Paleovegetation and Paleoenvironment of the Lower and Middle Holocene in Southeast of Iberá, Corrientes, Argentina

FERNANDEZ PACELLA, LIONEL

RIVISTA ITALIANA DI PALEONTOLOGIA E STRATIGRAFIA

UNIV STUDI MILANO

Lugar: Milan, Italia; Año: 2015 vol. 121 p. 343 - 350

0035-6883

Lacustrine sediments, which often evidence the history of environmental and climatic changes occurred during several hundreds or thousands of years, are one of the most effective sources to reconstruct Quaternary climates and envi-ronments. The Iberá wetlands, located in the heart of La Plata River Basin, occupy the central area of the Province of Corrientes (Argentina). The aim of this study was to reconstruct the plant communities in the southwestern part of the Iberá wetlands through pollen analysis of lake sediments, and infer the possible climate changes occurred in the Lower and Middle Holocene. For this study, we selected two small shallow lakes (no more than 5 meters), located southwest of the macrosystem: lake Rodeo Porá and lake San Ignacio. The palynological analysis of the lakes allowed distinguishing the following vegetation changes: Lake San Ignacio, about 6,200 years B.P. a predominance of the marsh-grass vegetation, mainly Poaceae, plus local humidity indicating species, aquatic vegetation and algae, and to a lesser extent dammed forming species is evident. Lake Rodeo Porá, from 4900 years to 3900 years B.P., a change is observed in the floristic composition, after trees as Arecastrum, Prosopis, Schinus and Anadenanthera began to be present, integrating regional vegetation characteristic of dry environments and continuing until today.