Radial growth of hardwoods following the 1998 ice storm in New Hampshire and Maine

Abstract

Ice storms and resulting injury to tree crowns occur frequently in North America. Reaction of land managers to injury caused by the regional ice storm of January 1998 had the potential to accelerate the harvesting of northern hardwoods due to concern about the future loss of wood production by injured trees. To assess the effect of this storm on radial stem growth, increment cores were collected from northern hardwood trees categorized by crown injury classes. For a total of 347 surviving canopy dominant and subdominant trees, a radial growth index was calculated (mean annual increment for 1998–2000 divided by the mean annual increment for 1995–1997). Sugar maple (Acer saccharum Marsh.), yellow birch (Betula alleghaniensis Britt.), white ash (Fraxinus americana L.), and red maple (Acer rubrum L.) categorized in injury class A (crown loss of less than one-half) had mean growth index values of approximately 1.0, indicating no loss of mean radial growth after 3 years. For injury class B (crown loss of one-half to three-quarters) and class C (crown loss greater than three-quarters), growth index values significantly decreased for sugar maple, yellow birch, and red maple. For white ash, growth index values of classes B and C were not significantly different from those of class A trees. Growth index values of A. saccharum and A. rubrum in injury class C were the lowest of those measured. These results indicated that the severity of growth loss due to crown injury depends on tree species and crown replacement as well as the extent of crown loss.