Universität zu Köln

Eugenia de Porras, Maria, Maldonado, Antonio, Abarzua, Ana M., Cardenas, Macarena L., Francois, Jean Pierre, Martel-Cea, Alejandra, Stern, Charles R., Mendez, Cesar ORCID: 0000-0003-2735-7950 and Reyes, Omar ORCID: 0000-0002-9003-9528 (2012). Postglacial vegetation, fire and climate dynamics at Central Chilean Patagonia (Lake Shaman, 44 degrees S). Quat. Sci. Rev., 50. S. 71 - 86. OXFORD: PERGAMON-ELSEVIER SCIENCE LTD. ISSN 0277-3791

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Abstract

A 19 cal ka BP pollen and charcoal record from Lake Shaman (44 S; 71 degrees W, Chile) was analyzed to establish vegetation, fire and climate dynamics of the forest-steppe ecotone in Central Chilean Patagonia. Lake Shaman record indicates that the upper Rio Cisnes valley was free of ice at around 19 cal ka BP. From this date and until 14.8 cal ka BP, a grass steppe with high proportions of shrubs associated to colder and drier conditions than present developed in this area. A continuous increase of Nothofagus accompanied by a decline in the steppe shrubs and sudden dominance of paludal over aquatic plants from 11 cal ka BP was associated to effective moisture increase but still under modern values. The replacement of the cold-dry grass-shrub steppe by a similar-than-present forest-steppe ecotone suggests an increase in temperature indicating the onset of the Holocene. At the same time, moderate fire activity suggested by the charcoal record could be related to major fuel availability as consequence of Nothofagus forest expansion. Between 8 and 3 cal ka BP, the record indicates the easternmost position of the forest-steppe ecotone suggesting the highest effective moisture with the establishment of seasonality between 5 and 3 cal ka BP. From 3 cal ka BP, the record indicates a retraction of the forest-steppe ecotone accompanied by a high pollen record variability and an increased fire activity. These late changes suggest decreased effective moisture associated with a high climatic variability. At regional and extra-regional scale, climatic changes at Lake Shaman's record are mostly associated to changes (latitudinal shifts and/or strengthening/weakening) of past Southern Westerlies that were previously recorded along Patagonia from the Lateglacial to the mid-Holocene. During the Late Holocene, a regional pattern characterized by high record variability emerges throughout Central Chilean Patagonia. This variability would be related to (1) low magnitude Southern Westerlies changes probably associated to ENSO and/or SAM or (2) the complex relationships between vegetation. fire and human occupations during the last 3 cal ka. (C) 2012 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Eugenia de Porras, Maria UNSPECIFIED UNSPECIFIED UNSPECIFIED Maldonado, Antonio UNSPECIFIED UNSPECIFIED UNSPECIFIED Abarzua, Ana M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Cardenas, Macarena L. UNSPECIFIED UNSPECIFIED UNSPECIFIED Francois, Jean Pierre UNSPECIFIED UNSPECIFIED UNSPECIFIED Martel-Cea, Alejandra UNSPECIFIED UNSPECIFIED UNSPECIFIED Stern, Charles R. UNSPECIFIED UNSPECIFIED UNSPECIFIED Mendez, Cesar UNSPECIFIED orcid.org/0000-0003-2735-7950 UNSPECIFIED Reyes, Omar UNSPECIFIED orcid.org/0000-0002-9003-9528 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-483082
DOI:	10.1016/j.quascirev.2012.06.015
Journal or Publication Title:	Quat. Sci. Rev.
Volume:	50
Page Range:	S. 71 - 86
Date:	2012
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Place of Publication:	OXFORD
ISSN:	0277-3791
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language LAST GLACIAL MAXIMUM; HOLOCENE TRANSITION; CHONOS ARCHIPELAGO; SOUTHERN PATAGONIA; TAITAO PENINSULA; SW PATAGONIA; RAIN-FOREST; REGIMES; HISTORY; REGION Multiple languages Geography, Physical; Geosciences, Multidisciplinary Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/48308