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在中国科学院海北高寒草甸生态系统定位站，研究放牧强度对土壤CO２释放速率的影响及其与环境条件的关系。结果表明，CO２释放速率具有明显的日变化规律，日最大值在12∶00～14∶00h出现，最低值出现于凌晨6∶00～8∶00h。轻牧和重牧区日释放速率分别为7.774±5.577 g·m－２·d －１和6.977±4.947 g·m－２·d－１。CO２释放速率具有明显的季节变化，最大值均出现在7月，而冬季则最低。CO２释放速率的日变化主要受气温和地表温度的制约，与气温和地表温度呈极显著的正相关(P＜0.01)。CO２释放速率的季节动态与气温和地温(0～30cm)呈极显著的正相关(P＜0.01)。放牧使CO2释放速率降低。
The effect of grazing intensity on the release rate of soil CO2 and its relationship with environmental conditions were studied at Haibei Alpine Meadow Ecosystem Positioning Station, Chinese Academy of Sciences. The results showed that there was a clear diurnal variation of the rate of CO2 release. The daily maximum appeared at 12:00 ~ 14:00 h, and the lowest appeared at 6:00 ~ 8:00 h. The daily release rates in light grazing and heavy grazing areas were 7.774 ± 5.577 gm-2d-1 and 6.977 ± 4.947 gm-2d-1, respectively. There was a clear seasonal change in the rate of CO2 release, with the maximum occurring in July and the lowest in winter. The diurnal variation of CO2 release rate was mainly controlled by air temperature and surface temperature, and had a significant positive correlation with air temperature and surface temperature (P <0.01). The seasonal dynamics of CO2 release rate was significantly and positively correlated with air temperature and ground temperature (0-30 cm) (P <0.01). Grazing reduces the rate of CO2 release.