Portland, Ore. August 31, 2010. "My job was to locate the previously marked study trees. . .and record data on the activity of treated blister rust cankers," wrote Charles "Terry " Shaw. "The work took [me] in rickety four-wheel drive vehicles to remote locations scattered across the white pine forests of northern Idaho." Shaw, now editor of a recently published special issue of Forest Pathology, described how 44 years ago, he and other young forestry students collected data about a destructive forest disease for senior scientists.
Today, Shaw and his colleague, Dr. Brian Geils of the Rocky Mountain Research Station are now the senior scientists. Together, they have compiled a collection of 12 journal article on the biology and management of Cronartium ribicola, an introduced invasive pathogen that causes white pine blister rust, a seriously damaging disease of North American white pines.
The August 2010 journal issue provides a synthesis of knowledge on C. ribicola, identifies policy and management actions to mitigate disease impacts, and reviews future issues facing white pine management such as climate change and new pathogen introductions. Through this comprehensive and scholarly review of the literature, Shaw, Geils, and thirty-three contributing authors provide a scientific basis for protecting and sustaining white pine ecosystems.
"The rust pathogen has a very complicated life cycle," explains Shaw, "with five different spore stages alternating between two different hosts." The disease produces stem cankers that can eventually girdle and kill susceptible host pines; spores that can only infect Ribes (currants and gooseberries) are produced on infected trees. The fungus intensifies on Ribes leaves and may cause early defoliation; but more importantly wind-born spores spread the rust back to nearby white pines. Until the 1960s, managers exploited this requirement in the rust's life cycle to control the disease by poisoning
|Contact: Sherri Richardson Dodge|
USDA Forest Service, Pacific Northwest Research Station