Carbon and nitrogen pools in thermokarst-affected permafrost landscapes in Arctic Siberia
- Ice-rich yedoma-dominated landscapes store con- siderable amounts of organic carbon (C) and nitrogen (N) and are vulnerable to degradation under climate warming. We investigate the C and N pools in two thermokarst-affected yedoma landscapes – on Sobo-Sise Island and on Bykovsky Peninsula in the north of eastern Siberia. Soil cores up to 3 m depth were collected along geomorphic gradients and anal- ysed for organic C and N contents. A high vertical sampling density in the profiles allowed the calculation of C and N stocks for short soil column intervals and enhanced under- standing of within-core parameter variability. Profile-level C and N stocks were scaled to the landscape level based on landform classifications from 5 m resolution, multispectral RapidEye satellite imagery. Mean landscape C and N storage in the first metre of soil for Sobo-Sise Island is estimated to be 20.2 kg C m −2 and 1.8 kg N m −2 and for Bykovsky Penin- sula 25.9 kg C m −2 and 2.2 kg N m −2 . Radiocarbon dating demonstrates the Holocene age ofIce-rich yedoma-dominated landscapes store con- siderable amounts of organic carbon (C) and nitrogen (N) and are vulnerable to degradation under climate warming. We investigate the C and N pools in two thermokarst-affected yedoma landscapes – on Sobo-Sise Island and on Bykovsky Peninsula in the north of eastern Siberia. Soil cores up to 3 m depth were collected along geomorphic gradients and anal- ysed for organic C and N contents. A high vertical sampling density in the profiles allowed the calculation of C and N stocks for short soil column intervals and enhanced under- standing of within-core parameter variability. Profile-level C and N stocks were scaled to the landscape level based on landform classifications from 5 m resolution, multispectral RapidEye satellite imagery. Mean landscape C and N storage in the first metre of soil for Sobo-Sise Island is estimated to be 20.2 kg C m −2 and 1.8 kg N m −2 and for Bykovsky Penin- sula 25.9 kg C m −2 and 2.2 kg N m −2 . Radiocarbon dating demonstrates the Holocene age of thermokarst basin de- posits but also suggests the presence of thick Holocene- age cover layers which can reach up to 2 m on top of in- tact yedoma landforms. Reconstructed sedimentation rates of 0.10–0.57 mm yr −1 suggest sustained mineral soil accu- mulation across all investigated landforms. Both yedoma and thermokarst landforms are characterized by limited accumu- lation of organic soil layers (peat). We further estimate that an active layer deepening of about 100 cm will increase organic C availability in a sea- sonally thawed state in the two study areas by ∼ 5.8 Tg (13.2 kg C m −2 ). Our study demonstrates the importance of increasing the number of C and N storage inventories in ice- rich yedoma and thermokarst environments in order to ac- count for high variability of permafrost and thermokarst en- vironments in pan-permafrost soil C and N pool estimates.…
Verfasserangaben: | Matthias FuchsORCiD, Guido GrosseORCiDGND, Jens StraussORCiDGND, Frank GüntherORCiD, Mikhail N. GrigorievORCiDGND, Georgy M. Maximov, Gustaf Hugelius |
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URN: | urn:nbn:de:kobv:517-opus4-418026 |
DOI: | https://doi.org/10.25932/publishup-41802 |
ISSN: | 1866-8372 |
Titel des übergeordneten Werks (Englisch): | Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe |
Schriftenreihe (Bandnummer): | Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe (654) |
Publikationstyp: | Postprint |
Sprache: | Englisch |
Datum der Erstveröffentlichung: | 26.02.2019 |
Erscheinungsjahr: | 2018 |
Veröffentlichende Institution: | Universität Potsdam |
Datum der Freischaltung: | 26.02.2019 |
Freies Schlagwort / Tag: | Late Quaternary; Lena River Delta; Tundra ecosystem; Yedoma region; climate-change; ice-rich permafrost; northern Siberia; periglacial landscape; soil organic-carbon; thaw-lake basins |
Band: | 15 |
Ausgabe: | 654 |
Seitenanzahl: | 19 |
Quelle: | Biogeosciences 15 (2018), pp. 953–971 DOI 10.5194/bg-15-953-2018 |
Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät |
DDC-Klassifikation: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie | |
Peer Review: | Referiert |
Publikationsweg: | Open Access |
Fördermittelquelle: | Copernicus |
Lizenz (Deutsch): | CC-BY - Namensnennung 4.0 International |
Externe Anmerkung: | Bibliographieeintrag der Originalveröffentlichung/Quelle |