This study was carried out in a 3,000 m² area of coastal plain forest at "Ilha do Mel" (25°30’ S; 48°23’ W). The qualitative survey was carried out on the whole area, while the quantitative survey was done on 100 assorted trees, separated into two meters-high strata starting from the ground level. In each strata we recorded all of the occurring epiphytic species. The epiphytic importance index was calculated from the frequencies found for each stratum, for each host tree and for each species of host tree. In this survey, 77 species (16 of Pteridophyta, 53 of Liliopsida and 8 of Magnoliopsida) were found, of which 70 were sampled in the trees surveyed. The richest families were Orchidaceae, Bromeliaceae and Polypodiaceae, while Vriesea, Encyclia and Maxillaria were the richest genera. The area located in the Torres County (RS) presented the closest floristic similarity to the one used in this survey. From the quantitative point of view, Microgramma vaccinifolia, Codonanthe gracilis, Epidendrum latilabre and E. rigidum were the most important species. The sampled species were grouped into three categories, exclusive, preferential or indifferent, according to their occurrence in the different height intervals in relation to the ground. The frequency of epiphytic individuals in a host tree varied from 1 to 35, while the number of species varied from 1 to 21 (average of 14 ±7.6 and 10 ± 4.6, respectively). The first (0-2, 2-4 and 4-6 m) strata were the richest in epiphytic species. For the host tree species, the highest frequencies of epiphytic individuals were found for Andira fraxinifolia and Ternstroemia brasiliensis, while Ocotea pulchella and Guapira opposita presented the largest number of species. Regarding to fidelity on host tree species, exclusive, preferential and generalist species were found, the last one included most of the species.
Coastal plain forests; floristic composition; vascular epiphytes; vertical distribution; restinga
