Deciphering the Intricate Control of Minerals on Deep Soil Carbon Stability and Persistence in Alaskan Permafrost

verfasst von: Yi Xuan Guo, Guang Hui Yu, Shuijin Hu, Chao Liang, Andreas Kappler, Mark Torre Jorgenson, Laodong Guo, Georg Guggenberger
Abstract: Understanding the fate of organic carbon in thawed permafrost is crucial for predicting climate feedback. While minerals and microbial necromass are known to play crucial roles in the long-term stability of organic carbon in subsoils, their exact influence on carbon persistence in Arctic permafrost remains uncertain. Our study, combining radiocarbon dating and biomarker analyses, showed that soil organic carbon in Alaskan permafrost had millennial-scale radiocarbon ages and contained only 10%–15% microbial necromass carbon, significantly lower than the global average of ~30%–60%. This ancient carbon exhibited a weak correlation with reactive minerals but a stronger correlation with mineral weathering (reactive iron to total iron ratio). Peroxidase activity displayed a high correlation coefficient (p < 10⁻⁶) with Δ¹⁴C and δ¹³C, indicating its strong predictive power for carbon persistence. Further, a positive correlation between peroxidase activity and polysaccharides indicates that increased peroxidase activity may promote the protection of plant residues, potentially by fostering the formation of mineral-organic associations. This protective role of mineral surfaces on biopolymers was further supported by examining 1451 synchrotron radiation infrared spectra from soil aggregates, which revealed a strong correlation between mineral OH groups and organic functional groups at the submicron scale. An incubation experiment revealed that increased moisture contents, particularly within the 0%–40% range, significantly elevated peroxidase activity, suggesting that ancient carbon in permafrost soils is vulnerable to moisture-induced destabilization. Collectively, this study offers mechanistic insights into the persistence of carbon in thawed permafrost soils, essential for refining permafrost carbon-climate feedbacks.
Organisationseinheit(en): Institut für Bodenkunde
Externe Organisation(en): Tianjin University
North Carolina State University
CAS - Shenyang Institute of Applied Ecology
Eberhard Karls Universität Tübingen
Alaska Ecoscience
University of Wisconsin Milwaukee
Typ: Artikel
Journal: Global change biology
Band: 30
ISSN: 1354-1013
Publikationsdatum: 25.10.2024
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Globaler Wandel, Umweltchemie, Ökologie, Allgemeine Umweltwissenschaft
Ziele für nachhaltige Entwicklung: SDG 13 – Klimaschutzmaßnahmen
Elektronische Version(en): https://doi.org/10.1111/gcb.17552 (Zugang: Geschlossen)

BibTeX

@article{f7578fa05d34435691c924b812fd0a4c,
title = "Deciphering the Intricate Control of Minerals on Deep Soil Carbon Stability and Persistence in Alaskan Permafrost",
abstract = "Understanding the fate of organic carbon in thawed permafrost is crucial for predicting climate feedback. While minerals and microbial necromass are known to play crucial roles in the long-term stability of organic carbon in subsoils, their exact influence on carbon persistence in Arctic permafrost remains uncertain. Our study, combining radiocarbon dating and biomarker analyses, showed that soil organic carbon in Alaskan permafrost had millennial-scale radiocarbon ages and contained only 10%–15% microbial necromass carbon, significantly lower than the global average of ~30%–60%. This ancient carbon exhibited a weak correlation with reactive minerals but a stronger correlation with mineral weathering (reactive iron to total iron ratio). Peroxidase activity displayed a high correlation coefficient (p < 10−6) with Δ14C and δ13C, indicating its strong predictive power for carbon persistence. Further, a positive correlation between peroxidase activity and polysaccharides indicates that increased peroxidase activity may promote the protection of plant residues, potentially by fostering the formation of mineral-organic associations. This protective role of mineral surfaces on biopolymers was further supported by examining 1451 synchrotron radiation infrared spectra from soil aggregates, which revealed a strong correlation between mineral OH groups and organic functional groups at the submicron scale. An incubation experiment revealed that increased moisture contents, particularly within the 0%–40% range, significantly elevated peroxidase activity, suggesting that ancient carbon in permafrost soils is vulnerable to moisture-induced destabilization. Collectively, this study offers mechanistic insights into the persistence of carbon in thawed permafrost soils, essential for refining permafrost carbon-climate feedbacks.",
keywords = "microbial necromass, microbial residues, mineral binding sites, nanozyme, permafrost, peroxidase, reactive minerals, soil carbon accrual, synchrotron radiation, μ-FTIR",
author = "Guo, {Yi Xuan} and Yu, {Guang Hui} and Shuijin Hu and Chao Liang and Andreas Kappler and Mark Torre Jorgenson and Laodong Guo and Georg Guggenberger",
note = "Publisher Copyright: {\textcopyright} 2024 John Wiley & Sons Ltd.",
year = "2024",
month = oct,
day = "25",
doi = "10.1111/gcb.17552",
language = "English",
volume = "30",
journal = "Global change biology",
issn = "1354-1013",
publisher = "Wiley-Blackwell Publishing Ltd",
number = "10",
}