Tree-ring δ18Ocellulose variations in two Nothofagus species record large-scaleclimatic signals in the South American sector of the Southern Ocean

Soto Rogel P, Aravena JC, Villalba R, Meier W, Grießinger J (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Palaeogeography, Palaeoclimatology, Palaeoecology Elsevier

Book Volume: 617

Article Number: 111474

DOI: 10.1016/j.palaeo.2023.111474

Abstract

In recent decades, southernmost South America (50–56° S) has experienced marked climate change (regional warming, decreased precipitation, reduced snow cover, and increased frequency of heat waves) related to variations in atmospheric circulation over varied timescales. In this paper, we develop oxygen isotopes from tree-ring cellulose (δ18OTRC) as a proxy for climate and atmospheric circulation in order to extend the regional meteorological record to deeper time intervals. Our work focuses on Nothofagus forests in two areas: (i) deciduous N. pumilio forest in the steppe transition zone near Punta Arenas and (ii) humid evergreen N. betuloides forest in the Navarino Island region. To investigate the potential for reconstructing palaeoclimate, δ18OTRC variations were correlated with local climate parameters as well as regional (Amundsen Sea Low, ASL) and hemispheric (Antarctic Oscillation, AAO) atmospheric circulation modes for the last 60 years. N. betuloides δ18OTRC variations show an overall positive trend, indicating isotopic enrichment over the study period, whereas no trend is recorded for the N. pumilio record. The strongest relationships with climate, together with the widest spatial representativeness, occur in the N. betuloides chronology during the growing season (spring to austral summer) and extend spatially from mid to high latitudes. In contrast, the sensitivity of the records is limited to summer months, and spatial correlations are much more limited. In addition, the N. betuloides record shows greater potential for reconstructing local climate features such as soil water (r = − 0.76), wind speed (r = 0.69), and precipitation (r = − 0.66), as well as regional (ASL, r = − 0.80) and hemispheric (AAO, r = 0.77) patterns of extratropical atmospheric circulation. Overall, we conclude that the N. betuloides record represents the most valuable tree-ring climate proxy for southernmost South America over past centuries.

Authors with CRIS profile

Pamela Soto Rogel Institut für Geographie Wolfgang Meier Institut für Geographie Jussi Grießinger Institut für Geographie

Involved external institutions

Cape Horn International Center for Global Change Studies and Biocultural Conservation (CHIC) CL Chile (CL) University of Magallanes / Universidad de Magallanes (UMAG) CL Chile (CL)

How to cite

APA:

Soto Rogel, P., Aravena, J.C., Villalba, R., Meier, W., & Grießinger, J. (2023). Tree-ring δ18Ocellulose variations in two Nothofagus species record large-scaleclimatic signals in the South American sector of the Southern Ocean. Palaeogeography, Palaeoclimatology, Palaeoecology, 617. https://doi.org/10.1016/j.palaeo.2023.111474

MLA:

Soto Rogel, Pamela, et al. "Tree-ring δ18Ocellulose variations in two Nothofagus species record large-scaleclimatic signals in the South American sector of the Southern Ocean." Palaeogeography, Palaeoclimatology, Palaeoecology 617 (2023).

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