Aquatic macrophytes in Paraguay River branches in the Brazilian Pantanal, Mato Grosso do Sul, Brazil

Abstract

Our objective was to inventory the flora of aquatic macrophytes and their life forms, and to determine the species similarity in different water bodies. Sampling of the vegetation was carried out in 333 plots of 0.5 x 0.5 m along ten transect lines on a boat to best cover the studied areas. Poaceae (18.9%), Cyperaceae (9.4%), Fabaceae, Onagraceae, and Pontederiaceae (7.5% each) were the most represented families. Emergent (56.6%), free floating (20.8%), rooted floating (18.9%), and amphibious (13.2%) were the most common life forms. We observed dissimilarity between most sampled points. We conclude from the inventory of aquatic macrophytes that the most prevalent species are common to other similar physiognomies in the Pantanal and the prevalent life forms corroborate the importance of flood in this environment, since they are typical of plants adapted to the flooded and dry transition. Even though the species richness is comparable to other areas, the plant communities inventoried separately are heterogeneous and respond in distinct ways to local environmental conditions.