FOREST DAMAGE AND RECOVERY FROM CATASTROPHIC WIND

The literature on the effects of catastrophic wind disturbance (windst orms, gales, cyclones, hurricanes, tornadoes) on forest vegetation is reviewed to examine factors controlling the severity of damage and the dynamics of recovery. Wind damage has been quantified in a variety of ways that lead to differing conclusions regarding severity of disturb ance, Measuring damage as structural loss (percent stems damaged) and as compositional loss (percent stems dead) is suggested as a standard for quantifying severity. Catastrophic wind produces a range of gaps f rom the size caused by individual treefalls to much larger areas, The spatial pattern of damage is influenced by both biotic and abiotic fac tors. Biotic factors that influence severity of damage include stem si ze, species, stand conditions (canopy structure, density), and the pre sence of pathogens. Abiotic factors that influence severity of damage include the intensity of the wind, previous disturbance, topography, a nd soil characteristics. Recovery from catastrophic wind disturbance f ollows one of four paths: regrowth, recruitment, release, or repressio n. The path of recovery for a given site is controlled both by the sev erity of disturbance and by environmental gradients of resources. Reco very is influenced also by frequency of wind disturbance, which varies across geographical regions. To develop robust theories regarding cat astrophic wind disturbance, the relative roles of different abiotic an d biotic factors in controlling the patterns of severity of damage mus t be determined. These patterns of severity and environmental gradient s must then be tied to long-term dynamics of recovery.