Foresters Seeing Red Over Pine Beetle Infestation

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Thousands of acres of Black Hills forests continue to be destroyed as an epidemic of tree-killing insects continues its sixth year.  Normally, the mountain pine beetle attacks small pockets of unhealthy or stressed trees scattered widely across the landscape.  But beginning in the year 2000, beetle populations skyrocketed and large infestations took hold in many parts of the forest.

The infestation is worst in areas surrounding Deerfield Lake and the Bear Mountain Basin.  Expanding pockets of beetle-killed trees are also present in the Norbeck Wildlife Preserve and Black Elk Wilderness Area, around Custer Peak, and near O’Neil Pass.

Research performed in the Black Hills has established that dense, over-grown forest conditions are the most at risk from beetle infestation.  Under these conditions, trees compete intensely with one another for the light, water, and nutrients they need to grow, decreasing their ability to fend off beetle attacks.  The US Forest Service estimates that high-risk conditions exist on about 440,000 acres of the Black Hills National Forest.

Forest managers are able to control the spread of mountain pine beetles with preventive thinning to encourage tree growth, and by removing trees infested with the beetle from existing outbreak areas. 

The US Forest Service completed a new management plan in October, 2005, called the “Phase II” Amendment, which was designed in part to reduce the risk of beetle infestations.  Whether the Forest Plan’s implementation will progress at a pace that keeps ahead of the beetles remains to be seen.  For right now, the beetles have the upper hand.

The mountain pine beetle is a native insect to Rocky Mountain forests, attacking ponderosa and lodgepole pine.  The beetles attack the tree in massive numbers, chewing through the tree’s growing tissue until the stem is girdled.  A blue stain fungus is also carried into the tree by the beetles, and serves to clog the tree’s water conducting tissues. 

Some portions of the Forest, such as the Black Elk Wilderness Area, prohibit timber harvest as a form of beetle management.  The BHFRA does not seek to permit tree harvest in Wilderness Areas.  However, the damage to these forests from unchecked pine beetle progression serves to illustrate that there are serious consequences for failure to undertake active management measures and that wholesale prohibitions on responsible timber harvest are not synonymous with forest protection.

For more information on mountain pine beetle biology, click HERE.

Thinned areas in the foreground of these photos (2006) resist beetle infestation
while surrounding denser areas are experiencing heavy mortality.
Deerfield Lake and Bear Mountain Area Infestation
Black Elk Wilderness and Norbeck Wildlife Preserve Infestation
All photos © 2006 BHFRA.  Ask permission for use, reprint, or transmission.