Vegetation, Climate and human impact during the Holocene, NW Argentinean Puna

LILIANA CONCEPCIÓN LUPO; JULIO JOSÉ KULEMEYER; MARTIN GROSJEAN; MARCELO MORALES; GUSTAVO GUZMÁN; ROLANDO BRAUN WILKE; ANTONIO MALDONADO

Marburg, Alemania

Conferencia; 37th Annual Conference of the Ecological Society of Germany, Switzerland and Austria (GfÖ); 2007

Plant Ecology, Conservation Biology and Animal Ecology of the Department of Biology, University of Marburg

  The Holocene environments in high-montain ecosystems in the part of the arid diagonal of South America, under natural and human influence, were reconstructed by using multiproxy analyses, including pollen and diatoms analyses, geomorphological and sedimentological studies, archaeological excavations and radiocarbon datings.   The Pleistocene-Holocene border in the Puna (22º 5 S; 65º 14 W and 3300 masl) gives evidence of more humid climate conditions than today and is archaeologically characterized by remains of hunters and gatherers. A dry phase with reduced fluvial morphodynamics and higher amounts of high Andean pollen taxa, partly sterile profiles follows between 8,5 to 2 ka BP. During this phase aeolian processes prevailed in the Puna plains. Beginning at about 3,7 ka BP conditions slightly turned more humid until about 1,5 ka BP with an expansion of grasslands and the presence of high Andean mountain belt elements in the profiles of the Puna. Pollen records from the Mid-Holocene semiarid sector of Argentina’s northern Puna(,) give information regarding the oldest human disturbances of natural landscapes in NW Argentina. Human presence in the region is well documented from 2 ka BP onwards, due to the increase of pollen types associated with disturbance. This youngest phase of landscape development was characterized by increasing desertification.   The relationship of pollen and diatom data from Laguna Pululos ~550 AD (14C y 210Pb) with previously published paleoenvironmental information from the Andean region is discussed, including broader scale climatic changes as during the Little Ice Age and the Medieval Climatic Anomaly chronozones.