OREGON STATE UNIVERSITY

New Approaches Needed to Address Forest Fire Risks

11/12/2008

CORVALLIS, Ore. – Even though fire suppression policies and an accumulation of fuels have created an enormous threat of catastrophic fire across the West, most management and fuel reduction treatments are still being done with little systematic evaluation of their impacts on fire risk in surrounding forests.

A recent study has outlined new methods to do just that, and when perfected they may become powerful tools to maximize the efficiency of fire prevention efforts and make the most of limited funding to address this issue.

“It’s just not efficient to do fuel management treatments of our forests without considering the stands that are nearby,” said Claire Montgomery, a professor of forest resources at Oregon State University. “Too often we have ignored these surrounding areas and spatial linkages, and we need to start looking at fire risks on a broader level.”

The problems are complex, researchers say, and some traditional approaches used in the past have been demonstrated to be effective, while others are now being called into question. But it’s increasingly clear that the type of forest or management in one area can affect the risks on nearby areas, and that more sophisticated approaches to this issue would make better use of the money being spent.

One way to reduce loss of timber to fire, of course, is to cut the trees before a major fire burns them down – and that is what’s often done, experts say. However, the equation is often more complex than that. Young stands that grow after a harvest often burn faster and spread fire more quickly than older, mature forests. So harvesting may increase fire risk to nearby stands.

The study, which was published in the journal Land Economics, confirms that some traditional approaches to reducing fire risk can work, such as mid-slope treatments that can slow the spread of a fire. But it’s not always true that harvesting stands at younger ages is the most effective approach to reduce risk. In fact, it may be better to let a timber stand continue to grow if nearby stands are of high value.

Another common strategy is to prioritize stands that are highly flammable for fuel treatment, regardless of their location. But it may be possible to reduce fire risk at a lower cost by strategically placing fuel treatments to block fire spread, or by protecting nearby high-value stands.

In recent years, the increasing numbers of landowners at the urban/wildland interface have also complicated these issues, since it’s more difficult to get any consensus on how land is managed or controlled, Montgomery said.

Continued advances in what is being called “computational sustainability” – the use of advanced computing systems to run simulations and consider multiple possibilities – may also be of some value in the future, she said.

According to this study, there are 12 million acres of dry forest land in Oregon and Washington alone that are at high risk of fire, usually due to accumulation of small trees, bushes, debris and other undergrowth resulting from fire suppression efforts in the past century.

Mechanical thinning, prescribed fire and other approaches are often useful in reducing the risk of catastrophic fire, but budgets to accomplish this are often hugely inadequate. This increases the need to maximize the cost-effectiveness of whatever fire reduction efforts are attempted, the researchers said.

This work should provide a framework for further research on fire risk management issues such as salvage logging, effectiveness of various fuel treatments, the tradeoffs between fuel treatment costs and fire suppression costs, non-timber values, and other issues, the study suggested.