Late Quaternary vegetation and climate dynamics in central‐eastern Brazil: insights from a ~35k cal a <scp>bp</scp> peat record in the Cerrado biome
Ingrid Horák‐Terra, Antonio Martı́nez Cortizas, Cynthia Fernandes Pinto da Luz, Alexandre Christófaro Silva, Tim Mighall, Plínio Barbosa de Camargo, Carlos Victor Mendonça‐Filho, Paulo Eduardo de Oliveira, Francisco W. Cruz, Pablo Vidal‐Torrado
Abstract
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 (δ 13 C, δ 15 N), 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 .