Variaciones en la vegetación, clima y la presencia humana en los últimos 15000 años en el borde oriental de la Puna, provincia de Jujuy y Salta, noroeste argentino

FRANK SCHÄBITZ; LILIANA C. LUPO; JORGE KULEMEYER; JULIO JOSÉ KULEMEYER

PUBLICACION ESPECIAL - ASOCIACION PALEONTOLOGICA ARGENTINA

ASOCIACIÓN PALEONTOLÓGICA ARGENTINA

Año: 2001 p. 155 - 162

0328-347X

We present results of an interdisciplinary research located at the eastern flank of the Andes, the Puna and the Cordillera Oriental (Sierra de Santa Victoria) of Jujuy and Salta. The study concerns about the environmental reconstruction for the Late Quaternary in this part of the arid diagonal of south America under natural and human influence on the Andean and high-mountain ecosystems. Different analyses were performed on cored sediment profiles of former lakes, on vegetational studies comparing the modern pollen rain with the actual vegetation cover, additionally archaeological excavations and radiocarbon datings were done. Interpretation of sediment and pollen profiles show two big paleoenvironmental phases: 1) the Lateglacial is characterized by a westwards displacement of the Yunga forest on the eastern flank of the Cordillera Oriental indicated by higher pollen amounts of Podocarpaceae and other tree taxa during 15-11,5 ka BP with a descreasing trend up to 11,5 ka BP. This forest phase corresponds to humid air with higher precipitation coming in by easterly winds and increasing temperatures. 2) the Holocene shows the decrease of arboreal pollen taxa until 8,5 ka BP, when a dry phase begins, documented in higher amounts of altoandean pollen taxa, partly sterile profiles due to seccation of lakes and no variations in the Puna profiles between 8,5 to 2 ka BP. During this phase aeolian processes dominated on the Puna plains. Beginning at about 3,7 ka BP conditions slightly turned to more humidity until about 1,5 ka BP with expansion of grasses in former dry lands and the presence of elements of the high Andean mountain belt in the profiles of the Puna. The Pleistocene-Holocene border in the Puna is characterized by archeological remains of hunters and collectors and different grades of manipulation of the environment until 4,5 ka BP later followed by increasing influence during the Spanish conquest.