In the southwestern U.S. and elsewhere, there is keen interest in restoring dry conifer forests to conditions that are conducive to low-severity fire. Yet, there has been surprisingly little research evaluating factors that promote low-severity fire.
The study was conducted in dry conifer forest in Arizona and New Mexico that historically experienced fairly frequent low-severity fire. Dominant forest types analyzed include ponderosa pine, pine-oak, and mixed conifer.
This study examined thirteen explanatory variables that potentially control low-severity fire; these variables were combined into four groups representing: live fuel, topography, climate (30-year normal characterizing spatial variability), and inter-annual climate variation (year-of-fire climate). Fire severity and live fuels were measured using satellite imagery, whereas topography, climate, and inter-annual climate variation were obtained from various sources. Fires from 1984 to 2015 were sampled.
The results of this study provide valuable information to land managers tasked with restoring forest structures and processes in the southwestern USA and other regions dominated by dry forest types.