Human subsistence changes during the late Holocene: resource overexploitation or climate change in the upper Atuel river valley, Argentina

NEME, G.; NAVARRO, D.; ANDREONI, D; LLANO, C.; GIARDINA, M.; OTAOLA, C.; FERNANDEZ, F; WHITLOCK, C.; GIL, A.

Bern

Congreso; XVIII International Union for Quaternary Research (INQUA) Congress; 2011

International Union for Quaternary Research (INQUA)

Significant changes in human subsistence strategies took place during the Holocene in the high-altitude environments of central west Argentina. During the last 9000 yr BP, the mountain environments in Atuel River had been exploited but it was during the last 2000 yr BP that they had been effectively and completely occupied. Important changes in the land use had been also recorded including the consumption of smaller preys, greater plant-use diversity and the appearance of new technologies (bow and arrow, pottery). The main explanation for these changes has been until now the resources overexploitation by humans. At the same time scattered paleoenvironmental information suggested that some environmental changes took place, but still the real impact over the human population is not completely understood. In this paper we present the archaeological record from El Sosneado Locality in the Atuel River upper basin (34°47’S, 69°52’W; 2000 m asl; Arroyo Malo -3, Arroyo Malo 1 and Laguna El Sosneado-3), and its comparison with high resolution paleoenvironmental information from a core from El Sosneado lake (ES). The archaeological information includes archaeofaunal, archaeobotanical, and charcoal records. Pollen and charcoal records analyzed from ES core were used as proxy data to reconstruct vegetation, fire and environmental changes over the last 7.000 cal yr BP. This record shows the development of Andean-Patagonian shrub steppes with wetter and colder than present conditions and frequent fire events between 6400 and 1900 cal yr BP. After that an abrupt change towards more sparse Patagonia-Monte vegetation indicates drier and warmer conditions. Intent to integrate this different line of research is presented in order to improve our comprehension of human-environment relationship in mountain ecosystems.