USA — Those of us who have ventured into the mountains west of Denver inrecent years have been startled to see the busy work of bark beetles.
The infestation has left expanses of dead lodgepole pines. Neighbors andvisitors alike have been dismayed to see the color of high-country forests turnreddish brown before their eyes.
Researchers from several universities, including University of Colorado andColorado State University, recently wrote an article about the bark beetlesituation that’s sure to raise a few eyebrows. The piece describes the beetleepidemic as a natural phenomenon that neither constitutes an emergency nor anincreased forest fire risk.
The beetles, they say, are conducting a large-scale forest thinning thatgovernment could never afford to undertake. The article was, in essence, anargument for no management. Let Mother Nature deploy beetles to deal with standsof old and weak trees, some the product of old policies of fire suppression andothers damaged by long-term drought.
That may have been the right perspective when things were really natural andthere were large, connected ecosystems unaffected by humans. Under thosecircumstances there’s no doubt that nature has efficient ways of dealing withits own problems.
But people have influenced forests in myriad ways, including taking wateraway to serve urban communities, generating pollution damage, intervening toprevent forest fires (and creating vast stands of old trees) and even burninghuge swaths of forest a century ago that resulted in regrowth that shares thesame age and vulnerabilities.
Many scientists believe such conditions have promoted the explosion of barkbeetle populations – not just the cycles of nature.
The bugs, which bore into the trees and lay eggs so that their larvae canfeed off tree pulp, have been the subject of considerable research andgovernment action. The U.S. Forest Service and other agencies are thinning deadand dying trees from 3,000 acres of Colorado land to reduce fuel in the event ofa fire. And there have been numerous attempts at trapping the insects, killingbeetle populations with insecticides and even culling healthy but vulnerabletrees from forests in advance of infestation.
It’s unclear which, if any, of these interventions will be viable in slowingthe spread of beetle infestation. Noting that bark beetles are a force of naturemay not account for changes in the timing and impact of their infestation. Aprudent and nuanced management policy – divined from today’s forestry experience- may yet be an appropriate course of action.