| 摘要: |
| 【目的】 草原刈割利用是我国最常用的草原利用方式，刈割强烈影响草原生态系统呼吸（Re）和甲烷（CH4）的排放，但对草甸草原的影响大小及机制尚未定论。【方法】 文章利用静态箱-气相色谱连用，分析了刈割对呼伦贝尔羊草草甸草原Re和CH4排放的影响。【结果】 （1）与对照相比，刈割处理组2021年和2022年的Re（P<0.01）和CH4（P<0.05）通量显著降低，平均分别降低45.0%和1.2%；2021年刈割和对照处理的Re分别为（10.66±0.24）mg/（m2·h）和（6.05±0.16）mg/（m2·h）；2022年刈割和对照处理的Re分别为（11.52±0.38）mg/（m2·h）和（6.29±0.27）mg/（m2·h）；2021年刈割和对照处理的CH4排放量为（0.43±0.01）mg/（m2·h）和（0.40±0.01）mg/（m2·h）；2022年刈割和对照处理的CH4排放量为（0.43±0.01）mg/（m2·h）和（0.41±0.01）mg/（m2·h）。（2）刈割处理的土壤温度（P<0.05）和土壤湿度（P<0.01）显著增加。（3）函数拟合分析表明地上生物量与Re正相关，土壤湿度与CH4通量正相关。【结论】 呼伦贝尔羊草草甸草原中，刈割处理会显著降低生态系统呼吸和CH4通量，这对于了解和掌握刈割处理下羊草草甸草原温室气体排放特征及其影响机制，准确评估草原生态系统温室气体排放具有重要意义，为草原生态系统碳管理和可持续利用提供了重要依据。 |
| 关键词: 刈割 温性草原 温室气体排放 |
| DOI：10.12105/j.issn.1672-0423.20230204 |
| 分类号: |
| 基金项目:国家自然科学基金委重大项目“不同管理措施下草原生产力和碳汇功能的协同与调控机制”（32192464），国家重点研发计划项目“天然草原智能放牧与草畜精准管控技术集成与应用”（2021YFD1300505） |
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| Effects of mowing on respiration and CH4 emissions in Hulunbuir meadow grassland ecosystems |
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Zhu Wen, Tsegaye Gemechu Legesse, Dong Xiaobing, Shao Changliang
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State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China； National Hulunber Grassland Ecosystem Observation and Research Station； Institute of Agricultural Resources and Regional Planning， Chinese Academy of Agricultural Sciences， Beijing 100081， China
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| Abstract: |
| 【Purpose】 Grassland mowing utilization is the most commonly used grassland utilization method in China，and mowing greatly affects the emission of respiration（Re）and methane in grassland ecosystems，but the size and mechanism of the impact in meadow grassland have not yet been determined.【Method】 The article analysed the effect of mowing on the emission of Re and CH4 in Hulunbuir sheep grassland steppe using static box-gas chromatography.【Result】 The results showed that compared with the control，the flux of Re（P<0.01）and CH4 in 2021 and 2022 were significantly reduced（P<0.05）by an average of 47.0% and 1.2%，respectively. In 2021，the Re values of mowing and control treatments were（10.66±0.24）mg/（m2·h）and（6.05±0.16）mg/（m2·h），respectively. In 2022，the Re values of mowing and control treatment were（11.52±0.38）mg/（m2·h） and（6.29±0.27）mg/（m2·h），respectively. In 2021，CH4 emissions from mowing and control treatment were（0.43±0.01）mg/（m2·h）and（0.40±0.01）mg/（m2·h）. In 2022，CH4 emissions from mowing and control treatment were（0.43±0.01）mg/（m2·h） and（0.41±0.01）mg/（m2·h）. The soil temperature（P<0.05）and soil moisture（P<0.01）increased significantly. Functional fitting analysis showed that aboveground biomass（AGB）was positively correlated with Re，and soil moisture was positively correlated with CH4 flux.【Conclusion】 In Hulunbuir sheep grassland grassland，mowing treatment can significantly reduce ecosystem respiration and CH4 flux，which is of great significance for understanding and mastering the greenhouse gas emissions characteristics and effect mechanism of mutton grass meadow grassland under mowing，accurately assessing the greenhouse gas emissions of grassland ecosystems，and providing an important basis for carbon management and sustainable utilization of grassland ecosystems. |
| Key words: mowing temperate steppe greenhouse gas emissions |
