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为了探讨不同演替阶段植被类型土壤微生物群落特征,分别选取镜泊湖岩溶台地草本、矮灌木、高灌木、小乔木与灌木混生(简称混生)群落、落叶阔叶林及针阔混交林6种典型植被类型,进行植物群落调查和对土壤微生物生物量、群落结构和多样性指标、土壤物理化学性质的测定。结果表明:从土壤微生物生物量、土壤微生物群落组成、土壤微生物代谢动力学过程和代谢功能多样性的角度来看,各种植被类型土壤微生物群落具有明显的差异。演替前期的草本群落土壤微生物生物量碳氮、细菌生物量、真菌生物量,代谢活性及丰富度指数均最低,但Shannon-Wiener多样性指数和均匀度指数显著(P<0.05)高于其它植被类型。矮灌木土壤微生物群落组成显著受植被类型的影响。高灌木群落和混生(小乔木与灌木混生)群落具有极强的相似性,但在碳源利用类型上两者表现出一定的差异。落叶阔叶林代谢活性最高,碳源利用能力最强,能利用BIOLOG微孔板中的所有31种碳源,这与其具有较高的微生物生物量碳氮和细菌生物量一致,其代谢功能丰富度最高。演替后期的针阔混交林下的土壤pH最低,真菌比例升高,在碳源丰富的条件下具有极强的竞争优势(仅次于落叶阔叶林),但在碳源贫瘠的条件下其利用碳源能力较弱(仅高于草本)。植被可能主要通过土壤全磷和有机质影响土壤微生物代谢功能多样性。
In order to discuss the characteristics of soil microbial community in different successional stages, six species of herbaceous plants, dwarf shrubs, tall shrubs, small mixed trees and shrubs, deciduous broad-leaved forests and coniferous and broad-leaved mixed forests Typical vegetation types, plant community survey and determination of soil microbial biomass, community structure and diversity, soil physicochemical properties. The results showed that there were significant differences in soil microbial community in different types of vegetation from the perspectives of soil microbial biomass, soil microbial community composition, soil microbial metabolic kinetics and metabolic functional diversity. The microbial biomass C and N, bacterial biomass, fungal biomass, metabolic activity and richness index were the lowest in the successional succession, but the Shannon-Wiener diversity index and evenness index were significantly higher (P <0.05) than other Vegetation Types. The composition of soil microbial community in dwarf shrubs is significantly affected by the type of vegetation. High shrub communities and mixed (small trees and shrubs) communities have strong similarity, but the two types showed some differences in the types of carbon source utilization. Deciduous broad-leaved forests have the highest metabolic activity and the strongest available carbon source, making use of all 31 carbon sources in BIOLOG microplates, which are consistent with their high microbial biomass C and N and bacterial biomass with abundant metabolic functions The highest degree. Under the succession succession of coniferous and broad-leaved mixed forest, the soil pH was the lowest, and the proportion of fungi was increased. Under the condition of abundant carbon sources, it had a very strong competitive advantage (second only to deciduous broad-leaved forest) Its ability to utilize carbon sources is weak (only higher than that of herbs). Vegetation may affect the metabolic diversity of soil microbes mainly through soil total phosphorus and organic matter.