Yan Jun-Xia, Hao Zhong, Jing Xue-Kai, Li Hong-Jian
Institute of Loess Plateau, Shanxi University, Taiyuan 030006, China.
Huan Jing Ke Xue. 2016 Sep 8;37(9):3625-3633. doi: 10.13227/j.hjkx.2016.09.046.
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 () and soil temperature () and soil water content (SWC), and to estimate soil carbon dioxide efflux in the region. For this purpose, we measured 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 and relationships between and both and SWC. The results showed that the seasonal variations of against day number of the year could be significantly fitted with a three-parameter Gaussian equation while there was no significant correlation between and SWC. Significant exponential relationship between and over the season was found, but not with . Interannual average estimation of soil efflux between March and December from the soil was (5.32±3.31) μmol·(m·s), and was equal to 1690.2 g·m from the same period ranging from 1294 to 2006 g·m. No significant difference in annual efflux was found between the years. The sensitivity of to , value, ranged from 1.54-2.20, 1.68-2.48 and 1.82-2.46, respectively, for the measurement at 5, 10 and 15 cm depths. The at 10℃, , ranged from 2.37 to 2.81, 2.43 to 3.13 and 2.59 to 3.47μmol·(m·s), respectively, for the measurement at 5, 10 and 15 cm depths. Both the and increased with increasing measurement depth. In comparison with the fitted one-variable of temperature model, the two-variable model combining both the and together could be well used to predict over the season. Our research results can bear important implications for the study of CO efflux in the region and similar regions.
太原市晋祠地区曾是水稻之乡，随着晋祠泉的断流，该地区土地利用从原来的水稻种植根本转变为玉米种植或果园利用。因此，研究土地利用变化后的土壤呼吸，分析土壤呼吸（）与土壤温度（）和土壤含水量（SWC）之间的关系，并估算该地区土壤二氧化碳通量非常重要。为此，我们在一块原为水稻田现种有枣树的田地里，于2006年至2012年的7年间，从3月至12月每月测量1至3次，分析了土壤呼吸的季节、年际变化以及土壤呼吸与土壤温度和土壤含水量之间的关系。结果表明，土壤呼吸随一年中天数的季节变化可用三参数高斯方程显著拟合，而土壤呼吸与土壤含水量之间无显著相关性。发现土壤呼吸与土壤温度在季节上存在显著指数关系，但与土壤含水量无此关系。3月至12月土壤年平均二氧化碳通量估算值为（5.32±3.31）μmol·（m²·s），同期相当于1690.2 g·m²，范围在1294至2006 g·m²之间。各年份年通量无显著差异。在5厘米、10厘米和15厘米深度测量土壤呼吸时，土壤呼吸对土壤温度的敏感性，即Q₁₀值分别为1.54 - 2.20、1.68 - 2.48和1.82 - 2.46。在10℃时，5厘米、10厘米和15厘米深度测量土壤呼吸时，土壤呼吸速率分别为2.37至2.81、2.43至3.13和2.59至3.47μmol·（m²·s）。土壤呼吸速率和Q₁₀值均随测量深度增加而增加。与拟合的单温度变量模型相比，将土壤温度和土壤含水量结合在一起的双变量模型可很好地用于预测季节土壤呼吸。我们的研究结果对该地区及类似地区二氧化碳通量的研究具有重要意义。
