内蒙古羊草草原根呼吸和土壤微生物呼吸区分的研究

利用根生物量回归法对内蒙古锡林河流域羊草草原根呼吸和土壤微生物呼吸进行了区分.结果表明,根呼吸占土壤呼吸的比例在13%~52%之间,平均为(24±3)%;土壤微生物呼吸占土壤呼吸的比例在48%~87%之间,平均为(76±3)%.土壤呼吸与根生物量的线性相关性不稳定.根呼吸活力与根冠比具有负指数相关关系(R2=0.661,P=0.20),与0~10、10~20、20~30和30~40 cm土壤含水量均有极显著的正指数相关关系(P<0.000 1).根呼吸与根呼吸活力具有极显著的指数相关关系(R2=0.848,P=0.01),根呼吸对土壤呼吸的贡献量与根呼吸活力具有显著的指数相关关系(R2=0.818,P=0.01).

Study on the Distinguishing of Root Respiration from Soil Microbial Respiration in a Leymus chinensis Steppe in Inner Mongolia, China

Root biomass exponential regression method was used to distinguish root respiration from soil microbial respiration in a Leymus Chinensis steppe in the Xilin River Basin of Inner Mongolia, China. The contribution of root respiration to soil respiration averaged (24±3)%, ranging from 13%-52%; while the contribution of microbial respiration to soil respiration averaged (76±3)%, ranging from 48%-87%. Correlation between soil respiration and root biomass was relatively unstable. Root respiration vitality decreased exponentially with the ratio of root to shoot biomass (R2=0.661,P=0.20), while it increased exponentially with soil water content at 0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm (P<0.0001). CO₂ released by root respiration and the contribution of root respiration to soil respiration increased exponentially with root respiration vitality (R2=0.848,P=0.01; R2=0.818,P=0.01, respectively).