Stewards of the Sequoia (Professional Forester's Point of View)

A Professional Forester's Point of View

By District Ranger Dave Freeland, Sequoia National Forest

The public may not be aware that their public forests are in a generally unnatural condition due to the exclusion of fire playing its natural role within the ecosystem for the last hundred years. This situation has created overcrowding of trees, along with other associated vegetation. Forest Ecologists have determined that in pre-settlement times, a range of 40 to 70 conifer trees per acre existed in the western landscape. Low intensity fires, burning on a regular basis, thinned the forest. In comparison, forested areas today contain as much as 400 to 500 trees per acre. Over crowded forests create an environment where individual trees have difficulty competing for limited sunlight, soil moisture and nutrients. As a result, trees become stressed and are more susceptible to premature mortality from extended periods of drought and from attack by insects and other forest pathogens.

Another unwanted condition from fire exclusion is that more shade tolerant trees become established on each acre due to tree density. White fir and incense cedar are two shade tolerant tree species common in our area. In contrast, Ponderosa and Jeffrey pine are less tolerant to shade as they grow. The foliage of young fir and cedars extend close to the forest floor, which creates a ³fuel ladder² where fire can quickly climb low hanging limbs and become established in the upper reaches of the tree canopy. What should have been a low intensity ground fire becomes a crown
fire potentially leading to a stand (forest) replacing event.

A more dramatic consequence from unnatural forests is the abnormal number of catastrophic fires that have occurred over the past 30 years. Excessive tree density, in combination with abundance of dead and down vegetation and old, decadent brush fields, has created a formula for disaster. Catastrophic fires have adversely affected millions of acres over the last several decades well beyond what occurred historically. As a recent member of a national incident management response team, I personally witnessed extreme fire behavior all over the country that took human life, personal property and destroyed ecosystems that will not be fully recover for several life times even under ideal conditions. The Manter (2000) and McNally (2002) are recent examples of unusually large and devastating fires. The McNally was the largest recorded fire to occur on the Sequoia National Forest.

What is the solution? Professional land managers, with the assistance of researchers, continually identify areas of concern, assess ecosystem function and health, and implement a number of management strategies. One common practice is to mechanically thin selected forested areas to reduce the number of trees to within acceptable limits. Other management actions within the Forester¹s tool bag include, but are not limited to, introducing fire back into the ecosystem where appropriate to reduce density of trees and brush, promote regeneration and establish younger age classes of vegetation mixed with the older age classes. Less catastrophic fires, endemic, rather than epidemic insect and disease intrusions, more succulent food sources for a variety of wildlife species and improved cattle grazing are positive outcomes.

There are currently two acceptable methods of introducing fire back into the ecosystem. One method is prescribed burning, which is the intentional ignition of fires within selected areas, by highly skilled fire professionals. Prescribed burning can only be initiated when air temperature, humidity, fuel moisture, wind speed and direction, optimum smoke lofting, etc. are within acceptable limits. A more recent technique being used on public lands is wildland fire use. When a naturally caused
fire starts by lightning, wildland fire use can be approved within predetermined areas, such as wilderness areas located on the Kern Plateau. In 2003, approximately 5000 acres were treated within the South Sierra Wilderness through wildland fire use. Additional acres were treated in 2004. The U.S. Forest Service intends to expand wildland fire use as a viable tool to allow fire to play a more natural role in the ecosystem for a variety of resource and social benefits.

Through continued and appropriate mechanical thinning, prescribed burning and wildland fire use, land management professionals have renewed hope to transition valuable public lands back into an acceptable natural and healthy condition, more resilient to unwanted catastrophic events. Though this multi-agency effort will take many decades to make a noticeable difference, won¹t it be worth the effort?

Dave Freeland
District Ranger
Cannell Meadow/Greenhorn Ranger Districts
Sequoia National Forest

Link to this article reprinted in Eco-Logic Powerhouse

A professional forester's point of view in Eco-Logic Powerhouse