Late Quaternary vegetation and climate dynamics in central-eastern Brazil: insights from a ~35k cal a bp peat record in the Cerrado biome |
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| Authors: | Ingrid Horák-Terra Antonio Martínez Cortizas Cynthia Fernandes Pinto Da Luz Alexandre Christófaro Silva Tim Mighall Plínio Barbosa De Camargo Carlos Victor Mendonça-Filho Paulo Eduardo De Oliveira Francisco Willian Cruz Pablo Vidal-Torrado |
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| Affiliation: | 1. Instituto de Ciências Agrárias, Universidade Federal dos Vales do Jequitinhonha e Mucuri – ICA/UFVJM, BR 251 Av. Universitária, 1000, Universitários, 38610000 Unaí, MG, Brazil;2. Eco-Past (GI-1553), Faculty of Biology, Universidade de Santiago de Compostela - USC, Santiago de Compostela, 15782, Spain;3. Núcleo de Pesquisa em Palinologia, Instituto de Botânica, Secretária de Infraestrutura e Meio Ambiente do Estado de São Paulo –IBt/SP, São Paulo, SP, 04301902 Brazil;4. Departamento de Engenharia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Diamantina, MG, 39100000 Brazil;5. School of Geosciences, University of Aberdeen, Aberdeen, G22 St Mary's, UK;6. Laboratório de Ecologia Isotópica, Centro de Energia Nuclear na Agricultura - CENA/USP, Piracicaba, SP, 13416-903 Brazil;7. Departamento de Ciências Biológicas, Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Diamantina, MG, 39100000 Brazil;8. Departamento de Geologia Sedimentar e Ambiental, Instituto de Geociências – IGc/USP, São Paulo, SP, 05508-080 Brazil;9. Departamento de Ciência do Solo, Escola Superior de Agricultura ‘Luiz de Queiroz’ – ESALQ/USP, Piracicaba, SP, 13418900 Brazil |
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| Abstract: | The late Quaternary evolution of central-eastern Brazil has been under-researched. Questions remain as to the origin of the Cerrado, a highly endangered biome, and other types of vegetation, such as the Capões – small vegetation islands of semi-deciduous and mountain forests. We investigated the factors that influenced the expansion and contraction of the Cerrado and Capões during the late Quaternary (last ~35 ka), using a multi-proxy approach: stable isotopes (δ13C, δ15N), geochemistry, pollen and multivariate statistics derived from a peat core (Pinheiro mire, Serra do Espinhaço Meridional). Five major shifts in precipitation, temperature, vegetation and landscape stability occurred at different timescales. Our study revealed that changes in the South Atlantic Convergence Zone (SACZ) seem to have been coeval with these shifts: from the Late Glacial Maximum to mid-Holocene the SACZ remained near (~29.6 to ~16.5k cal a bp ) and over (~16.5 to ~6.1 k cal a bp ) the study area, providing humidity to the region. This challenges previous research which suggested that climate was drier for this time period. At present, the Capões are likely to be a remnant of a more humid climate; meanwhile, the Cerrado biome seems to have stablished in the late Holocene, after ~3.1 k cal a bp . |
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| Keywords: | geochemistry paleoclimatology peatlands pollen stable isotopes |
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