HR: 0830h
AN: B11D-0719    [PDF]
TI: The El Ni\~{n}o Drought and its Consequent Peatland Fires Changed CO$_{2}$ Exchange of a Tropical Peat Swamp Forest in Central Kalimantan, Indonesia
AU: * Hirano, T
EM: hirano@env.agr.hokudai.ac.jp
AF: Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, 060-8589 Japan
AU: Segah, H
AF: Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, 060-8589 Japan
AU: Limin, S H
AF: University of Palangkaraya, Kampus Tunjung Nyaho, Palangkaraya, 73111 Indonesia
AU: June, T
AF: Biotrop-ICSEA, Seameo-Biotrop, Jl. Raya Tajur Km. 6, Bogor, 16710
AU: Hirata, R
AF: Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, 060-8589 Japan
AU: Osaki, M
AF: Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, 060-8589 Japan
AB: Peatlands existing in the tropics have accumulated a large amount of carbon as organic matter. Indonesia contains the largest area of tropical petlands, and the petalands usually coexist with tropical peat swamp forests. Recently, however, deforestation and drainage are in progress on a large scale owing to a growing demand for timber and farmlands. In addition, the El Ni\~{n}o drought and its consequent large-scale fires are accelerating the devastation of the peatlands. The devastation promotes the decomposition of organic matter stored in peatlands, and consequently increases carbon release to the atmosphere as CO$_{2}$. This suggests that tropical peatlands will be a major CO$_{2}$ source in the near future. To evaluate the CO$_{2}$ balance of tropical peatlands, we have measured CO2 flux above a tropical peat swamp forest left in a devastated area in Central Kalimantan, Indonesia since November 2001. In 2002 the El Ni\~{n}o event occurred, and the consequent drought caused large-scale peatland fires in Central Kalimantan. The fires, which surrounded the forest, emitted smoke and decreased solar irradiance on the forest in September and October. Consequently, GPP decreased rapidly and NEE increased up to 8 mol m$^{-2}$ month$^{-1}$ in September, although NEE had been around zero until August, before the El Ni\~{n}o fires. Relatively large positive NEE continued until December. Annual NEE, ecosystem respiration, GPP in 2002 was 27.3 (= 3.28 tC ha$^{-1}$), 326.6 and -299.3 mol m$^{-2}$ respectively. In 2002 the tropical peat swamp forest was a large CO$_{2}$ source, although the forest was not burnt by the fires.
DE: 0315 Biosphere/atmosphere interactions
DE: 1615 Biogeochemical processes (4805)
DE: 1630 Impact phenomena
DE: 3322 Land/atmosphere interactions
SC: Biogeosciences [B]
MN: 2003 Fall Meeting