[A-CG39] 陸域生態系の物質循環

[ACG39-02] インドネシア・中部カリマンタン州の熱帯泥炭林における二酸化炭素収支

*平野 高司¹、大久保 晋治郎¹、伊藤 雅之²、都築 勇人³、坂部 綾香⁴、高橋 英紀⁵、クシン キッソ⁶、大崎 満¹ (1.北海道大学、2.兵庫県立大学、3.愛媛大学、4.京都大学、5.北海道水文気候研究所、6.パランカラヤ大学)

キーワード：渦相関法、排水、火災、干ばつ、ENSO

Tropical peat swamp forest (PSF) is a unique ecosystem rich in carbon and water, which is widely distributed in Southeast Asia’s coastal lowlands, mainly in Borneo, Sumatra, and Malay Peninsula. This ecosystem has accumulated a huge amount of organic carbon in peat soil over millennia under the condition of high groundwater level. However, PSF has been reduced and degraded by logging, drainage, and burning during the last two decades. Such human disturbances change its carbon dioxide (CO₂). Drainage potentially increases CO₂ emissions through enhanced oxidative peat decomposition because of groundwater level lowering. Thus, it is essential to assess the CO₂ balances of PSFs in different disturbance conditions to understand the role of PSF in the regional and global environments. We had continuously measured eddy CO₂ and energy fluxes above three peat ecosystems of a little drained PSF, a drained PSF, and a degraded PSF by burning and drainage in Central Kalimantan, Indonesia for more than 12 years. Based on the long-term monitoring data, I’ll talk about the effects of human and natural disturbances due to drainage, burning, and ENSO drought.