Scientists for the first time have simultaneously compared widespread impacts from two of the most common forest insects in the West – mountain pine beetle and western spruce budworm – an advance that could lead to more effective management policies.
By combining data from satellites, airplanes and ground-based crews, the researchers have shown in unprecedented detail how insects affect Western forests over decades.
In the past, forest managers relied on airplane surveys to evaluate insect damage over broad areas. However, satellites can reveal patterns at a much finer scale. By combining both types of data, scientists are refining estimates of damage and showing how they may relate to other factors that determine forest structure and composition.
“This is the first time anyone has compared the impacts from these two insects in consistent units of change going all the way back to 1970,” said Garrett Meigs, a post-doctoral researcher at the University of Vermont. Meigs conducted his analysis while he was a Ph.D. student in the College of Forestry at Oregon State University. He worked with Robert Kennedy, an expert in landscape analysis and an assistant professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences.
They published their findings in this week’s issue of Forest Ecology and Management, a professional journal.
Outbreaks of both insects occur in cycles and can affect millions of acres of forest lands from year to year. The mountain pine beetle has killed lodgepole pine trees across much of western Canada and the United States in recent decades. Western spruce budworm defoliates – but does not normally kill – Douglas-fir, spruce and true firs. However, repeated years of western spruce budworm attack can weaken trees and make them vulnerable to other stresses, which may eventually kill them.
Forest image credit Oregon State University.