Greenhouse Gas Fluxes from Tropical Peatland and Global Warming Potential

Tropical peatlands are important sources and sinks of atmospheric methane (CH4) and major sources of carbon dioxide (CO2) and nitrous oxide (N2O). Recently, large areas of tropical peatland have been developed for agriculture plantations in Southeast Asia whereby drainage is a prerequisite, which can increase greenhouse gas (GHG) emissions substantially and therefore, global warming potential (GWP). Despite this, there is still a paucity knowledge on GHG emissions from different ecosystems on tropical peatland and their roles and contribution to the global gas budget. This project was mainly conducted by Dr. Lulie Melling, Department of Agriculture, Sarawak and Dr. R. Hatano, Hokkaido University. The primary objectives are:
  • To quantify the amount of soil CO2 fluc under the forest, sago and oil palm ecosystems and to determine the underlying environmental factors related to soil respiration.
  • To quantify the amount of CH4 flux under the forest, sago and oil palm ecosystems and to determine the underlying environmental factors that explain the differences in CH4 flux among the three ecosystems, particularly the effects of drainage and compaction.
  • To quantitatively determine the rates of N2O emissions from the forest, sago and oil palm ecosystems and to characterize the variations in N2O emissions and relate them to the environmental parameters that control N2O exchange between the soil and the atmosphere.
  • To quantify the effect of urea under oil palm ecosystem on the seasonal CH4 variation and to determine the environmental factors controlling it.
  • To estimate the relative contribution of the individual GHGs under forest, sago and oil palm ecosystems to the net global warming potential (GWP) of the three ecosystems on tropical peatland.

Some major results are:

Tropical peatlands function as a significant source of atmospheric CO2on a global scale.
Dry season in peatland (photo)
Wet season in peatland (photo)
Peat profile
Soil respiration rate was highest in forest ecosystem on tropical peatland compared to oil palm and sago ecosystems.
The oil palm and forest ecosystems on tropical peatland behaved like aerobic system in most months whereas the sago ecosystem remained mainly anaerobic throughout the year. Thus, different factors regulated the activity of greenhouse gases in each ecosystem.
  • For further details,
  • Meilling, L., Hatano, R. and Goh K.J.(2005). Soil CO2 flux from three ecosystems in tropical peatland of Sarawak, Malaysia. Tellus (2005) 57B:1-11.
  • Meilling, L., Hatano, R. and Goh K.J.(2005). Methane fluxes from three ecosystems in tropical peatland of Sarawak, Malaysia. Soil Boilogy and Biochemistry: 1445-1453.

Poster