HR: 11:20h
AN: B32B-05    [Abstracts]
TI: Functional convergence of tundra vegetation simplifies the interpretation of flux observations at larger spatial scales
AU: * Stoy, P C
EM: paul.stoy@ed.ac.uk
AF: Institute for Atmospheric and Environmental Science School of Geosciences University of Edinburgh, Crew Building King's Buildings, Edinburgh, eh9 3jn, United Kingdom
AU: Williams, M
EM: mwilliam@staffmail.ed.ac.uk
AF: Institute for Atmospheric and Environmental Science School of Geosciences University of Edinburgh, Crew Building King's Buildings, Edinburgh, eh9 3jn, United Kingdom
AU: Evans, J G
EM: jge@ceh.ac.uk
AF: Centre for Ecology and Hydrology, CEH Wallingford Maclean Building Benson Lane Crowmarsh Gifford, Wallingford, OX10 8BB, United Kingdom
AU: Lloyd, C R
EM: crl@ceh.ac.uk
AF: Centre for Ecology and Hydrology, CEH Wallingford Maclean Building Benson Lane Crowmarsh Gifford, Wallingford, OX10 8BB, United Kingdom
AU: Prieto-Blanco, A
EM: prieto@geog.ucl.ac.uk
AF: Department of Geography, UCL, 26 Bedford Way, London, WC1H 0AP, United Kingdom
AU: Disney, M
EM: mdisney@geog.ucl.ac.uk
AF: Department of Geography, UCL, 26 Bedford Way, London, WC1H 0AP, United Kingdom
AU: Street, L E
EM: l.e.street@sms.ed.ac.uk
AF: Institute for Atmospheric and Environmental Science School of Geosciences University of Edinburgh, Crew Building King's Buildings, Edinburgh, eh9 3jn, United Kingdom
AU: Shaver, G R
EM: gshaver@mbl.edu
AF: The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, United States
AB: A central challenge in terrestrial carbon cycle research is upscaling measurements of vegetation function to larger spatial and temporal scales. A solution is required to, for example, make chamber-based measurements relevant at larger spatial scales and to make eddy covariance measurements applicable to leaf or chamber- based studies. Here we demonstrate that a simple model for photosynthesis and ecosystem respiration parameterized using pan-arctic chamber flux measurements closely matches eddy covariance flux observations in a tundra ecosystem near Abisko, Sweden. The agreement holds when using a generic parameter set that does not account for vegetation type or measurement location. Inverting the model to predict leaf area using eddy covariance-measured net ecosystem exchange closely approximates tower-based LAI estimates across seasons and during periods of drought stress. Thus, recent findings documenting functional convergence of arctic vegetation holds at multiple spatial as well as temporal scales using both chamber and tower measurements. After validating the model using the eddy covariance measurements, we integrate the model with meteorological and LAI observations using a simple data assimilation scheme. The reduction of error achieved via data assimilation is compared to standard techniques of estimating eddy covariance error. Our analysis demonstrates that accurate estimates of C flux at multiple spatial scales across the tundra biome are possible given accurate estimates of photosynthetically active radiation, temperature, and leaf area index given the observed functional convergence of tundra vegetation.
DE: 0428 Carbon cycling (4806)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0466 Modeling
DE: 0475 Permafrost, cryosphere, and high-latitude processes (0702, 0716)
DE: 0476 Plant ecology (1851)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting