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Titel |
Organic carbon and total nitrogen stocks in soils of the Lena River Delta |
VerfasserIn |
S. Zubrzycki, L. Kutzbach, G. Grosse, A. Desyatkin, E.-M. Pfeiffer |
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 ; 10, no. 6 ; Nr. 10, no. 6 (2013-06-03), S.3507-3524 |
Datensatznummer |
250018266
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Publikation (Nr.) |
copernicus.org/bg-10-3507-2013.pdf |
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Zusammenfassung |
The Lena River Delta, which is the largest delta in the Arctic, extends over an area of 32 000 km2 and likely holds
more than half of the entire soil organic carbon (SOC) mass stored in the seven major deltas in the northern permafrost regions. The
geomorphic units of the Lena River Delta which were formed by true deltaic sedimentation processes are a Holocene river terrace
and the active floodplains. Their mean SOC stocks for the upper 1 m of soils were estimated at
29 kg m−2 ± 10 kg m−2 and at 14 kg m−2 ± 7 kg m−2,
respectively. For the depth of 1 m, the total SOC pool of the Holocene river terrace was estimated at
121 Tg ± 43 Tg, and the SOC pool of the active floodplains was estimated at
120 Tg ± 66 Tg. The mass of SOC stored within the observed seasonally thawed active layer
was estimated at about 127 Tg assuming an average maximum active layer depth of 50 cm. The SOC
mass which is stored in the perennially frozen ground at the increment 50–100 cm soil depth, which is currently excluded from intense
biogeochemical exchange with the atmosphere, was estimated at 113 Tg. The mean nitrogen (N) stocks for the upper
1 m of soils were estimated at 1.2 kg m−2 ± 0.4 kg m−2 for the Holocene river terrace
and at 0.9 kg m−2 ± 0.4 kg m−2 for the active floodplain levels, respectively. For the depth of
1 m, the total N pool of the river terrace was estimated at 4.8 Tg ± 1.5 Tg, and the total N pool
of the floodplains was estimated at 7.7 Tg ± 3.6 Tg. Considering the projections for deepening of the
seasonally thawed active layer up to 120 cm in the Lena River Delta region within the 21st century, these large
carbon and nitrogen stocks could become increasingly available for decomposition and mineralization processes. |
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