The undetected loss of aged carbon from boreal mineral soils
(2021) In Scientific Reports 11(1).- Abstract
The boreal forest is among the largest terrestrial biomes on earth, storing more carbon (C) than the atmosphere. Due to rapid climatic warming and enhanced human development, the boreal region may have begun transitioning from a net C sink to a net source. This raises serious concern that old biogenic soil C can be re-introduced into the modern C cycle in near future. Combining bio-decay experiments, mixing models and the Keeling plot method, we discovered a distinct old pre-bomb organic carbon fraction with high biodegradation rate. In total, 34 ± 12% of water-extractable organic carbon (WEOC) in podzols, one of the dominating boreal soil types, consisted of aged (~ 1000 year) labile C. The omission of this aged (i.e., Δ14C... (More)
The boreal forest is among the largest terrestrial biomes on earth, storing more carbon (C) than the atmosphere. Due to rapid climatic warming and enhanced human development, the boreal region may have begun transitioning from a net C sink to a net source. This raises serious concern that old biogenic soil C can be re-introduced into the modern C cycle in near future. Combining bio-decay experiments, mixing models and the Keeling plot method, we discovered a distinct old pre-bomb organic carbon fraction with high biodegradation rate. In total, 34 ± 12% of water-extractable organic carbon (WEOC) in podzols, one of the dominating boreal soil types, consisted of aged (~ 1000 year) labile C. The omission of this aged (i.e., Δ14C depleted) WEOC fraction in earlier studies is due to the co-occurrence with Δ14C enriched modern C formed following 1950s nuclear bomb testing masking its existence. High lability of aged soil WEOC and masking effects of modern Δ14C enriched C suggests that the risk for mobilization and re-introduction of this ancient C pool into the modern C cycle has gone undetected. Our findings have important implications for earth systems models in terms of climate-carbon feedbacks and the future C balance of the boreal forest.
(Less)
- author
- Hensgens, Geert LU ; Laudon, Hjalmar ; Johnson, Mark S. and Berggren, Martin LU
- organization
- publishing date
- 2021
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Scientific Reports
- volume
- 11
- issue
- 1
- article number
- 6202
- publisher
- Nature Publishing Group
- external identifiers
-
- pmid:33737556
- scopus:85102731549
- ISSN
- 2045-2322
- DOI
- 10.1038/s41598-021-85506-w
- language
- English
- LU publication?
- yes
- id
- a6211f16-39e7-4243-9a59-79c28912c5cc
- date added to LUP
- 2021-03-30 09:52:57
- date last changed
- 2025-01-26 08:13:50
@article{a6211f16-39e7-4243-9a59-79c28912c5cc,
abstract = {{<p>The boreal forest is among the largest terrestrial biomes on earth, storing more carbon (C) than the atmosphere. Due to rapid climatic warming and enhanced human development, the boreal region may have begun transitioning from a net C sink to a net source. This raises serious concern that old biogenic soil C can be re-introduced into the modern C cycle in near future. Combining bio-decay experiments, mixing models and the Keeling plot method, we discovered a distinct old pre-bomb organic carbon fraction with high biodegradation rate. In total, 34 ± 12% of water-extractable organic carbon (WEOC) in podzols, one of the dominating boreal soil types, consisted of aged (~ 1000 year) labile C. The omission of this aged (i.e., Δ<sup>14</sup>C depleted) WEOC fraction in earlier studies is due to the co-occurrence with Δ<sup>14</sup>C enriched modern C formed following 1950s nuclear bomb testing masking its existence. High lability of aged soil WEOC and masking effects of modern Δ<sup>14</sup>C enriched C suggests that the risk for mobilization and re-introduction of this ancient C pool into the modern C cycle has gone undetected. Our findings have important implications for earth systems models in terms of climate-carbon feedbacks and the future C balance of the boreal forest.</p>}},
author = {{Hensgens, Geert and Laudon, Hjalmar and Johnson, Mark S. and Berggren, Martin}},
issn = {{2045-2322}},
language = {{eng}},
number = {{1}},
publisher = {{Nature Publishing Group}},
series = {{Scientific Reports}},
title = {{The undetected loss of aged carbon from boreal mineral soils}},
url = {{http://dx.doi.org/10.1038/s41598-021-85506-w}},
doi = {{10.1038/s41598-021-85506-w}},
volume = {{11}},
year = {{2021}},
}