杭州湾生长不同植物的潮滩土壤微生物群落特征

Microbial Community Characteristic of Soils with Different Vegetation in Tidal Flat in Hangzhou Bay

2011年10月,在杭州湾滨海潮滩,分别利用稀释平板法和Biolog-Eco微平板检测技术,研究生长不同植物的土壤微生物数量与群落的功能多样性。结果表明,与光滩相比,海三棱藨草(Scirpus mariqueter)、芦苇(Phrag mites australis)和互花米草(Spartina abcerniflora)3种植物的生长促进了潮滩土壤中微生物数量的增加,细菌的数量在3大类微生物中占绝对优势(>98%);生长不同植物潮滩的土壤微生物群落功能多样性存在差异,光滩与生长海三棱藨草、芦苇和互花米草潮滩的土壤微生物群落生理功能多样性具有显著差异(p<0.05),生长互花米草与生长芦苇和海三棱藨草潮滩的土壤微生物群落生理功能多样性之间具有显著差异(p<0.05);植物的生长没有从根本上改变潮滩土壤的微生物群落结构,光滩与生长3种植物潮滩的土壤微生物群落具有相似的优势种;糖类及其衍生物和氨基酸及其衍生物是杭州湾潮滩土壤微生物群落代谢过程中的碳源利用的主要分异点。

Microbial functional diversity in tidal flat in Hangzhou Bay were investigated to study the possible influences of vegetation on soil microbial community in October, 2011. Surface （0-10 cm） and subsurface （10-20 cm） soils from Scirpus mariqueter, Phragmites australis, Spartina aherniflora tidal flat as well as the soil from bare tidal flat were collected and analyzed in laboratory. Spread-Plate and the Biolog-Eco technique were utilized together for microbial community analysis. The numbers of 3 major groups （bacteria, fungi and actinomycetes） in soils were counted separately. The difference among 4 types of soils were analyzed via curve fitting, principal component analysis and variance analysis. The results showed that compared with the bare fiat, the soils with vegetations had more microorganisms. For the surface soils, the number of bacteria and fungi in the soil of Spartina alterniflora tidal flat was the maximum, the other ones were Phragmites austra- lis, Scirpus mariqueter and bare tidal fiat, while for actinomycetes, the order was Phragmites australis, Spartina aherniflora, bare and Scirpus mariqueter tidal fiat. For the subsurface soil, the order of bacteria number was Phragmites australis, Spartina alterniflora, bare and Scirpus mariqueter tidal fiat; the order of fungi number was Scirpus mariqueter, Phragmites australis, Spartina alterniflora and bare tidal fiat; and the order of actinomy- cetes number was Phragmites australis, bare, Scirpus mariqueter and Spartina alterniflora tidal fiat. Therefore the vegetatation might facilated microbial community. In the soil microorganism profile, bacteria was most abundant and determined the number of the whole community in 4 types of soils, which accounted more than 98% in the soils. There some differences of microbial functional diversity were observed among different veg- etation types. Significant differences in the microbial function diversity was found between soils of bare and the other soilsof tidal flat （p〈0.05）. Difference of metabolic capacity between the soils from Spartina alterniflo- ra and Scirpus mariqueter communities was significant. Soils in Spartina alterniflora tidal fiat had the largest numbers and strongest growth activity, followed by Phragmites australis, Scirpus mariqueter and bare Flat. In contrast, soil microbial community in bare fiat had higher richness indicated by McIntosh index. This suggest- ed that soil microbial communities in bare fiat soil may had more species than the soil with vegetation. Be- cause of a very short succession time in Hangzhou Bay, vegetation development did not changed the microbial community species composition remarkably. It seemed that because the structure and species of microbial communities were not changed by the vegetation fundamentally, 4 kinds of soil microbial communities had similar dominant species. Sugars, amino acids and their derivatives were the major differentiation substrates for the microbial communities in soils intidal flat of Hangzhou Bay.