Floristic composition and spatial distribution of vascular epiphytes in the restingas of Maracanã, Brazil

Vascular epiphytes constitute a life form that is important to maintaining the biological diversity of forest ecosystems, because they provide food resources and specialized microenvironments for fauna in the forest canopy. This study aimed to describe the floristic composition and ecological aspects of vascular epiphytes occurring in the restingas (coastal woodlands) within the Algodoal-Maiandeua Environmentally Protected Area, located in the municipality of Maracanã, in the state of Pará, Brazil. We sampled five 50 × 50 m plots (three in dry restinga forest and two in floodplain restinga forest), the sampled area therefore totaling 1.25 ha. In the plots sampled, vascular epiphytes were identified and described according to their frequency, abundance, importance value (IV), functional group and vertical distribution (trunk, lower crown or upper crown of the host). For both forest types, we identified 477 individuals belonging to five families, nine genera and 11 species. The most species-rich families were Araceae and Orchidaceae. The species with the highest density, frequency and IV were the secondary hemiepiphytes Philodendron acutatum, Anthurium pentaphyllum and Philodendron muricatum, collectively accounting for 92.1% of all sampled individuals. The true epiphytes predominated. Epiphytic species richness and abundance was greater on the host trunk than in the lower or upper crown. The seasonal climate and structure of the forest favored greater abundance of secondary hemiepiphytes and a higher frequency of epiphytes on the trunks of their hosts.