HR: 16:30h
AN: C24A-03    [Abstracts]
TI: The North American Arctic Transect: Patterned-Ground Ecosystems Across the Full Arctic Bioclimate Gradient
AU: * Walker, D A
EM: ffdaw@uaf.edu
AF: Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Daanen, R
EM: ffrd@uaf.edu
AF: Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Epstein, H
EM: hee2b@virginia.edu
AF: Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904 United States
AU: Gonzalez, G
EM: ggonzalez@fs.fed.us
AF: Institute of Tropical Forestry, USDA Forest Service, San Juan, PR 00926 United States
AU: Gould, W
EM: wgould@fs.fed.us
AF: Institute of Tropical Forestry, USDA Forest Service, San Juan, PR 00926 United States
AU: Kade, A
EM: anja_kade@yahoo.com
AF: Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Kelley, A
EM: amk5d@virginia.edu
AF: Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904 United States
AU: Krantz, W
EM: bkrantz@alpha.che.uc.edu
AF: Department of Chemical Engineering, University of Cincinnati, Cincinatti, OH 45221 United States
AU: Michaelson, G
EM: pngjm@uaa.alaska.edu
AF: Ag. and Forestry Experiment Station, University of Alaska Fairbanks, Palmer, AK 99645 United States
AU: Munger, C
EM: fncam1@uaf.edu
AF: Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Nickolsky, D
EM: mddnick@hotmail.com
AF: Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Peterson, R
EM: ffrap1@aurora.uaf.edu
AF: Department of Civil and Environmental Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Ping, C
EM: pfclp@uaa.alaska.edu
AF: Ag. and Forestry Experiment Station, University of Alaska Fairbanks, Palmer, AK 99645 United States
AU: Raynolds, M
EM: fnmkr@uaf.edu
AF: Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Romanovsky, V
EM: ffver@uaf.edu
AF: Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Shur, Y
EM: ffys@uaf.edu
AF: Department of Civil and Environmental Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Tarnocai, C
EM: tarnocaict@agr.gc.ca
AF: Ag.and Agri-Food Canada, 960 Carling Avenue, Ottawa, K1A0C6 Canada
AU: Tipenko, G
EM: ffgst@uaf.edu
AF: Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Timling, I
EM: ftit@uaf.edu
AF: Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AU: Vonlanthen, C
EM: Corinne.Vonlanthen@giub.unibe.ch
AF: Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AB: We studied the ecosystems related to small patterned-ground features at 12 locations along an 1800-km long transect in the western North American Arctic. We examined permafrost-soil-vegetation relationships from treeline to the extreme High Arctic (bioclimate subzones A to E on the Circumpolar Arctic Vegetation Map; 10 degrees of latitude, Toolik Lake, Alaska to Isachsen, Canada and approximately 11 degrees C of mean July temperature). Here we present some of the early results that demonstrate the intimate relationship between climate, vegetation, soil type, and patterned-ground morphology. Frost heave, up to 21 cm in the centers of non-sorted circles, is strongest in silty soils. Modeling the processes involved in small-patterned-ground formation focuses on the flow of heat and water within the features in relationship to the differential heat flux at the soil surface. Cryoturbation redistributes carbon in the soil profiles, and much of this becomes sequestered in frozen organic horizons at the permafrost table. The amount of carbon in the permafrost varies considerably depending on the climate regime and the patterned-ground form. Microbiotic crusts are common on the surface of patterned-ground features and are likely early sources of nitrogen fixation in vegetation succession. The transect now provides a baseline of observations along the complete Arctic climate gradient including ecosystems at the cold extreme and should be considered for long-term observations and monitoring related to the International Polar Year.
DE: 0700 CRYOSPHERE (4540)
DE: 0706 Active layer
DE: 0710 Periglacial processes
DE: 0718 Tundra (9315)
DE: 0793 Biogeochemistry (0412, 0414, 1615, 4805, 4912)
SC: Cryosphere [C]
MN: Fall Meeting 2005