Changes in soil iron biogeochemistry in response to mangrove dieback

Autor(es)

Queiroz, Hermano Melo ; Ferreira, Tiago Osorio ; Asensio Fandino, Veronica ; Barbosa Ferraz Bragantini, Isadora Okuma ; Barcellos, Diego ; Nobrega, Gabriel Nuto ; Ferreira, Amanda Duim ; de Oliveira Gomes, Luiz Eduardo ; Bernardino, Angelo Fraga

• Tipo de documento: Artigo Científico
• Fonte: BIOGEOCHEMISTRY; v. 158, n. 3, p. 16-pg., 2022-02-11.

Resumo

Fe biogeochemistry is associated with important ecosystem services provided by mangrove forests, including carbon sequestration and the retention of potentially toxic elements. The biogeochemical processes controlling Fe fate in mangroves are naturally affected by the soil geochemical environment, which controls Fe dynamics. However, ongoing climate changes and the associated extreme weather events may drastically affect the biogeochemistry of this important micronutrient for both terrestrial and oceanic environments. Therefore, this study aimed to evaluate how massive mangrove mortality after an extreme weather event altered the Fe dynamics in mangrove soils. The results show a significant decrease in soil carbon stock in the dead mangrove forests (25 kg m(-2)), as compared with the undisturbed forests (37 kg m(-2)). In addition, we observed a substantial Fe loss (greater than 50% of soil Fe forms, i.e., 17,000 mg kg(-1)) in the dead mangrove soils, which was associated with pyrite (9000 mg kg(-1)) and low crystallinity Fe oxyhydroxides (2400 mg kg(-1)). These impacts led to a decrease in the pyritization in soils, which resulted in a loss of 170 tons of Fe from 500 ha of dead mangrove forests within one year. Thus, the pyritization process may critically compromise a mangrove forests' ability to immobilize pollutants (e.g., metals) and sequester carbon in the long term, thereby altering their ability to provide these ecosystem services. Overall, our results revealed that the Fe biogeochemical cycle of mangrove forests is very sensitive to future climate change scenarios and increased extreme weather events. (AU)

• Processo FAPESP: 19/14800-5 - Plantas estuarinas e seu controle na biogeoquímica de metais em solos impactados pelo `desastre de Mariana´
• Beneficiário: Amanda Duim Ferreira
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 19/02855-0 - Flutuações redox, dinâmica de ferro e metais em solos do estuário do Rio Doce após o "desastre de Mariana (MG)": uma abordagem experimental
• Beneficiário: Diego Barcellos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 18/04259-2 - Biogeoquímica de ferro e seu controle sobre a dinâmica de metais traço nos solos do estuário do Rio Doce após o "desastre de Mariana"
• Beneficiário: Hermano Melo Queiroz
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 19/19987-6 - Solos e plantas do estuário do Rio Doce e seu controle sobre a biogeoquímica de ferro e metais em resposta ao desastre de Mariana (MG)
• Beneficiário: Tiago Osório Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular