Hurricane Gilbert and structural changes in a tropical forest in south-eastern Mexico.

This paper describes structural change and damage to the natural tree vegetation in the Dr Alfredo Barrera Marín Botanical Garden, following Hurricane Gilbert in September, 1988. Posthurricane data were compared with pre-hurricane data from the same plots, focusing mainly on composition and structure. Near complete defoliation of trees and plants of the understorey occurred and average foliage loss was estimated to be 4.5 t/ha. The density of trees decreased by 33%, and the basal area decreased by 12%. Small diameter trees accounted for the great majority of losses and trees in the largest diameter classes survived best. The average height of trees in the lower canopy decreased by 6% and for those in the upper canopy by 9%. The frequency of understorey plants decreased by 51% and their cover decreased by 70%. Floristic richness decreased only slightly after the hurricane. [ABSTRACT FROM AUTHOR]