Carbon and nitrogen isotope studies in an arctic ecosystem

• Main Author: Schell, D.M.
• Language: unknown
• Published: 2008
• Subjects: 54 ENVIRONMENTAL SCIENCES; TUNDRA; CARBON CYCLE; NITROGEN CYCLE; ARCTIC REGIONS; ALASKA; BASELINE ECOLOGY; CARBON 14; Arctic; Tundra; Alaska
• Online Access: http://www.osti.gov/servlets/purl/10137214; https://www.osti.gov/biblio/10137214; https://doi.org/10.2172/10137214

This proposal requests funding for the completion of our current ecological studies at the MS-117 research site at Toolik Lake, Alaska. We have been using a mix of stable and radioisotope techniques to assess the fluxes of carbon and nitrogen within the ecosystem and the implications for long-term carbon storage or loss from the tundra. Several tentative conclusions have emerged from our study including: Tundra in the foothills is no longer accumulating carbon. Surficial radiocarbon abundances show little or no accumulation since 1000--2500 yrs BP. Coastal plain tundra is still accumulating carbon, but the rate of accumulation has dropped in the last few thousand years. Carbon export from watersheds in the Kuparuk and Imnavait Creek drainages are in excess of that expected from estimated primary productivity; and Nitrogen isotope abundances vary between species of plants and along hydrologic gradients.