Ecosystem-scale methane flux in tropical peat swamp forest in Indonesia
Ecosystem-scale methane flux in tropical peat swamp forest in Indonesia
复制标题
印度尼西亚热带泥炭沼泽森林生态系统规模的甲烷通量
DOI：
10.1111/gcb.14410
复制
发表时间：
2018
影响因子：
11.6
通讯作者：
Kusin Kitso
中科院分区：
文献类型：
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作者：
Sakabe Ayaka;Itoh Masayuki;Hirano Takashi;Kusin Kitso
目前，全球CH4预算中缺乏热带泥炭地生态系统尺度CH4通量的数据。虽然印度尼西亚的泥炭地是东南亚泥炭碳含量最高的地区，但生态系统规模的CH4预算尚未报告，尽管这些泥炭地有可能排放CH4。我们观察了1年的变化，在生态系统尺度的CH4通量在不排水的次生泥炭沼泽森林在加里曼丹中部，印度尼西亚，使用涡度协方差法。我们发现，泥炭沼泽森林从旱季的CH4汇（低至− 8.9 mg C m − 2day − 1）转变为雨季的CH4源（高达10.7 mg C m − 2day − 1），这取决于地下水位（GWL）的变化。丰水期的高GWL促进了表层有机质含量较高的厌氧CH4的产生。然而，CH4排放量也增加时，GWL下降，在旱季在雨季。研究的热带泥炭沼泽森林的CH4年收支（0.09 - 0.17 g C m − 2year − 1）远低于北方、温带和亚热带湿地。我们发现，CH4通量几乎没有影响全球变暖的气体收支的泥炭沼泽森林，值只有百分之几，低于CO2通量在同一地点。此外，我们还进行了厌氧土壤培养实验，以研究土地利用变化对CH4产生的影响。结果表明，未排水森林土壤的CH4产生潜力远高于排水或排水和燃烧的前森林土壤。然而，虽然CH4生产下降排水土壤相对于不排水土壤，保护原始泥炭沼泽森林具有高GWL是重要的，以抑制全球变暖，因为CO2排放量增加排水泥炭地。
Data on ecosystem‐scale methane (CH4) fluxes in tropical peatlands are currently lacking in the global CH4budget. Although the waterlogged Indonesian peatlands contain the largest share of peat carbon in South‐East Asia, ecosystem‐scale CH4budgets have not yet been reported, although these peatlands have the potential to emit CH4. We observed 1‐year variations in the ecosystem‐scale CH4flux in an undrained secondary peat swamp forest in central Kalimantan, Indonesia, using the eddy covariance method. We found that the peat swamp forest switched from being a CH4sink during the dry season (as low as −8.9 mg C m−2day−1) to a source of CH4during the wet season (up to 10.7 mg C m−2day−1), and this was dependent on changes in the groundwater level (GWL). The high GWL during the wet season enhanced the anaerobic CH4production in the surface layer that had more labile organic matter. However, the CH4emission also increased when the GWL dropped during dry spells in the wet season. The annual CH4budget in the studied tropical peat swamp forest (0.09–0.17 g C m−2year−1) was much lower than that in northern, temperate, and subtropical wetlands. We found that CH4fluxes had almost no effect on the global warming gas budget of the peat swamp forest, and values were only a few percent less than the CO2fluxes at the same site. In addition, we conducted anaerobic soil incubation experiments to examine the effect of land‐use change on CH4production. The results indicated much higher CH4production potential in undrained forest soil than in drained or drained and burned ex‐forest soils. However, although CH4production decreased in drained soils relative to undrained soils, conserving pristine peat swamp forests with high GWLs is important to suppress global warming because CO2emissions increase in drained peatlands.