Spatial distribution of vascular epiphytes on three emergent canopy trees in French Guiana

The distribution of vascular epiphytes was analyzed on three emergent trees (Hura crepitans, Ceiba pentandra, and Couratari stellata). A total number of 77 species, including 46 orchids, in 17 families was recorded. Number of species was highest in the center of the tree crowns while cover was highest in the middle third of the crown or equally distributed. This leads to the assumption that succession does not always reach equilibrium on old branches towards crown center. Distribution patterns of single species do not necessarily correspond to that of the total epiphyte mass. The entire epiphyte cover is highest on the top of branches while certain species, that could be discussed as specialists on the basis of particular life-form characteristics, are equally abundant on the bottom. There was no clear distribution pattern with respect to branch inclination. Distribution patterns are partly explained by the life-form of the plants.