Changes in vegetation and human-environment interactions during the Holocene in the Lake Pueyrredón area (southern Patagonia)

MARCOS, MARÍA ALEJANDRA; BAMONTE, FLORENCIA PAULA; ECHEVERRIA, MARCOS EMANUEL; SOTTILE, GONZALO DAVID; MANCINI, MARÍA VIRGINIA

VEGETATION HISTORY AND ARCHAEOBOTANY

SPRINGER

Año: 2022 vol. 31 p. 291 - 305

0939-6314

This paper reconstructs the vegetation history of the Lake Pueyrredón area during the Holoceneand contextualizes the use of space and sources by hunter-gatherer groups according topaleoenvironmental evolution. The pollen analysis of the Los Flamencos lake sequence ispresented and integrated with local archaeological pollen data. Early Holocene vegetationconsisted of a dwarf-shrub-grass steppe associated with cold conditions. From 7600 years calBP a shrub vegetation with forest patches is inferred, suggesting a high moisture availability andpossibly involving an eastwards displacement of the forest-steppe ecotone boundary. Humanoccupation, previously interrupted for Hudson volcano eruption, and use of space is evident inthis period. Between 6600-5400 years cal BP an environmental change to drier conditionssuggests a heterogenous shrub steppe and the higher availability of floristic resources possiblyused by hunter-gatherer groups. The predominance of shrub steppe with dwarf shrubs from5400 years cal BP indicates more arid than current conditions, which correlates with a higherhuman-environment interaction related to changes in the lake configuration allowing new northsouth circulation roads and vice versa, and major floristic resources availability. A decrease indwarf-shrubs indicates a slight increase in moisture availability since 3550 years cal BP,suggesting a weakening of the westerlies winds. The results indicate local and regional changesin vegetation linked mainly to moisture availability and SWW fluctuations. The integration ofpollen, archaeological and paleogeographic information available and its comparison with otherfossil records studied in Patagonia complement paleoenvironmental reconstruction and explainthe changes in a regional paleoenvironmental framework