Xilin Golmeng Meteorological Bureau, Xilinhot 026000, Inner Mongolia, China.
Xilinhot National Climate Observatory, Xilinhot 026000, Inner Mongolia, China.
Ying Yong Sheng Tai Xue Bao. 2023 Jun;34(6):1509-1516. doi: 10.13287/j.1001-9332.202306.006.
To understand carbon sequestration capacity of grasslands, the changes of CO flux in Xilinhot grasslands and the influence of environmental factors were analyzed by using the eddy data of Xilinhot National Climate Observatory in 2018-2021, and the distribution of flux source areas was analyzed. The results showed that the southwest wind prevailed in the study area throughout the year, the source area in the growing season was larger than that in the non-growing season, and the source area under stable atmospheric conditions was larger than that under unstable conditions. The maximum length of source region with a contribution rate of 90% was close to 400 m, which was consistent with the length estimated by the classical law. The net ecosystem exchange (NEE) of Xilinhot grasslands had obvious diurnal and seasonal dynamics, which was manifested as a carbon sink in the daytime and a carbon source at night during the growing season and weak carbon source in the non-growing season. From 2018 to 2021, the annual total NEE were -15.59, -46.28, -41.94, and -78.14 g C·m·a, respectively, with an average value of -45.49 g C·m·a, indicating that Xilinhot grassland had strong carbon sequestration capacity. Vapor pressure deficit and photosynthetically active radiation helped grasslands absorb atmospheric CO. At night, when temperature was above 0 ℃, the increases in air and soil temperature promoted vegetation respiration to release CO.
为了了解草原的碳固存能力，利用 2018-2021 年锡林浩特国家气候观测站的涡度数据，分析了锡林浩特草原 CO 通量的变化及其环境因素的影响，并分析了通量源区的分布。结果表明，研究区全年盛行西南风，生长季源区大于非生长季源区，稳定大气条件下的源区大于不稳定大气条件下的源区。贡献率为 90%的源区最长长度接近 400 m，与经典定律估计的长度一致。锡林浩特草原的净生态系统交换（NEE）具有明显的日变化和季节变化，表现为生长季白天为碳汇，夜间为碳源，非生长季为弱碳源。2018-2021 年，年总 NEE 分别为-15.59、-46.28、-41.94 和-78.14 g C·m·a，平均值为-45.49 g C·m·a，表明锡林浩特草原具有较强的碳固存能力。水汽压亏缺和光合有效辐射有助于草原吸收大气中的 CO。夜间，当温度高于 0℃时，空气和土壤温度的升高促进了植被呼吸释放 CO。
