Title: Patterns of conifer regeneration following high severity wildfire in ponderosa pine - dominated forests of the Colorado Front Range
Author: Chambers, Marin E.; Fornwalt, Paula J.; Malone, Sparkle L.; Battaglia, Michael;
Source: Forest Ecology and Management. 378: 57-67.
Publication Series: Scientific Journal (JRNL)
Many recent wildfires in ponderosa pine (Pinus ponderosa Lawson & C. Lawson) - dominated forests of the western United States have burned more severely than historical ones, generating concern about forest resilience. This concern stems from uncertainty about the ability of ponderosa pine and other co-occurring conifers to regenerate in areas where no surviving trees remain. We collected post-fire conifer regeneration and other data within and surrounding five 11-18 year-old Colorado Front Range wildfires to examine whether high severity burn areas (i.e., areas without surviving trees) are regenerating, and how regeneration density is related to abiotic and biotic factors such as distance from surviving forest, elevation, and aspect. We found that some conifer regeneration has occurred in high severity burn areas (mean and median of 118 and 0 stems ha-1, respectively), but at densities that were considerably lower than those in unburned and in low to moderate severity burn areas. Generalized estimating equation analyses revealed that distance from surviving forest was the most important predictor of conifer regeneration in high severity burn areas, with regeneration declining as distance from surviving forest increased; estimates of conifer regeneration were 211 stems ha-1 immediately adjacent to surviving forest but only 10 stems ha-1 200 m from surviving forest. These analyses also revealed that conifer regeneration densities declined as elevation decreased. Regression tree analyses likewise showed that distance from surviving forest and elevation were important predictors of conifer regeneration in high severity burn areas; within 50 m of surviving forest mean (median) regeneration was 150 (0) stems ha-1 at elevations ⩽2490 m and 1120 (1000) stems ha-1 at elevations >2490 m, but at distances ⩾50 m from surviving forest mean (median) regeneration was only 49 (0) stems ha-1, regardless of elevation. Applying regression tree results spatially to the 2002 Hayman Fire, Colorado’s largest and most severe known wildfire, we found that 70% of the area without surviving forest exceeded this 50 m threshold. These patterns of conifer regeneration suggest that Colorado Front Range ponderosa pine - dominated forests may not be resilient to high severity wildfire, particularly where surviving forest is not in close proximity. We recommend that land managers consider planting conifers within the interiors of large high severity burn patches, as well as implementing treatments to reduce the risk of uncharacteristic high severity wildfire in unburned forests, where maintaining a forested condition is desired.
Keywords: : Colorado Front Range, fire severity, Pinus ponderosa Lawson & C. Lawson, Pseudotsuga menziesii (Mirb.) Franco, tree regeneration, forest resilience
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
XML: View XML
Chambers, Marin E.; Fornwalt, Paula J.; Malone, Sparkle L.; Battaglia, Mike A. 2016. Patterns of conifer regeneration following high severity wildfire in ponderosa pine - dominated forests of the Colorado Front Range. Forest Ecology and Management. 378: 57-67.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility