Planting Density Impacts on Slash Pine Stand Growth, Yield, Product Class Distribution and Economics

E. David Dickens, Associate Professor; and Rodney E. Will, Assistant Professor of Forest Productivity and Tree Physiology, Daniel B. Warnell School of Forest Resources, The University of Georgia, Statesboro, GA 30460, and Athens, GA 30602-2152.

The establishment phase is a very critical decision-making phase in the life of a pine plantation. Key choices
in site preparation intensity and type, pre-plant competition control, species selection, seedling genetic quality and size, fertilization, and first year post plant herbaceous weed control have large and long lasting effects on wood yields, rotation length, and products grown. Within a level of forest management, planting density, spacing configuration, and subsequent survival rate can affect stand access, time of canopy closure, time to first pine straw harvest, age to first thinning, number of thinnings, and product class distributions over time. Initially, higher planting densities yield more volume. Eventually, without thinning, stand volumes converge between lower and higher initial stand densities. The more intensive the management and the higher the site productivity the sooner this convergence occurs. An attractive initial spacing for slash pine ( Pinus elliottii Engelm. var. elliottii) may not be so attractive for loblolly pine ( Pinus taeda, L.) or longleaf ( Pinus palustris, Mill.). This is due to differences in self-pruning characteristics, branch base diameter, number of branches, branch angle, or potential survival differences by species on certain sites. This paper will discuss the impacts of planting density under different levels of site productivity and management on slash pine stand biology, yields, and economic returns using several long-term studies.