Toggle Main Menu Toggle Search

Open Access padlockePrints

Physicochemical differences between wildfire pyrogenic carbon and slow-pyrolysis biochar suggest variations in elemental transport potential

Lookup NU author(s): Dr Shannon FlynnORCiD

Downloads


Licence

This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).


Abstract

© 2025 The Royal Society of Chemistry. Wildfires play a crucial role in the carbon cycle. Their contribution to the global carbon cycle is expected to increase with climate change as fire activity, particularly in boreal forests, escalates. As 8-28% of annually produced pyrogenic carbon is transported through riverine systems, its impact on fluvial environmental conditions will likely increase in coming years. However, the impact of pyrogenic carbon on metal and nutrient transport remains poorly understood. Here, we compare the chemical composition of wildfire-derived pyrogenic carbon (F-PyC) with slow-pyrolysis biochar-derived pyrogenic carbon (B-PyC), both originating from the same mountainous boreal forest biomass, to determine if F-PyC shares physicochemical properties with artificial B-PyC. The results reveal notable differences in the physicochemical properties and bulk composition of F-PyC compared to B-PyC, even when both are produced under similarly high temperatures, due to the rapid heating and cooling during wildfires. These differences in pyrolysis conditions result in F-PyC having a smaller ash fraction (<2.7% vs. >5.0%), a more acidic pH (<7.0 vs. >7.8), and a less thermally mature mineral composition and surface functionality. Together these differences in properties result in markedly different leaching behaviors and suggest that F-PyC and slow pyrolysis B-PyC play different roles in elemental transport. Consequently, this work supports earlier claims that B-PyC is not a suitable proxy for the F-PyC, particularly with respect to elemental transport in fluvial environments. Our work highlights the necessity for research specifically focusing on F-PyC to accurately quantify the contribution of wildfires to global elemental cycling, presently and in the geologic past.


Publication metadata

Author(s): Snihur KN, Tang L, Rozanitis KJ, Gutierrez-Rueda D, Lazowski CN, Kononovs D, Swaren LR, Gingras MK, Kenney JPL, Flynn SL, Konhauser KO, Alessi DS

Publication type: Article

Publication status: Published

Journal: Environmental Science: Processes and Impacts

Year: 2025

Pages: Epub ahead of print

Online publication date: 23/04/2025

Acceptance date: 22/04/2025

Date deposited: 13/05/2025

ISSN (print): 2050-7887

ISSN (electronic): 2050-7895

Publisher: Royal Society of Chemistry

URL: https://doi.org/10.1039/d4em00558a

DOI: 10.1039/d4em00558a

Data Access Statement: The data supporting this article have been included as part of the Electronic supplementary information: https://www.rsc.org/suppdata/d4/em/d4em00558a/d4em00558a1.pdf


Altmetrics

Altmetrics provided by Altmetric


Funding

Funder referenceFunder name
Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grants
NSERC CGS-D Scholarship

Share