Document: ANN-3-69-31

Characterizing susceptibility to and effects of the January 1998 ice storm in the White Mountain National Forest, NH.

RHOADS, A.G.* ¹, S.P.HAMBURG ¹, T.J.FAHEY ², T.G.SICCAMA ³ and E.N.HANE ¹

Brown University, Providence, RI 02912, U.S.A. ¹
Cornell University, Ithaca, NY U.S.A. ²
Yale University, New Haven, CT U.S.A. ³

Abstract:
A major ice storm struck the northeastern United States and southeastern Canada in January 1998. The storm, considered the worst forest disturbance in the area since the hurricane of 1938, provided a rare opportunity to study ice storm disturbance at Hubbard Brook Experimental Forest (HBEF), a long-term ecological research site. The purpose of this study was to document susceptibility to ice damage in portions of the northern hardwood forest. Methods used to measure damage included leaf area index (LAI) measurements using Li-Cor's LAI-2000 and visual damage class assessments based on branch loss. We found that elevation, tree diameter (dbh), species composition, and tree health were key factors in determining susceptibility at HBEF. No elevational effect on damage was found within the impacted zone, but there was significantly higher damage above approximately 600 m. Damage was also significantly greater in trees with larger diameters (dbh). Plot damage increased with higher beech (Fagus grandifolia) biomass, while sugar maple (Acer saccharum) was the most resistant of the dominant species at HBEF. The susceptibility of beech can be partly explained by its mechanical properties and also by the presence of beech bark disease. Trees with more severe beech bark disease experienced more ice damage. Because storm damage was heterogeneous across the impacted areas, data was also collected at four other sites near HBEF. Elevation, tree size, and species composition continued to determine susceptibility, though patterns differed across the sites. The varied damage patterns and inter-specific differences in susceptibility within and between sites suggest that both local and landscape-level changes in community structure may result from this rare event.

Keywords: ice storm; disturbance; northern hardwood forest; susceptibility; elevation; dbh; species composition; beech bark disease

This abstract is being presented at: 8:15 AM in session:
Oral Session #42: Disturbance Ecology: Effects of Storms.