Invertebrate communities in a tropical rain forest canopy in Puerto Rico following Hurricane Hugo

1. Canopy invertebrate responses to Hurricane Hugo, tree species, and recov ery time were examined at the Luquillo Experimental Forest in Puerto Rico d uring 1991-92 and 1994-95. Six tree species representing early and late suc cessional stages were examined in paired plots representing severe hurrican e disturbance (most trees toppled) and light hurricane disturbance (all tre es standing and most branches intact). 2. Hurricane disturbance affected invertebrate abundances significantly. Sa psuckers and molluscs were more abundant, and defoliators, detritivores, an d emergent aquatic insects were less abundant in recovering tree-fall gaps than in intact forest during this 5-year period. These changes in functiona l organisation are consistent with comparable studies of arthropod response s to canopy removal during harvest in temperate forests. 3. Tree species also affected invertebrate abundances significantly, but in vertebrate communities did not differ significantly between the three early successional and three later successional tree species. 4. Most taxa showed significant annual variation in abundances, but only tw o Homoptera species showed a significant linear decline in abundance throug h time, perhaps reflecting long-term trends during recovery: 5. Leaf area missing, an indicator of herbivore effect on canopy processes, showed significant seasonal and annual trends, as well as differences amon g tree species and hurricane treatments. Generally, leaf area missing peake d during the wet season each year, but reached its highest levels during an extended drought in 1994. Leaf area missing also tended to be higher on th e more abundant tree species in each disturbance treatment. 6. Herbivore abundances and leaf area missing were not related to concentra tions of nitrogen, phosphorous, potassium, or calcium in the foliage. 7. This study demonstrated that invertebrate community structure and herbiv ory are dynamic processes that reflect the influences of host species and v ariable environmental conditions.