Draft SNFPA Management Review and Recommendations

Review of the Fire Strategy and Effectiveness of Fuels Treatment

Background

The SNFPA ROD emphasizes two key goals: (1) maintaining existing habitat for species associated with old forest ecosystems, particularly the California spotted owl and (2) strategically placing fuels treatments across broad landscapes to reduce the size and severity of wildland fires.

Modifying Wildland Behavior Across Landscapes

Across much of the Sierra Nevada, the historic regime of short-interval, low- to moderate-severity fire has been changed to a long-interval, high severity, stand-replacing fire regime.^[1] Addressing this issue was defined as one of the five problem areas that drove various approaches analyzed under the SNFPA effort. Moving the forests of the bioregion back towards their historic fire regime is also a goal of the National Fire Plan. Any approach designed to alter forest vegetation to moderate fire behavior across the landscape must balance two supremely important factors. These are the adverse effects from continued large scale high-intensity, stand-replacing fires, and the adverse effects of the fuel treatments themselves. There is little argument that unnaturally high severity fires are harmful to people and wildlife. Likewise that fuel reduction carried to an extreme would also be harmful to the environment. The root of the problem lies in finding a balance.

A reasonable array of approaches to resolving this conundrum was analyzed in the FEIS. Clear and concise analysis was and is difficult, because of major uncertainty that surrounds the two factors to be balanced. Because of this, no clearly definable “correct” course exists. Instead, the Regional Forester must use the best information available, judgment, and his own sense of the balance of risks in making the decision. In light of the overarching concern about catastrophic wildfires and perpetuating the conditions that led to them, the Team was charged with seeing if there was another approach to achieving that balance.

The objective of the fuels treatment strategy in the ROD is to modify wildland fire behavior across broad landscapes. The strategy is based on research conducted by Mark Finney^[2] (1999) that suggested the rate at which a fire spreads across the landscape could be reduced, even outside treatment areas, when the fire was forced to flank around individual treatment units. His research revealed that, for a given landscape, there is an optimum pattern for placing treatment units to have the greatest impact on fire spread. The benefit of using this “strategic” approach to fuels treatments is that, given an effective treatment unit shape and pattern, 30-40 percent of the landscape would need to be treated to produce the desired modifications in wildland fire behavior.

Finney’s theory is carried forward in the ROD in the form of “strategically placed area treatments“ (SPLATs), which can vary from 50 to over 1,000 acres in size that are to be positioned across the landscape in a manner that will interrupt fire spread. Within the individual SPLATs, fuel loading must be reduced to the point that a fire entering the treated area will burn at a much lower intensity and slower rate of spread than comparable untreated areas. The SPLATs act as “speed bumps” and work to slow both the spread and intensity of an oncoming fire, reducing damage to both treated and untreated areas, and effectively modifying wildland fire behavior to mitigate the consequences of large, damaging wildland fires.

Managing Fuels while Maintaining Wildlife Habitat

Managers are directed to design fuel treatments in defense zones (areas in closest proximity to structures and communities approximately one quarter mile wide) to prevent the loss of life and property by creating defensible space. Threat zones are adjacent to the defense zone and extend out a mile and one quarter beyond. In this zone, SPLATs are to be designed to modify the behavior of wildland fires approaching communities. This allows firefighters to take advantage of reduced spotting, lower rates of spread, and lower intensity to more quickly contain fires. Together, the defense and threat zone comprise the urban-wildland intermix (UWI) which is to receive priority consideration for fuels treatments.

Away from structures and communities, fuel treatments are designed to support treatments in the urban wildland intermix, protect sensitive habitats from catastrophic fire, and reintroduce fire into fire-dependent ecosystems. The ROD takes a cautious approach to fuel treatments in PACs, the Southern Sierra Fisher Conservation Area, Old Forest Emphasis Areas, California spotted owl home range core areas, and stands comprised of medium to large trees.

To implement this cautious approach, the ROD limited the tools and techniques available to managers to address fire hazard outside of the defense zone. For example, prescribed fire is the only treatment option in PACs outside defense zones, and it is the preferred method of treatment in old forest emphasis areas and California spotted owl home range core areas. Mechanical treatments are allowed in old forest emphasis areas and home range core areas only when prescribed burning is determined to have: (1) high likelihood for prescribed fire escape due to excessive fuel accumulations, (2) high potential for unacceptable smoke impacts, or (3) a high risk for prescribed fire to result in canopy structure loss due to excessive surface and ladder fuels.

A number of restrictions were imposed on mechanical treatments to address uncertainty about the risks they pose to old forest associated species and their habitats and to conserve special components of the landscape, such as stands of mid and late seral forests with large trees, structural diversity and complexity, and moderate to high canopy cover. Standards and guidelines for mechanical treatments also limit the area of each stand that can be treated.

The direction in the ROD applies on a stand-by-stand basis, and, for the most part, the stand condition (rather than land allocation) determines which standards and guidelines apply. A single treatment unit typically includes several stands, each of which must be delineated to ensure that the appropriate standards and guidelines are applied. Although the language in the ROD is complex, careful review shows that it overlaps and repeats in several areas. Moreover, as noted above, the layer of complexity introduced by the land allocations has a limited effect on the actual application of the standards and guidelines. As a result, the Team was able to reduce several pages of direction for fuels treatments outside the defense zone to one general rule and a set of exceptions (see Table 4, page 16).

National forest managers encounter a complex situation as they begin to implement the ROD across a highly varied and dynamic landscape. Landscape conditions continue to change as large fires like the recent Star Fire (Tahoe and Eldorado National Forest) and McNally Fire (Sequoia National Forest) burn at high intensities over tens of thousands of acres. Managers must deal with other agents of change as well, including insects, diseases, invasive non-native plants, drought conditions, and so forth. These can pose serious threats to old forest ecosystems and species associated with these ecosystems, especially when multiple change agents operate together.

¹ SW-GTR-133 (CASPO Technical Report), Chapter 12.
²  

USDA Forest Service · Pacific Southwest Region