Resumo

ROSAS, Chloe et al. Vegetation and climate history over the past 3200 years on the southern coast of Quintana Roo, Mexico. Rev. mex. cienc. geol [online]. 2025, vol.42, n.1, pp.31-43.  Epub 03-Out-2025. ISSN 2007-2902.  https://doi.org/10.22201/igc.20072902e.2025.1.1854.

Changes in vegetation and environmental history for the last 3200 years at Laguna Cementerio, Xcalak, Quintana Roo were identified using fossil pollen and geochemical analyses of a 1.5 m depth sediment core. Changes in abundance and composition of Rhizophora mangle, Conocarpus erectus, Avicennia germinans, and Laguncularia racemosa allowed to infer changes in hydrological variability. At the beginning of the 3200 cal yr BP moist conditions were exhibited. Dominant vegetation was tropical forest, mainly composed of Moraceae, Fabaceae, Euphorbiaceae, Rubiaceae, and Bursera simaruba. During this period, mangroves were dominated by Avicennia germinans along with the presence of foraminifera. The first record of Z. mays around 850 B.C. (2800 cal yr BP) allowed the identification of agricultural activities close to the study area from the Middle Preclassic to the Late Classic. The dominant mangrove species was C. erectus, suggesting strong changes in the hydrological variability. Two drought periods were identified around 1700 and 850 cal yr BP, respectively, with the Ca/Σ (Ti, Fe, Al) curve. The drought at 1700 cal BP may be associated with changes in sea surface temperatures (SST) and sea surface salinity (SSS) that affect the strength of the Caribbean Low-Level Jet causing a decrease in the amount of rainfall for Mesoamerica. During this same period, the highest reduction of tropical forest was observed, changing the landscape to a more open vegetation that allowed the deposit of Pinus sp. The drought that occurred around 850 cal yr BP corresponds to the Terminal Classic Period. Further comparison with other climate proxy records from the region and Circum-Caribbean area suggests that the Terminal Classic Droughts were alternated with wet periods. Around 700 cal yr BP, moist conditions returned and allowed the recovery of the tropical forest. This study contributes to new evidence of changes experienced in Laguna Cementerio during the last 3200 cal yr BP, an area that has been poorly studied from a paleoenvironmental point of view.

Palavras-chave : vegetation; mangrove; paleoenvironment; fossil pollen; geochemistry; drought; Quintana Roo; Mexico.

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