Structural Differences in Herbaceous Communities on Edge and Interior Atlantic Forest in South Brazil

Abstract

The Atlantic Forest is recognized worldwide as hotspots due to its megadiversity. This study aimed to evaluate whether there are differences between the floristic and structural diversity of the herbaceous component in an edge and interior region of the southern Brazilian Atlantic Forest. The study was developed in a forest fragment located in the state of Santa Catarina, south Brazil. The edge of the fragment is characterized by an area up to 10-15m wide, covered massively by herbaceous-subshrub vegetation and rare arboreal individuals. The interior is discontinuously shaded by the arboreal and shrub component contained in the upper strata of the forest. The phytosociological survey used the plot method. 100 plots of 1 m² were established, 50 on the edge of the forest fragment and 50 plots inside it. The phytosociological parameters studied for both areas were absolute frequency (AF), relative frequency (RF), absolute coverage (AC) and relative coverage (RC). Through the treatment and analysis of these data, the importance value index (IVI) of each species was obtained. At the edge of the forest fragment, 18 families and 34 species were identified. Of the 34 species found, 31 are angiosperms (24 dicots and 7 monocots) and 3 are monilophytes. All species are native to the Brazilian flora, with the exception of Centella asiatica and 2 lycophytes. In the interior, 14 species were found, being represented by 10 families. All species in the interior were angiosperms (4 dicots and 8 monocots) and 2 monilophytes. All species are native to the Brazilian flora and have herbaceous habit. The herbaceous community in the interior is different from the herbaceous community at the forest edge. The initial hypothesis of the work was confirmed, since none of the species present at the edge of the forest occurs in the interior of the forest.