Integrated reconstruction of Holocene millennial-scale environmental changes in Tierra del Fuego, southernmost South America

This study presents new paleoenvironmental data obtained from sedimentary cores from Lago Fagnano, an elongated lake located at 54°S in southernmost South America. Data from palynomorphs (pollen, spores and algae) and associated palynofacies as well as from diatom taxa retrieved from these cores com...

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Detalles Bibliográficos
Autores principales: Waldmann, N., Borromei, A.M., Recasens, C., Olivera, D., Martínez, M.A., Maidana, N.I., Ariztegui, D., Austin, J.A., Anselmetti, F.S., Moy, C.M.
Formato: JOUR
Materias:
Lacustrine sediments
Limnogeology
Multi-proxy analyses
Paleoenvironment and Paleoclimate reconstruction
Palynology
Southern Hemisphere Westerlies
colonization
environmental change
Holocene
lacustrine deposit
paleoclimate
paleoenvironment
paleolimnology
palynology
proxy climate record
reconstruction
sediment core
Southern Hemisphere
vegetation history
Tierra del Fuego [(ARC) South America]
algae
Bacillariophyta
Bacteria (microorganisms)
Nothofagus
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00310182_v399_n_p294_Waldmann
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:This study presents new paleoenvironmental data obtained from sedimentary cores from Lago Fagnano, an elongated lake located at 54°S in southernmost South America. Data from palynomorphs (pollen, spores and algae) and associated palynofacies as well as from diatom taxa retrieved from these cores compared with other regional proxies contribute to evaluate the similarities and differences in the climate patterns based on different proxies from southernmost Patagonia. The pollen analysis reveals that a grass steppe environment existed during the early Holocene (11,300-~. 8000. cal. a. BP) followed by a major vegetation change characterized by development of forest-steppe ecotone communities between ~. 8000 and ~. 6500. cal. a. BP, under more humid conditions. Between ~. 6500 and ~. 4000. cal. a. BP, expansion and colonization by Nothofagus forests reflect an increase in effective moisture levels, while openness in the forest communities characterizes the region after ~. 1100. cal. a. BP. The palynological organic matter combined with the algal content reflects hydrological changes occurring in the lake and its nutrient status, probably in close relation with past climate oscillations. All these past ecological changes are closely related to oscillations in precipitation and temperature as a response to the variations in the latitudinal position and/or strength of the Southern Westerlies wind belt during the Holocene. © 2014 Elsevier B.V.

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