Clim. Past Discuss., 9, 5747-5784, 2013
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This discussion paper is under review for the journal Climate of the Past (CP).
Environmental and climatic changes in Central Chilean Patagonia since the Late Glacial (Mallín El Embudo, 44° S)
M. E. de Porras1, A. Maldonado1,2, F. A. Quintana3, A. Martel-Cea1,4, O. Reyes5, and C. Méndez6
1Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Raúl Bitran s/n, La Serena, Chile
2Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
3CENAC, Parque Nacional Nahuel Huapi, Fagnano 244, Bariloche, Río Negro, Argentina
4Departamento de Biología, Universidad de La Serena, Raúl Bitrán s/n, La Serena, Chile
5Centro de Estudios del Hombre Austral, Instituto de la Patagonia, Universidad de Magallanes, Avenida Bulnes 01855, Casilla 113-D, Punta Arenas, Chile
6Departamento de Antropología, Facultad de Ciencias Sociales, Universidad de Chile, Ignacio Carrera Pinto 1045, Ñuñoa, Santiago, Chile

Abstract. Multi-millennial environmental and climatic changes in Central Chilean Patagonia (44–49° S) during the Last Glacial–Interglacial cycle have been of particular interest as changes in the position and strength of the Southern Westerlies are the major forcing factor conditioning the environmental dynamics. Recent attempts to reconstruct regional environmental and climatic signals from Central Chilean Patagonia reveal some discrepancies and unclear issues among the records. This paper presents the 13 ka pollen and charcoal records from Mallín El Embudo (44°40' S; 71°42' W) located in the deciduous Nothofagus forest in the middle Río Cisnes valley. The paper aims to (1) establish the timing and magnitude of local vegetation changes and fire activity since the Late Glacial and (2) integrate these results at the regional scale in order to discuss the discrepancies and depict the Central Chilean Patagonia environmental and climatic dynamics since Late Glacial. Open landscapes dominated by grasses associated with scattered Nothofagus forest patches dominated middle Río Cisnes valley between 13–11.2 ka suggesting low effective moisture but also reflecting that landscape configuration after glacial retreat was still ongoing. At 11.2 ka, a sudden development of an open and quite dynamic Nothofagus forest probably associated to the synchronous high fire activity occurred suggesting a rise in effective moisture. Since 9.5 ka, the record reflects the presence of a closed Nothofagus forest related to higher/similar effective moisture conditions than before but under an unmarked precipitation seasonality. The forest experienced a slight canopy opening since 5.7 ka, probably due to slightly drier conditions than before followed by a sudden change around 4.2 ka associated with fire and volcanic disturbances. The recovery of an open Nothofagus forest related to slight wetter conditions (similar to present) occurred around 2 ka and persisted under highly variable climatic conditions up to 0.1 ka when massive forest burning and logging due to European settlements occurred. Central Chilean Patagonian climatic and environmental changes at millennial-centennial time scales since Late Glacial were driven by changes in the Southern Westerlies latitudinal shift and/or intensity but during the Late Holocene fire, volcanism and humans arise as major forcings contributing to environmental dynamics.

Citation: de Porras, M. E., Maldonado, A., Quintana, F. A., Martel-Cea, A., Reyes, O., and Méndez, C.: Environmental and climatic changes in Central Chilean Patagonia since the Late Glacial (Mallín El Embudo, 44° S), Clim. Past Discuss., 9, 5747-5784, doi:10.5194/cpd-9-5747-2013, 2013.
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