In recent decades the western United States has witnessed substantial increases in area burned by wildfire, uncharacteristic accumulation of wildland fuels in some forest types, and a dramatic expansion of the wildland-urban interface (WUI). Under the direction of the National Fire Plan (NFP), federal land management agencies treated over 24 million acres during 2001-2007 with the goals of mitigating fire risk to private property and restoring forests that may now experience uncharacteristically high-severity fire due to increased fuel loads associated with past fire suppression, logging and grazing. This study is the first to comprehensively analyze the National Fire Plan Operations and Reporting System (NFPORS) database, which tracks restoration and wildfire mitigation treatments implemented under the National Fire Plan by five federal agencies. We spatially analyzed recent treatments (2004-06) across 11 western states to assess the extent to which they were 1) conducted in vegetation types characterized by high levels of departure from historic stand structures and fire regimes, 2) located within the WUI, and 3) in proximity to subsequent wildfires.
Results/Conclusions About 60% of the total area treated was classified by Landfire as historically experiencing 35-200 yr fire frequencies of any severity, where the need for forest restoration to correct departures from historic fire regimes is either ambiguous or unwarranted. About 30% of the total area treated was classified by Landfire as historically experiencing high-frequency (≤ 35 yr), low- to mixed-severity fire regimes where restoration may be needed. This fire regime group occupied only 10% of the West, suggesting preferential treatment. Of 194 existing vegetation types treated, the highest percent of area treated was in the Southern Rocky Mountain Ponderosa Pine Woodland (9%), which occurs in only 1% of the West. Less than 10% of the area treated fell within the WUI, which contrasts with NFPORS designations, where 47% of the area treated was classified as within the WUI. The average distance of treatments to subsequent fires was > 25 km, with < 5% of treatments within 1 km of subsequent fires. Overall, the majority of the area treated is not classified as having historical fire regimes clearly in need of restoration, over 90% of the area treated was outside the WUI, and a very small proportion of the area treated encountered fire 1-3 yrs after implementation, suggesting a need for improved targeting of NFP goals of fire mitigation and forest restoration.
