Flora and vegetation structure of Vereda in southwestern Cerrado

Abstract

This work was carried out aiming to evaluate phytosociological parameters and the influence of topographic gradient and water levels on plant distribution in a vereda. That for, we sampled two sites (wet grassland and floodable transition to pond) in two seasons (rainy and dry). Along permanent transects, every 10 m we placed transversally four quadrats of 1 m2, 2 m apart, a total of 280 plots, to estimate percentage cover of each species and water depth. To evaluate the influence of relief and flood level on plant distribution we performed a Principal Coordinate Analysis (PCoA) and Analysis of Permutational Multivariate Variance (PERMANOVA). We recorded 174 species, the richest families were Poaceae (40), Cyperaceae (25) and Asteraceae (14) and the richest genera Paspalum, Rhynchospora and Utricularia (8 each), Hyptis and Cyperus (6), Eleocharis, Ludwigia and Xyris (5). The phytosociological parameters revealed the importance of Poaceae, Cyperaceae and Asteraceae in these communities, corroborating other reports on veredas. We found discrete difference in the species richness between sampling periods, in both wet grassland and transition areas. The slope varied from 0 to 314 cm and was significant for species distribution in both seasons, with a continuum related to waterlogging and surface water on the distinct topographic quotas. In general, we found discrete groupments of species, particularly in lower quotas. The main indicator species were the filiform Eriochrysis holcoides (Poales, Poaceae), Rhynchospora emaciata (Poales, Poaceae), Andropogon virgatus (Poales, Poaceae), Paspalum erianthoides (Poales, Poaceae) and P. flaccidum (Poales, Poaceae). Some species tend to be selective whilst others show plasticity regarding microhabitat.