| 太原晋祠地区果园土壤呼吸的年际变化及其温度敏感性 |
| 摘要点击 1875 全文点击 1036 投稿时间：2016-01-11 修订日期：2016-04-08 |
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| 中文关键词 土地利用 土壤呼吸 环境因子 年际变化 太原晋祠地区 |
| 英文关键词 landuse soil respiration environmental factors interannual variation Jinci area of Taiyuan |
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| 中文摘要 |
| 太原晋祠地区曾经是著名的稻米之乡，随着晋祠泉的断流，区内土地利用从之前的以水稻田为主转变为以玉米和果园为主.因此，研究土地利用变化后土壤呼吸对于准确估算区域碳循环具有一定意义.基于此目的，本研究以原来为稻田、现为果园利用方式的样地为对象，对其土壤呼吸进行了7 a（2006～2012年）、每月1～3次的定位观测，分析了土壤呼吸的年际、季节变化及其与环境因子年际、季节变化的关系.结果表明，土壤呼吸与土壤温度的季节变化与天数的关系可以用3参数高斯方程模型进行拟合.土壤呼吸的季节变化与土壤温度的季节变化关系为极显著的指数关系，但其与土壤水分季节变化的关系不显著.土壤呼吸速率年平均值为（5.32±3.31）μmol·（m2·s）-1；碳通量年平均值为1690.2 g·m-2，在1294.0～2006.0 g·m-2之间变化，年际均值差异不显著.土壤呼吸的温度敏感性指数（Q10）值的年际变化以5、10和15 cm温度测定深度计算分别在1.54～2.20、1.68～2.48和1.82～2.46之间；土壤温度10℃ 对应的土壤呼吸（R10）值的年际变化在2.37～2.81、2.43～3.13和2.59～3.47 μmol·（m2·s）-1之间；Q10和R10值均随土壤温度测定深度增加而增加.Q10的年际变化与10 cm深度的土壤温度（T10）的年际变化关系极显著（P=0.016），与其它因子的关系不显著；在拟合方程中增加土壤水分因子不能提高对Q10年际变化的预测精度，说明在本样地水分对Q10的影响较小.R10值的年际变化与环境因子的年际变化关系不显著.与土壤呼吸与土壤温度的单因素模型相比，土壤温度和土壤水分的双变量指数模型可以提高预测土壤呼吸季节变化的准确性.研究结果可以为本地区及同类地区的土壤呼吸估算提供一定参考. |
| 英文摘要 |
| Jinci area of Taiyuan city is a former hometown of rice, and with the cutoff of the Jinci spring the land use in the area changed fundamentally from original paddy rice to corn or orchard use. So it is very important to investigate soil respiration after land use change and to analyze the relationship between soil respiration (Rs) and soil temperature (Ts) and soil water content (SWC), and to estimate soil carbon dioxide efflux in the region. For this purpose, we measured Rs for seven years (2006 to 2012) with an interval of 1 to 3 times per month from March to December in a field originally for rice but now Chinese jujube, and analyzed seasonal, annual variations of Rs and relationships between Rs and both Ts and SWC. The results showed that the seasonal variations of Rs against day number of the year could be significantly fitted with a three-parameter Gaussian equation while there was no significant correlation between Ts and SWC. Significant exponential relationship between Rs and Ts over the season was found, but not with SWC. Interannual average estimation of soil efflux between March and December from the soil was (5.32±3.31) μmol·(m2·s)-1, and was equal to 1690.2 g·m-2 from the same period ranging from 1294 to 2006 g·m-2. No significant difference in annual efflux was found between the years. The sensitivity of Rs to Ts, Q10 value, ranged from 1.54-2.20, 1.68-2.48 and 1.82-2.46, respectively, for the Ts measurement at 5, 10 and 15 cm depths. The Rs at 10℃, R10, ranged from 2.37 to 2.81, 2.43 to 3.13 and 2.59 to 3.47μmol·(m2·s)-1, respectively, for the Ts measurement at 5, 10 and 15 cm depths. Both the Q10 and R10 increased with increasing Ts measurement depth. In comparison with the fitted one-variable of temperature model, the two-variable model combining both the Ts and SWC together could be well used to predict Rs over the season. Our research results can bear important implications for the study of CO2 efflux in the region and similar regions. |
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