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.