PARENT SESSION
Organized Oral Session 37: Post-fire conversion of forest to non-forest: Do we need new theory?
Organizer(s): RG Balice, B Romme, and TW Swetnam
Wednesday, August 10, 1:30 PM - 5:00 PM, Meeting Room 511 C, Level 5, Palais des congrès de Montréal
How resilient are southwestern ponderosa pine forests after crown fire?
Savage, Melissa*,1, Nystrom Mast, Joy2, 1 UCLA, Los Angeles, CA, USA2 Carthage College, Kenosha, WI, USA
ABSTRACT- The exclusion of low-severity surface fire from ponderosa pine forests of the Southwest has changed ecosystem structure and function such that severe crown fires are increasingly causing extensive stand mortality. This altered fire regime has resulted from the intersection of natural drought cycles with human activities that have suppressed natural fires for over a century. What is the trajectory of forest recovery after such fires? This study explores the regeneration response of ponderosa pine and other species to crown fires that occurred in the region from the late 1940s to the mid-1970s. We address two main questions: 1) what is the success of ponderosa regeneration and establishment, and 2) can these sites, burned in stand-destroying fires, be "captured" by other species on the scale of decades. Two main trajectories of recovery were found: 1) establishment of unnaturally dense ponderosa pine stands vulnerable to further crown fire, and 2) establishment of non-forested, grass or shrub communities.
Key words: fire, disturbance, regeneration, suppression