It has been suggested that vascular epiphyte composition and abundance may be influenced by forest host composition. We studied the epiphyte species distribution among host species of a tropical dry forest in Mexico. All the epiphyte stands supported by woody plants (dbh > 3 cm) of ten forest plots (0.1 ha each) were counted. We measured the dbh of all the hosts, noted their bark characteristics (texture and peeling behaviour), and measured the bark thickness of the most abundant host species. Epiphyte distribution was biased toward a high concentration of epiphytes in three host species and a lower abundance of epiphytes on five host species. This was consistent among epiphyte taxa and host species, allowing us to classify hosts as preferred (with more epiphyte stands than expected by chance) and limiting species (with fewer epiphyte stands than expected by chance), at a community level. Host quality did not relate to mean phorophyte size (measured as basal area) or to bark characteristics (peeling behaviour, thickness and texture) between species. For some epiphyte taxa, the observed distribution indicated that the forest contained preferred and limiting host species mainly. Our data suggest that the epiphyte species in the forest studied could be host limited. We concluded that neither host size nor obvious bark characteristics can be used to predict epiphyte distribution and that further research is necessary.

The diversity, abundance and frequency of vascular epiphytes on the lower trunk were compared between two host groups of a Mexican cloud forest: angiosperm trees (n = 72) and tree ferns (n = 28). The bark of the five most frequent host trees and the root mantle of the two tree ferns were analysed for their thickness, water content, water retention capacity and pH. A total of 55 epiphyte species and 910 individuals were found on the 27 host species. On hosts with a dbh range of 5–10 cm, epiphytes were significantly more diverse (4.3±0.9 species per host) and more abundant (12.5±2.2 individuals per host) on tree ferns than on angiosperm trees (1.9±0.2 species per host and 3.9±0.6 individuals per host). However, these differences were not significant for the dbh class of 10–20 cm, because epiphyte numbers increased on angiosperm trees with larger host size, but not in tree ferns. Most epiphyte species had no preference for any host group, but four species were significantly more frequent on tree ferns and two species on angiosperm trees. The higher epiphyte diversity and abundance on tree fern trunks of the smallest dbh class is attributed to their presumably greater age and to two stem characteristics, which differed significantly between host groups, the thicker root mantle and higher water retention capacity of tree ferns. These bark characteristics may favour germination and establishment of epiphytes.