Anthropogenic and natural drivers of vegetation & fire history along the forest-steppe border of the eastern Andes (38-52°S)

VALERIA OUTES; MA. EUGENIA DE PORRAS; GUSTAVO VILLAROSA; CATHY WHITLOCK; WILLIAM NANAVATI; VIRGINIA IGLESIAS

Congreso; 20th INQUA CONGRESS; 2019

Although it is well established that climate and fire have greatly influenced the postglacial Patagonian forest-steppe border (41-55°S)1,2,3, many questions remain about the extent to which humans have altered the vegetation and fire history of this region.Here, we present a 10,580-year history of vegetation, fire, climate, and land use from Laguna Portezuelo (37.9°S, 71.0°W; 1730 m elev.), located along the Araucaria araucana forest-steppe border in southern South America. We then compare the last 1000 years of paleoenvironmental history along a north-south flammability gradient from dry L. Portezuelo, intermediate Lago Mosquito3 (42.5°S, 71.4°W; 560 m elev.), and wet Río Rubens Bog4 (52.0°S, 71.9°W; 220 m elev.).Research questions:What is the Holocene vegetation and fire history of the Araucaria araucana forest-steppe border near L. Portezuelo?How did humans alter the local vegetation and fire history?How has land use altered vegetation and fire history in Patagonia along a flammability gradient?