Mean stem size and total volume development of various loblolly pine seed sources planted at one location

Abstract

Data from one location of the loblolly phase of the Southwide Pine Seed Source Study were analyzed to determine the effect of seed source on the self-thinning trajectory for loblolly pine (Pinustaeda L.). Stand trajectories for mean stem size and total volume were examined. Seed source affected the level of both the mean stem size and total volume per unit area trajectories. The rate of change of mean stem size and of total volume per unit decrease in number of stems did not appear to be affected by seed source. The levels of the stand trajectories for total volume per unit area were positively correlated with the site indexes of the seed sources at this location. These results indicate that site productivity of loblolly pine, measured by total volume production per unit area and mean stem volume, varies by seed source.