Evaluation of greenhouse gas emissions from wetland and agriculture ecosystems in Sanjiang Plain

Abstract

Carbon dioxide (CO₂), nitrous oxide (N₂O) and methane (CH₄) are important greenhouse gases (GHGs). The objective of this study is to quantify the aggregate GHG (CH₄, N₂O and CO₂) emissions and estimate economic losses of three ecosystems (marsh, paddy field and upland) in the Sanjiang Plain, excluding the Muling-Xiangkai Plain, south of Wanda Mountain. The results indicate the economic losses from GHG emissions of marshes were from 6.40 to 7.75 × 10⁹ CNY (Chinese Yuan), those of paddy fields were from 1.41 to 3.20 × 10⁹ CNY; and from uplands were from 0.26 to 0.49 × 10⁹ CNY. Using linear trend analysis, the economic losses through GHG emissions of marshes fell between 1982 and 2005, but those from paddy fields and uplands increased. In our study, the sequence in magnitude of the economic losses from GHG emissions was: marshes > paddy fields > uplands. In fact, the economic value of GHG emissions was negative because of these adverse impacts on the environment. This article could provide a reference for calculation of GHG exchange. The results suggest that improvement of fertiliser use efficiency for more precise agricultural management and returning straw to cropland could mitigate GHG emissions and would help to achieve sustainable development.

Keywords:

• GHG fluxes
• CO₂-C equivalent
• economic losses
• greenhouse effects
• sustainable development

Acknowledgements

The work was financially supported by the National Natural Science Foundation of China (No. 40830535, No. 41001110 and No. 40901065), the National Basic Research Program of China (973 Program) (2009CB421103), and the Frontier of NEIGAE, CAS (No. KZCX3-SW-NA09-04). It was also supported by the Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences. The remote sensing data was from Zhang Shuqing and his remote sensing group at the Northeast Institute of Geography and Agroecology.