5th Symposium on Fire and Forest Meteorology and the 2nd International Wildland Fire Ecology and Fire Management Congress

Monday, 17 November 2003: 4:30 PM
Methods, dilemmas, and solutions
Wendel Hann, USDA Forest Service, Silver City, NM
A natural fire regime is a general classification of the role fire would play across a landscape in the absence of modern human mechanical intervention. Five natural (historical) fire regime groups have been classified and defined by Hardy et al. (2001) and Schmidt et al. (2002) and interpreted for fire and fuels management by Hann and Bunnell (2001). Using these natural fire regimes as a baseline reference for understanding options for wildland fire and fuels is critical in achieving management objectives and in achieving consistency in strategic planning and reporting. Interagency fire and fuels methods for fire regime classification and mapping are hierarchical to this classification and definition. As scale of application becomes finer the five classes may be defined with more detail, or any one class may be split into finer classes, but the hierarchy to the coarse scale definitions must be retained. A fire regime condition class (FRCC) is a classification of the amount of departure from the natural regime. There are three condition classes for each fire regime. The classification is based on a relative measure describing the degree of departure from the natural (historical) fire frequency and severity, and landscape vegetation-fuel composition and structure. Methods, tools, and training have been developed and implemented to support consistent field and mapping applications of fire regimes and FRCC (fire.org/frcc). For field procedures the standard guidebook method can achieve high accuracy depending on the amount of ground truth and reference value assessment, with relatively consistent application between users and across administrative boundaries. This contrasts substantially with the poor accuracy and consistency resulting from users estimating the fire regime and FRCC using only definitions and photo examples. The latter method produces results similar to a random assignment. A scorecard method has been developed that can produce moderate accuracy and consistency if users have been trained in using the standard guidebook method. Guidebook methods and GIS tools have been developed for local FRCC mapping, and where the LANDFIRE project has been completed techniques and tools are available to improve fire regime and FRCC accuracy through local ground truth and GIS applications. Use of these methods can produce FRCC maps with high accuracy and consistency given adequate ground truth and assessment of reference values. In comparison, local FRCC mapping using non-guidebook techniques, or different definitions and classifications, result in poor accuracy and consistency. Given the national emphasis on FRCC as a key variable for prioritization, planning, reporting, and monitoring, and the associated need for consistency, agencies plan to aggressively move forward with implementation of guidebook FRCC methods.

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