摘要
利用ACE土壤呼吸作用自动测定仪对希拉穆仁草原围封6年的克氏针茅（Stipa krylovii）群落从4月末至10月初每隔10d进行土壤呼吸作用日动态监测，并结合土壤温度和水分状况分析其复合相关关系。结果表明，1）生长季内土壤呼吸日动态均呈单峰曲线，最高值出现在中午12：00—14：00，夜间土壤呼吸速率很低，最低值出现在凌晨1：00-3：00。2）土壤呼吸昼夜变化在不同物候期明显不同，特别是在地温低于0℃时出现了土壤呼吸负通量现象。提高土壤呼吸通量的观测频率，加强相应物理化学机制的深入探讨将有助于我们对草地土壤年呼吸量的准确估算。3）土壤水分与日均土壤呼吸速率的关系为二次函数关系，理论日均呼吸速率最高值为456．2mg／（m^2·h），对应的土壤体积含水量为20％，与田间持水量21％基本吻合。4）生长季Q10值介于1．16～6．28，与土壤水分呈二次函数关系，不同于以往研究结果，这对于全球变化条件下研究土壤呼吸具有指导意义。
ACE soil respiration measurement system was used to monitor the diurnal changes of the soil respiration rate of fencing grassland from the end of April to the early October every ten days in Xilamuren regions and the correlation relationships between the soil respiration rate and soil temperature and moisture were discussed in this study. This study indicated that diurnal changes of soil respiration was one-peak curve with the highest value at 12：00-14：00 and the lowest value at 1：00-3 ：00. The soil respiration flux was different day and night at the different phonological stage and showed a negative value while soil temperature was under 0 ℃ implying that the increase in observation frequency of soil respiration observation and sighting into the related mechanism were helpful to estimate accurately the whole year carbon flux. Soil respiration rate showed a quadratic function with soil water content and the theoretical highest respiration rate was 456.2 mg/（m^2· h） when soil water content was 21%, coinciding with field water-holding capacity with 20%. During growing season, Q10 value were between 1.16 and 6.28, and showed a quadratic function with soil water content, differing from previous study results, which would be a important guidance to soil respiration under global change.
出处
《草业科学》
CAS
CSCD
北大核心
2011年第1期33-38,共6页
Pratacultural Science
基金
中国水科院科研专项--内蒙古不同类型草原区水土流失生态基础数据监测研究[MKSX(1)09]草地碳汇功能与植被盖度及地表生物量关系研究[MKSX(1)10]
关键词
希拉穆仁草原
土壤呼吸
土壤水分
Q
10值
Xilamuren grassland
soil respiration； soil water content
Q10 value
