CO_2,CH_4 and N_2O flux changes in degraded grassland soil of Inner Mongolia,China |
| |
| Authors: | BAI Yunxiao LI Xiaobing WEN Wanyu MI Xue LI Ruihua HUANG Qi ZHANG Meng |
| |
| Institution: | 1.Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China;2. State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing100875, China;3. Institute of Wetland Research, Chinese Academy of Forestry, Beijing 100091, China;4. School of Surveying & Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, China; |
| |
| Abstract: | The main purpose of this study was to explore the dynamic changes of greenhouse gas(GHG)from grasslands under different degradation levels during the growing seasons of Inner Mongolia, China.Grassland degradation is associated with the dynamics of GHG fluxes, e.g., CO_2, CH_4 and N_2O fluxes. As one of the global ecological environmental problems, grassland degradation has changed the vegetation productivity as well as the accumulation and decomposition rates of soil organic matter and thus will influence the carbon and nitrogen cycles of ecosystems, which will affect the GHG fluxes between grassland ecosystems and the atmosphere. Therefore, it is necessary to explore how the exchanges of CO_2,CH_4 and N_2O fluxes between soil and atmosphere are influenced by the grassland degradation. We measured the fluxes of CO_2, CH_4 and N_2O in lightly degraded, moderately degraded and severely degraded grasslands in Inner Mongolia of China during the growing seasons from July to September in 2013 and 2014. The typical semi-arid grassland of Inner Mongolia plays a role as the source of atmospheric CO_2 and N_2O and the sink for CH_4. Compared with CO_2 fluxes, N_2O and CH_4 fluxes were relatively low. The exchange of CO_2, N_2O and CH_4 fluxes between the grassland soil and the atmosphere may exclusively depend on the net exchange rate of CO_2 in semi-arid grasslands. The greenhouse gases showed a clear seasonal pattern, with the CO_2 fluxes of –33.63–386.36 mg/(m·h), CH_4 uptake fluxes of 0.113–0.023 mg/(m·h) and N_2O fluxes of –1.68–19.90 μg/(m·h). Grassland degradation significantly influenced CH_4 uptake but had no significant influence on CO_2 and N_2O emissions. Soil moisture and temperature were positively correlated with CO_2 emissions but had no significant effect on N_2O fluxes.Soil moisture may be the primary driving factor for CH_4 uptake. The research results can be in help to better understand the impact of grassland degradation on the ecological environment. |
| |
| Keywords: | grassland degradation semi-arid grassland greenhouse gases CO2 CH4 N2O Inner Mongolia |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《干旱区科学》浏览原始摘要信息 |
| 点击此处可从《干旱区科学》下载免费的PDF全文 |
|
