黄土丘陵沟壑区机修梯田与坡地土壤呼吸特征研究

Characteristics of Soil Respiration in Machine-building Terrace Field and Slope Land of Loess Hilly and Gully Region

利用LI-8100开路式土壤呼吸仪对陇西县现有梯田和自然坡耕地温室气体CO2通量进行观测。结果表明,土壤温度,梯田低于坡地1℃左右,土壤呼吸速率,梯田低于坡地0.67μmol·m^-2·s^-1,土壤呼吸速率存在明显差异（P=0.00）。土壤水分在温度最高时,梯田土壤含有较高的体积含水量达0.224%,而坡地处在较低的0.153%,差值为0.071%。土壤呼吸速率在单因子模型下拟合程度不高（R^2=0.1-0.5）,但是双因子模拟下R2达到0.9以上,表明该区土壤呼吸速率受到这2个因子的共同影响;梯田的土壤呼吸特征更适应于黄土丘陵沟壑区的气候变化。

In this paper, the greenhouse gas CO2 flux of open terrace and natural slope in Longxi country by Li-8100A automated soil CO2 flux system were studied. The results showed that the soil temperature of terraced field was 1 ℃ below slope laud at the same time, the soil respiration rate was 0.67 μmol·m^-2·s^-1 below slope, and the soil respiration rates had a obvious difference （ P = 0.00）. When the soil water was in the highest temperature,the terraced field soll contained 0.224 % higher volumetric water,while the slope land was 0. 153 %, and the difference was 0.071%. Under single factor analysis model,the soli respiration rate＇ s fitting degree was not high（R^2 = 0.1 - 0.5）, but under the double factor analysis,R^2 over 0.9. The result indicated that the soil respiration rate was the mutual effects of two factors;The characteristics of soil respiration on terraced was more adaptable to the change of climate on loess hilly and gully region.