Hurricane Damage and Regeneration in Fringe Mangrove Forests of Southeast Florida, USA

Abstract

I BALDWIN, A.H.; PLATT, W.J.; GATHEN, K.L.; LESSMANN, J.M., and RAUCH, T.J., 1995. Hurricane damage and regeneration in fringe mangrove forests of southeast Florida, USA. Jour nal of Coastal Research, SI No. 21, pp. 169-183. Fort Lauderdale (Florida). ISSN 0749-0208. Hurricane damage was surveyed at two sites in mangrove forests fringing Biscayne Bay in south Florida that were hit by Hurricane Andrew on 24 August 1992. Two sites not impacted by An drew and last hit by a major hurricane in 1965 were also surveyed. Avicennia germinans (L.) Stearn (black mangrove), Laguncularia racemosa Gaertn.f. (white mangrove), and Rhizophora mangle L. (red mangrove) were found to differ in their susceptibility to hurricane-related damage and mor tality and in their mechanism of regeneration following hurricanes. The highest mortality asso ciated with Hurricane Andrew was observed in R. mangle (85.1%); mortality was lower in A. germinans (65.0%) andL. racemosa (59.5%), values nonetheless much higher than tree mortality rates in other communities in south Florida. The ability to resprout epicormically in A. germinans and L. racemosa following the hurricane is probably the primary reason for their higher survival; epicormic sprouts were not observed in R. mangle. Despite its higher mortality, R. mangle sus tained proportionally less severe structural damage than A. germinans and L. racemosa. Reestab lishment of the population of R. mangle is occurring primarily through seedling recruitment, while regeneration of A. germinans and L. racemosa is primarily via epicormic sprouting. At the two sites not impacted by Hurricane Andrew, patterns of regeneration similar to those observed fol lowing Hurricane Andrew appear to have occurred following Hurricane Betsy in 1965. ADDITIONAL INDEX WORDS: Avicennia germinans, Laguncularia racemosa, Rhizophora man gle, Hurricane Andrew, mortality, recruitment, resprouting, seedlings, wind direction.