Exchange of CO2 and heat between mangrove forest and the atmosphere in wet and dry seasons in southern Thailand

Characteristics of CO2 and heat fluxes over a mangrove forest are investigated during dry and wet seasons in southern Thailand. Fluxes are estimated by the modified gradient method presented in Monji et al. (2002). Turbulent fluxes show considerable differences between wet and dry seasons. When it rains the latent heat flux exceeds the net radiation considerably and the sensible heat flux shows large negative values. CO2 flux during the rain is slightly upward. The relationship between global solar radiation and CO2 flux was not significantly different between dry and wet seasons. CO2 stored inside the canopy atmosphere during the night was found to be consumed in the morning by its photosynthesis. The storage rate is large when wind is low and its magnitude is not negligible in the CO2 exchange process.