Effects of an intense ice storm on the structure of a northern hardwood forest

Abstract

A major ice storm in January 1998 provided an opportunity to study the effects of a rare, intense disturbance on the structure of the northern hardwood forest canopy. Canopy damage was assessed using visual damage classes within watersheds of different ages at the Hubbard Brook Experimental Forest (HBEF) and changes in leaf area index in two of these watersheds. Ice thickness was measured, and ice loads of trees were estimated using regression equations. In the 60- to 120-year-old forests (mean basal area 26 m2·ha–1), damage was greatest in trees >30 cm diameter at breast height and at elevations above 600 m. Of the dominant tree species, beech (Fagus grandifolia Ehrh.) was the most damaged, sugar maple (Acer saccharum Marsh.) was the most resistant, and yellow birch (Betula alleghaniensis Britt.) was intermediate. Trees with advanced beech bark disease experienced heavier ice damage. Little damage occurred in the 14-year-old forest, while the 24- to 28-year-old forest experienced intense damage. In the young stands of this forest, damage was greatest between 600 and 750 m, in trees on steep slopes and near streams, and among pin cherry (Prunus pensylvanica L.). Recovery of the canopy was tracked over three growing seasons, and root growth was monitored 1 year after the storm. Because of the high density of advance regeneration from beech bark disease and root sprouting potential in ice-damaged beech, HBEF will likely see an increase in beech abundance in older forests as a result of the storm. There will also be a more rapid change from pioneer species to mature northern hardwoods in the younger forests. These predictions illustrate the ability of rare disturbances to increase heterogeneity of forest structure and composition in this ecosystem, especially through interactions with other disturbances.

Modelling and Mapping Damage to Forests from an Ice Storm Using Remote Sensing and Environmental Data

“…For example, species such as sugar maple and red oak, with average scores of 1.79 and 1.82, respectively, were significantly less damaged (t-test, p < 0.01) than species such as basswood and black cherry with average scores of 2.64 and 2.76, respectively. Again these results agree with those of other studies (e.g., Rhoads et al, 2002). In 2000, repeat assessment of 830 dominant trees and 1142 intermediate trees found that the average score had improved significantly by 0.52 and 0.26, respectively (p < 0.01).…”

“…This agrees with Rhoads et al (2002) who found greater damage on south facing slopes and at higher elevations, although their study elevations were higher than those of the Gatineau Park. Damage also varied according to species.…”

“…The third and fourth columns essentially represent pre-storm data as DBH was not affected by the storm, and crown diameter was measurably reduced only for the most severely damaged trees. These data show that larger trees were more susceptible to damage and agree with results of Rhoads et al (2002). However, relations between damage and tree height were non-significant.…”

Decreased water flowing from a forest amended with calcium silicate

“…The lack of an initial peak in soil water Ca concentration, like Si concentration, is attributed to Ca immobilization in the soil either by soil cation exchange or plant uptake (24). Soil water Ca began increasing in late 1998, after a significant ice storm and before the wollastonite application (22,23). The impact of the ice storm with the wollastonite treatment remains unknown; however, the lack of a similar hydrological response in other watersheds disturbed by the ice storm suggests that our results are because of wollastonite application (Fig.…”

“…A more recent disturbance occurred in 1998 when an ice storm caused localized structural damage to the forest. Most of the damage was restricted to an elevation band between 600 and 800 m (22), and by 2001 leaf area had recovered in affected areas (23). The forest was monitored before and after the 1999 wollastonite addition to evaluate biogeochemical, ecological, and physical responses.…”