Commercial Logging for Wildfire Prevention: Facts Vs Fantasies

— By Timothy Ingalsbee, Ph.D., Western Fire Ecology Center

The notion that commercial logging can prevent wildfires has its believers and loud proponents, but this belief does not match up with the scientific evidence or history of federal management practices. In fact, it is widely recognized that past commercial logging, road-building, livestock grazing and aggressive firefighting are the sources for "forest health" problems such as increased insect infestations, disease outbreaks, and severe wildfires.

How can the sources of these problems also be their solution? This internal contradiction needs more than propaganda to be resolved. It is time for the timber industry and their supporters to heed the facts, not fantasies, and develop forest management policies based on science, not politics.

FACT: Commercial logging removes the least flammable portion of trees-their main stems or "trucks," while leaving behind their most flammable portions-their needles and limbs, directly on the ground. Untreated logging slash can adversely affect fire behavior for up to 30 years following the logging operations.

FACT: Commercial logging reduces the "overstory" tree canopy which moderates the "microclimate" of the forest floor. This reduction of the tree canopy exposes the forest floor to increased sun and wind, causing increased surface temperatures and decreased relative humidity. This in turn causes surface fuels to be hotter and drier, resulting in faster rates of fire spread, greater flame lengths and fireline intensities, and more erratic shifts in the speed and direction of fires.

FACT: Small-diameter surface fuels are the primary carriers of fire. Current fire spread models such as the BEHAVE program do not even consider fuels greater than three inches (3) in diameter because it is mainly the fine-sized surface fuels that allows fire spread. Commercial logging operations remove large-diameter fuels which are naturally fire resistant, and leave behind an increased amount of fire-prone small-diameter fuels.

FACT: Timber plantations comprised of densely-stocked, even-aged stands of young conifers are extremely flammable and vulnerable to catastrophic fire effects. When plantations burn they normally result in 100% mortality of trees, yet have no native seed sources to naturally regenerate stands. Thus, burned plantations require expensive and repeated management inputs to achieve successful reforestation.

FACT: Commercial logging spreads invasive weeds and stimulates the growth of "chaparral" brush which are much more flammable than the original forest cover. Once the commodity timber outputs have been removed, federal agencies have no economic incentives to manage the vegetation that colonizes sites disturbed by logging operations; thus, fires will continue to burn through logged areas.

FACT: Watersheds that have experienced extensive logging and road-building also experience greater fire severity than unlogged and unroaded watersheds.