HR: 13:40h
AN: C13C-01 INVITED     [Abstracts]
TI: Postglacial Development of the Circumpolar Peatland Complex and Its Potential Impact on Atmospheric Methane Concentrations
AU: * MacDonald, G M
EM: macdonal@geog.ucla.edu
AF: Department of Geography, UCLA 405 Hilgard Ave., Los Angeles, 90095-1524 United States
AU: Smith, L C
EM: lsmith@geog.ucla.edu
AF: Department of Geography, UCLA 405 Hilgard Ave., Los Angeles, 90095-1524 United States
AU: Velichko, A A
EM: paleo@online.ru
AF: Institute of Geography, Russian Academy of Sciences, Moscow, 109017 Russian Federation
AU: Beilman, D W
EM: dbeilman@ucla.edu
AF: Department of Geography, UCLA 405 Hilgard Ave., Los Angeles, 90095-1524 United States
AU: Kremenetski, K V
EM: costya@geog.ucla.edu
AF: Department of Geography, UCLA 405 Hilgard Ave., Los Angeles, 90095-1524 United States
AU: Kremenetski, K V
EM: costya@geog.ucla.edu
AF: Institute of Geography, Russian Academy of Sciences, Moscow, 109017 Russian Federation
AB: The development of extensive peatlands in the circumpolar subarctic and arctic zones produced immense alterations in edaphic conditions, hydrology, vegetation, animal forage and habitat conditions, human land-use potential, carbon storage and land-atmosphere fluxes of CO2 and CH4. There has been much speculation regarding the impact that circumpolar peatland development may have played on Holocene atmospheric CH4 concentrations as recorded in ice-core records from Greenland and Antarctica. A recently acquired network of 226 basal dates from the western Siberian Lowlands has been combined with over 1300 similar dates from peatlands throughout the circumpolar region to provide continental and hemispheric scale reconstructions of northern peatland development. The data suggest there was only very limited peatland development, even in unglaciated regions, prior to 12,000 Cal yr BP. Euarasian peatlands experienced a sharp rise in development between 12,000 and 10,000 Cal yr BP. This corresponds with a period of high atmospheric concentrations of CH4. Although North American peatlands also expanded during this period, the tempo of development in North America also strongly reflected the more gradual retreat of the Laurentide Ice Sheet and the associated exposure of land surfaces for peatland expansion. Following 8000 to 6000 Cal yr BP there was a general decrease in the rate of peatland development.
DE: 0315 Biosphere/atmosphere interactions
DE: 0400 Biogeosciences
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting