Influence of glaze ice storms on growth rates of loblolly pine Pinus taeda and shortleaf pine Pinus echinata in the Southern Appalachian Piedmont

Data on ring-width increments taken from loblolly Pinus taeda L. and shortleaf pines Pinus echinata Mill. were analyzcd to determine the degree of impact by ice storms on radial growth at 3 sites in the Southern Appalachian Piedmont. For each of the 3 sites a dendrocllmatological model of the temperature and precipitation signal in annual ring widths was produced Residuals from each model were regressed against the timing (date) and seventy (ice accumulation) of ice storms. Information on the timing of an Ice storm increased the R2 for the shortleaf stand by an additional 0 19 (0.25 to 0.43). Storms late in the winter produced the greatest reductions in ring widths. For the 2 loblolly sites, ice storm severity increased the explained variance by 0.11 (0.35 to 0.46) and by 0.10 (0.39 to 0.49), respectively. Each severe ice storm occurrence was associated with a large negative residual. Radial growth reduction appears to be confined to the immediate growing season following the storm. No ice storm signals could be found for the second and third years following a storm, nor did the trees show any permanent structural damage. The models presented in this study suggest that the economic impacts of an ice storm, or the cumulative effects of ice storms on a stand, can be estimated.