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Keywords:

  • Aristida beyrichiana, wiregrass, Pinus palustris, longleaf pine, canopy thinning, plantation forestry, restoration

Abstract

Restoration of the longleaf pine ecosystems of the southeastern United States has focused interest on the regeneration and establishment of Aristida sp. (wiregrass) as a means to reestablish ecological function and structure of the ecosystem. This study examined dispersal distance from planted adults and canopy cover and density effects on establishment and reproduction. In 1994 wiregrass plugs were planted in two densities (500 seedlings/100 m2 and 49 seedlings/100 m2) and three canopy-thinning treatments (25 m2 basal area/ha, 16 m2 basal area/ha, and 8 m2 basal area/ha) were implemented in a 20-year-old longleaf plantation in southwestern Georgia. Due to the intense site preparation and the density of pines planted, virtually no understory vegetation was present. The site was burned in June 1995, which promoted seed production of the planted wiregrass. Results indicate that the 8 m2 basal area/ha treatment results in larger plants that in turn produce a greater number of seedling recruits. No seedling recruitment occurred in control plots. Dispersal distances of up to 594 cm were recorded. Natural seedling recruitment occurred at low-density transplanting (5 plants/10 m2), denoting that high-density planting similar to natural density (5 plants/m2) is not required for successful establishment or reproduction. However, overstory thinning in dense pine plantations is required for reproduction and increases the survival of individual plants due to changes in the environmental conditions at the forest floor.