Skip to main content

Research Repository

Advanced Search

Abundant pre-industrial carbon detected in Canadian Arctic headwaters: implications for the permafrost carbon feedback

Dean, J.F.; van der Velde, Y.; Garnett, M.H.; Dinsmore, K.J.; Baxter, R.; Lessels, J.S.; Smith, P.; Street, L.E.; Subke, J.-A.; Tetzlaff, D.; Washbourne, I.; Wookey, P.A.; Billett, M.F.

Abundant pre-industrial carbon detected in Canadian Arctic headwaters: implications for the permafrost carbon feedback Thumbnail


Authors

J.F. Dean

Y. van der Velde

M.H. Garnett

K.J. Dinsmore

J.S. Lessels

P. Smith

L.E. Street

J.-A. Subke

D. Tetzlaff

I. Washbourne

P.A. Wookey

M.F. Billett



Abstract

Mobilization of soil/sediment organic carbon into inland waters constitutes a substantial, but poorly-constrained, component of the global carbon cycle. Radiocarbon (14C) analysis has proven a valuable tool in tracing the sources and fate of mobilized carbon, but aquatic 14C studies in permafrost regions rarely detect 'old' carbon (assimilated from the atmosphere into plants and soil prior to AD1950). The emission of greenhouse gases derived from old carbon by aquatic systems may indicate that carbon sequestered prior to AD1950 is being destabilized, thus contributing to the 'permafrost carbon feedback' (PCF). Here, we measure directly the 14C content of aquatic CO2, alongside dissolved organic carbon, in headwater systems of the western Canadian Arctic—the first such concurrent measurements in the Arctic. Age distribution analysis indicates that the age of mobilized aquatic carbon increased significantly during the 2014 snow-free season as the active layer deepened. This increase in age was more pronounced in DOC, rising from 101–228 years before sampling date (a 120%–125% increase) compared to CO2, which rose from 92–151 years before sampling date (a 59%–63% increase). 'Pre-industrial' aged carbon (assimilated prior to ~AD1750) comprised 15%–40% of the total aquatic carbon fluxes, demonstrating the prevalence of old carbon to Arctic headwaters. Although the presence of this old carbon is not necessarily indicative of a net positive PCF, we provide an approach and baseline data which can be used for future assessment of the PCF.

Citation

Dean, J., van der Velde, Y., Garnett, M., Dinsmore, K., Baxter, R., Lessels, J., …Billett, M. (2018). Abundant pre-industrial carbon detected in Canadian Arctic headwaters: implications for the permafrost carbon feedback. Environmental Research Letters, 13(3), Article 034024. https://doi.org/10.1088/1748-9326/aaa1fe

Journal Article Type Article
Acceptance Date Dec 15, 2017
Online Publication Date Feb 27, 2018
Publication Date Feb 27, 2018
Deposit Date Mar 15, 2018
Publicly Available Date Mar 19, 2018
Journal Environmental Research Letters
Publisher IOP Publishing
Peer Reviewed Peer Reviewed
Volume 13
Issue 3
Article Number 034024
DOI https://doi.org/10.1088/1748-9326/aaa1fe

Files

Published Journal Article (2.4 Mb)
PDF

Publisher Licence URL
http://creativecommons.org/licenses/by/4.0/

Copyright Statement
Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.





You might also like



Downloadable Citations