Paleovegetation seesaw in Brazil since the Late Pleistocene: Amultiproxy study of two biomes

Author(s):Show less -

Azevedo, Vitor ^{[1, 2]} ; Strikis, Nicolas M. ^[2] ; Novello, Valdir F. ^[1] ; Roland, Camila L. ^[2] ; Cruz, Francisco W. ^[1] ; Santos, V, Roberto ; Vuille, Mathias ^[3] ; Utida, Giselle ^[1] ; De Andrade, Fabio Ramos Dias ^[1] ; Cheng, Hai ^{[4, 5]} ; Edwards, R. Lawrence ^[5]

Affiliation

^[1] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil

^[2] Univ Fed Fluminense, Dept Geoquim, BR-24020141 Niteroi, RJ - Brazil

^[3] SUNY Albany, Dept Atmospher & Environm Sci, Albany, NY 12222 - USA

^[4] Xi An Jiao Tong Univ, Inst Global Environm Change, Xian 710049, Shaanxi - Peoples R China

^[5] Univ Minnesota, Dept Earth Sci, Minneapolis, MN 55455 - USA

• Document type: Journal article
• Source: Earth and Planetary Science Letters; v. 563, JUN 1 2021.
• Web of Science Citations: 0

Abstract

Paleovegetation studies in Brazil have been mostly based on pollen analysis and geochemical proxies in lacustrine and soil records. These records, however, are sparsely located in the continent and, in most of the cases, centered over the Holocene, giving a minor picture of past vegetation since the Last Glacial Maximum. Stalagmites have been long used as recorders of paleoprecipitation and monsoon activity over time in tropical and subtropical South America by using delta O-18 analyses, but recently they also showed the potential to record past vegetation and soil changes through the combined use of delta C-13 and Sr-87/Sr-86. We utilize this new approach to determine the periods of paleovegetation transition and soil development in the Cerrado (Brazilian savanna) biome from central Brazil. Our results show a coherent period of transition from sparser vegetation and shallower soil above the cave to denser vegetation and thicker soil since the last deglaciation circa 15 ka BP. The timing of this transition is different from the multiproxy evidence found in the Caatinga (dry forest) biome, in northeastern Brazil, circa 4.2 ka BP, resulting in a period of paleovegetation seesaw pattern between central and northeastern regions of Brazil. Additionally, atmospheric pCO(2) and temperature variations may have played a major role on the paleovegetation transition in the Cerrado region whereas precipitation linked to the Intertropical Convergence Zone was the major modulator of paleovegetation in the Caatinga. (C) 2021 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 16/15807-5 - Paleoclimate and paleoenvironmental reconstructions over the last glacial period in the mid-west Brazil
• Grantee: Valdir Felipe Novello
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/50085-3 - PIRE: climate research education in the Americas using tree-ring speleothem examples (PIRE-CREATE)
• Grantee: Francisco William da Cruz Junior
• Support Opportunities: Research Projects - Thematic Grants