Vegetation of frequently burned old-growth longleaf pine (Pinus palustris mill.) savannas on choccolocco mountain, Alabama, USA

Fire-maintained longleaf pine (Pinus palustris Mill.) savannas are imperiled throughout their range in the United States, reduced in extent by 97% since European settlement. Only half of extant stands show evidence of fire; fire suppression has led to dramatic changes in composition and declines in plant diversity. Examples of pristine vegetation are known for most of longleaf pine's distinct regions-a notable exception being mountainous communities in Alabama and Georgia, USA, collectively termed the mountain longleaf pine savannas. We sampled over- and understory vegetation in two frequently burned old-growth mountain longleaf pine stands at Fort McClellan, a U.S. Army garrison in the Blue Ridge Physiographic Province of Alabama. Over the spring, summer, and fall 1999 study period, 82 native plant species were encountered in plots, representing 60 genera and 35 families. Overstory composition was dominated by longleaf pine, with blackjack oak (Quercus marilandica Muenchh.) and sand hickory (Carya pallida [Ashe] Engl. & Graeb.) as co-dominants in both stands. Understory communities were species-rich, dominated by grasses (principally Andropogon ternarius Michx.), asters (Coreopsis major Walt., Chrysopsis graminifolia [Michx.] Elliott, Helianthus microcephallus Torrey & Gray, Solidago odora Ait., and others), and many legumes. Non-native species were not encountered in sampling plots. Evidence suggests that historic fires in mountain longleaf pine savannas were frequent (1-to 5-y return interval) and frequent fire is needed to maintain this ecosystem in the contemporary southeastern landscape.