Climate warming, land use change, and altered fire regimes are driving ecological transformations that can have critical effects on Earth’s biota. Fire refugia – locations that are disturbed less frequently or severely than their surroundings – may act as sites of relative stability during this period of rapid change by being resistant to fire and supporting post-fire recovery in adjacent areas. Because of their potential value to forest ecosystems, there is an urgent need to anticipate (1) where refugia are most likely to be found and (2) where they align with environmental conditions that support post-fire tree recruitment. Using biophysical predictors and patterns of burn severity from 1,180 recent fire events, we mapped the locations of potential fire refugia across upland conifer forests in the southwestern United States (US) (99,428 km2 of forest area), a region that is highly vulnerable to fire-driven transformation. We found that low pre-fire forest cover, flat slopes or topographic concavities, moderate weather conditions, spring-season burning, and areas affected by low- to moderate-severity fire within the previous 15 years were commonly associated with refugia. Based on current (i.e., 2021) conditions, we predicted that 67.6% and 18.1% of conifer forests in our study area would contain refugia under moderate and extreme fire weather, respectively. However, refugia were 36.4% (moderate weather) and 31.2% (extreme weather) more common across forests that experienced recent fires, as compared to recently unburned areas, supporting increased fire use during moderate weather and shoulder seasons to promote fire-resistant landscapes. When overlaid with models of tree recruitment, 23.2% (moderate weather) and 6.4% (extreme weather) of forests were classified as refugia with a high potential to support post-fire recruitment in the surrounding landscape. These locations may be disproportionately valuable for ecosystem sustainability, providing habitat for fire-sensitive species and maintaining forest persistence in an increasingly fire-prone world.

This archive includes statistical models and spatial data used to predict the locations of forested fire refugia and post-fire tree recruitment potential throughout four ecoregions (EPA Level III Ecoregions #19, 21, 23, and 79) in Arizona, Colorado, Idaho, New Mexico, Utah, and Wyoming, USA.

See "README.md" for information about datasets and their collection.

We place no restrictions on the use of the newly developed data or code included in this archive. Open-source R and R Studio software are necessary to reproduce our analyses.

Several of the datasets included in this archive were derived from external sources (e.g., USGS 3DEP topographic data, GridMET climate data, Landsat imagery, MODIS/VIIRS thermal anomalies, Rangeland Analysis Platform vegetation cover, LANDFIRE vegetation type, MTBS/NIFC fire perimeters, EPA ecoregions, and USFS species basal area maps). For reproducibility, some of these datasets are redistributed in this archive. The authors confirm that these data are dedicated to the public domain, without restrictions on use.