Microclimate and environmental change decades following repeat wildfire and vegetation type conversion in a central Arizona ponderosa pine forest
| Authors: | Matthew D. Petrie, Keegan D. Hammond, Joel A. Biederman, Charles J. Devine, Jackson M. Leonard, Roger Tyler |
| Year: | 2026 |
| Type: | Scientific Journal |
| Station: | Rocky Mountain Research Station |
| DOI: | https://doi.org/10.1016/j.agrformet.2026.111297 |
| Source: | Agricultural and Forest Meteorology |
Abstract
Wildfire is altering forested landscapes across the southwestern United States. There is opportunity to better understand regional landscape change by comparing more and less wildfire-affected forest areas at local scales. We evaluated meteorological and above- and belowground environmental variables in less-disturbed (PIPO: 2016 low-severity wildfire) and more-disturbed (PIPO-burned: 2000 stand-replacing, 2016 low-severity) ponderosa pine forest in central Arizona, USA. PIPO-burned experienced low conifer recovery and extensive woody plant type conversion following the 2000 wildfire. Using ground-based instrumentation and snow transect data, we found considerable abiotic differences between PIPO and PIPO-burned during a recent period (2022–2025 water years) with near-average air temperatures and precipitation, and one very low precipitation season (2025). These included significantly higher warm season (April–September) and cool season (October–March) solar radiation, wind speed, surface and soil temperature, and reference evapotranspiration. Although average snow depth was significantly higher at PIPO-burned, its snow often melted earlier in the spring. Near surface soil moisture (10, 20, 40 cm depth) at PIPO-burned was significantly lower than PIPO in both the warm and cool seasons. Indeed, we found that the density distributions of soil temperature and moisture were often dissimilar between PIPO and PIPO-burned. Underscoring the severity of these changes, we found that many meteorological and environmental variables at PIPO-burned (2168 m) were on average more similar to those of a lower elevation piñon pine–juniper woodland (1605 m) than they were to the adjacent PIPO (2190 m). These local abiotic changes, here associated with repeat wildfire and woody plant type conversion over the past 25 years, illustrate the considerable transformation of forested landscapes in the southwestern US.