[A-CG39] 陸域生態系の物質循環

[ACG39-05] 熱帯泥炭地のオイルパーム農園における二酸化炭素収支

*平野 高司¹、Frankie Kiew²、平田 竜一³、Guan Xhuan Wong²、Edward Baran Aries²、Kevin Kemudang²、Joseph Wenceslaus²、Lo Kim San²、Lulie Melling² (1.北海道大学大学院農学研究院、2.サラワク州熱帯泥炭研究所、3.国立環境研究所地球環境研究センター)

キーワード：CO2フラックス、渦相関法、熱帯泥炭林、森林伐採、排水

Oil palm plantations have been expanding rapidly over recent decades especially in Indonesia and Malaysia, the two largest oil palm producers in the world. The greatest concern associated with such expansion is its environmental impact. Carbon rich tropical peat swamp forest is also not excluded from such expansion, because it is accessible for developers. Carbon dioxide (CO₂) release through accelerated oxidative peat decomposition is one of the main environmental concerns in the land conversion from peat swamp forest into oil palm plantations, which were drained and compacted to increase yield. Changes in aboveground biomass also might significantly alter the CO₂ exchange dynamics of the ecosystems. Despite the possible significant changes in the CO₂ balance through the land conversion, there is still no study on the ecosystem-scale CO₂ balance of oil palm plantations established on tropical peat. Thus, we have monitored CO₂ flux above an oil palm plantation established on tropical peatland in Sarawak, Malaysia by the eddy covariance technique since 2011. We quantify the annual CO₂ balance of the oil palm plantation and compare it with that of a secondary peat swamp forest in the same region.