Data from: Limitations to recovery following wildfire in dry forests of southern Colorado and northern New Mexico, USA

Climate warming is contributing to increases in wildfire activity throughout the western U.S., leading to potentially long-lasting shifts in vegetation. The response of forest ecosystems to wildfire is thus a crucial indicator of future vegetation trajectories, and these responses are contingent upon factors such as seed availability, interannual climate variability, average climate (e.g., 30-year normals), and other components of the physical environment. To better understand variation in forest resilience to fire across vulnerable dry forests, we performed field surveys of conifer seedling abundance in 15 recent (1988-2010) wildfires and characterized temporal variation in seed cone production and seedling establishment. We then modeled post-fire seedling abundances for each species at a 30 m resolution using downscaled climate data, monthly water balance models, and canopy cover of surviving mature conifers. Widespread ponderosa pine (Pinus ponderosa) seed cone production occurred at least twice following each fire surveyed and pulses of conifer seedling establishment coincided with years of above-average moisture availability. Ponderosa pine and Douglas-fir (Pseudotsuga menziesii) seedling abundances were higher on more mesic sites and adjacent to surviving trees, though there were also important interspecific differences, likely attributable to drought- and shade-tolerance. We estimated that 41.8% (for ponderosa pine) and 68.5% (for Douglas-fir) of the total area burned did not meet tree density thresholds consistent with historical densities for each species. Spatial models demonstrated that the availability of seed trees (particularly in the interior of large, high-severity patches) limited seedling abundances in many areas, but 30-year average actual evapotranspiration and climatic water deficit also limited abundances on marginal sites. A better understanding of the limitations to post-fire recovery is likely to aid in developing adaptation and mitigation strategies through the improvement of models of future ecosystem change throughout the western U.S.