Is Water Table the Most Important Factor Influencing Soil C Flux in Tropical Peatland?

Authors:
Lulie Melling, Kah Joo Goh, Angelyn Kloni, Ryusuke Hatano

Book:
Proceedings of the 14th International Peat Congress

Venue:
Stockholm

Keywords:
carbon-flux, ch4, co2, tropical-peatland, water-table

Documentfile:
Melling et al 2012: Is Water Table the Most Important Factor Influencing Soil C Flux in Tropical Peatland?

Summary:

Theme IX. Tropical peatlands

SUMMARY

This paper aims to further investigate the role of the water table on soil carbon (C) flux in tropical peatland. Closed-chamber measurements were conducted for 12 months at an oil palm plantation, logged-over peat swamp forest and tropical peat swamp forest. The mean water table levels at these three (3) ecosystems were -67.6 cm, -14.7 cm and -3.9 cm, respectively. Mean soil CH4 flux was lowest at the oil palm plantation (24.0 μg C m-2 h-1), followed by logged-over peat swamp forest (577.8 μg C m-2 h-1) and tropical peat swamp forest (1532.8 μg C m-2 h-1). However, even though the mean water table levels in the three ecosystems differed by an average of 42.5 cm, the mean soil CO2 fluxes were quite similar: oil palm plantation (102.5 mg C m-2 h-1), logged-over peat swamp forest (128.1 mg C m-2 h-1) and tropical peat swamp forest (140.5 mg C m-2 h-1). These findings indicated that on tropical peatland soil CH4 flux was highly influenced by water table but not soil CO2 flux. Since the total soil CH4 flux was much lower compared with soil CO2 flux, it was concluded that water table was not the most important factor influencing the soil C flux in tropical peatland.