Diversity and distributional patterns of aroids (Alismatales: Araceae) along an elevational gradient in Darién, Panama

Abstract

ABSTRACT The family Araceae (aroids) represents an ecologically important and diverse group of plants in Panama, represented by 25 genera, 615 species, of which 277 (45%) are considered endemic. The aim of this study is to analyse the diversity and distributional patterns of aroids along an elevation gradient in the species-rich forests of Darién, Panama. We confined our study to three study sites, selected across gradients of elevation (ranges): 100–300, 500–700 and 1100–1300 m. We recorded 3187 specimens, of which 397 were terrestrials, 637 epiphytes and 2153 nomadic vines, distributed in 10 genera and 61 species. Our study shows that the most diverse areas were those between 500 and 700 m and the highest abundance were measured at 1100–1300 m. The epiphytic aroids displayed greater species richness and abundance at 1100–1300 m; the nomadic vines had greater richness between 500 and 700 m and greater abundance from 100 to 300 m. Similarly, terrestrial aroids showed greater richness at 500–700 m, and exhibited abundance values similar to that of the epiphytes. We measured a high degree of aroid species turnover along the elevation gradient and some genera and species (many being endemic) appeared strongly associated with sites at specific elevations.