Physiognomic and Multivariate Phytosociological Analyses of a Subtropical Peat Bog Located on the Eastern Plateau in Southern Brazil

Abstract

Subtropical peat bog vegetation in southern Brazil was examined using physiognomic and phytosociological approaches. The analysis included vascular (angiosperms, pteridophytes) and non-vascular species (bryophytes, mat-forming algae, lichens, macroscopic fungi). The breadth of this approach is novel among wetland studies in southern Brazil. The study examined the Banhado Amarelo peat bog (29°19′05″S, 50°08′18″W), which is located in the Brazilian highlands of Rio Grande do Sul (RS) state. Plant cover data extracted from 125 plots distributed among 13 physiognomically recognizable vegetation patches were analyzed using the Braun-Blanquet procedure. In total, 165 species were identified. Multivariate analysis distinguished four groups of patches. The distinctions among groups were particularly evident when all floristic elements were included, i.e., vascular + non-vascular species. When the peat soil in these 13 vegetation patches was analyzed, the proportional clay content of the soil was related to the distribution of patches. The integrated analysis of the Banhado Amarelo bog demonstrated the relevance of physiognomic studies to support phytosociological analyses and the importance of including all floristic elements and soil composition data in a comprehensive approach. These findings can be extended to other studies of subtropical bogs of southern Brazilian highlands that aim to conserve these important South American ecosystems.