Dados da Submissão

Título

HOLOCENE CLIMATIC IMPACTS ON MANGROVE DYNAMICS IN SOUTHERN BRAZIL: INSIGHTS FROM SANTO ANTÔNIO LAGOON

Texto do resumo

The mangrove ecosystem in the Santo Antônio Lagoon, located in Laguna (SC), Southern Brazil, represents the southernmost limit of mangrove occurrence in South America and serves as a study site for understanding past climatic changes. This study aims to explore the dynamics of this mangrove ecosystem in response to climatic variations during the mid- to late-Holocene. A sediment core, RP-01 (4.75 m depth), was collected and subjected to a comprehensive multi-proxy analysis, including geochemical assessments (Total C, Total N, C/N, C/S, δ13C, and δ15N) and radiocarbon dating. Our findings reveal a significant increase in terrestrial organic matter contributions, particularly from the late Holocene onwards. The intensified input from the Sambaqui and Tubarão Rivers has facilitated the development of the distributary mouth within the lagoon. Pollen data suggest that the mid-Holocene period was dominated by herbaceous plants, indicative of a less humid climate compared to present conditions. This climatic pattern is likely associated with the southward shifting of the Intertropical Convergence Zone (ITCZ) and the intensification of the South American Monsoon System (SAMS), resulting in higher precipitation rates. The establishment and expansion of the studied mangrove site primarily occurred in recent centuries, reflecting significant climatic shifts in the Laguna (SC) region towards a warmer and more humid environment compared to the mid-Holocene. These findings highlight the impact of climatic changes on the evolution of mangrove ecosystems and provide valuable insights into the environmental history of Southern Brazil.

Palavras Chave

Mangrove ecosystems; paleoenvironmental reconstruction; Southern Brazil