Eco-Justice Ministries  

Eco-Justice Notes
The E-mail Commentary from Eco-Justice Ministries

Hot News About Beetles
distributed 7/23/04 - ©2004

The sweeping mountain vistas made me think of the beautiful New England scenes that attract swarms of autumn tourists -- mile after mile of slopes covered with trees in varying shades of red, orange and yellow.

Unfortunately, I was seeing Colorado evergreens in July, not New Hampshire maples in September. The trees are all dying. Bark beetles are devastating the forests.

The rusty colors of these high mountain pines don't speak of an annual cycle of seasons. It will take centuries for the mountains to revegetate with this sort of forest.

I can't bring myself to say that a view of hundreds of square miles of dead and dying forest is beautiful. But neither is it ugly. For the most part, what the beetles are doing is nature at work, doing exactly what is to be expected in a highly stressed system.

Large areas of the American west are encountering extreme bark beetle infestations. In northern New Mexico, 90% of the pinyon pines have been killed by beetles. In the high mountains of Colorado where I went hiking a few weeks ago, there are large areas where most of the mature lodgepole pines are dead or dying. The younger trees seem to be less hard-hit. Utah, Idaho and Alaska are other US states with major outbreaks.

Beetles have always been part of the ecosystem of pine and spruce forests. They have always killed lots of trees in fairly localized outbreaks. The very widespread impacts of recent years are shaped by several factors.

  1. Much of the region has had five or more years of extreme drought. The weakened trees have far less ability to resist the bugs.

  2. A century of almost total fire suppression has created forests that are unnaturally dense, and that are composed of single-species stands of trees. The beetles spread quickly and easily through these thick monocultures.
Combine drought stress with overgrown forests, and a bark beetle explosion is natural, normal, and to be expected. The beetles are one part of a complex interplay of natural forces which is re-balancing the system, thinning the forests, and re-introducing diversity.

The beetles, just like fire, are a natural part of the forest system. And, just like fire, forest managers are learning that we need to live with the insects -- not try to eradicate them.

However, there is a new and unnatural factor involved in the most recent beetle outbreak. Global climate change -- global warming -- is allowing the rapid spread of beetles.

Cold weather is one of the natural factors that limits the impact of beetles. Freezing temperatures limit the range where beetles can survive, and cuts their numbers in other areas. Global warming is removing those limits. The insects are moving into higher elevations in the mountains, and are spreading farther north. Where short summers used to force some beetles into a fragile 2-year lifecycle, longer seasons are now allowing a 1-year cycle that encourages their explosive growth.

In Canada, the reach of the beetle outbreak has been doubling every year since 1998. 10 million acres of lodgepole pines were killed in 2002 (an area the size of Switzerland). The beetles are spilling across the northern margin of their historical range, causing ecological disruptions in areas that have never faced this threat.

The Canadian insects are now just 60 miles from vast stands of jack pine, a species not previously acquainted with mountain pine beetles. These trees have no natural defenses, and studies show that the beetles will thrive -- and trees will die -- in that type of forest.

Ecologist Allan Carroll sketches out a plausible scenario where the beetles will race eastward through the jack pine forests in Canada, opening a new route around the biological barrier of the Great Plains. As they come to the Eastern Seaboard, they would spread into other forests that have no defenses -- eastern white pine, then south into the loblolly pine forests of the southern US. From there, they could circle back west as far as southern Texas.

If global warming allows the beetles to expand their range just a few hundred miles farther north into Canada, their spread across a vast new sweep of the continent may be impossible to stop. That would be an environmental and economic disaster.

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So what should we do? I have a very mixed answer.

On one hand, the beetle outbreaks are a powerful lesson to us about the dangers of trying to control nature. Forests need fire, and the western forests need beetles. We should advocate for policies that allow these natural forces to function within their historic range. We should try not to panic when the infestations hit close to home.

On the other hand, the spread of beetles into entirely new areas reveals the catastrophic and unexpected impacts of global warming. Vast areas of insect-killed pine trees are one more indicator of the urgent need to cut humanity's carbon dioxide emissions. To save our forests, we need to lobby for tough fuel efficiency standards for cars, an intense program for renewable energy, and incentives for home and business energy efficiency.

The web of life is responding appropriately to drought, dense forests and climate change. Bugs are not the problem -- the recent outbreaks are a symptom of a stressed system.

Human impacts from fire control and global warming are significant parts of the beetle's rapid spread. May we adapt our way of life to be less disruptive of nature's balance.


Peter Sawtell
Executive Director
Eco-Justice Ministries

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