Characteristics of the gas exchange of a tropical rain forest in peninsular Malaysia

Understanding the energy/H2O/CO2 exchange processes of tropical rain forests is very important for evaluating their roles in climate change. We measured sensible heat, latent heat, and CO2 fluxes above a tropical rain forest in Peninsular Malaysia using the eddy covariance method for the year 2003. The average daily sensible and latent heat fluxes were 3.0 and 6.1 MJ, respectively. After considering the calculated heat storage terms, energy budget closure was estimated to be approximately 65%, even during the day. The average daily CO2 flux was -2.1 g C m(-2) in 2003. The average diurnal change of CO2 flux ranged from -18.0 to 10.0 mu mol m(-2) s(-1), and no significant seasonal changes were observed. In the night time, CO2 efflux measured using the eddy covariance method increased with friction velocity, suggesting an underestimation of ecosystem respiration under poor mixing conditions.