Description of Heliconia phytotelmata communities in Central and South America

In tropical Central and South America, phytotelmata communities develop in water-filled flower bracts of Heliconia that harbor a diverse collection of aquatic insects. The spatial and temporal pattern of bracts on flower clusters, known as racemes, offer the ability to investigate patterns in community colonization. It was hypothesized that island and mainland Heliconia communities would differ in richness, abundance, and community composition. The relationship between abundance and species richness across bract positions was examined to test the hypothesis that the number of species is a result of the number of individuals in a bract. Racemes were sampled in French Guiana and compared to existing data from Puerto Rico. For each bract separately, patterns of richness, abundance, and community composition were analyzed between sites and bract age across raceme sizes of 3-11 bracts. Island and mainland comparisons were restricted to sizes 5 and 8 bracts per raceme. Aquatic insects were identified to species or the lowest taxonomic level possible based on morphological differences. The two communities from French Guiana and Puerto Rico were not shown to differ significantly in abundance and richness among bracts in both sites. However, a difference in total richness was detected where the island communities contained 27 species and continental communities contained a higher total species richness at 37 species. Thus, these systems which differ in composition of species, are comparable in terms of biodiversity and could prove useful for testing general ecological theories regarding the mechanisms that affect species diversity.