent literature there exists no consensus on naming of these lineages. Here we propose a system for naming clonal lineages of P.(More)
Wood density, moisture content, tracheid width and cell wall size were examined in trees from plots that were sprayed for 5 years with chlorothalonil (Bravo) fungicide to reduce the impact of Swiss needle cast (SNC) and from trees in adjacent unsprayed plots. The unsprayed (more heavily diseased) trees had significantly narrower sapwood, narrower growth(More)
ease wherever Douglas-fir is grown outside its native range. Although the fungus was recognized as ubiquitous in native Douglasfir forests, it had never been considered a significant threat to forest health (Boyce 1940, Peace 1962). In the 1970s, however, SNC was recognized as a problem in Christmas tree plantations in western Washington and Oregon, and by(More)
Swiss needle cast (SNC) causes premature loss of foliage and subsequent growth decline in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Although the mechanisms leading to this growth decline include loss of photosynthetic surface area and physiological disruption of surviving foliage, estimating the relative contribution of these two primary sources(More)
An effort to eradicate Phytophthora ramorum, causal agent of sudden oak death, has been underway since its discovery in Oregon forests. Using an information-theoretical approach, we sought to model yearly variation in the size of newly infested areas and dispersal distance. Maximum dispersal distances were best modeled by spring and winter precipitation 2(More)
Leaf area density is a biologically appealing index of forest tree health because it can provide an assessment of foliage loss or retention; however, it is difficult to measure directly. In contrast, the ratio of crown length to sapwood area (CL:SA) is quite amenable to objective field measurement, and could be interpreted as an index of crown sparseness.(More)
During the past decade, Swiss needle cast (SNC) damage has intensified in many Douglas-fir plantations in the Coast Range of Oregon, particularly along the immediate north coast. In plantations with severe symptoms, growth losses and reduced tree vigor are evident, but the magnitude of growth losses associated with varying intensities of damage is not(More)
Sudden oak death caused by the oomycete Phytophthora ramorum was first discovered in California toward the end of the 20th century and subsequently emerged on tanoak forests in Oregon before its first detection in 2001 by aerial surveys. The Oregon Department of Forestry has since monitored the epidemic and sampled symptomatic tanoak trees from 2001 to the(More)
Swiss needle cast (SNC), a foliar disease specific to Douglas-fir (Pseudotsuga menziesii), is caused by an endemic Ascomycete fungus (Phaeocryptopus gaeumannii). In the late 1980s and early 1990s significant symptoms began to appear in coastal Oregon, and these have been associated with the planting of Douglas-fir in the Sitka spruce zone, leaf wetness(More)
Causes of apical bud abortion in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were examined in two nurseries in western Oregon. Insect and damage surveys indicated that leafhoppers and Lygus hesperus Knight increased in abundance during August and September, coincident with damage accumulation. Caging studies confirmed that L. hesperus can cause bud(More)