Influence of Age, Diameter, and Location on Compression Wood Formation in White Pine Following Ice Storm Damage

In 1994, two ice storms hit the ridge-and-valley region of southwestern Virginia. Large-diameter trees experienced high levels of branch breakage and many small-diameter trees were bent under the weight of the ice. To right themselves, the conifers formed compression wood. The objective of this study was to quantify the influence of stem diameter, age, crown class, tree location, and influence of nearest neighbor on compression wood formed following the 1994 ice storms in eastern white pine (Pinus strobus, L.). Pinus strobus within a 50 x 100 m plot were destructively sampled at Virginia Techs’ Fishburn Forest in southwestern Virginia and cross-sectional disks were removed at stump height. Disks were sanded, cross-dated, and scanned. Tree locations were spatially mapped with a laser transit, along with distance and attributes of the nearest neighboring trees. The images of the scanned disks were imported into Photoshop and the amount of compression wood formed in the years following 1994 was measured as a percentage of total area in the cross-section. The white pine exhibited a two-age structure with younger trees establishing in 1990s and older trees in the 1960s. Through a comparison of these two age classes, the formation of compression wood appeared to be age independent; however diameter and crown class were related to amount of compression wood formed by the white pines following the 1994 ice storms with smaller diameter and lower crown classes forming relatively more compression wood compared to larger, dominant individuals