Soil CO2 flux from tropical peatland under different land clearing techniques

Measurement of C02 flux was carried out at five sites at MARDI Peat Research Station in Sessang, Sarawak. The sites represented four different types of land clearing technique namely felling and burning (FB), felling and stacking-outside the plot (FSO), felling, stacking and chipping (FSC), and selective clearing (SC). The C02 flux was measured using static chamber method connected to a portable C02 infrared gas analyser. Soil C02 -C flux exhibited diurnal pattern with peak rates as high as 950 mg m~2 h1 occurred during the mid afternoon (1100-1300). Emission of C02 was highly correlated with soil temperature (r2 = 0.86) and water table (r2 = 0.63). Annual C02 flux from the peat soil surface varies significantly among land clearing techniques. The highest estimated annual carbon loss as C02 emission was 48.3 t/ha/year under FB area. The FSO and FSC land clearing methods significantly reduced the emission of C02 with the estimated C loss around 33 t/ha/year. Annual emissions of C02 from SC are lower compared to other land clearing techniques. There were no significant differences between the annual C02 flux from SC and undisturbed forest.