Underplanted shortleaf pine seedling survival and growth in the North Carolina Piedmont

Abstract

A study was established to evaluate underplanting as a method of reestablishing shortleaf pine (Pinus echinata Mill.) in the Piedmont Region of North Carolina. Replicated treatment plots were harvested to retain 0, 15, 30, or 45 square feet of basal area per acre. Bareroot and containerized stock with small and large plugs were established within the treatment plots. Large plug seedlings achieved the highest first year survival followed by the small plug and bareroot seedlings. Underplanted seedling growth was inversely related to residual overstory density after two growing seasons. Large plug seedlings achieved the greatest height and diameter growth, followed by the small plug and bareroot seedlings. The results of this study suggest that underplanting may be a suitable regeneration option for the initial establishment of shortleaf pine on Piedmont sites. Further improvements in seedling survival and growth may be realized by planting containerized seedlings with large plugs.