Presenters: Marin Chambers, Colorado Forest Restoration Institute, CSU
Wildfires in ponderosa pine - dominated forests of the southern Rocky Mountains are increasingly burning with a high severity component that is unprecedented in the available historical record. The ability of ponderosa pine and other co-occurring conifers (e.g., Douglas-fir, Rocky Mountain juniper, Colorado blue spruce) to regenerate in uncharacteristically large severely burned patches of such fires is unclear, as seeds must disperse from surviving trees. We measured post-fire regenerating conifers in eleven 10+ year-old fires across Colorado, Wyoming, and South Dakota to characterize regeneration in severely burned patches, and how regeneration characteristics are governed by abiotic and biotic factors. Our results from the Colorado Front Range indicate that conifers have regenerated in severely burned areas, but at low densities (~100 stems ha-1). This contrasts with conifer regeneration in unburned and lightly to moderately burned areas, which was more than four times greater. Our Colorado results also illustrate that as distance from live trees increased, conifer regeneration decreased; transects averaged ~170 stems ha-1 25 m from the live forest edge and ~10 stems ha-1 250 m from the edge. Preliminary analyses from Wyoming and South Dakota indicate similar conifer regeneration densities in high severity burn areas in comparison to lightly to moderately burned and unburned areas. Additionally, as distance from living trees increased, post-fire conifer regeneration density sharply decreased, suggesting that it will likely be compromised in the interiors of large severely burned patches across the region. Click here to register NOW!