By Wes Melo / For The Herald
We are in the heart of wildfire season and daily news reports summarize destructive wildfires throughout the western states.
Many of us who are not personally affected by an evacuation, or worse, the loss of one’s home, are living with the health hazard of breathing smoke day after day.
Most western lands are “fire prone” and in many circumstances have become heavily overgrown since fire suppression over many decades has interrupted fire’s natural action of reducing fuels.
Fire is a natural disturbance that occurs in most wildlands of the west and has influenced plants and animals for millennia, long before man came on the scene. Think through how fire occurred in nature before human intervention. Science confirms combustion requires heat, oxygen and fuel, and requires a source of ignition. Once fire ignites, natural conditions such as temperature, humidity, wind, terrain, as well as fuel conditions and volume, influence fire behavior.
Burning will continue until a change in one or more of those factors interrupts the combustion process. Wind — even minor breezes — and thermals from fire can carry embers long distances, depositing them on additional combustible material and extending the burn. Fire usually stops when it burns into areas without enough fuel to support combustion, fuels get wet from precipitation, and/or external temperatures will no longer support fire.
Significant changes to ecosystems occur when human activity interrupts natural cycles, including wildfire, enabling substantial fuels to accumulate before ignition. Fire exclusion has led to major changes from historical wildland ecologies in many wildlands of the West. If we hope to reduce the damages currently occurring from catastrophic wildfires, active management of fire-prone wildlands is critical to mimic the outcome of natural, low intensity fire activity.
Natural fire ignition occurs mostly through lightning strikes igniting combustible materials. Studies indicate that before humans intervened, wildland fires generally reoccurred between five and 50 years in most fire-prone wildlands, significantly minimizing major fuel buildup while lessening damage to fire resistant vegetation. Unlike past centuries, human activity is now a major source of wildland fire ignition.
Where there is heavy fuel buildup, once ignition occurs (regardless of the source) wildfires can be devastating, resulting in death of wildlife, degradation of water quality, damage to soils, destruction of fire-resistant species and creation of severe smoke conditions that are especially dangerous for people with respiratory conditions. Wildfires also endanger the safety and lives of firefighters and civilians, and in the past several years, have destroyed thousands of homes.
Many recent fires in California were reportedly mostly caused by multiple lightning storms and are an example of what happens when excessive fuels and weather conditions create severe wildfire conditions.
Since humans interrupted the natural cleansing process of wildfires, it is time for proactive wildland management to aggressively focus work on controlling fuels to minimize further severe destructive fire behavior. Fuels management must focus on thinning, prescribed burning and in some cases understory removal, mowing or mulching to reduce fuel loads.
Given the scientific understanding of combustion, that is really the only practical option we have if we hope to minimize destructive wildfires.
Wes Melo is the vice-chairman of Communities for Healthy Forests, a nonprofit founded in Roseburg, Ore., to inform the public and policymakersregarding forestland management. He is a 1966 graduate of the University of California-Berkeley with a B.S. degree in Forestry. He is also a worked and volunteered as a firefighter and fire chief.
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