No Cover Image

Journal article 36 views 8 downloads

Manganese Oxidation during Vegetation Burning

Shyrill Mae F. Mariano, Lingqun Zeng, Rixiang Huang Orcid Logo, Carmen Sanchez-Garcia, Cristina Santin Nuno, Jonay Neris Tome, Peng Yang Orcid Logo, Lu Ma, Andrew Kiss

Environmental Science & Technology

Swansea University Authors: Carmen Sanchez-Garcia, Cristina Santin Nuno, Jonay Neris Tome

  • 72046.VOR.pdf

    PDF | Version of Record

    © 2026 The Authors. This publication is licensed under CC-BY 4.0 .

    Download (5.82MB)

Abstract

Redox recycling of manganese (Mn) plays a key role in organic matter decomposition and nutrient cycling in terrestrial vegetated ecosystems, and it is expected to be changed by fires. This study revealed how Mn is oxidized during vegetation burning, by characterizing the chemical speciation of Mn in...

Full description

Published in: Environmental Science & Technology
ISSN: 0013-936X 1520-5851
Published: American Chemical Society (ACS) 2026
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa72046
Abstract: Redox recycling of manganese (Mn) plays a key role in organic matter decomposition and nutrient cycling in terrestrial vegetated ecosystems, and it is expected to be changed by fires. This study revealed how Mn is oxidized during vegetation burning, by characterizing the chemical speciation of Mn in fire ash from wildland fires and laboratory burning and evaluating the factors governing its average oxidation state (AOS) and speciation. Manganese in wildland fire ash from different ecosystems showed variable AOS that ranges from 2.5 to 3.3. Laboratory burning experiments showed that Mn oxidation was primarily controlled by fire thermal intensity (temperature × duration) and burning completeness. As heating time increased from 5 min to 5 h at 550 and 700 °C, Mn AOS in the lab-burned vegetation ash increased from 2.7 to 4.0 and the oxidation rate was faster at higher temperature. Diverse Mn species can present in wildland fire ash and differ structurally from biogenic Mn oxides. The oxidized Mn species enable fire ash to mediate oxidative degradation of catechol, demonstrating its potential in mediating organic matter decomposition. This study revealed a new paradigm of Mn redox recycling, as compared to the microbe-mediated Mn redox cycling in the absence of fires.
Keywords: wildland fires, ash, manganese cycling, speciation, X-ray absorption spectroscopy
College: Faculty of Science and Engineering
Funders: This work was supported by SUNY System Administration under SUNY Research Seed Grant Award#241038 and National Science Foundation (#2120547). We appreciate the support from beamline scientists Ryan Davis at SSRL Beamline 11-2 and Bruce Ravel at NSLS-II Beamline 6-BM. Portions of this research were conducted at the Stanford Synchrotron Radiation Lightsource (SSRL) and the National Synchrotron Light Source II. The authors are grateful to Neil Gifford, Amanda Dillon and Tyler Briggs at the Albany Pine Bush Preserve for assistance in collecting the prescribed fire samples. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. This research used 5-ID, 6-BM, and 7-BM of the National Synchrotron Light Source II, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Brookhaven National Laboratory under contract no. DE-SC0012704. C. Sánchez-García, C. Santín, and J. Neris acknowledge funding by the Natural Environment Research Council grant (NE/R011125/1). During manuscript preparation, C. Sánchez-García was supported by the European Union’s Horizon 2020 research and innovation program under grant agreement #101003890.