准噶尔盆地梭梭群落下土壤CO2释放规律及其影响因子的研究

 采用开路式自动土壤碳通量测量系统（LI-8100）测定了准噶尔盆地荒漠梭梭群落生长季的土壤呼吸速率,并分析了温度和土壤水分对土壤呼吸的影响,结果表明:土壤CO2释放速率有明显的日变化和季节动态,日最大排放速率出现在13:00—15:00时,最小排放速率在8:00时。土壤CO2释放速率日变幅最大值为0.90 μmol·m-2·s-1、最小值为0.24 μmol·m-2·s-1、平均速率是(0.548±0.076)μmol·m-2·s-1;土壤呼吸作用在生长季中的动态呈单峰曲线,顺序为6月＞7月＞8月＞9月＞5月＞10月。相关性分析表明,土壤呼吸速率与气温、地表温度和5 cm、10 cm、15 cm、20 cm、25 cm、30 cm、35 cm、40 cm、50 cm层土壤温度呈极显著和显著正相关关系,土壤呼吸速率与地表温度间的线性关系为Y=0.017X+0.033,（R2=0.566, P<0.001）,并得出Q10值为1.65。土壤含水量与土壤呼吸速率间的相关性不显著。

Soil Carbon Dioxide Emission and Affecting Factors under Haloxylon ammodendron Community in Junggar Basin

Using a LI-8100 automated soil CO2 flux system we determined the rate of soil carbon dioxide emission in Haloxylon Ammodendron growing season (May—October) in the Junggar Basin, also evaluated the influence of temperature and soil moisture on soil respiration rate. The results indicated that: the CO2 emission rate had significant diurnal fluctuation and seasonal dynamics. The maximum rate of CO2 emission appeared at 13:00—15:00 and the minimum at 8:00. The maximum diurnal amplitude was 0.90 μmol·m-2·s-1, the minimum amplitude was 0.24 μmol·m-2·s-1. The rate of CO2 emission was different with changing of the phenological periods, following an order of June＞July＞August＞September＞May＞October, the mean soil respiration rate during the plant growing season was (0.548±0.076)μmol ·m-2·s-1. Correlation analysis showed that soil respiration rate significantly correlated with air temperature, soil surface temperature, 5 cm, 10 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, and 50 cm depths. The relationship between soil respiration rate (Y) and soil surface temperature (X) could be described by the following linear regression equation: Y=0.017X+0.033, (R2=0.566, P<0.001), the calculated Q10 value based on the above equation was 1.65. Correlation analysis showed that soil respiration rate didnt correlate with soil moisture significantly.