Fluxes of carbon dioxide and water vapour over an undisturbed tropical forest in south-west Amazonia
Article first published online: 27 APR 2006
Global Change Biology
Volume 1, Issue 1, pages 1–12, February 1995
How to Cite
GRACE, J., LLOYD, J., MCINTYRE, J., MIRANDA, A., MEIR, P., MIRANDA, H., MONCRIEFF, J., MASSHEDER, J., WRIGHT, I. and GASH, J. (1995), Fluxes of carbon dioxide and water vapour over an undisturbed tropical forest in south-west Amazonia. Global Change Biology, 1: 1–12. doi: 10.1111/j.1365-2486.1995.tb00001.x
- Issue published online: 27 APR 2006
- Article first published online: 27 APR 2006
- Received 19 September 1994; revision accepted 14 December 1994
- CO2/H2O fluxes;
- eddy covariance;
- stomatal conductance;
- canopy ventilation
- 1Carbon dioxide and water vapour fluxes were measured for 55 days by eddy covariance over an undisturbed tropical rain forest in Rondonia, Brazil. Profiles of CO2 inside the canopy were also measured.
- 2During the night, CO2 concentration frequently built up to 500 ppm throughout the canopy as a result of low rates of exchange with the atmosphere. In the early morning hours, ventilation of the canopy occurred.
- 3Ecosystem gas exchange was calculated from a knowledge of fluxes above the canopy and changes of CO2 stored inside the canopy. Typically, uptake by the canopy was 15 μmol m−2 s−1 in bright sunlight and dark respiration was 6-7 μmol m−2 s−1 The quantum requirement at low irradiance was: 40 mol photons per mol of CO2.
- 4Bulk stomatal conductance of the ecosystem was maximal in the early morning (0.4-1.0 mol m−2 s−1) and declined over the course of the day as leaf-to-air vapour pressure difference increased.