Thursday, January 25, 2007
When forest management and climate change collide: the eruption and spread of mountain pine beetle populations in western North America
The mountain pine beetle is native to the pine forests of western North America where it normally exists at very low densities, infesting only weakened or damaged trees. Under conditions conducive to survival, populations may temporarily increase allowing beetles to infest healthy trees. On rare occasions, these increases are rapid and widespread, leading to landscape-level outbreaks and the mortality of large numbers of trees. Although there have been 4 outbreaks during the past century in western North America, the ongoing epidemic is unprecedented in its size and severity – causing the mortality of mature pine over 12-13 million hectares in British Columbia alone. It is projected to continue until the majority of mature pines in the province have been killed. This paper will examine the independent and interacting influences of forest management practices and climate change on the course of this extraordinary forest disturbance event.
Dr. Allan Carroll is a Research Scientist in Insect Ecology with the Canadian Forest Service, Pacific Forestry Centre. Dr. Carroll specializes in herbivore-plant interactions and studies the role of forest stand conditions in the spatial dynamics of forest insect populations.