Tuesday, August 7, 2007

PS 28-51: Effects of fire on the structure of two old-growth longleaf pine stands in the mountains of Alabama, USA

John C. Gilbert and John S. Kush. Auburn University

The structure of longleaf pine (Pinus palustris Mill.) forests of the southeastern coastal plains has been the focus of numerous studies.  By comparison, the longleaf pine forests in the mountains of Alabama and Georgia are not well-understood.  Much of the work conducted in these areas occurred prior to the mid 20th-century.  In 1998, a study was established on what was then Fort McClellan Army Base, now the U.S. Fish and Wildlife Services Mountain Longleaf National Wildlife Refuge.  The Refuge is located in northeastern Alabama, USA and contains among the finest remaining mountain longleaf pine stands known.  The purpose of that study was to describe the age and stand structure and shed light on the past disturbance and replacement patterns of two remnant old-growth longleaf pine stands.  As a part of the study, every longleaf pine greater than 2.5 cm DBH was stem-mapped and had its DBH recorded.  In 2006, these two stands were re-measured to document what changes had occurred in the following years.  One stand was subjected to a relatively intense prescribed fire in the interim while the second stand was not.  Both stands suffered a decline in tree density, but only the stand which had been burned experienced a loss in basal area.  The effects fire had on the structure of the one longleaf stand will be examined.