OOS 48
Understanding the Structure and Function of Fire Maintain Ecosystems: Honoring the Research Influences of Dr. Robert Mitchell

Friday, August 15, 2014: 8:00 AM-11:30 AM
203, Sacramento Convention Center
Organizer:
Gregory Starr, University of Alabama
Co-organizers:
Doug P. Aubrey, Georgia Southern University; Joseph J. O'Brien, USDA Forest Service; and Jerry F. Franklin, University of Washington
Moderator:
Christina L. Staudhammer, University of Alabama
Frequent low-intensity fires maintain the structure and function of ecosystems with an evolutionary history of chronic fires whereas fire suppression transforms the structure and modifies the function. Fires burn as much as 4 million km2 globally and release as much as 2-3 Pg of C annually, effecting ecosystem to global carbon dynamics. Fire also influences carbon dynamics by altering the structure of the above- and belowground allocation and investment of plant C due to changes in life form (woody trees and shrubs versus grasses). These structural ecosystem changes lead to functional alteration, such as reduction in C4 carbon fixation. While climate, particularly temperature and moisture, sets limits on the distribution and productivity of the world’s biomes, fire resets systems far from their physiognomic limits. Fire’s impact is fully expressed in humid grasslands and savannas; if fire is suppressed, vegetative structure moves from a C3/C4 savanna to closed canopy shrubland, causing a concomitant loss of biodiversity. Future suppression could extend the global area of closed canopy shrub/forest lands from 27% to 56% and have subsequent consequences on biodiversity. The influence that fire—or the lack of fire—exerts on ecosystem structure and function identifies it as a key management tool to conserve species and regulate ecosystem development. This is true especially of forest management where silviculture and fire are intimately linked through the interaction of spatial and temporal controls on litter production and resulting fire behavior. Understanding the influence of structure and function is a necessity for enhancing our ability to adaptively manage dynamic ecosystem that are maintained by fire. Dr. Robert Mitchell dedicated his life to contributing toward a better understanding and appreciation of the structure and function of ecosystems maintained by fire. The objective of this oral session is to bring together a series of researchers that focus their studies on understanding the structure and function of fire-maintained ecosystems with an emphasis on ecosystem carbon dynamics, resource allocation patterns, restoration leading to enhanced biodiversity, and ecological management practices. Included in this session are a small but representative sample of the numerous students and colleagues fortunate enough to have worked with Bob in his life-long commitment to science, management, policy, and mentoring. Understanding the complex linkages between these fields of ecological study becomes even more important with growing anthropogenic pressures across the globe that may hinder fire management activities and ultimately change the ecosystems that are maintained by fire.
8:00 AM
 The longleaf pine paradigm
Wendell P. Cropper Jr., University of Florida
8:20 AM
 Inserting ecology into forestry practices: A Mitchell legacy
Brian J. Palik, USDA Forest Service; Jerry F. Franklin, University of Washington
8:40 AM
 Stored carbon in longleaf pine ecosystems: The intersection of evolutionary history, physiological function, and ecological process
Doug P. Aubrey, Georgia Southern University; Michael J. Drews, Georgia Southern University; Andres Baron, Joseph Jones Ecological Research Center; Joshua Mims, Georgia Southern University; Robert O. Teskey, University of Georgia; Robert J. Mitchell, Joseph W. Jones Ecological Research Center
9:00 AM
 Linking structure and function in tree roots
Dali Guo, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences
9:40 AM
9:50 AM
 Water table depth and nitrogen availability affects productivity and water use in a savanna ecosystem
Robert O. Teskey, University of Georgia; Chelcy Ford, USDA Forest Service; Robert Mitchell, Joseph W. Jones Ecological Research Center
10:10 AM
 The cyclic role of fire in the movement of carbon through longleaf pine ecosystems
Gregory Starr, University of Alabama; Christina L. Staudhammer, University of Alabama; Susanne Wiesner, University of Alabama; Henry W. Loescher, University of Colorado; Andres Baron, Joseph Jones Ecological Research Center; Andrew Whelan, University of Alabama; Robert J. Mitchell, Joseph W. Jones Ecological Research Center
10:30 AM
 Regeneration dynamics in longleaf pine: Challenging conventional wisdom to improve management
Steven B. Jack, Joseph W. Jones Ecological Research Center; Stephen D. Pecot, Larson & McGowin, Inc.