The relationship between soil characteristics and vegetation as a function of landform position in an area of the Flooding Pampa [Argentina]

Abstract

The Flooding Pampa is a grassland with gentle slopes (<1%) and a completely flat appearance. Nevertheless, the unevenness of the land at the local scale conditions differences in the runoff, leading to the formation of swampy areas. A thematic grassland map was produced, correlating the soils and plant communities via variables that condition their presence. The working methodology included the analysis of a geomorphologically homogeneous area using cartographic materials and aerial photographs. Based on data obtained from the analysed sampling units, the system used allows extrapolations to be made at the landscape scale. The soils show important changes over the toposequence. The vegetation alters with changes in the soil, leading to the appearance of species groups with hydromorphic, hydrohalomorphic or halomorphic characteristics. The worsening of natural drainage is related to variations in the organic carbon content, an increase in pH and the percentage of exchangeable sodium, more intense signs of hydromorphism, and the appearance of characteristic species groups.