Abstract
Carbon dioxide (CO2) emission by peat and litter decomposition and by tree respiration were measured in a primary peat swamp forest of southern Thailand. The obtained emission rates from foliage, branch, stem, peat soil, litter and ponding water surface were integrated to estimate the total CO2 emission from the forest ecosystem. The open-airflow chamber method with an infrared gas analyzer was employed for all the emission measurements except for litter decomposition. For litter decomposition, the mesh bag method was applied to estimate the emission. Root respiration was estimated from the difference between the CO2 emission rate of ponding water and peat and litter decomposition. On the basis of unit surface area, the branch had the greatest respiration rate among the aboveground components. However, the foliage had the greatest rate per unit ground surface area. Annual CO2 emission from the ecosystem was estimated to 8.84 t C ha-1 year-1 on the carbon weight basis. The breakdown of the value to each component was 6, 6, 28, 28, 18 and 14% for stems, branches, foliage, roots, litter and peat, respectively. This indicates that emission from underground plays quite important role to assess the carbon balance of the peat swamp forest.
