Fire, vegetation, and Holocene climate in a southeastern Tibetan lake: A multi-biomarker reconstruction from Paru Co

Alice Callegaro, Dario Battistel, Natalie M. Kehrwald, Felipe Matsubara Pereira, Torben Kirchgeorg, Maria Del Carmen Villoslada Hidalgo, Broxton W. Bird, Carlo Barbante

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

The fire history of the Tibetan Plateau over centennial to millennial timescales is not well known. Recent ice core studies reconstruct fire history over the past few decades but do not extend through the Holocene. Lacustrine sedimentary cores, however, can provide continuous records of local environmental change on millennial scales during the Holocene through the accumulation and preservation of specific organic molecular biomarkers. To reconstruct Holocene fire events and vegetation changes occurring on the southeastern Tibetan Plateau and the surrounding areas, we used a multi-proxy approach, investigating multiple biomarkers preserved in core sediment samples retrieved from Paru Co, a small lake located in the Nyainqentanglha Mountains (29°47045.600N, 92°21007.200 E; 4845ma.s.l.). Biomarkers include n-alkanes as indicators of vegetation, polycyclic aromatic hydrocarbons (PAHs) as combustion proxies, fecal sterols and stanols (FeSts) as indicators of the presence of humans or grazing animals, and finally monosaccharide anhydrides (MAs) as specific markers of vegetation burning processes. Insolation changes and the associated influence on the Indian summer monsoon (ISM) affect the vegetation distribution and fire types recorded in Paru Co throughout the Holocene. The early Holocene (10.7- 7.5 cal kyr BP) n-alkane ratios demonstrate oscillations between grass and conifer communities, resulting in respective smouldering fires represented by levoglucosan peaks, and high-temperature fires represented by high-molecular-weight PAHs. Forest cover increases with a strengthened ISM, where coincident high levoglucosan to mannosan (L = M) ratios are consistent with conifer burning. The decrease in the ISM at 4.2 cal kyr BP corresponds with the expansion of regional civilizations, although the lack of human FeSts above the method detection limits excludes local anthropogenic influence on fire and vegetation changes. The late Holocene is characterized by a relatively shallow lake surrounded by grassland, where all biomarkers other than PAHs display only minor variations. The sum of PAHs steadily increases throughout the late Holocene, suggesting a net increase in local to regional combustion that is separate from vegetation and climate change.

Original languageEnglish (US)
Pages (from-to)1543-1563
Number of pages21
JournalClimate of the Past
Volume14
Issue number10
DOIs
StatePublished - Oct 23 2018

Bibliographical note

Funding Information:
Acknowledgements. This work was funded as part of the Early Human Impact project, “Ideas” Specific Programme – European Research Council – Advanced Grant 2010 – grant agreement no. 267696, and was part of a PhD programme in Environmental Sciences at Ca’ Foscari University. This research was supported in part by the United States National Science Foundation (grant nos. 1405072 and 1023547) and the National Natural Science Foundation of China (grant no. 41150110153). The work of the data contributors and the Neotoma community is gratefully acknowledged. We are thankful to all colleagues who helped in the lab and all the research teams. We thank Aaron Diefendorf, Laura Strickland, the three anonymous referees, and Jaime L. Toney for their helpful suggestions for improving the work.

Publisher Copyright:
© 2018 Author(s).

Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.

Continental Scientific Drilling Facility tags

  • TIBET

Fingerprint

Dive into the research topics of 'Fire, vegetation, and Holocene climate in a southeastern Tibetan lake: A multi-biomarker reconstruction from Paru Co'. Together they form a unique fingerprint.

Cite this