Global warming phenomenon ought to be affected by converting peat swamp forest to agricultural fields since peat contains huge amounts of soil carbon and nitrogen.  The emissions of greenhouse gases were examined in forest and agricultural fields of coastal and inland peat of Kalimantan in order to elucidate the global warming effect of converting forest to agricultural fields.  Three land-use (i.e., secondary forest, paddy field and rice-upland crop rotation field) were selected in each of coastal peat and inland peat, respectively.  The emission of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) were measured in monthly basis and calculated for one year period.  Climatic and edapict data of the studied area were also collected to understand the mechanism involved in greenhouse gas dynamics in tropical peatlands.  Converting forest to agricultural fields affected the CO2, CH4 and N2O emission and soil properties.  In inland peat, for example, annual emission of N2O was the highest (nearly 1.4 g N m-2y-1) from forest (site A-1), while there was no significant difference in annual N2O emission from paddy fields (site A-2) and mixture-crop fields (site A-3).  Paddy fields (site A-2) emitted annually more CH4 compared to other land-uses.  There was no significant different in annual CH4 emission among the two other land-uses.  The annual CO2 emission was the highest (about 3.5 kg C m-2y-1) in forest (site A-1), followed by mixture-crop fields (site A-3) (about 2.0 kg C m-2y-1).  Paddy fields (A-2) had the lowest CO2 emission (about 1.4 kg C m-2y-1).  Number of bacteria and fungi in agricultural fields was comparable to or 10 times lower than that of forest.  Similarly, the number of NH4+ oxidizers and denitrifiers in agricultural fields were 10 to 100 times lower than that in forest.  However, considering the global warming potential, converting forest to agricultural fields had no effect or some cases even decreased the greenhouse gas emissions.  This probably due to the decrease in number of bacteria and fungi releasing CO2.  Climatic factors has also affected the emissions of greenhouse gases, especially methane emissions from coastal peat were positively correlated with precipitation. 

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