Yan Jun-Xia, Li Hong-Jian, Tang Yi, Zhang Yi-Hui
Institute of Loess Plateau, Shanxi University, Taiyuan 030006, China.
Huan Jing Ke Xue. 2009 Nov;30(11):3121-9.
Soil respiration was measured from April 2005 to December 2007 using a LICOR-6400-09 chamber connecting a LiCor-6400 portable photosynthesis system at 3 sites with same elevation and soil texture but different vegetation types. The results indicated that seasonal trend of soil respiration showed a distinct temporal change with the higher values in summer and autumn months and the lower values in winter and spring. Annual means (March to December) of soil respiration for 3 the sampling sites were(3.58 +/- 2.50), (3.82 +/- 2.75) and (4.42 +/- 3.38) micromol x (m2 x s)(-1) (p > 0.05), respectively. Released annual amount (March to December) of CO2 efflux from 3 sites was from 854.9 to 1 297.2 g x (m2 x a)(-1) and the amount was no difference between sites and among years. The fitted exponential equations of soil respiration and soil temperature for 3 sites were all significant with the R2 from 0.61 to 0.81, and the Q10 and R10 calculated from fitted parameters of the equations ranged from 2.60 to 4.50, and from 1.70 to 3.02 micromol x (m2 x s)(-1). The relationships between soil respiration and soil water content were not significant for all 3 sites with a maximum R2 of the regression equations only 0.12 (p > 0.05). However, when the soil temperature was above 10 degrees C, the relationships between soil respiration and soil water content was significant (p < 0.05). Four combined regression equations including soil temperature and soil water content could be used to model relationships between soil respiration and both soil temperature and soil water content together, with the R2 most above 0.7, and maximum of 0.91.
2005年4月至2007年12月期间，使用连接LiCor-6400便携式光合作用系统的LICOR-6400-09气室，在3个海拔和土壤质地相同但植被类型不同的地点测量土壤呼吸。结果表明，土壤呼吸的季节趋势呈现出明显的时间变化，夏季和秋季的值较高，冬季和春季的值较低。3个采样点土壤呼吸的年平均值（3月至12月）分别为(3.58±2.50)、(3.82±2.75)和(4.42±3.38)微摩尔×(平方米×秒)(-1)（p>0.05）。3个地点3月至12月期间释放的二氧化碳年通量为854.9至1297.2克×(平方米×年)(-1)，各地点之间以及各年份之间的通量没有差异。3个地点土壤呼吸与土壤温度的拟合指数方程均显著，R2在0.61至0.81之间，根据方程拟合参数计算的Q10和R10分别在2.60至4.50之间以及1.70至3.02微摩尔×(平方米×秒)(-1)之间。所有3个地点土壤呼吸与土壤含水量之间的关系均不显著，回归方程的最大R2仅为0.12（p>0.05）。然而，当土壤温度高于10℃时，土壤呼吸与土壤含水量之间的关系显著（p<0.05）。包括土壤温度和土壤含水量的4个联合回归方程可用于模拟土壤呼吸与土壤温度和土壤含水量之间的关系，R2大多高于0.7，最大值为0.91。
