Endogenous circadian regulation of carbon dioxide exchange in terrestrial ecosystems

Academic Article

Abstract

  • AbstractIt is often assumed that daytime patterns of ecosystem carbon assimilation are mostly driven by direct physiological responses to exogenous environmental cues. Under limited environmental variability, little variation in carbon assimilation should thus be expected unless endogenous plant controls on carbon assimilation, which regulate photosynthesis in time, are active. We evaluated this assumption with eddy flux data, and we selected periods when net ecosystem exchange (NEE) was decoupled from environmental variability in seven sites from highly contrasting biomes across a 74° latitudinal gradient over a total of 36 site‐years. Under relatively constant conditions of light, temperature, and other environmental factors, significant diurnal NEE oscillations were observed at six sites, where daily NEE variation was between 20% and 90% of that under variable environmental conditions. These results are consistent with fluctuations driven by the circadian clock and other endogenous processes. Our results open a promising avenue of research for a more complete understanding of ecosystem fluxes that integrates from cellular to ecosystem processes.
  • Authors

  • Resco de Dios, Victor
  • Goulden, Michael L
  • Ogle, Kiona
  • Richardson, Andrew D
  • Hollinger, David Y
  • Davidson, Eric A
  • Alday, Josu G
  • Barron-Gafford, Greg A
  • Carrara, Arnaud
  • Kowalski, Andrew S
  • Oechel, Walt C
  • Reverter, Borja R
  • Scott, Russell L
  • Varner, Ruth
  • Diaz-Sierra, Ruben
  • Moreno, Jose M
  • Status

    Publication Date

  • June 2012
  • Has Subject Area

    Published In

    Keywords

  • biosphere-atmosphere interactions
  • canopy conductance
  • circadian clock
  • ecosystem exchange
  • gas exchange
  • global change
  • photosynthesis
  • sink regulation
  • source
  • Digital Object Identifier (doi)

    Start Page

  • 1956
  • End Page

  • 1970
  • Volume

  • 18
  • Issue

  • 6