Edge effect on vascular epiphytes in a subtropical Atlantic Forest fragment

Abstract

Epiphytes are efficient indicators of environmental quality. The Atlantic Forest is a hotspot for epiphyte richness; however, it is experiencing one of the highest rates of degradation, exposing epiphytes to edge effects. This study aimed to evaluate the floristic composition and richness of vascular epiphytes and their relationship with phorophyte features and microenvironmental variables at the edge and in the interior of a subtropical Atlantic Forest fragment in Brazil. Twenty-five trees were analyzed, respectively, at the edge and in the interior of the fragment. Height and diameter of phorophytes, temperature, relative air humidity, photosynthetically active radiation and canopy opening were measured. A total of 41 epiphytic species were recorded, 40 occurring in the interior and 23 at the edge. Orchidaceae, Bromeliaceae, and Polypodiaceae were the richest families, representing 75% of all species. The average number of species per tree in the interior was twice that for the edge. Pleopeltis pleopeltifolia, Microgramma squamulosa, M. vacciniifolia and Rhipsalis teres concentrated great biomass in both environments, with twice as much in the interior. Epiphyte richness and biomass was lower on thinner trees with more open canopies at the edge. Our results indicate that the forest interior is more beneficial for epiphytes, which are sensitive to environmental changes caused by the edge effect. The contrast between the epiphytic communities of the edge and the interior reveals the need to increase richness and abundance of native trees and prevent cattle grazing, the planting of exotic species and more human settlements in the habitat matrix.

Climatic triggers of the phenophases of Elaphoglossum macrophyllum in Southern Brazil

“…2023 it is isolated, it is under the direct influence of the edge effect in all its cardinal limits. Previous studies in this location revealed biological elements, such as high epiphyte diversity, which classify this area as a secondary forest with advanced ecological succession (Endres Júnior et al 2015;Lippert et al 2022;Quevedo et al 2014;Brasil 1994).…”