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研究了植物生长季节海北高寒草甸生态系统高寒嵩草草甸覆被下草毡寒冻雏形土的 CO2 释放速率。其结果表明 :CO2 释放速率有明显的日变化和季节动态。日最大排放速率多出现在 1 4 :0 0～ 1 6:0 0时 ,最小排放速率在 6:0 0～ 8:0 0时。植物生长季日最大振幅为 797.75mg/m2·h,最小振幅 1 97.33mg/m2·h。CO2 排放白天大于夜晚。不同物候期 CO2 释放速率不同 ,其顺序为草盛期 >枯黄期 >返青期。生长季土壤 CO2 释放速率的范围是 4 41 .72 mg/m2 · h± 1 55.2 9mg/m2· h,最大日均值为 681 .0 6mg/m2 · h( 7月 1 6日 ) ,最低值 1 76.65mg/m2 · h ( 6月 1日 )。退化草地土壤 CO2 释放速率明显低于未退化草地 ,生长季平均日均值低 1 37.4 7mg/m2·h。相关分析表明 :土壤 CO2 排放速率与气温、地表温度、土壤5cm、1 0 cm、1 5cm、2 0 cm、30 cm地温均呈显著和极显著相关关系。温度是影响土壤 CO2 释放速率的主要因子。
The CO2 release rate of felled frozen soil under the cover of the Alpine Kobresia meadow in the Haibei alpine meadow ecosystem during the plant growing season was studied. The results showed that: CO2 release rate obvious diurnal changes and seasonal dynamics. The maximum daily discharge rate appears at 14: 0 0 ~ 16: 0 0, the minimum discharge rate is 6: 0 0 ~ 8: 0 0. The maximum amplitude of plant growth season was 797.75 mg / m 2 · h and the minimum amplitude was 97.33 mg / m 2 · h. CO2 emissions are greater than nighttime during the day. The CO2 release rates in different phenophases were different, the order of which was grassy> yellowing> greening. The range of soil CO2 release rate during the growing season was 4 41.72 mg / m 2 · h ± 1 55.2 9 mg / m 2 · h and the maximum daily average was 681.0 6 mg / m 2 · h (July 16) with the lowest 1 76.65mg / m2 · h (June 1). The degradation rate of CO2 in degraded grassland was significantly lower than that of non-degraded grassland, and the average daily average of growth season was 1 37.4 7mg / m2 · h. Correlation analysis showed that the soil CO2 emission rate had a significant and highly significant correlation with air temperature, surface temperature, soil temperature of 5cm, 10cm, 15cm, 20cm and 30cm. Temperature is the main factor affecting soil CO2 release rate.