Molecular changes of aquatic humic substances formed from four aquatic macrophytes decomposed under different oxygen conditions

Author(s)

de Almeida Assuncao, Argos Willian ^{[1, 2]} ; de Souza, Brayan Petrick ^[1] ; Lopes da Silva, Wilson Tadeu ^[3] ; Cunha-Santino, Marcela Bianchessi ^{[1, 4]} ; Bianchini, Jr., Irineu ^{[1, 4]}

Affiliation

^[1] Univ Fed Sao Carlos, PPGERN, Rodovia Washington Luis, Km 235 SP-310, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Biol Dept, Ribeirao Preto, SP - Brazil

^[3] Empresa Brasileira Pesquisa Agr, Embrapa Instrumentacao CNPDIA, Sao Carlos, SP - Brazil

^[4] Univ Fed Sao Carlos, Dept Hidrobiol, Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: CHEMISTRY AND ECOLOGY; v. 33, n. 10, p. 918-931, 2017.
• Web of Science Citations: 1

Abstract

Aquatic macrophytes' decomposition is a source of recalcitrant carbon in the long term contributing to humic substances (HS) formation. Understanding the influence of plant detritus quality and oxygen availability over molecular changes of these compounds provides ecological information related to their cycling. This study described the molecular variation of dissolved HS from Eichhornia azurea, Egeria najas, Oxycaryum cubense and Salvinia molesta decomposition under aerobic and anaerobic conditions. The aquatic HS formed from the four aquatic macrophytes showed similar features (e.g. molecular weight and aromaticity). This fact indicates little influence of the detritus quality or availability of oxygen on the fulvic acids (FA) and humic acid characteristics. Under aerobic condition a decrease in the polysaccharides content in FA occurred. HS from E. najas were related to less-recalcitrant features, while HS from S. molesta were related to recalcitrant. (AU)

• FAPESP's process: 11/10178-6 - Kinetics and molecular variations of humic compounds formed from the decomposition of aquatic macrophytes.
• Grantee: Argos Willian de Almeida Assunção
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 11/16990-4 - Kinetics and molecular variations of humic substances formed from the decomposition of aquatic macrophytes
• Grantee: Irineu Bianchini Júnior
• Support Opportunities: Regular Research Grants