HR: 0830h
AN: B51D-0999    [PDF]
TI: Seasonal Variations in Night-time NEE from EUROFLUX
AU: * Swann, A
EM: aswann@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, P.O. Box 1000 61 Route 9W, Palisades, NY 10964-1000 United States
AU: Fung, I
EM: inez@atmos.berkeley.edu
AF: Berkeley Atmospheric Sciences Center, 307 McCone Hall, Berkeley, CA 94720-4767 United States
AB: Night-time temperatures and net ecosystem exchange (NEE) during 1997 measured by eddy covariance techniques from 14 FLUXNET towers in Europe were analyzed to identify the factors controlling ecosystem respiration. Empirical orthogonal function/principle component analysis of temperature and NEE identifies the 5 sites where night-time NEE shows no coherent seasonal variations or detectable climate control on respiration. Temperature proved to be the principle control on night-time NEE at nine of fourteen sites. These nine sites show a residual distinct seasonal cycle in NEE peaking in the fall. _The residual does not correspond with variations in soil moisture or precipitation. We hypothesize that NEE variations at the EUROFLUX sites capture variations in the quality, quantity and microclimate of the litter beneath the canopy.
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2003 Fall Meeting