Journal cover Journal topic
Climate of the Past An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/cpd-11-2121-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
03 Jun 2015
Review status
This discussion paper is a preprint. It has been under review for the journal Climate of the Past (CP). The revised manuscript was not accepted.
Eastern Andean environmental and climate synthesis for the last 2000 years BP from terrestrial pollen and charcoal records of Patagonia
G. D. Sottile1, M. E. Echeverria1, M. V. Mancini1, M. M. Bianchi2,3, M. A. Marcos1, and F. P. Bamonte1 1Laboratorio de Paleoecología y Palinología, Departamento de Biología, Facultad de Ciencias Exactas y Naturales, UNMDP-IIMyC-CONICET, Funes 3250, 7600, Mar del Plata, Argentina
2CONICET, Instituto Nacional de Antropología y Pensamiento Latinoamericano (INAPL), Buenos Aires, Argentina
3Museo Argentino de Ciencias Naturales (MACN), Buenos Aires, Argentina
Abstract. The Southern Hemisphere Westerly Winds (SWW) constitute an important zonal circulation system that dominates the dynamics of Southern Hemisphere mid-latitude climate. Little is known about climatic changes in the Southern South America in comparison to the Northern Hemisphere due to the low density of proxy records, and adequate chronology and sampling resolution to address environmental changes of the last 2000 years. Since 2009, new pollen and charcoal records from bog and lakes in northern and southern Patagonia at the east side of the Andes have been published with an adequate calibration of pollen assemblages related to modern vegetation and ecological behaviour. In this work we improve the chronological control of some eastern Andean previously published sequences and integrate pollen and charcoal dataset available east of the Andes to interpret possible environmental and SWW variability at centennial time scales. Through the analysis of modern and past hydric balance dynamics we compare these scenarios with other western Andean SWW sensitive proxy records for the last 2000 years. Due to the distinct precipitation regimes that exist between Northern (40–45° S) and Southern Patagonia (48–52° S) pollen sites locations, shifts on latitudinal and strength of the SWW results in large changes on hydric availability on forest and steppe communities. Therefore, we can interpret fossil pollen dataset as changes on paleohydric balance at every single site by the construction of paleohydric indices and comparison to charcoal records during the last 2000 cal yrs BP. Our composite pollen-based Northern and Southern Patagonia indices can be interpreted as changes in latitudinal variation and intensity of the SWW respectively. Dataset integration suggest poleward SWW between 2000 and 750 cal yrs BP and northward-weaker SWW during the Little Ice Age (750–200 cal yrs BP). These SWW variations are synchronous to Patagonian fire activity major shifts. We found an in phase fire regime (in terms of timing of biomass burning) between northern Patagonia Monte shrubland and Southern Patagonia steppe environments. Conversely, there is an antiphase fire regime between Northern and Southern Patagonia forest and forest-steppe ecotone environments. SWW variability may be associated to ENSO variability especially during the last millennia. For the last 200 cal yrs BP we can concluded that the SWW belt were more intense and poleward than the previous interval. Our composite pollen-based SWW indices show the potential of pollen dataset integration to improve the understanding of paleohydric variability especially for the last 2000 millennial in Patagonia.

Citation: Sottile, G. D., Echeverria, M. E., Mancini, M. V., Bianchi, M. M., Marcos, M. A., and Bamonte, F. P.: Eastern Andean environmental and climate synthesis for the last 2000 years BP from terrestrial pollen and charcoal records of Patagonia, Clim. Past Discuss., https://doi.org/10.5194/cpd-11-2121-2015, 2015.
G. D. Sottile et al.
Interactive discussionStatus: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version      Supplement - Supplement
 
RC C1087: 'Review of Sottile et al (cp-2015-44)', Anonymous Referee #1, 16 Jul 2015 Printer-friendly Version Supplement 
 
RC C1431: 'paleoclimate', Vera Markgraf, 20 Aug 2015 Printer-friendly Version 
 
AC C1798: 'Authors response to reviewers', Gonzalo David Sottile, 26 Sep 2015 Printer-friendly Version Supplement 
G. D. Sottile et al.
G. D. Sottile et al.

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