Effects of Simulated Ice Storm Damage on Midrotation Loblolly Pine Stands

We simulated ice damage by shooting a portion of live crown from midrotation (ages 14 -16 years) loblolly pine (Pinus taeda L.) stands in southeastern Oklahoma to study the postice damage effects in thinned, thinned-pruned, and nonthinned-nonpruned stands. Four years after damage, diameter growth was faster in the thinned plots than the nonthinned plots as expected. Relative basal area growth (rBAgrowth; basal area growth over the 4-year period/initial basal area) decreased as the fraction of live crown ratio loss (LCRloss) increased in all stands. While the slope of the relationship was similar among silvicultural treatments, the intercept for the nonthinned plots was lower. The result was that a 50% loss of live crown predicted rBAgrowth reductions of 28% in thinned and 64% in nonthinned plots. Canopy opening due to the simulated damage did not have a positive growth effect on the undamaged trees. We did not detect any differences in stem taper, probably because the study included data for only a 4-year recovery period. We conclude that stands can recover from moderate ice storm damage without large loss in production and that thinned stands have less reduction in basal area growth than nonthinned stands.