Conversations about the consequences of global warming often spark discussions on the melting glaciers and sea level rise. But there are also other effects of global warming, such as the spread of climate-sensitive diseases as well as the spread of infestations. The mountain pine beetle outbreak is an example of an infestation that has a direct link to the effects of global warming. It is also an example of a situation where humans have the opportunity to learn from their mistakes.
The mountain pine beetle is a bark beetle that aggressively attacks and causes the mortality of pine trees throughout western North America. Since the 1990s, the population of the species has increased to the largest forest insect infestation ever recorded in North American history. The mountain pine beetle is considered one of the most destructive forest pests in western Canada largely because of its impacts on timber supply, the forest industry, and forest dependent communities.
The mountain pine beetle outbreak has caused a slowdown in many of the major markets in British Columbia. Over the past decade, the beetle has killed 46% of the merchantable pine in the province. Projections for the current epidemic include a $2.5 billion decrease in manufacturing activity, a loss of 27,000 direct jobs, and a loss of $250 million in government stumpage and royalty revenues in British Columbia alone.
Understandably, studies show that the infestation is an important issue for the public living in western Canada. Most of the people in British Columbia and Alberta strongly believe that the mountain pine beetle is a threat to biodiversity, is an ecological disaster for national parks, and its presence results in economic losses in tourism. The public supports measures to control the mountain pine beetle population, as most people believe this beetle should not have a right to exist in national parks. At the same time, studies show the public is not well-informed about the mountain pine beetle and reasons for the infestation.
I recently did extensive research on the subject and discovered the mountain pine beetle infestation is more complex than most people realize. It’s clear the species has become destructive and is in turn negatively impacting humans as well as some of the wildlife and ecosystems in national parks. However, while much of the public is horrified that an insect can have such a tremendous negative effect on forests, research shows that human activity can be directly linked to some of the reasons for the mountain pine beetle outbreak.
I learned that mountain pine beetle infestations spread rapidly due to increasingly warmer winters and the availability of susceptible pine trees. Due to fire suppression in British Columbia, large areas of even-age mature lodgepole pine forests exist. Fire suppression contributes to outbreaks of the mountain pine beetle infestation because pine forests depend on frequent fires to mineralize nutrients and remove competing fire-intolerant vegetation. Frequent fires maintain open, park-like forests that are resistant to pest spread.
In this way, fire suppression by humans as well as a warming climate, to which human lifestyles contribute, provide a suitable environment for mountain pine beetle infestations to initiate, expand, and cause extensive levels of tree mortality.
Temperatures across western Canada increased by as much as 1.7°C between 1895 and 1995, resulting in higher survival rates for mountain pine beetles and enabling a higher proportion of beetles to survive and attack susceptible host trees. As a result of increasing temperatures, infestations occur at higher elevations and in areas that have no historical record of mountain pine beetle attack.
The mountain pine beetle has been a subject of intense research and management efforts for over a century. With all the information available, I find it ironic that the majority of the public focuses exclusively on population management rather than also examining human lifestyles as instigators of the infestation. I believe people need to look at their practices to discover how they can prevent further and future infestations. We need to learn from our mistakes above all and let the lessons be our wake-up call.
*Please note that I have obtained the statistics described in this post mainly through academic journals. I have not cited my sources so as not to overwhelm my readers with citations. However, if you’re interested, leave a comment about references below and I will provide you with the citations. -Aneta Tasheva