Wind damage effects of Hurricane Andrew on mangrove communities along the southwest coast of Florida, USA

Abstract

/'fflfffit. DOYLE, T.W.; SMITH, T.J., III, and ROBBLEE, M.B., 1995. Wind damage effects of Hurricane Andrew on mangrove communities along the southwest coast of Florida, USA. Journal of Coastal Research, SI No. 21, pp. 159-168. Fort Lauderdale (Florida). ISSN 0749-0208. On August 24, 1992, Hurricane Andrew downed and defoliated an extensive swath of mangrove trees across the lower Florida peninsula. Permanent field sites were established to assess the extent of forest damage and to monitor the rate and process of forest recovery. Canopy trees suffered the highest mortality particularly for sites within and immediately north of the storm's eyewall. The type and extent of site damage, windthrow, branch loss, and defoliation generally decreased exponentially with increasing distance from the storm track. Forest damage was greater for sites in the storm's right quadrant than in the left quadrant for the same given distance from the storm center. Stand exposure, both horizontally and vertically, increased the susceptibility and probability of forest damage and accounted for much of the local variability. Slight species differences were found. Laguncularia racemosa exceeded A vicennia germinans and Rhizophora mangle in damage tendency under similar wind conditions. Azimuths of downed trees were strongly correlated with maximum wind speed and vector based on a hurricane simulation of the storm. Lateral branch loss and leaf defoliation on sites without windthrow damage indicated a degree of crown thinning and light penetration equivalent to treef all gaps under normally intact forest conditions. Mangrove species and forests are susceptible to catastrophic disturbance by hurricanes; the impacts of which are significant to changes in forest structure and function. ADDITIONAL INDEX WORDS: Mangroves, hurricanes, Florida, tropical cyclones, forest dam age, windthrow, disturbance, canopy structure, gap dynamics, defoliation.