Vegetational and climatic dynamics during the Holocene of the Peruaçu river valley, Minas Gerais, Brazil: palynological evidences

• Grant number: 19/25480-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2020
• End date: April 30, 2021
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Paulo Eduardo de Oliveira
• Grantee: João Paulo de Souza Bueno
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 17/50085-3 - PIRE: climate research education in the Americas using tree-ring speleothem examples (PIRE-CREATE), AP.TEM

Abstract

The present Scientific Initiation project, linked to the FAPESP-NSF PIRE Thematic Project2017 (Partnership for International Research and Education) Proc. 2017 / 50085-3, has as its main objective to analyze the palynological content, i.e. pollen grains and spores, preserved in the sediments of the Lagoa Azul, located in Cavernas do Peruaçu National Park. Among the objectives of this study is the testing of the following vegetation and climate hypotheses: H1. The Holocene pollen spectra of the Peruaçu Caves National Park are in agreement with the ´18O records in cave speleothems to be performed by researchers in the Pire Thematic Project and confirm moments of high humidity in areas of Brazil during the intensification of SAMS (an acronym for South American Monsoon System); H2. The Caatinga/Cerrado mosaic or ecotone remained floristically intact for the last thousands of years; H3. There was no change in floristics and vegetation cover during the climatic eventsLIA (Little Ice Age) and MCA (Medieval Climate Anomaly); H4. The five abrupt anomalous precipitation events, indicated by the position of tree trunks at levels above the current level of the Peruaçu River and preserved in caves in the region, are identified in palynological analysis and H5. Human presence, evidenced by the increase of microparticles of coal and indicated by the existence of several archaeological sites in the Peruaçu Valley Caverns National Park, did not significantly affect the floristic composition and structure of the local vegetation over the last thousands of years. (AU)