Windsock behavior: climatic control on iron biogeochemistry in tropical mangroves

Author(s)

Ferreira, Tiago Osorio ^[1] ; Nobrega, Gabriel Nuto ^[2] ; Queiroz, Hermano Melo ^[1] ; de Souza Junior, Valdomiro S. ^[3] ; Barcellos, Diego ^{[1, 4]} ; Ferreira, Amanda Duim ^[1] ; Otero, Xose L. ^[5]

Affiliation

^[1] Univ Sao Paulo ESALQ USP, Luiz de Queiroz Coll Agr, Av Padua Dias 11, BR-13418900 Piracicaba, SP - Brazil

^[2] Fed Fluminense Univ, Dept Geochem, Grad Program Earth Sci Geochem, BR-24020140 Niteroi, RJ - Brazil

^[3] Univ Fed Rural Pernambuco, Dept Agron, Av Dom Manoel de Medeiros S-N, BR-52171900 Recife, PE - Brazil

^[4] Fed Univ Sao Paulo UNIFESP, Dept Environm Sci, Rua Sao Nicolau, BR-21009913 Diadema, SP - Brazil

^[5] Univ Santiago de Compostela, Fac Biol, CRETUS Inst, Dept Edaphol & Agr Chem, Campus Sur, Santiago De Compostela 15782 - Spain

• Document type: Journal article
• Source: BIOGEOCHEMISTRY; v. 156, n. 3 OCT 2021.
• Web of Science Citations: 0

Abstract

Iron is one of the most abundant elements on the planet and a micronutrient for most organisms. In many coastal regions worldwide, mangrove forests affect the dynamics and mobility of different elements to the oceans especially through their soils. The biogeochemistry of mangrove soils responds to numerous factors that vary within different spatial and time scales. In this sense, seasonality can be crucial in determining the role of these ecosystems towards the iron biogeochemical cycle. Thus, the main goal of the present study was to assess the effects of contrasting climatic conditions on iron biogeochemistry in different mangrove forests along the Brazilian coast. We studied the soils (n = 435) of 14 different mangrove forests distributed along two contrasting climate regions: the semi-arid Northeast and the humid Southeast coasts of Brazil. In the SE region, water surplus and lower temperatures in both seasons did not cause significant changes in iron concentrations (wet season: 216 mu mol g(-1); dry season: 230 mu mol g(-1)) where oxyhydroxides and pyrite immobilize iron in the mangrove soils. In contrast, in the semi-arid mangroves, a marked water deficit during the dry season caused both pyrite oxidation and iron reprecipitation as oxyhydroxides. Contrarily, in the rainy season, the establishment of a suboxic environment (Eh similar to + 100 mV) favored significant iron losses via iron reduction. We conclude that seasonality can affect the maintenance and cycling of iron in mangrove soils, which may function as important sources of this element for adjacent ecosystems. (AU)

• FAPESP's process: 18/04259-2 - Iron biogeochemistry and its control on dynamics of trace metals in the soils of Doce River estuary after the "Mariana disaster"
• Grantee: Hermano Melo Queiroz
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 19/14800-5 - Estuarine plants and their control in metals biogeochemistry in soils impacted by the `Mariana disaster´
• Grantee: Amanda Duim Ferreira
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 19/19987-6 - Soils and plants of the Rio Doce estuary controlling the biogeochemistry of iron and metals in response to the Mariana (MG) disaster
• Grantee: Tiago Osório Ferreira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/02855-0 - Redox fluctuations, iron and heavy metals dynamics in soils from Rio Doce estuary after the "Mariana (MG) disaster": an experimental approach
• Grantee: Diego Barcellos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral