EGU2020-21496, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-21496
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Ecosystem-scale measurements of CO2 and CH4 fluxes from a tropical peatland in Sarawak, Malaysia

Frankie Kiew1, Guan Xhuan Wong1, Ryuichi Hirata2, Angela Tang1, and Lulie Melling1
Frankie Kiew et al.
  • 1Sarawak Tropical Peat Research Institute, Environmental Research Division, Kota Samarahan, Sarawak, Malaysia
  • 2Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba 305-8506, Japan

Tropical peatlands of Southeast Asia are a globally important carbon reservoir, storing an enormous amount of soil organic carbon as peat. These ecosystems are complex and poorly understood with large unknown biogeochemical processes. Despite the huge carbon stocks in these ecosystems, data on ecosystem-scale carbon dioxide (CO2) and methane (CH4) fluxes are still limited in comparison with mid- and high-latitude peatland ecosystems. The recent increase in the intensity of climate anomaly such as El Niño may alter the hydrological regime of this ecosystem, thus affects its carbon cycling. It is crucial to quantify the CO2 and CH4 fluxes of the ecosystem and understand their responses to environmental changes to predict the role of peat swamp forest in global carbon cycles. To date, the application of the eddy covariance technique to measure the ecosystem-scale CO2 and CH4 fluxes in tropical peatlands is still limited to few studies in Malaysia and Indonesia.

In 2010, we established a long-term greenhouse gas fluxes monitoring using the eddy covariance technique over a peat swamp forest in Sarawak, Malaysia. Here, we present the net ecosystem exchange of CO2 (NEE) and CH4 (FCH4) from February 2014 to January 2017 (3 years). We had quantified the NEE and FCH4, the diurnal and seasonal variations of NEE and FCH4, and the response of NEE and FCH4 to GWL. The FCH4 was determined half-hourly as the sum of eddy CH4 flux and CH4 storage change in an air column below the flux measurement height. We had determined the global warming potential of this ecosystem from annual NEE and FCH4 using sustained-flux global warming potential (SGWP).  The annual FCH4 was converted into a CO2 equivalent unit using an SGWP factor of 45 which represents the SGWP for CH4 over a timescale of 100 years. Our preliminary result showed that the CH4 emission potentially offset the CO2 sequestration, which was higher than those reported in other regions in the world.

How to cite: Kiew, F., Wong, G. X., Hirata, R., Tang, A., and Melling, L.: Ecosystem-scale measurements of CO2 and CH4 fluxes from a tropical peatland in Sarawak, Malaysia, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21496, https://doi.org/10.5194/egusphere-egu2020-21496, 2020