亚热带几种典型林被下土壤微生物对比研究

Comparative Studies of Soil Microbes under Several Typical Subtropical Forest Vegetations

对缙云山马尾松近纯林(PMF)、毛竹林(PPF)、慈竹林(NF)、斑苦竹林(AF)和四川山矾阔叶林(SBF)5种亚热带典型林被下土壤微生物量碳测定和细菌、真菌和放线菌分离计数以及林被中优势树种的微生物根际效应进行研究.结果表明,林被不同,土壤各类微生物量明显不同,特别是细菌,总的来看,四川山矾阔叶林土壤微生物量最多,其次为毛竹林,慈竹林、斑苦竹林再次之,马尾松林显著最少.各林地土壤微生物数量存在垂直分布的变化,即A层高于B层,微生物量与土壤有机质含量呈密切相关性.四川山矾、毛竹、慈竹、马尾松的微生物根际效应明显,根际的微生物量碳和3大类群微生物数量总体高于非根际,微生物根际效应因植物、微生物类群和土层而不同:四川山矾、毛竹和慈竹的效应强,尤其四川山矾,而马尾松相对较弱;细菌、真菌根际效应强,真菌因植物种类差异大,放线菌相对最弱;土壤B层微生物根际效应强于A层.

Aiming to study the characteristics of the soil microbes under typical subtropical forests vegeta- tions, 5 typical forest vegetations have been sampled in Mt. Jinyun, including Pinus massoniana forest, Phyllostachys pubescens forest, Neosinocalamus a f finis forest, Arundinaria oleosa forest and Symplocos setchuanensis broad leaved forest. The results indicate that the soil microbial biomass C and the numbers of bacteria, fungi and actinomyces, especially the numbers of bacteria, vary considerably during different for est vegatations. Generally, the microbial biomass C and the microbial population numbers are highest un- der Symplocos setchuenensis broad leaved forest, then under Phyllostachys pubescens forest, and lowest under Pinus massoniana forest. The quantity of soil microbes changes markedly with soil depth, all the in- dexes in layer A are significantly higher than in layer B. The microbe correlates well with soil organic mat- ter. Much more biomass C and numbers of microbes have been observed in rhizosphere of the dominant plants than those non rhizosphere. The rhizosphere effect varies with dominant plants, microbial commu nity and soil depth： Symplocos setchuanensis with marked rhizosphere effects ranks first among dominant plants, then Phyllostachys pubescens and Neosinocalarnus with marked effects too, and with relatively weak effects. The effects of both bacteria and fungi are highly significant nomyces has no significance almost. The effects in soil layer B are more obvious than th Pinus massoniana , but that of acti- at in layer A.