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| Titel |
Estimated stocks of circumpolar permafrost carbon with quantified uncertainty ranges and identified data gaps |
| VerfasserIn |
G. Hugelius, J. Strauss, S. Zubrzycki, J. W. Harden, E. A. G. Schuur, C.-L. Ping, L. Schirrmeister, G. Grosse, G. J. Michaelson, C. D. Koven, J. A. O'Donnell, B. Elberling, U. Mishra, P. Camill, Z. Yu, J. Palmtag, P. Kuhry |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 23 ; Nr. 11, no. 23 (2014-12-01), S.6573-6593 |
| Datensatznummer |
250117703
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| Publikation (Nr.) |
 copernicus.org/bg-11-6573-2014.pdf |
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| Zusammenfassung |
| Soils and other unconsolidated deposits in the northern circumpolar
permafrost region store large amounts of soil organic carbon (SOC). This SOC
is potentially vulnerable to remobilization following soil warming and
permafrost thaw, but SOC stock estimates were poorly constrained and
quantitative error estimates were lacking. This study presents revised
estimates of permafrost SOC stocks, including quantitative uncertainty
estimates, in the 0–3 m depth range in soils as well as for sediments
deeper than 3 m in deltaic deposits of major rivers and in the Yedoma region
of Siberia and Alaska. Revised estimates are based on significantly larger
databases compared to previous studies. Despite this there is evidence of
significant remaining regional data gaps. Estimates remain particularly
poorly constrained for soils in the High Arctic region and physiographic
regions with thin sedimentary overburden (mountains, highlands and plateaus)
as well as for deposits below 3 m depth in deltas and the Yedoma region.
While some components of the revised SOC stocks are similar in magnitude to
those previously reported for this region, there are substantial differences
in other components, including the fraction of perennially frozen SOC.
Upscaled based on regional soil maps, estimated permafrost region SOC stocks
are 217 ± 12 and 472 ± 27 Pg for the 0–0.3 and 0–1 m soil
depths, respectively (±95% confidence intervals). Storage of SOC in
0–3 m of soils is estimated to 1035 ± 150 Pg. Of this, 34 ±
16 Pg C is stored in poorly developed soils of the High Arctic.
Based on generalized calculations, storage of SOC below 3 m of surface soils
in deltaic alluvium of major Arctic rivers is estimated as 91 ±
52 Pg. In the Yedoma region, estimated SOC stocks below 3 m depth
are 181 ± 54 Pg, of which 74 ± 20 Pg is stored in
intact Yedoma (late Pleistocene ice- and organic-rich silty sediments) with
the remainder in refrozen thermokarst deposits. Total estimated SOC storage
for the permafrost region is ∼1300 Pg with an uncertainty range
of ∼1100 to 1500 Pg. Of this, ∼500 Pg is in
non-permafrost soils, seasonally thawed in the active layer or in deeper
taliks, while ∼800 Pg is perennially frozen. This represents a
substantial ∼300 Pg lowering of the estimated perennially
frozen SOC stock compared to previous estimates. |
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