Does Private Forest Land Management Result in Higher Burn Severity from Wildfires in Timberlands of the Pacific States?

There are many pressing scientific questions surrounding the topic of whether forest management has resulted in higher burn severity from recent wildfires in timberlands of the Pacific states (CA, OR, and WA). Using burn severity maps from Landsat satellite imagery, we show that management (logging and thinning) of private forest lands in these western states has not increased the overall severity of wildfire burning since 2013 in the majority of these privately owned timberlands. Comparison of the burned severity class by individual managed forest area showed that 42% of these timberlands burned at significantly lower severity (p < 0.05) than their surrounding (unmanaged) buffer zones in large wildfires between 2013 and 2022. In addition, 30% of managed forest lands were not significantly different from their unmanaged buffer zones in burn severity. The highest burn severity did occur in landscapes where extremely high levels of pre-fire live forest biomass remained in large patches around equally large and thinned or logged forest areas. We conclude that this type of mixed-age management plan may create a potentially explosive fuel-loading status in a forest, whereby wildfire can be readily carried by high winds from dense fuel areas (not recently thinned or managed) over and around patches of low biomass stands that have been recently thinned and logged.