Reply to Fitzsimmons: Transparency needed in defining fire-mitigation effort near the wildland–urban interface

We appreciate the perspectives provided by Fitzsimmons (1) in response to our recent PNAS paper (2). The goal of our study was to provide an independent, methodologically transparent spatial analysis of fuel-reduction treatments, using data provided directly by federal agencies, in order to quantitatively assess the degree to which treatments have been located near the wildland–urban interface (WUI). A critical aspect of our work is that we applied a quantitative definition of the WUI based on census data—listed in the January 4, 2001 Federal Register (3). This yielded results consistent with the only other census-derived WUI map that spans the West (4). A quantitatively defined WUI offers a defensible, objective way to assess fire-mitigation effort and to better target the WUI zone across agencies, regions, and legislative authorities.

Although agency experience and expertise are extremely valuable, without stated, consistent definitions of the WUI we cannot begin to resolve discrepancies between our quantitative results and Fitzsimmons' experience. Additionally, Fitzsimmons' comment reflects his experience with the US Department of the Interior (DOI); only about half of the total treatment area analyzed was implemented by DOI. Our analysis includes treatments by the USDA Forest Service as well as the DOI agencies with which Dr. Fitzsimmons was involved. Lastly, the dataset we examined encompassed fuels treatments under the National Fire Plan, of which Healthy Forest Restoration Act treatments were only a small subset.

Our research intent was to conduct a quantitative analysis of fuel treatments to assist federal land managers in evaluating fire-mitigation efforts near the WUI. We have benefitted from numerous interactions with federal land managers and believe that sustained, open dialogue will help improve management and policy strategies to reduce fire risk to communities in and near wildlands.