Woodsmen harvesting white pines in the hills surrounding Cottage Grove first spotted it in the 1950s: white pine blister rust. The pathogen migrated from Europe to the East Coast at the turn of the 20th century. By mid-century it had moved west, putting hundreds of thousands of West Coast pines in jeopardy. What were they to do?
The first thought was to cut off infected bark and limbs. Then efforts turned to the eradication of gooseberries and currents—secondary hosts for blister rust spores. But both strategies proved largely fruitless. That’s when forest workers first noticed that certain individual white pines seemed resistant to the disease. In 1966, the U.S. Forest Service responded by establishing the Dorena Genetic Resource Center.
“Part of what we’re doing,” says Brianna McTeague, a biologist at Dorena, “is identifying disease-resistant trees so we can target those trees for protection.” That’s no small challenge, given that 99 percent of white pines are susceptible to blister rust. Yet, the challenge is being met.
Key activities at Dorena represent the scientific method in action: collect pine cones to harvest seeds; plant seeds and grow trees for two years; put trees in the world’s largest inoculation chamber and infect them with disease-bearing fungus; track results for six years, measuring the severity of disease symptoms; rate resistance of specific parent trees; and save seed stock from the most durable family offspring.
The approach has led to the successful replanting of once-decimated white pine stands at Crater Lake, a renewed Port Orford cedar population in the Redwood National Forest, and new sugar pine and Port Orford stands at Warm Springs Reservation. The results also have implications for other tree species much farther afield.
Geneticist Richard Sniezko is passionate about the ecological implications of his work at the Dorena Center. “We’re hoping to balance the equation,” says Sniezko. “We’ll never get to where things once were, to where we’ve gotten rid of all the disease and made all trees immune. But we’re hoping to balance it in a way that’s durable and, if we’re lucky, will maybe last forever!”
www.fs.usda.gov/goto/r6/dorena
