Hurricane disturbance and forest resilience: Assessing structural vs. functional changes in a Caribbean dry forest

Dry forests of the Caribbean islands are among the most endangered tropical ecosystems. Above and beyond several centuries of anthropogenic disturbances, most of these forests are prone to natural, catastrophic disturbances such as hurricanes. This study was conducted in a set of 2400-m(2) permanent inventory plots established in an old-growth dry forest on the calcareous island of Grande-Terre, Guadeloupe (FWI). It aimed at assessing various aspects of forest recovery after the forest had been struck by Hurricane Hugo (1989). Floristic composition, litterfall, stem density, basal area and tree growth (girth increment) for trees with girth >= 10 cm at breast height, were monitored from 1987 to 1996-98. Species richness remained quite stable over the period of study (30-34 species), although some qualitative changes occurred. Nine years after the hurricane, neither stem density and basal area, nor girth increment, had returned to pre-hurricane values (respectively 3800 stems ha(-1), 21.5 m(2) ha(-1) and 7.1 mm year(-1)). Stem growth, however, had clearly been impeded by drought in the last 4 years of the study. Leaf litter production was restored both qualitatively and quantitatively as of the fourth year following Hurricane Hugo, whereas wood and reproductive components had not fully attained pre-hurricane values by the end of the study. Though hardly distinguishable from the superimposed effects of other recurrent anthropogenic (e.g. charcoal production) or natural stressors (e.g. wildfires and drought), hurricane disturbance in dry forests appears to affect the forest structure on a longer time-scale rather than the functioning of the forest ecosystem. (C) 2008 Elsevier B.V. All rights reserved.