PARENT SESSION
Oral Session # 97: Restoration Ecology II: Rivers and Forests.
Presiding: J Weishampel
Friday, August 8. 8:30 AM to 12:00 PM, SITCC Meeting Room 203.
Natural re-invasion and artificial restoration of upland hardwoods in the coastal plain of South Carolina.
Jones, Robert*,1, Showalter, Julia1, Stevens, Glen1, Neatour, Matthew1, 1 Department of Biology, Blacksburg, VA
ABSTRACT- In the upper coastal plain of the southeastern USA, past agricultural activities have reduced the abundance and distribution of some valuable upland hardwood species. To identify ecological factors limiting natural re-invasion, and to develop methods for restoration, we planted seeds of five hardwood species in spring 1997, and bare-root seedlings of four species in spring 1998. Soils were mesic to xeric, and stand structures included uncut versus recently clearcut 40+ year old pine plantations. Some understory seedlings were located in trenched plots, and others were released by removing the pine overstory three years after planting. Five-year survival and growth were influenced by our treatments (i.e., presence of an overstory and timing of overstory release), but also by factors that we did not plan or control, including competition with herbs, soil moisture during the dormant season, and seed predation. At age five, very few planted seeds had emerged and survived (0-42% depending on species and site), and all survivors were short (< 20 cm). High seed predation of Carya spp. occurred in one of four test sites. Compared with planted seeds, planted seedlings had superior performance. Quercus alba seedlings performed best when planted in clearcuts (mean five-year survival >60% and height >110 cm). Cornus florida seedlings performed best when planted in the understory and then released after three years (mean five-year survival > 70% and height >210 cm). Carya spp. seedlings did very poorly regardless of treatment (five-year survival <20% and total height < 20 cm). In trenched understory plots, five-year height and base diameter of Q. alba and C. florida seedlings were nearly four times greater than in untrenched plots. Our experiments suggest that dispersal is a limiting factor to natural re-invasion. Furthermore, seedling planting with attention paid to minimizing competition may be a practical option for restoration.
Key words: Cornus florida, Quercus alba, Savannah River Site