Factors affecting limited reproduction by loblolly pine in a large old field

PRINDER, J. E., III (Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802), F. B. GOLLEY (Institute of Ecology, University of Georgia, Athens, GA 30602) AND R. F. LIDE (Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802). Factors affecting limited reproduction by loblolly pine in a large old field. Bull. Torrey Bot. Club 122:306-311. 1995.-Pines readily invade small old fields in the southeastern United States, but continuing observations on a large old field in South Carolina have indicated limited initial invasion and subsequently poor reproductive success by loblolly pines. To generate hypotheses concerning the poor reproductive success of pines, studies were conducted of seed production, seedling establishment, and seedling survival and growth. Production of viable seeds was similar to data for other loblolly pine sites, but seed dispersal distances were short with most seeds being deposited within 20 m of the parent. The rate of establishment of 1 yr old seedlings was 1< seedling per 3000 viable seeds, which was small compared to data for other loblolly pine sites. Most seedlings were established within 20 m of their parents. Once established, seedlings showed survivorship and growth that was typical for loblolly pines. These initial results suggest: 1) that the most important limitation to reproductive success may be the low rates of seedling establishment from seeds; but 2) that limited seed dispersal distances may represent an important secondary limitation.