Ramped oxidation and fine scale serial 14C analyses of saltmarsh soils

Alexander Houston; Mark Henry Garnett; William Edward Newns Austin

doi:10.1017/RDC.2026.10245

Ramped oxidation and fine scale serial ¹⁴C analyses of saltmarsh soils

Alexander Houston^*
, Mark Henry Garnett
, William Edward Newns Austin

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

Combined ramped oxidation and radiocarbon analysis (RO-¹⁴C) determines the age of carbon pools that have differing thermochemical stability (decomposability), providing powerful insights for studying the carbon cycle. We performed RO-¹⁴C of surface soils from a saltmarsh and dated the narrowest temperature intervals so far undertaken for any samples, finding that no modern (post-bomb) ¹⁴C contents were resolved. We compared these ramped oxidation measurements to the ¹⁴C content of respired CO₂ from the same soils, demonstrating that the most biologically available organic carbon was younger (more ¹⁴C-enriched) than any of the thermal fractions for surface soils. In our saltmarsh soils, ramped oxidation alone is therefore not able to isolate both the youngest and the most biologically available OC pools. However, we show that a combined approach of RO-¹⁴C and measurements of the ¹⁴C content of respired CO₂ (e.g., incubation experiments) may provide more powerful insights for unravelling carbon cycling.

Original language	English
Article number	68
Pages (from-to)	1101-1110
Number of pages	10
Journal	Radiocarbon
Volume	FirstView
Issue number	68
Early online date	21 Sept 2026
DOIs	https://doi.org/10.1017/RDC.2026.10245
Publication status	Published - 2026

Keywords

Carbon
Coastal
Radiocarbon
Sediments
Soils

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Houston_2026_Radiocarbon_Ramped-oxidation-14C-analyses-saltmarsh_CC
© The Author(s), 2026. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.
Final published version, 358 KBLicence: CC BY

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Carbon sequestration in BLUe (C-BLUES): Carbon sequestration in BLUe EcoSystems (C-BLUES)
Austin, W. (PI)
Innovate UK
1/01/24 → 31/12/27
Project: Standard

Cite this

@article{c18e9dbca65b4ddc9087929a9862cbfd,

title = "Ramped oxidation and fine scale serial 14C analyses of saltmarsh soils",

abstract = "Combined ramped oxidation and radiocarbon analysis (RO-14C) determines the age of carbon pools that have differing thermochemical stability (decomposability), providing powerful insights for studying the carbon cycle. We performed RO-14C of surface soils from a saltmarsh and dated the narrowest temperature intervals so far undertaken for any samples, finding that no modern (post-bomb) 14C contents were resolved. We compared these ramped oxidation measurements to the 14C content of respired CO2 from the same soils, demonstrating that the most biologically available organic carbon was younger (more 14C-enriched) than any of the thermal fractions for surface soils. In our saltmarsh soils, ramped oxidation alone is therefore not able to isolate both the youngest and the most biologically available OC pools. However, we show that a combined approach of RO-14C and measurements of the 14C content of respired CO2 (e.g., incubation experiments) may provide more powerful insights for unravelling carbon cycling.",

keywords = "Carbon, Coastal, Radiocarbon, Sediments, Soils",

author = "Alexander Houston and Garnett, \{Mark Henry\} and Austin, \{William Edward Newns\}",

note = "Funding: The authors thank the NERC SUPER DTP for funding the PhD through which this research was undertaken (NE/S007342/1). We acknowledge support from the National Environmental Isotope Facility in funding the 14C measurements for this study under grant NE/S011587/1 (allocation numbers 2594.1022, 2709.1023, 2863.1024). WENA and AH also acknowledge support provided by the HORIZON-CL5-2023-D1-02-02 grant C-BLUES, Innovation to advance the evidence base for reporting of Blue Carbon inventories and greenhouse gas fluxes in coastal wetlands.",

year = "2026",

doi = "10.1017/RDC.2026.10245",

language = "English",

volume = "FirstView",

pages = "1101--1110",

journal = "Radiocarbon",

issn = "0033-8222",

publisher = "Cambridge University Press",

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T1 - Ramped oxidation and fine scale serial 14C analyses of saltmarsh soils

AU - Houston, Alexander

AU - Garnett, Mark Henry

AU - Austin, William Edward Newns

N1 - Funding: The authors thank the NERC SUPER DTP for funding the PhD through which this research was undertaken (NE/S007342/1). We acknowledge support from the National Environmental Isotope Facility in funding the 14C measurements for this study under grant NE/S011587/1 (allocation numbers 2594.1022, 2709.1023, 2863.1024). WENA and AH also acknowledge support provided by the HORIZON-CL5-2023-D1-02-02 grant C-BLUES, Innovation to advance the evidence base for reporting of Blue Carbon inventories and greenhouse gas fluxes in coastal wetlands.

PY - 2026

Y1 - 2026

N2 - Combined ramped oxidation and radiocarbon analysis (RO-14C) determines the age of carbon pools that have differing thermochemical stability (decomposability), providing powerful insights for studying the carbon cycle. We performed RO-14C of surface soils from a saltmarsh and dated the narrowest temperature intervals so far undertaken for any samples, finding that no modern (post-bomb) 14C contents were resolved. We compared these ramped oxidation measurements to the 14C content of respired CO2 from the same soils, demonstrating that the most biologically available organic carbon was younger (more 14C-enriched) than any of the thermal fractions for surface soils. In our saltmarsh soils, ramped oxidation alone is therefore not able to isolate both the youngest and the most biologically available OC pools. However, we show that a combined approach of RO-14C and measurements of the 14C content of respired CO2 (e.g., incubation experiments) may provide more powerful insights for unravelling carbon cycling.

AB - Combined ramped oxidation and radiocarbon analysis (RO-14C) determines the age of carbon pools that have differing thermochemical stability (decomposability), providing powerful insights for studying the carbon cycle. We performed RO-14C of surface soils from a saltmarsh and dated the narrowest temperature intervals so far undertaken for any samples, finding that no modern (post-bomb) 14C contents were resolved. We compared these ramped oxidation measurements to the 14C content of respired CO2 from the same soils, demonstrating that the most biologically available organic carbon was younger (more 14C-enriched) than any of the thermal fractions for surface soils. In our saltmarsh soils, ramped oxidation alone is therefore not able to isolate both the youngest and the most biologically available OC pools. However, we show that a combined approach of RO-14C and measurements of the 14C content of respired CO2 (e.g., incubation experiments) may provide more powerful insights for unravelling carbon cycling.

KW - Carbon

KW - Coastal

KW - Radiocarbon

KW - Sediments

KW - Soils

U2 - 10.1017/RDC.2026.10245

DO - 10.1017/RDC.2026.10245

M3 - Article

SN - 0033-8222

VL - FirstView

SP - 1101

EP - 1110

JO - Radiocarbon

JF - Radiocarbon

IS - 68

M1 - 68

ER -