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

摘要

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 x 109CNY (Chinese Yuan), those of paddy fields were from 1.41 to 3.20 x 109CNY; and from uplands were from 0.26 to 0.49 x 109CNY. 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.