Vegetation diversity in a large Neotropical wetland during two different climatic scenarios

Abstract

We aim to analyze the spatial patterns of the vegetation at local and landscape scale during a scenario characterized by abnormally dry period (2007–2008) and a reference scenario (1976–1977). We used the frequency occurrence of the species and the number of species belonging to five life forms to compare the two temporal scenarios. In five water bodies of Esteros del Ibera we surveyed vascular aquatic macrophytes and the wetland plants during spring-summer with up to three samples of 20 m2 each. A total of 161 species were found during the two study periods (120 and 117 species respectively). Cyperaceae and Poaceae were the most species-rich families at both periods. At waterbody scale, beta diversity showed a high spatial heterogeneity and at wetland scale, the turnover rate of S is low. At both scenarios, the vegetation composition showed relevant differences between the sub-rounded lakes and the elongated waterbodies. The floristic composition and the life forms spectra were affected by the change in the water supply. The knowledge of the baseline of the spatial and temporal variability of this particular wetland is key to support future assessments of the ecosystem response to the global change.