桑科草原不同草地利用方式土壤呼吸的动态研究

Studyon soil respiration rate of alpine meadow under different utilization patterns in Sangkok of Gansu

为探寻更加合理的草地利用方式,以甘肃省夏河县桑科乡高寒草原为研究区,分别设置放牧草地,放牧＋施肥草地,放牧＋划破补播草地、封育草地、人工草地处理,测定不同草地利用方式土壤呼吸的动态变化。结果表明：（1）土壤呼吸速率大小顺序为放牧＋施肥〉人工〉封育〉放牧＋划破补播〉放牧,最大值10.41μmol/（m^2·s）,最小值4.69μmol/（m^2·s）,日变化和季节变化均呈单峰曲线,日变化峰值出现在13∶00-14∶00,7月各处理土壤呼吸速率达最大。（2）土壤呼吸温度敏感性Q10值为放牧＋施肥〉放牧〉人工〉放牧＋划破补播〉封育,最大值1.826,最小值1.157。（3）土壤呼吸与土壤湿度的非线性相关关系P值大小为放牧＋划破补播〈放牧〈人工〈封育〈放牧＋施肥。放牧＋施肥处理为最优草地利用方式。

In order to explore better grassland utilization and management,the soil respiration of alpine meadow under different utilization patterns（grazing,grazing＋fertilizing,grazing＋reseeding,sward ripping,zero grazing,sown pasture）was studied in Sangkok of Gansu Province.The results showed that the rank of soil respiration rate was grazing＋fertilizing 〉sown pasture〉zero grazing 〉grazing＋sward ripping 〉grazing.The maximum of soil respiration rate was 10.41μmol/（m^2·s）and the minimum was 4.69μmol/（m^2·s）.The curve of daily and seasonal changes of soil respiration were unimodal type,and the daily and month peaks were13∶00to 14∶00and July respectively.The rank of Q10 was grazing＋fertilizing 〉grazing〉 sown pasturegrazing＋sward ripping 〉zero grazing,the maximum and minimum of Q10 was 1.826 and 1.157 respectively.The rank of non-linear correlations value between soil respiration rate and soil humidity was grazing＋sward ripping 〈grazing 〈sown pasture 〈zero grazing 〈grazing＋fertilizing.In conclusion,the proper utilization pattern in Sangkok was grazing＋fertilizing.