Risk of beetle outbreaks rise, along with temperature, in the warming West

Sep 08, 2010

The potential for outbreaks of spruce and mountain pine beetles in western North America's forests is likely to increase significantly in the coming decades, according to a study conducted by USDA Forest Service researchers and their colleagues. Their findings, published in the September issue of the journal BioScience, represent the first comprehensive synthesis of the effects of climate change on bark beetles.

"Native are responsible for the death of billions of coniferous trees across millions of acres of forests ranging from Mexico to Alaska," said Barbara Bentz, research entomologist with the Forest Service's Rocky Mountain Research Station and lead author of the study. "Our study begins to explain how their populations respond to the climatic changes being projected by the Intergovernmental Panel on Climate Change."

In the study, Bentz and her colleagues synthesized what is currently known about the effects of climate change on several species of bark beetles that cause extensive, landscape-scale in North America. They then used a combination of models to analyze the likely response of and generate case studies for two specific species—the spruce beetle and .

"Our models suggest that climatic changes on the order of what is expected would increase the population success of both spruce beetle and mountain pine beetle throughout much of their range, although there is considerable variability," said Chris Fettig, a research entomologist with the Pacific Southwest Research Station and a coauthor of the study. "Bark beetles are influenced directly by shifts in temperature, which affect developmental timing and temperature-induced mortality, and indirectly, through climatic effects on the species associated with beetles and their ."

One effect the study detected is the likelihood, in a warming climate, of a substantial increase in areas of spruce forest dominated by spruce beetles that reproduce annually rather than every two years, as is common today. Annual reproduction of the beetle can contribute significantly to population growth and the occurrence of outbreaks.

In addition, the study's models also helped to address concerns about the potential for mountain pine beetles to expand their range across forests of central Canada into the central and Eastern United States. The researchers found that, without adaptation to warming temperatures, the likelihood of this occurring is low to moderate throughout this century.

"Understanding how bark beetle populations will be affected under different climate scenarios in different regions is key to developing appropriate management strategies in North American forests," Bentz said.

Explore further: A European bear's point of view, finally on film

add to favorites email to friend print save as pdf

Related Stories

Complex dynamics underlie bark beetle eruptions

Jun 02, 2008

Forest management that favors single tree species and climate change are just two of the critical factors making forests throughout western North America more susceptible to infestation by bark beetles, according to an article ...

Landscape-scale treatment promising for slowing beetle spread

Feb 02, 2009

Mountain pine beetles devastating lodgepole pine stands across the West might best be kept in check with aerial application of flakes containing a natural substance used in herbal teas that the insects release to avoid overcrowding ...

Tree deaths have doubled across the western US

Jan 22, 2009

(PhysOrg.com) -- A new study led by the U.S. Geological Survey and involving the University of Colorado at Boulder indicates tree deaths in the West's old-growth forests have more than doubled in recent decades, ...

Recommended for you

Sharks contain more pollutants than polar bears

20 hours ago

The polar bear is known for having alarmingly high concentrations of PCB and other pollutants. But researchers have discovered that Greenland sharks store even more of these contaminants in their bodies.

Moth study suggests hidden climate change impacts

Apr 15, 2014

A 32-year study of subarctic forest moths in Finnish Lapland suggests that scientists may be underestimating the impacts of climate change on animals and plants because much of the harm is hidden from view.

User comments : 0

More news stories

Patent talk: Google sharpens contact lens vision

(Phys.org) —A report from Patent Bolt brings us one step closer to what Google may have in mind in developing smart contact lenses. According to the discussion Google is interested in the concept of contact ...

Wireless industry makes anti-theft commitment

A trade group for wireless providers said Tuesday that the biggest mobile device manufacturers and carriers will soon put anti-theft tools on the gadgets to try to deter rampant smartphone theft.