兰州市郊干旱半干旱黄土丘陵区不同立地条件土壤微生物区系特征

Patterns of Soil Microbial Population in Different Types of Sites in Arid and Semiarid Loess Hills of Lanzhou

应用稀释平板法对兰州市郊干旱半干旱黄土丘陵区4种立地类型土壤中不同土层微生物分布特征进行了研究。结果表明:①同一种立地类型土壤中各类微生物数量差异很大,各类群数量排序为细菌>放线菌>真菌。并且各类群数量随着土层深度的增加而明显减少。②由于立地条件不同,4种立地类型土壤中微生物数量差异显著,呈现出南山坡地>北山坡地>盐碱滩地>梁坡红黏土地的规律。③4种立地类型土壤中微生物数量与土壤环境因子密切相关。在南山坡地,土壤微生物与有机质显著相关;在北山坡地,土壤微生物与有机质、有效P显著相关;在梁坡红板岩地,与有效P、K显著相关;在盐碱滩地,微生物与有机质和有效K显著相关。

Patterns of soil microbial population in four different types of sites in arid and semiarid loess hills of Lanzhou were studied. The results showed that （1） There were obvious difference among the amount of different soil microbe types in same site, following an order： bacteriaactinomycetefungi. The total amount of soil microbes all decreased with soil depth. （2） There were also obvious difference among the amount of soil microbes in different sites, following an order： South Hill slopeNorth Hill slopesaline beachhillside red clay. （3） The amount of soil microbes in different sites were correlated differentially with soil factors： that in South Hill slope was positively correlated with soil organic matter; that in North Hill slope was positively correlated with soil organic matter and available P; that in saline beach was positively correlated with available P and K; and that in hillside red clay was positively correlated with soil organic matter and available K.