Contribution to the floristic knowledge of the Eastern Chaco, Formosa province, Argentina.

Abstract

Contribution to the floristic knowledge of the Eastern Chaco, Formosa province, Argentina. The southeastern of Formosa province integrates part of the Oriental Chaco, characterized by a great environmental heterogeneity, where woody components and grassland are mixed. This complex characteristic is linked to the forms of the landscape, which it is the result of alluvial dynamics during the Pleistocene-Holocene and of the migration of fluvial belts of principal rivers. In this contribution, the floristic composition of different communities of Laishi (Formosa) is analyzed, in order to establish the composition and variability of its elements. For this, species collected near the town, herbarium and bibliography data showed the presence of 625 species, where Asteraceae, Poaceae and Fabaceae families were predominated. There are different vegetation units: forests, palms, shrubs, mesophyte and hydrophyte grasslands, and marshes, where forests and hydrophyte grasslands are dominated. Spatial distribution of the vegetation was analyzed according to the topographic height preference, especially the distribution of tree communities. This information was obtained from satellite images. In addition, Amazon forest components (Yungas and Paranaense) among Chaquenian species were found.