Response of a tundra ecosystem to elevated atmospheric carbon dioxide and CO{sub 2}-induced climate change. Annual technical report

• Main Author: Oechel, W.C.
• Other Authors: United States. Department of Energy.
• Format: Report
• Language: English
• Published: San Diego State Univ., CA (United States). Dept. of Biology 1993
• Subjects: Climatic Change; Plants; Carbon Dioxide; Terrestrial Ecosystems; Seasonal Variations; Progress Report; Tundra; Carbon Cycle; 54 Environmental Sciences; Permafrost; Arctic Regions; Arctic; Barrow; Climate change; permafrost; Alaska
• Online Access: https://doi.org/10.2172/230308; http://digital.library.unt.edu/ark:/67531/metadc664512/

Northern ecosystems contain up to 455 Gt of C in the soil active layer and upper permafrost, which is equivalent to approximately 60% of the carbon currently in the atmosphere as CO{sub 2}. Much of this carbon is stored in the soil as dead organic matter. Its fate is subject to the net effects of global change on the plant and soil systems of northern ecosystems. The arctic alone contains about 60 Gt C, 90% of which is present in the soil active layer and upper permafrost, and is assumed to have been a sink for CO{sub 2} during the historic and recent geologic past. Depending on the nature, rate, and magnitude of global environmental change, the arctic may have a positive or negative feedback on global change. Results from the DOE- funded research efforts of 1990 and 1991 indicate that the arctic has become a source of CO{sub 2} to the atmosphere. Measurements made in the Barrow, Alaska region during 1992 support these results. This change coincides with recent climatic variation in the arctic, and suggests a positive feedback of arctic ecosystems on atmospheric CO{sub 2} and global change. There are obvious potential errors in scaling plot level measurements to landscape, mesoscale, and global spatial scales. In light of the results from the recent DOE-funded research, and the remaining uncertainties regarding the change in arctic ecosystem function due to high latitude warming, a revised set of research goals is proposed for the 1993--94 year. The research proposed in this application has four principal aspects: (A) Long- term response of arctic plants and ecosystems to elevated atmospheric CO{sub 2}. (B) Circumpolar patterns of net ecosystem CO{sub 2} flux. (C) In situ controls by temperature and moisture on net ecosystem CO{sub 2} flux. (D) Scaling of CO{sub 2} flux from plot, to landscape, to regional scales.