Influences of deforestation on carbon balance in a natural tropical peat swamp forest in thailand

摘要

The effects of deforestation on carbon balance in a natural tropical peat swamp forest were evaluated by micrometeorological monitoring. The monitoring sites were the primary forest at To-Daeng and the secondary forest at Bacho in Narathiwat Province, Thailand. The concentration gradient method (CG) and the relaxed eddy accumulation method (REA) were used to estimate the CO_2 flux above the canopies. We estimated the annual amount of carbon absorption for both sites, using the relationship between CO_2 flux and solar radiation for each site. An annual net carbon absorption of 5.32 t C ha-(-1) year-(-1), was estimated for the primary forest. The accumulation of the released organic matterfrom the forest into logged-water caused the net carbon absorption in the peat swamp forest. In the secondary forest, annual net carbon absorption was estimated at 5.22 t C ha-(-1) year-(-1), which is almost the same range of absorption as the primary forest, because of plant growth in the secondary forest. A greater quantity of net carbon absorption, 9.69 t C ha-(-1) year-(-1), was expected, assuming that the ground surface remained water-logged throughout the year. On the other hand, assuming it remained dry throughout the year, a net carbon emission of -0.40t C ha-(-1) year-(-1), was expected.