Dong Yun-She, Qi Yu-Chun, Liu Ji-Yuan, Domroes Manfred, Liu Li-Xin, Geng Yuan-Bo, Liu Xing-Ren, Yang Xiao-Hong, Li Ming-Feng
Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
J Environ Sci (China). 2006;18(3):488-94.
Using the static opaque chamber method, the soil respiration rates (SR) were measured through the continuous experiments in situ in semiarid Stipa grandis steppe in Xilin River Basin of Inner Mongolia, China from June 2001 to June 2003, in parallel, the difference between the SR and the ecosystem respiration rates (TER) were compared. The results indicated that the seasonal variations of the SR and TER were obvious with higher emissions in growing season and a relatively low efflux level in non-growing season, furthermore, the negative effluxes were found in the observation site in winter; the annual CO2 efflux of total ecosystem ranged from 160.5 gC/(m2 x a) to 162.8 gC/(m2 x a) and that of soil ranged from 118.7 gC/(m2 x a) to 152.3 gC/(m2 x a). The annual SR accounted for about 74.0% to 93.5% of the annual TER, but the results of Analysis of Variance (ANOVA) indicated that the difference between the annual average TER and SR did not reach the significance level of 0.05. The TER was under similar environmental controls as SR, in growing seasons of drought years, the variations of soil moisture at 0-10 cm and 10-20 cm depth could account for 79.1%-95.6% of the changes of the SR and TER, but in non-growing season, more than 75% of the variations of the SR and TER could be explained by the changes of the ground temperature of soil surface layers.
采用静态不透明箱法，于2001年6月至2003年6月在中国内蒙古锡林河流域半干旱大针茅草原原位进行连续实验，测定土壤呼吸速率（SR），同时比较SR与生态系统呼吸速率（TER）的差异。结果表明，SR和TER的季节变化明显，生长季排放较高，非生长季排放水平相对较低，此外，冬季观测点出现负排放；整个生态系统的年CO₂排放量在160.5 gC/(m²·a)至162.8 gC/(m²·a)之间，土壤的年CO₂排放量在118.7 gC/(m²·a)至152.3 gC/(m²·a)之间。年SR约占年TER的74.0%至93.5%，但方差分析（ANOVA）结果表明，年平均TER和SR之间的差异未达到0.05的显著水平。TER与SR受相似的环境控制，在干旱年份的生长季，0-十厘米和十-二十厘米深度土壤湿度的变化可解释SR和TER变化的79.1%-95.6%，但在非生长季，则有超过75%的SR和TER变化可由土壤表层地温的变化来解释。
