The authors evaluated both climate and biophysical factors that influence the occurrence of low severity fire in the Southwest. Low severity fire is an important component of many high frequency, fire-adapted ecosystems in the southwest, so understanding those conditions which promote low severity fire is highly relevant to land managers.

Using two mechanistic ecosystem-fire models, Fire BGCv2 in the Jemez Mountains and LANDIS-II in the Kaibab, the authors projected contemporary climate and two future emissions scenarios (“warm-dry” and “hot-arid”) to the year 2100 to predict changes to forests and fire regimes in a ponderosa pine and a mixed-conifer ecosystem. They also modeled four management strategies (suppression-only, current treatment intensity, and three and six times current treatment intensity) to see if management may be able to counteract the effects of climate change on forest composition and structure.

The authors quantified the contribution of past anthropogenic climate change to increases in area burned based on observed increases in fuel aridity metrics from 1979 to 2015, including temperature and vapor pressure deficit.

The authors examined the effects of spruce beetle infestation on fire severity during the drought years of 2012 to 2013.

The authors reconstructed the historical stand structure and fire regimes along a gradient of ponderosa pine to wet mixed-conifer and aspen stands within the habitat of the endangered Jemez Mountains salamander. They further related the variability of climate to the historic fire regime.

The authors examined synchrony of stand age and structure between geographically separated sites, or sky islands, to determine the influence of moisture and/or drought variability versus fire frequency on historic stand development.

The authors sampled field plots that reburned to examine how biophysical characteristics, topography, fire weather, time-since-fire, and initial fire severity affected subsequent reburn severity

The authors examined the effect of climate, topography, vegetation, and human land use on the spatiotemporal patterns of fire occurrence, severity, and size across the western U.S. using boosted regression tree analysis.

The authors assessed global trends in fire weather season length.

The authors examined the size of historical high-severity fire in mixed-conifer and aspen stands on the North Rim of Grand Canyon National Park and compared them to present day patches of high severity fire. The further explored historical climate conditions that produced the largest patches of high severity fire prior to Euro-American settlement.