How can process-based modeling improve peat CO 2 and N 2 O emission factors for oil palm plantations?

Autor: Swails E; Center for International Forestry Research, Jalan CIFOR, Situ Gede, Sindang Barang, Bogor 16115, Indonesia. Electronic address: e.swails@cgiar.org., Hergoualc'h K; Center for International Forestry Research, Jalan CIFOR, Situ Gede, Sindang Barang, Bogor 16115, Indonesia., Deng J; Earth Systems Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, 8 College Road, Durham, NH 03824, USA., Frolking S; Earth Systems Research Center, Institute for the Study of Earth, Oceans and Space, University of New Hampshire, 8 College Road, Durham, NH 03824, USA., Novita N; Yayasan Konservasi Alam Nusantara, Graha Iskandarsyah 3(rd) floor, Jalan Iskandarsyah Raya 66 C, 12160 Jakarta, Indonesia.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Sep 15; Vol. 839, pp. 156153. Date of Electronic Publication: 2022 May 21.
DOI: 10.1016/j.scitotenv.2022.156153
Abstrakt: Oil palm plantations on peat and associated drainage generate sizeable GHG emissions. Current IPCC default emission factors (EF) for oil palm on organic soil are based on a very limited number of observations from young plantations, thereby resulting in large uncertainties in emissions estimates. To explore the potential of process-based modeling to refine oil palm peat CO 2 and N 2 O EFs, we simulated peat GHG emissions and biogeophysical variables over 30 years in plantations of Central Kalimantan, Indonesia. The DNDC model simulated well the magnitude of C inputs (litterfall and root mortality) and dynamics of annual heterotrophic respiration and peat decomposition N 2 O fluxes. The modeled peat onsite CO 2 -C EF was lower than the IPCC default (11 Mg C ha -1 yr -1 ) and decreased from 7.7 ± 0.4 Mg C ha -1 yr -1 in the first decade to 3.0 ± 0.2 and 1.8 ± 0.3 Mg C ha -1 yr -1 in the second and third decades of the rotation. The modeled N 2 O-N EF from peat decomposition was higher than the IPCC default (1.2 kg N ha -1 yr -1 ) and increased from 3.5 ± 0.3 kg N ha -1 yr -1 in the first decade to 4.7-4.6 ± 0.5 kg N ha -1 yr -1 in the following ones. Modeled fertilizer-induced N 2 O emissions were minimal and much less than 1.6% of N inputs recommended by the IPCC in wet climates regardless of soil type. Temporal variations in EFs were strongly linked to soil C:N ratio and soil mineral N content for CO 2 and fertilizer-induced N 2 O emissions, and to precipitation, water table level and soil NH 4 + content for peat decomposition N 2 O emissions. These results suggest that current IPCC EFs for oil palm on organic soil could over-estimate peat onsite CO 2 emissions and underestimate peat decomposition N 2 O emissions and that temporal variation in emissions should be considered for further improvement of EFs.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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