Post-fire Tree Mortality
My passion for nearly decade has centered on tree death and survival following fires. In particular, I am interested in understanding tree damage as related to fire behavior. Duff heating and its effects on soil, roots, and stem bark need better work to inform fire management and refine burn prescriptions to meet fuel reduction goals while not compromising tree survival.
I have on-going research in three area in the southeastern US, in collaboration with Kevin Hiers (Eglin Air Force Base, PI), Jack Putz (University of Florida, Co-PI), Doria Gordon (The Nature Conservancy and University of Florida, Co-PI), and John Kush (Auburn University and the Longleaf Alliance, PI). Our research has been funded by two USDA/DI Joint Fire Science Program -grants including the USDA Forest Service Pacific Northwest Fire Lab (Roger Ottmar and Bob Vihnanek, Co-PIs), the Jones Ecological Research Center (Bob Mitchell Co-PI), and the USDA Forest Service Southern Research Station (Dale Wade and Joe O’Brien, Co-PIs). Additional funding has been provided by the Department of Defense, University of Florida, The Nature Conservancy, and Humboldt State University.
Portions of this project have been featured in a Joint Fire Science News Brief: .
Fire Lab Publications to date (two others are in submission):
O'Brien, J.J., J.K. Hiers, R.J. Mitchell, J.M. Varner, and K. Mordecai. 2010. Acute physiological stress and mortality following fire in a long-unburned longleaf pine ecosystem. Fire Ecology. In press.
Varner, J.M., F.E. Putz, J.J. O'Brien, R.J. Mitchell, J.K. Hiers, and D.R. Gordon. 2009. Post-fire tree stress and growth following smoldering duff fires. Forest Ecology and Management 258: 2467-2474.
Varner, J.M., J.K. Hiers, R.D. Ottmar, D.R. Gordon, F.E. Putz, and D.D. Wade. 2007. Tree mortality resulting from re-introducing fire to long-unburned longleaf pine ecosystems. Canadian Journal of Forest Research 37: 1348-1358.
Varner, J.M., D.R. Gordon, F.E. Putz, and J.K. Hiers. 2005. Novel fire effects in southeastern pine forests: smoldering fire and overstory pine mortality. Restoration Ecology 13: 539-544.
Varner, J.M. 2005. Smoldering fire in long-unburned longleaf pine forests: Linking fuels with fire effects. Dissertation. University of Florida, Gainesville. 118 p.
Varner, J.M. and J.S. Kush. 2004. Old-growth longleaf pine forests and savannas of the southeastern USA: Status and trends. Natural Areas Journal 24:141-149.
Varner, J.M., J.S. Kush, and R.S. Meldahl. 2000. Ecological restoration of an old-growth longleaf pine stand utilizing prescribed fire. Tall Timbers Fire Ecology Conference Proceedings 21: 216-219.
In addition to other presentations, I coordinated a special session at the International Association of Wildland Fire's Conference on Fire Behavior in Destin, Fl in 2007.
I am also involved as a presenter in a special session at the International Fire Congress in Savannah, Georgia during late 2009.