Age Structure and Possible Origins of Old Pinus taeda Stands in a Floodplain Forest

Abstract

PEDERSON, N. A. (School of Forestry, Auburn University, AL 36849), R. H. JONES (Department of Biology, Virginia Tech, Blacksburg, VA 24061), AND R. R. SHARITZ (Savannah River Ecology Laboratory, Aiken, SC 19802 and Department of Botany, University of Georgia, Athens GA 30602). J. Torrey Bot. Soc. 124:111-123. 1997.-Stand structure and ages were measured in six old stands of Pinus taeda L. (loblolly pine) and one younger stand within Congaree Swamp National Monument, South Carolina. Dominant overstory species included loblolly pine, shade intolerant hardwoods and tolerant hardwoods. All overstory species except pine also occurred in the sapling layer. Five of the six old stands had two or more pine age classes. All but one individual pine was less than 200 years old. According to estimates of future survival, current loblolly pine seedling densities in recently hurricane-disturbed and clearcut areas are inadequate to reproduce tree densities measured in extant old stands. Spatial distributions of mature trees suggest that pines have established in gaps as large as 0.3 ha and as small as a single overstory tree. No evidence of fire (scars on existing trees or charcoal in the upper 10 cm of soil) was found in any old stand. From these results, we speculate that the old loblolly pine stands in Congaree Swamp resulted from small-scale agricultural activities, although wind storms, fires, or combinations of these may have played contributing roles. Because of its apparent ability to regenerate in gaps, loblolly pine will probably remain in Congaree Swamp for several centuries as small clumps and scattered individuals.