March April 2005




Battling the Bugs

Larger,More Frequent Forest Insect Infestations — A Manmade Problem

By Tony Kryzanowski

The relationship between humans and insects has often been described as a battle for supremacy of planet. Nowhere is that more evident than in the discolored landscape in various parts of the western United States resulting from insect infestations, which are a consequence of overstocked forests and drought. The main culprits are a handful of bark beetle species, the tussock moth, and a few varieties of budworms.

Mortality Rate
In 2003, California estimated that about 2.7 million acres of forestland had experienced some level of mortality. At present, Washington state estimates that 1.13 million acres of its 21.6 million acres of forestland has some level of defoliation or recent tree mortality. Oregon estimates that bark beetles have caused 700,000 acres of devastation this year, its highest level since 1995. The number of affected acres has been on an upward trend since 2001. A major concern with insect infestation is the extreme fire hazard it creates, especially during long periods of dry weather. The cost associated with fighting fire and the potential danger to property has legislators at both the state and federal level searching for ways to predict and counteract massive insect outbreaks.

Human Contribution
Forestry experts have a good understanding of why insect infestations are occurring more frequently and with greater ferocity, and the answer is that we are primarily masters of our own misery. A decade-long policy of fire suppression and forest management practices has led to the overstocking of the land base. "The general understanding is that the land has more trees than its carrying capacity," says Washington’s Department of Natural Resources (DNR) entomologist Karen Ripley. She works with the Resource Protection Division’s Forest Health program, and at the behest of state legislators is coordinating a working group that has just drafted a proposal for a new Forest Health strategy for the state of Washington. She says the forest is now more crowded with both shade tolerant and shade intolerant trees. Some of these shade tolerant trees are the most susceptible to more virulent defoliators and the most aggressive rot diseases. Entomologist with the Oregon Department of Forestry, Dave Overhulser, says there is no doubt human intervention into the normal forest lifecycle is contributing to the current condition of many American forests. "It seems that when it comes to management, what you choose to do or choose not to do oftentimes has unintended consequences," he says. "It’s cer-tainly true that fire suppression allows more trees to survive over the landscape, which means you have a higher density of trees and less vigorous trees."

Lack of Rain
A prolonged drought in southern California has contributed greatly to insect outbreaks in that region, according to supervising entomologist with the United States Forest Service, Forest Health Protection Branch in Susanville, California, Sheri Smith. "Many areas of the state have experienced four to five years of below normal precipitation, so the forests are stressed," she says. "California typically has an increase in tree mortality whenever precipitation is 80 percent or less of normal for any given year." The entomologists agree that the situation with insect outbreaks will get worse if drought conditions persist and if there is a less than aggressive approach to thinning overstocked stands.

Inspecting bug infested Douglas Fir

Taking Action
While insects play a vital role in healthy forest ecology by killing trees in overstocked stands and decomposition of wood, there is a point where action is required to contain the damage wrought by an insect outbreak, if it has the potential to seriously jeopardize the landowner’s management plan. Scientists deny that forest insect infestations are epidemic. However, they agree that the frequency of insect infestations is on an upward trend, and that there is a need to continue to deal with the overstocking issue to counteract future potential outbreaks.

While there are decidedly different approaches to dealing with the overstocking issue from one state to the next, there is agreement that public education and technical support must play a leading role to inform and mobilize all forestland owners, should an undesirable outbreak occur. When presented with an outbreak scenario, most landowners are usually eager to deal with the problem if has the potential to become a serious problem and a liability. However, there is a definite need for more education. "We have people living in the rural interface that have little knowledge of trees and how to maintain healthy trees," Overhulser says. "So this puts an increased load on our forestry service and our stewardship efforts across Oregon." Population growth in California is also putting more people in harm’s way, says Smith. "As the population continues to increase, more and more homes are being built in the forests or on the edges of the forests. With or without bark beetles killing trees, many of these homes are threatened by too much vegetation close to their homes and defending them from wildfires is nearly impossible."

Cost for Noncompliance
Overhulser says that laws in Oregon give state officials virtually no ability to compel landowners to manage for native pests. However, Washington’s approach has been to put more teeth into what has been described as a very old-fashioned and obsolete forest management strategy aimed more at exotic insects. "There is recognition by the Legislature that we have a forest health problem in Washington," says Ripley. While the proposed new Forest Health strategy is primarily focused on general education and technical assistance, "part of our marching orders were that the Legislature really desires that we maintain a regulatory hammer in the end if there is noncompliance." What this means is that if an outbreak is deemed to be an extreme fire hazard and the landowner spurns all attempts by the DNR to assist him with managing the problem, he will be liable for any costs associated with fire protection. Where a problem is identified, the Commissioner of Public Lands can issue a warning based on the recommendations from an advisory committee, along with a required course of action. The advisory committee monitors progress toward implementing the required corrective action. In very rare instances of noncompliance, the Commissioner can declare that the landowner is not in compliance and he is notified that he will be liable for any costs associated with fire protection should a fire occur.

The Economic Factor
A major challenge to dealing with the overstocking issue is economics. Logging has a critical role to play, as forest thinning is one of the most effective ways to counteract insect outbreaks. Unfortunately, a lot of the wood fiber in overstocked areas is undersized, low-value wood, located great distances from pulp or sawmills. Still, in some areas like eastern Oregon, smaller-diameter wood is helping to keep many sawmills operating. Overall, however, there is a lack of industry capacity to use this undersized wood within reasonable distances from the source. Smith says outbreaks in southern California have resulted in a lot of dead trees with little commercial value because the nearest sawmill is several hundred miles away. Ripley cites building infrastructure and finding a commercial use for the salvaged timber as critical pieces of the puzzle to managing the overstocking issue. "There are tens of thousands of acres out there in need of treatment," she says. "We’re facing a tremendous backlog of work that should be done, and often it’s low-value work." One of the few upsides to large insect outbreaks from a commercial forestry perspective is that salvage logging has developed into a new business opportunity for some logging companies. Landowners often need logging assistance to carry out the recommendations made by technical experts.


   This service is temporarily unavailable



This page was last updated on Monday, April 18, 2005