Hydrologic Control of CO2 Fluxes from Tropical Peat
Abstract
Hydrological processes play an important role in tropical peat swamp forests. High water levels inhibit decomposition due to anoxic conditions. This study examines the extent to which water level controls CO2 fluxes from tropical peat. Peat surface CO2 emissions were measured with high frequency using an automated chamber system and were compared against the groundwater table depth and temperature. Measurements were taken over five months in a peat forest in Brunei Darussalam which was deforested but not drained. Over the study period water levels varied from 35cm below the peat surface to 20cm above the surface. For low water levels, CO2 flux increased with temperature and emissions followed a diurnal cycle with larger daytime fluxes. For higher water levels temperature had little effect on emissions. Overall, water level in the peat was the strongest driver of peat surface CO2 fluxes. CO2 flux increased linearly with increasing depth to water table, when the water table was below the peat surface. Under flooded conditions, fluxes were small and constant. This forest is flooded throughout much of the year, leading to a strong seasonal cycle in peat surface CO2 emissions. Changes in future climate and corresponding changes in hydrology will affect regional emissions due to peat exposure.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMPP12B..04H
- Keywords:
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- 0428 BIOGEOSCIENCES Carbon cycling;
- 1813 HYDROLOGY Eco-hydrology