Dissolved organic carbon from three ecosystems in tropical peatland of Sarawak, Malaysia
2007
Gan, H.Y. | Mohd. Hanafi M. | Melling, L.
Decompostion, humification, and stabilization of soil organic matter (SOM) are closely related to dissolve organic matter (DOM). Apparently, the DOM is closely related to dissolve organic carbon (DOC). Estimation of the degree of peat humification has frequently been determined using sodium pyrophosphate solubility index extracting solution. Currently, there was no simple procedure to determine the quality of tropical peatland to produce CO2. A study was conducted to determine the relationship between the potential of tropical peatland to produce carbon dioxide as measured by the sodium pyrophosphate solubility index (PSI) and dissolved organic carbon (DOC) from 3 ecosystems on tropical peatland in Mukah, Sarawak. Composite peat samples at two depths, 0.025 and 25-50 cm were collected from three ecosystems, forest, sago and oil palm ecosystems. The samples were analyzed using the 0.025M sodium pyrophosphate extracting solution (PSI) for the determination on humification; the DOC for water solube C, and Fourier Transform-Infrared (FTIR) spectroscopy for identification of functional groups. The PSI values varied markedly between the three ecosystems with the highest in forest ecosystems with the highest in forest ecosystems (229.85±5.66-231.97±5.42) and the lowest in the oil palm plantation 95.82±0.91-62.49±1.69). Similar trend in the values of DOC were also obtained in all the three ecosystems (0.09±0.013-0.12±0.03%). Oil palm and sago ecosystems contained similar functional groups (amines, ketones, carboxylic acids, alkanes, aldehydes, and alkynes). The sub-soil of sago and forest top soil contained phenyl ring substitution overtones and alkane groups; and forest sub-oil contained amines and alkynes groups. These results suggest that the trend of the carbon dioxide emission produced from tropical peatland is related to the labile C present in each ecosystem.
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