Journal metrics

Journal metrics

  • IF value: 8.792 IF 8.792
  • IF 5-year value: 8.414 IF 5-year 8.414
  • CiteScore value: 8.18 CiteScore 8.18
  • SNIP value: 2.620 SNIP 2.620
  • SJR value: 4.885 SJR 4.885
  • IPP value: 7.67 IPP 7.67
  • h5-index value: 28 h5-index 28
  • Scimago H index value: 24 Scimago H index 24
Discussion papers | Copyright
https://doi.org/10.5194/essd-2018-29
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

  19 Apr 2018

19 Apr 2018

Review status
This discussion paper is a preprint. A revision of this manuscript was accepted for the journal Earth System Science Data (ESSD) and is expected to appear here in due course.

Radiocarbon Measurements of Ecosystem Respiration and Soil Pore-Space CO2 in Utqiaġvik (Barrow), Alaska

Lydia J. S. Vaughn1,2 and Margaret S. Torn2,3 Lydia J. S. Vaughn and Margaret S. Torn
  • 1Integrative Biology, University of California, Berkeley, Berkeley, CA, 94720, USA
  • 2Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
  • 3Energy and Resources Group, University of California, Berkeley, Berkeley, CA, 94720, USA

Abstract. Radiocarbon measurements of ecosystem respiration and soil pore space CO2 are useful for determining the sources of ecosystem respiration, identifying environmental controls on soil carbon cycling rates, and parameterizing and evaluating models. We measured flux rates and radiocarbon contents of ecosystem respiration, as well as radiocarbon in soil profile CO2 in Utqiaġvik (Barrow), Alaska, during the summers of 2012, 2013, and 2014. We found that radiocarbon in ecosystem respiration ranged from +60.5 to −160‰ with a median value of +23.3‰. Ecosystem respiration became more depleted in radiocarbon from summer to autumn, indicating increased decomposition of old soil organic carbon and/or decreased CO2 production from fast-cycling carbon pools. Across permafrost features, ecosystem respiration from high-centered polygons was depleted in radiocarbon relative to other polygon types. Radiocarbon content in soil pore-space CO2 varied between −7.1 and −280 ‰, becoming more negative with depth in individual soil profiles. These pore-space radiocarbon values correspond to CO2 mean ages of 410 to 3350 years, based on a steady-state, one-pool model. Together, these data indicate that soil respiration is derived primarily from old, slow-cycling carbon pools, but that total CO2 fluxes depend largely on autotrophic respiration and heterotrophic decomposition of fast-cycling carbon within the shallowest soil layers. The relative contributions of these different CO2 sources are highly variable across microtopographic features and time in the sampling season. The highly negative Δ14C values in soil pore-space CO2 and autumn ecosystem respiration indicate that when it is not frozen, very old soil carbon is vulnerable to decomposition. Radiocarbon data and associated CO2 flux and temperature data are stored in the data repository of the Next Generation Ecosystem Experiments (NGEE-Arctic) at http://dx.doi.org/10.5440/1364062.

Lydia J. S. Vaughn and Margaret S. Torn
Interactive discussion
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Interactive discussion
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
Lydia J. S. Vaughn and Margaret S. Torn
Data sets

Radiocarbon in Ecosystem Respiration and Soil Pore-Space CO2 with Surface Gas Flux, Air Temperature, and Soil Temperature and Moisture, Barrow, Alaska, 2012-2014 L. J. S. Vaughn, M. S. Torn, R. C. Porras, J. B. Curtis, and O. Chafe https://doi.org/10.5440/1364062

Lydia J. S. Vaughn and Margaret S. Torn
Viewed
Total article views: 339 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
272 59 8 339 25 6 9
  • HTML: 272
  • PDF: 59
  • XML: 8
  • Total: 339
  • Supplement: 25
  • BibTeX: 6
  • EndNote: 9
Views and downloads (calculated since 19 Apr 2018)
Cumulative views and downloads (calculated since 19 Apr 2018)
Viewed (geographical distribution)
Total article views: 339 (including HTML, PDF, and XML) Thereof 338 with geography defined and 1 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited
Saved
No saved metrics found.
Discussed
No discussed metrics found.
Latest update: 21 Oct 2018
Download
Short summary
This paper discusses radiocarbon in CO2 from Arctic Alaska. From soil chamber measurements, we observed strong seasonal and spatial patterns in 14C of ecosystem respiration, which declined throughout the summer and differed among permafrost features. Radiocarbon in pore-space CO2 indicated decomposition of carbon as old as 3,000 years near the permafrost table. Together, these data reveal different rates of old carbon decomposition from distinct permafrost features.
This paper discusses radiocarbon in CO2 from Arctic Alaska. From soil chamber measurements, we...
Citation
Share