Arid Zone Research ›› 2020, Vol. 37 ›› Issue (5): 1183-1193.doi: 10.13866/j.azr.2020.05.11

Previous Articles     Next Articles

Study on CO2, CH4, and N2O emissions from reed wetlands in typical freshwater lake and saltwater lake in Xinjiang

WANG Shun-ke1,2, LI Yan-hong1,2, LI Fa-dong1,2,3,4, WANG Jin-long1,2   

  1. (1. College of Geographic Science and Tourism, Xinjiang Normal Univeristy, Urumqi 830054, Xinjiang, China; 2. Key Laboratory of Xinjiang Uygur Autonomous Region, Xinjiang Laboratory of Lake Environment and Resource in Arid Area, Urumqi 830054, Xinjiang, China; 3. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; 4. College of Resources and Environment,University of Chinese Academy of Sciences, Beijing 100190, China)
  • Received:2020-06-16 Revised:2020-07-17 Online:2020-09-15 Published:2020-12-16

Abstract: We compare and analyze the monitoring data of Bosten Lake, China’s largest inland freshwater lake, and Ebinur, Xinjiang’s largest saltwater lake, from December 2016 to November 2017, using static chamber gas chromatography, researching the difference of soil greenhouse gas emissions between typical freshwater lake and saltwater lake reed wetlands in Xinjiang. It showed that (1) by analyzing the average daily emissions during the observation period, it is found that the CO2 emission trend of the freshwater lake shows a single peak curve, and the CH4 emission trends at the adjacent time points are not prominent. The N2O of freshwater lake and saltwater lake are between 9 o’clock and 13 o’clock, and the differences in emissions between 17:00 and 21:00 were not obvious. (2) The seasonal changes of soil CO2, CH4, and N2O in the freshwater lake and saltwater lake reed wetlands showed a single peak curve trend. The peak of greenhouse gas emissions was mainly concentrated in summer. The peak of saltwater lake N2O emissions appeared in autumn. There were no significant differences in CO2 and N2O emissions between the freshwater lake and the saltwater lake (P>0.05), The difference of CH4 emissions between the two lakes is significant (P<0.05). (3) Lake wetlands store large amounts of greenhouse gases in winter. The release of CO2, CH4, and N2O from Bosten Lake in the spring melt accounts for 22%, 30%, and 12% of the total cumulative emissions for the year, and Lake Ebinur accounted for 40%, 0.8%, and 47%. (4) The effects of soil temperature, soil moisture content, and soil organic matter on the CO2 emissions of the saltwater lake were weak. pH inhibited N2O emissions from Bosten Lake, and soil salinity had a strong inhibitory effect on CO2 and CH4 emissions from Ebinur. (5) The global warming potential of lake reed wetland soil in arid areas was as follows: freshwater lake > saltwater lake. Both the freshwater lake and the saltwater lake reed wetlands contribute to global warming on the centennial scale.

Key words: Bosten Lake, Ebinur Lake, greenhouse gases, freeze-thaw, global warming potential