一、方法 (一)研究对象与材料制备 1984年7月,分别自内蒙古锡林河流域羊草(An(?)urolepidium chinense)草原与线叶菊(Filifolium sibiricum)草原群落,从5～100厘米的土层中每隔5厘米采集25×25×5cm~3土壤样本38个,用0.5毫米筛孔土壤筛洗净备用。试验表明通过0.5毫米筛孔的根是那些 I. Methods (1) Research objects and material preparation In July 1984, from the communities of An (?) Urolepidium chinense grassland and Filipendia sibiricum in the Xilin River basin of Inner Mongolia, Soil every 5 cm collected 25 × 25 × 5cm ~ 3 soil samples 38, with 0.5 mm sieve soil sieve washed spare. Tests showed that the roots that passed through the 0.5 mm mesh were those