Applications for Fire Severity Data

Central to the missions of both the Western Wildland Environmental Threat Assessment Center and the Eastern Forest Environmental Threat Assessment Center is the early detection, identification, and assessment of multiple environmental threats such as insects, disease, invasive species, fire, loss or degradation of forests, and weather-related risks. The MTBS project will contribute to successfully accomplishing this mission by informing and supporting a variety of fire severity-related analysis applications.

It is beyond the scope of this paper for us to describe, in detail, specific examples of fire severity data use. The few examples that follow suggest that burn severity or fire severity, or both, have been reported in a variety of research applications including: surface runoff and sediment yields (Robichaud and Waldrop 1994), burned area relationships to natural reforestation (Lopez-Garcia and Caselles 1991), forest stand conversion and regeneration establishment (Blackwell and others 1992, Blackwell and others 1995), restoration of natural fire regimes with prescribed fire programs (Brown and others 1995, Keifer and Stanzler 1995), and wildlife habitat components (Hutto 1995).

Although explicit analytical uses of the MTBS data are not provided in this paper, a general discussion on scale of application is warranted. Multiscale, integrated analysis to support planning at both strategic and tactical levels has been presented as an effective way to accomplish management objectives within the context of ecological function (Hann and Bunnell 2001). As described in previous sections, MTBS data provide a practical basis for multiscale analysis. Barbour and others (2005) emphasized the need to look across scales in order to understand potential differences in perception of wildfire risk between planning scales and between management objectives. Using the analysis scales described by Barbour and others (2005), a simple conceptual step-down analysis demonstrates how MTBS data can generally be applied at broad, mid, and fine planning and monitoring scales.

At the broad scale, general spatial and temporal patterns of fire can be juxtaposed against generalized depictions of biophysical setting, current vegetation, and historical vegetation conditions to identify landscapes that are experiencing fire frequency and behavior outside estimated historical ranges of variability. This information may serve the purpose of streamlining resource allocation decisions at the national level and provide risk strata for larger scale analysis. Landscapes with potential for higher risk can be assessed at the midlevel for specific patterns of fire occurrence and magnitude that threaten resource and social values, (e.g., sensitive species habitat, hydrologic function, rural communities, and recreational opportunities) identified in regional and forest plans. The spatial resolution of MTBS products align closely with resource data layers commonly found at the regional and forest unit levels of the Forest Service (Brewer and others 2003, Franklin and others 2000, Mellin and others 2004). The scalable nature of dNBR values also allows for severity characterizations specific to analysis needs. Management activity planning and design intended to specifically address issues identified in midscale planning efforts are based principally on fine-scale analyses. Management activities designed to mitigate potential future threats, including severe fire and insect and disease outbreaks, require precise information about landscape condition and disturbance history. At site-specific scales, MTBS data reveal important information about severity patterns within fires, which are necessary to understand current condition and to relate past management activities.

It is our belief that the geographic and temporal extents, along with the consistency of MTBS data products, will provide a rich data legacy from the project. These data will provide the analytical basis for research that would have been logistically impossible without the MTBS project. These data provide the opportunity to stratify by appropriate biophysical environment settings and generate efficient and effective sampling strategies for agents such as insects, pathogens, and invasive plant species. They also provide the basis to substitute space for time to evaluate factors such as climatic effects or site water balance characteristics on timing and duration of water yield. Whereas these data do not address all environmental threat assessment needs, they do provide high-quality, consistent data and a contextual framework for the keystone disturbance agent for many wildland ecosystems.