Fuel treatment effectiveness in forests of the upper Atlantic Coastal Plain – An evaluation at two spatial scales

Fuel treatment effectiveness in Southern forests has been demonstrated using fire behavior modeling and observations of reduced wildfire area and tree damage. However, assessments of treatment effectiveness may be improved with a more rigorous accounting of the fuel characteristics. We present two case studies to introduce a relatively new approach to characterizing fuels and predicting potential fire behavior, fuel consumption, and emissions in Southern forests using the Fuel Characteristic Classification System (FCCS) and Consume. The first case study provides fine-scale (<100 ha) examples of fuel treatments (prescribed fire, mechanical thinning, mastication, and herbicide treatment) and their potential effect on predicted fire behavior and effects on measured treatment units. The second case study evaluates potential fire behavior across a managed forest landscape (74,000 ha) in the upper Atlantic Coastal Plain, South Carolina.Results from the fine-scale assessment indicate that fuel treatments reduce reaction intensity, rate of spread, and flamelength by up to 58%, 57%, and 63%, respectively. Fuel loading of strata that control surface fire behavior (i.e., shrubs, grasses, fine woody fuels, and litter) range from 32.0 Mg ha−1 in the thinned, untreated unit to 8.5 Mg ha−1 in the unthinned unit treated with herbicides and prescribed fire. Based on model predictions, up to 80% less fuel would be consumed with concomitant reduction in emissions during a wildfire occurring in the treated units compared to the untreated unit.Assessments of potential fire behavior across the study area indicate that overall hazard is low to moderate for this forested landscape. However, localized areas of high surface fire and crown fire potential were identified. Plot- and stand-based modeling both suggest that the potential for high to extreme fire behavior exists for this landscape. Combined, the two case studies highlight the ability of the FCCS to represent measured fuel characteristics and predict differences in potential fire behavior resulting from fuel treatments. Even small differences in fuel characteristics resulting from fuel treatments or site variation could be detected, allowing the effects of both ecological processes and management actions to be quantified.

► We modeled fuel treatment effectiveness in southeastern US forests.
► Fuel treatments can reduce predicted surface fire behavior by up to 63%.
► Overall surface fire behavior is low to moderate across the study area.
► FCCS and Consume are tools available for assessing fuel treatments and fire hazard.