Effects of small-scale forest treatments on reducing wildfire burn severity

Abstract

Background Intensive fire suppression and climate change have escalated wildfire intensity in fire-adapted forests. Although the consequences of fire suppression policies are well documented, fuel reduction treatment effectiveness – particularly across varying treatment sizes – remains debated. Aims We evaluated a recent large wildfire in New Mexico, USA, to determine whether small fuel treatments reduced burn severity. Methods Using paired plot analysis, we compared burn severity between treated and untreated sites. We used multiple regression analysis to evaluate how treatment effectiveness related to treatment size, topography, and time since treatment. Key results Treated sites had significantly lower burn severity than untreated sites. Treatment effectiveness did not vary with treatment size, regardless of slope, aspect, and time since treatment (≤9 years). Conclusions Small fuel treatments (≤4 ha) effectively reduced burn severity. Implications Because treated boundary areas can still experience high burn severity, these findings provide a baseline to evaluate treatment size effects under site-specific conditions and inform future size guidelines.