Synchrotron-based X-ray microscopy for assessing elements distribution and speciation in mangrove tree-rings

Author(s)

Novais Alves, Elton Eduardo ; Ortega Rodriguez, Daigard Ricardo ; Rocha, Pablo de Azevedo ; Vergutz, Leonardus ; Santini Junior, Luiz ; Hesterberg, Dean ; Ruiz Pessenda, Luiz Carlos ; Tomazello-Filho, Mario ; da Costa, Liovando Marciano

• Document type: Journal article
• Source: RESULTS IN CHEMISTRY; v. 3, p. 10-pg., 2021-01-01.

Abstract

Micro-X-ray fluorescence (mu-XRF) spectroscopy has been used for dendrochemistry as a high spatial resolution, multi-elemental and non-destructive technique. Furthermore, micro-X-ray absorption near edge structure ( mu XANES) spectroscopy has a potential application in environmental studies by adding speciation information under in-situ conditions. Both, mu-XRF and mu-XANES, techniques were used to assess the inter-ring and intraring chemical content variations of Avicennia schaueria mangrove tree from Southeastern Brazil. Ca, Cl, K, P, and S were the major chemical elements distributed in almost all tree-rings. Ca was the most abundant element and showed a decreasing trend from heartwood to sapwood tree-rings. Calcium also showed a characteristic distribution pattern along the growth layer, acting as a chemical marker of growth layers. Ca chemical species were distinct in sapwood (calcium oxalate and carbonate-rich) and heartwood tree-rings (calcium sulfate-rich), showing different physiological Ca roles on tree performance. The synchrotron radiation-based techniques at micrometer scale provided information on the distribution and speciation of chemical elements within and between tree-rings. We also present a mu-XANES procedure for data collection and processing for dendrochemical studies. Altogether, we opened opportunities for further studies aiming to understand which environmental or physiological variables are responsible for tree-ring chemical speciation and distribution changes in tree species. (AU)

• FAPESP's process: 18/22914-8 - Global climate change in the Amazon tropical forest assessed by dendrocronological multi-proxy
• Grantee: Daigard Ricardo Ortega Rodriguez
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 18/08877-2 - CLIMATE AND ENVIRONMENTAL CHANGES IMPACTS ON BIOGEOCHEMISTRY OF BRAZILIAN MANGROVE ECOSYSTEM
• Grantee: Elton Eduardo Novais Alves
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 09/53951-7 - Set up of a Multi-User Laboratory specializing in the use of near-infrared spectroscopy and X-ray densitometry in agroforestry applications
• Grantee: Mario Tommasiello Filho
• Support Opportunities: Multi-user Equipment Program