Title Selective preservation of old organic carbon fluvially released from sub-Arctic soils
Author Vonk, J.E.; van Dongen, B.E.; Gustafsson, O.
Author Affil Vonk, J.E., Stockhom University, Department of Applied Environmental Science and Bert Bolin Centre for Climate Research, Stockholm, Sweden. Other: University of Manchester, United Kingdom
Source Geophysical Research Letters, 37(11), Citation L11605. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0094-8276
Publication Date 2010
Notes In English. 29 refs. GeoRef Acc. No: 309536
Index Terms carbon isotopes; climatic change; ecosystems; isotopes; peat; permafrost; Quaternary deposits; radioactive isotopes; sediments; soils; soil temperature; suspended sediments; temperature; tundra; vegetation; Arctic region; Russia--Ob River; Scandinavia; Russia--Yenisei River; Asia; C-14; carbon; Cenozoic; climate change; climate effects; Commonwealth of Independent States; deposition; Europe; Holocene; Kalix River; Ob River; organic carbon; particulate materials; Quaternary; Russian Federation; stream transport; suspended materials; tracers; transport; Western Europe; Yenisei River
Abstract Amplified climate warming in the Arctic may cause thaw-remobilization of its large soil organic carbon (SOC) pool. Here we assess the remobilization and preservation of old SOC by the watershed-integrated radiocarbon signature of molecular SOC markers released from northernmost Scandinavia. The radiocarbon analyses revealed a remarkable fractionation for identical vascular plant markers (~420ppm or ~6000 14C years) upon settling from surface water to the underlying sediments. From this, we infer fluvial export of two SOC pools; a young surface peat component, and an old deep mineral soil component. The young pool exists as an easily degradable humic suspension, while the old pool is matrix protected from degradation and ballasted for preferential settling. The two soil types with highest OC in Arctic permafrost evidently exhibit different susceptibilities to degradation. Hence, a significant part of the thaw- released OC may simply be fluvially relocated to sediments instead of being emitted to the atmosphere.
URL http://hdl.handle.net/10.1029/2010GL042909
Publication Type journal article
Record ID 65006571