2008), The fate of terrestrial carbon following permafrost degradation: Detecting changes over recent decades
As boreal and arctic regions of North America have been undergoing considerable warming since the 1950s, a key question remains as to the fate of permafrost and carbon over this important time period. We used 137Cs as an age constraint for soil carbon that has accumulated since the first occurrence...
| Main Authors: | , , , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.552.4979 http://biogeo.botanik.uni-greifswald.de/fileadmin/user_upload/_temp_/Martin/Harden_2008_the_fate_of_terestrial_carbon_following_permafrost_degradation.pdf |
| Summary: | As boreal and arctic regions of North America have been undergoing considerable warming since the 1950s, a key question remains as to the fate of permafrost and carbon over this important time period. We used 137Cs as an age constraint for soil carbon that has accumulated since the first occurrence of 137Cs in 1954. We tested this approach by comparing profiles of Δ14C to 137Cs for soils of different plant communities near Delta Junction, central Alaska. Both isotopes indicate upward accumulating, organic systems that have little evidence for mixing or leaching. We then used inventories of these isotopes to normalize the C storage between frozen and thawed site-pairs. To date, we identified a net loss of carbon from a tundra-forest transition in northern Alaska. We measured net increases of C resulting from forest-bog and forest-fen transition in Alaska and Canada. |
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