Authors: Asha H. Paudel, Florida Atlantic University, Scott H. Markwith*, Florida Atlantic University, Michelle Coppoletta, US Forest Service, Kyle Merriam, US Forest Service, Brandon Collins, US Forest Service
Topics: Earth Science, Biogeography, Hazards, Risks, and Disasters
Keywords: Chaparrals, Fire severity, Regeneration, Restoration, Succession
Session Type: Poster
Start / End Time: 3:05 PM / 4:45 PM
Room: Lincoln 2, Marriott, Exhibition Level
Presentation File: Download
Vegetation dynamics of the Western U.S. has historically been maintained by fire. However, this process has been altered by various management approaches and climate change, leading to extreme fire events. The verdant conifer forest of the Sierra Nevada, California, is increasingly burning with intense crown fire, killing seed sources, favoring expansion of large shrub patches, and increasing continuous hazardous fuel loads (i.e. standing snags, down wood, and dense shrub vegetation) that promote high severity fires. This feedback trajectory with subsequent fires (i.e. extensive stand-replacing fire will promote more stand-replacing fire) has the capacity for long-term state change. In this study, the following hypotheses were tested: 1) in mixed conifer forests affected by fire suppression, successive high severity fires create a positive feedback that promotes shrub dominance, and homogenization of vegetation structure across the landscape, and 2) multiple low to moderate intensity fires in mixed conifer forests result in a stabilizing negative feedback by decreasing surface fuels and small tree density, while maintaining larger overstory trees and promoting landscape-scale forest heterogeneity and diversity. Our study area was located in the northern Sierra Nevada, California in Plumas and Lassen National Forests. We resampled field plots that were established after the 2000 Storrie and 2008 Rich fires, and reburned by the 2012 Chips Fire. Our aim was to provide managers with critical information for managing post-fire landscapes before long-term vegetation and fuels trajectories establish as a result of successive, high severity fires.