Jyrki Jauhiainen, Aljosja Hooijer
Proceedings of the 14th International Peat Congress
ch4, co2, drainage, land-use-change, n2o
Theme IX. Tropical peatlands
Peat surface CO2, CH4 and N2O emissions, groundwater table depth and peat temperature were monitored along transects in an Acacia tree plantation on thick tropical peat in Sumatra, Indonesia. The autotrophic root respiration was separated from heterotrophic CO2 emissions resulting from organic matter decomposition. There was a positive correlation between mean long-term water table depth and heterotrophic CO2 emission. On average, the contribution of autotrophic respiration to daytime CO2 emission was 21% in mature Acacia stands. At locations 0.5 m from trees this was up to 80% of the total emissions, but it was negligible at locations more than 1.3 m away. Mean cumulative daytime heterotrophic CO2 emission was 94 t ha-1 y-1 at a mean water table depth of 0.8 m, with a minimum emission of 80 t ha-1 y-1 after correction for the effect of diurnal temperature fluctuations. CO2 formed 90%, CH4 0.3% and N2O 9.7% of the total emission GWP impact of these gases along all transects combined.