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Fluxes of carbon dioxide and water vapour over an undisturbed tropical forest in south‐west Amazonia
Author(s) -
GRACE JOHN,
LLOYD JON,
MCINTYRE JOHN,
MIRANDA ANTONIO,
MEIR PATRICK,
MIRANDA HELOISA,
MONCRIEFF JOHN,
MASSHEDER JON,
WRIGHT IVAN,
GASH JOHN
Publication year - 1995
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/j.1365-2486.1995.tb00001.x
Subject(s) - amazon rainforest , environmental science , carbon dioxide , tropical forest , carbon cycle , atmospheric sciences , tropical atlantic , climatology , ecology , ecosystem , geology , biology , sea surface temperature
1 Carbon dioxide and water vapour fluxes were measured for 55 days by eddy covariance over an undisturbed tropical rain forest in Rondonia, Brazil. Profiles of CO 2 inside the canopy were also measured. 2 During the night, CO 2 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. 3 Ecosystem gas exchange was calculated from a knowledge of fluxes above the canopy and changes of CO 2 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 CO 2 . 4 Bulk 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.