中文摘要：

采用根钻法,分析了宁夏大罗山4种主要植被类型（青海云杉纯林、油松纯林、落叶灌木和荒漠草原）0～40cm土层的细根生物量、土壤含水量和土壤容重,并对50a、70a和100a3种树龄的青海云杉纯林细根生物量进行了研究.结果表明：4种植被类型的细根生物量集中分布在0～20cm土层,大小顺序为油松纯林〉青海云杉纯林〉落叶灌木〉荒漠草原,其中油松纯林显著高于其他3种植被类型;不同树龄青海云杉纯林细根生物量表现为70a〉100a〉50a,且其活细根和死细根生物量分配比例无显著性差异;4种植被类型下0～40cm土壤含水量的大小表现为：青海云杉纯林〉油松纯林〉落叶灌木〉荒漠草原;土壤容重则呈相反的规律,并与细根生物量呈极显著负相关.

英文摘要：

By the method of soil core sampling, this paper studied the fine root biomass, soil water content, and soil bulk density in 0-40 cm soil layer of four main vegetation types （ Picea crassifolia forest, Pinus tabulaeformis forest, deciduous shrubs, and desert grassland） in Daluo Mountain of Ningxia, and the fine root biomass in the 0-40 cm soil layer of P. crassifolia forests with the ages of 50-, 70-, and 100 a. The fine root biomass of the four vegetation types was mainly distributed in 0-20 cm soil layer, with the rank of P. tabulaeformis forest 〉 P. crassifolia forest 〉 deciduous shrubs 〉 desert grassland, and the fine root biomass of P. tabulaeformis forest was significantly higher than that of the other three vegetation types. The fine root biomass of the P. crassifolia forests with different ages was 70 a 〉 100 a 〉 50 a, and there were no significant differences in the live fine root biomass ratio and dead fine root biomass ratio among the three P. crassifolia forests. The soil water content in the 0-40 cm soil layer of the four vegetation types was P. crassifolia forest 〉 P. tabulaeformis forest 〉 deciduous shrubs 〉 desert grassland, while the soil bulk density fol- lowed an opposite pattern, and was significantly negatively correlated with the fine root biomass.