Soil greenhouse gas emissions reduce the contribution of mangrove plants to the atmospheric cooling effect

作者：Guangcheng Chen, Бин Чэн, Dan Yu, N.F.Y. Tam, Yong Ye, Shunyang Chen · 发表于：Environmental Research Letters · 年份：2016 · DOI：10.1088/1748-9326/11/12/124019 · 被引用次数：94 · 研究领域：Coastal wetland ecosystem dynamics、Peatlands and Wetlands Ecology、Geology and Paleoclimatology Research

Mangrove soils have been recognized as sources of greenhouse gases, but the atmospheric fluxes are poorly characterized, and their adverse warming effect has rarely been considered with respect to the potential contribution of mangrove wetlands to climate change mitigation. The current study balanced the warming effect of soil greenhouse gas emissions with the plant carbon dioxide (CO 2 ) sequestration rate derived from the plants' net primary production in a productive mangrove wetland in South China to assess the role of mangrove wetlands in reducing the atmospheric warming effect. Soil characteristics were also studied in the summer to examine their relationships with gas fluxes. The soil to atmosphere fluxes of nitrous oxide (N 2 O), methane (CH 4 ) and CO 2 ranged from −1.6 to 50.0 μ g m −2 h −1 , from −1.4 to 5360.1 μ g m −2 h −1 and from −31 to 512 mg m −2 h −1 , respectively, which indicated that the mangrove soils act as sources of greenhouse gases in this area. The gas fluxes were higher in summer than in the cold seasons and were variable across mangrove sites. Gas fluxes in summer were positively correlated with the soil organic carbon, total nitrogen, and ammonia contents. The mangrove plants sequestered a considerable amount of atmospheric CO 2 at rates varying from 3652 to 7420 g CO 2 m −2 yr −1 . The ecosystem acted as a source of CH 4 and N 2 O gases but was a more intense CO 2 sink. However, the warming effect of soil gas emissions accounted for 9.3–32.7% of...