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Pellegrinetti, Thierry A. ; Cotta, Simone R. ; Feitosa, Yara B. ; Melo, Paul L. A. ; Bieluczyk, Wanderlei ; Silva, Antonio M. M. ; Mendes, Lucas W. ; Sarmento, Hugo ; Camargo, Plinio B. ; Tsai, Siu M. ; Fiore, Marli F.

• Tipo de documento: Artigo Científico
• Fonte: Science of The Total Environment; v. 947, p. 13-pg., 2024-07-17.

Resumo

Although anthropogenic activities are the primary drivers of increased greenhouse gas (GHG) emissions, it is crucial to acknowledge that wetlands are a significant source of these gases. Brazil 's Pantanal, the largest tropical inland wetland, includes numerous lacustrine systems with freshwater and soda lakes. This study focuses on soda lakes to explore potential biogeochemical cycling and the contribution of biogenic GHG emissions from the water column, particularly methane. Both seasonal variations and the eutrophic status of each examined lake significantly influenced GHG emissions. Eutrophic turbid lakes (ET) showed remarkable methane emissions, likely due to cyanobacterial blooms. The decomposition of cyanobacterial cells, along with the influx of organic carbon through photosynthesis, accelerated the degradation of high organic matter content in the water column by the heterotrophic community. This process released byproducts that were subsequently metabolized in the sediment leading to methane production, more pronounced during periods of increased drought. In contrast, oligotrophic turbid lakes (OT) avoided methane emissions due to high sulfate levels in the water, though they did emit CO 2 and N 2 O. Clear vegetated oligotrophic turbid lakes (CVO) also emitted methane, possibly from organic matter input during plant detritus decomposition, albeit at lower levels than ET. Over the years, a concerning trend has emerged in the Nhecola ndia subregion of Brazil 's Pantanal, where the prevalence of lakes with cyanobacterial blooms is increasing. This indicates the potential for these areas to become significant GHG emitters in the future. The study highlights the critical role of microbial communities in regulating GHG emissions in soda lakes, emphasizing their broader implications for global GHG inventories. Thus, it advocates for sustained research efforts and conservation initiatives in this environmentally critical habitat. (AU)

• Processo FAPESP: 17/12644-0 - Comunidades microbianas e genes funcionais envolvidos na ciclagem de nutrientes em lagoas do Pantanal da Nhecolândia (MS)
• Beneficiário: Thierry Alexandre Pellegrinetti
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 16/14227-5 - Mudanças climáticas e impactos ambientais em áreas alagadas (wetlands) do Pantanal (Brasil): quantificação, fatores de controle e previsão em longo prazo
• Beneficiário: Adolpho José Melfi
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático
• Processo FAPESP: 18/24049-2 - Biogeografia de comunidades microbianas em lagoas salino-alcalinas do pantanal brasileiro
• Beneficiário: Simone Raposo Cotta
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado