Though longleaf pine (Pinus palustris Mill.) forests have been primarily managed with even-aged methods, interest is increasing in uneven-aged systems, as a means of achieving a wider range of stewardship goals. Selection silviculture has been practiced on a limited scale in longleaf pine, but difficulty with using traditional approaches and absence of an evaluation across a range of site types has left managers in doubt concerning its suitability. This study was conducted to quantify the effects on stand dynamics of applying single-tree selection, group selection, irregular shelterwood and uniform shelterwood in longleaf pine forests on flatwoods and uplands of the southeastern United States. Selection treatments reduced stand basal area to ~11.5 m2 ha-1 and shelterwood treatments left a basal area of ~5.8 m2 ha-1. In spite of initial decreases in tree density and standing volume, growth rates were normal in all stands (1–5% per year), as were subsequent increases in basal area and tree density. Despite the continuing abundance of saw-palmetto (Serenoa repens W. Bartram) cover and absence of prescribed fire during the eight post-treatment years, significant increases in pine regeneration were observed in all treated stands in the flatwoods. Because of a multi-year drought in the uplands, pine seedling numbers dramatically declined, no matter which reproduction approach was employed. Although seedling numbers eventually began to recover, they were again precipitously depressed by a wildfire in 2013. Even with such losses, sufficient pine seedlings remained in each treatment to foster successful stand regeneration. Single-tree selection produced less overall change in the forest ecosystem than group selection, which caused less alteration than shelterwood treatment. Single-tree selection appears to be an effective way for achieving stand regeneration, while maintaining a continuous canopy cover that aids in the control of woody competitors and supports an array of resource values. Selection silviculture seems to be a lower risk approach for guiding forests along a trajectory of gradual improvement, with adjustments provided by frequent surface fires and periodic tree harvest. Long-term observation will be required to verify that selection can sustain forest ecosystems on sites characterized by differing environments.
Brockway, Dale G.; Outcalt, Kenneth W. 2017. Influence of reproduction cutting methods on structure, growth and regeneration of longleaf pine forests in flatwoods and uplands. Forest Ecology and Management. 389: 249-259.