Variation in Soil Properties Regulate Greenhouse Gas Fluxes and Global Warming Potential in Three Land Use Types on Tropical Peat

This study investigated spatial factors controlling CO₂, CH₄, and N₂O fluxes and compared global warming potential (GWP) among undrained forest (UDF), drained forest (DF), and drained burned land (DBL) on tropical peatland in Central Kalimantan, Indonesia. Sampling was performed once within two weeks in the beginning of dry season. CO₂ flux was significantly promoted by lowering soil moisture and pH. The result suggests that oxidative peat decomposition was enhanced in drier position, and the decomposition acidify the peat soils. CH₄ flux was significantly promoted by a rise in groundwater level, suggesting that methanogenesis was enhanced under anaerobic condition. N₂O flux was promoted by increasing soil nitrate content in DF, suggesting that denitrification was promoted by substrate availability. On the other hand, N₂O flux was promoted by lower soil C:N ratio and higher soil pH in DBL and UDF. CO₂ flux was the highest in DF (241 mg C m⁻² h⁻¹) and was the lowest in DBL (94 mg C m⁻² h⁻¹), whereas CH₄ flux was the highest in DBL (0.91 mg C m⁻² h⁻¹) and was the lowest in DF (0.01 mg C m⁻² h⁻¹), respectively. N₂O flux was not significantly different among land uses. CO₂ flux relatively contributed to 91–100% of GWP. In conclusion, it is necessary to decrease CO₂ flux to mitigate GWP through a rise in groundwater level and soil moisture in the region. View Full-Text