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Huazhong Agricultural University (2006)

The Study on the Biodiversity, Temporal and Spatial Distribution of Soil Microorganism in Desert Steppe of Ningxia

高婷; Gao Zuo

Titre : The Study on the Biodiversity, Temporal and Spatial Distribution of Soil Microorganism in Desert Steppe of Ningxia

Auteur : 高婷; Gao Zuo

Grade : Master’s Theses 2006

Université : Huazhong Agricultural University

Résumé
Research on the decomposer subsystem is the key link of clarifying the energy flow and the circulation of materials in the prairie ecosystem, the soil microorganism is playing the extremely vital role in the second ecosystem. The composition and quantity of soil microorganism in some degree are related to prairie ecosystem energy flow and the material transformation process. The composition and quantity of soil microorganism are affected by different prairie vegetation type, the soil texture, nutrition and moisture condition. The research on this aspect have a important theoretical and practical significance in the degenerated pasture restoration as well as enhancing the prairie productive forces.The research on the biodiversity, temporal and spatial distribution of soil microorganism in sierozem arid area wildemess prairie of Ningxia indicated that the soil microorganism area have a close correlationship with the prairie vegetation type and the soil texture, also restricts each other.The research of wildemess prairie soil microorganism biodiversity indicated that the 12 "genera" bacteria are : Bacillus、Alcaligenes、A grobacterium、Pscudomonas、Erwinia、Enterobacteriaceae、Arthrobacter、Xanthomonas、Flavobacterium、Acinetobacter、Corynebacterium and Miorococcus. There is quite a number of Bacillus in type(④, in type①there are no Bacillus nearly, but there are many Agrobacterium in this type, It can be concluded initially that : The Bacillus adapts growth in the type④, but in type①the Pscudomonas favors growth. The 9 "genera" actinomycetes are : Atreptomyces、Streptoverticillium、Micromonspora、Actinoplanes、Planomonospora、Intrasporangium、Kitasatosporia、Spirillospra、Streptosporangium. Most species of actinomycetes is in type①, and the "genera" are about 8. That is to say actinomycetes are more suitable to survive in the alkalinity sandy soil, simultaneously it has great significance to improve degenerated prairie soil quality, and it may be the main fungi for governing desert. The 7 "genera" fungi are : Penicillium, Aspergillus、Cephalosporium Corda、Coniothecium、Cladosporium、Alternaria、Mucor. There is a single genera fungi in type①, which is only belong to Penicillium, but in type④there are 7 genera. This demonstrated initially : When the soil texture is bad and the vegetation type is unitary, so the types of fungi will reduce and vice versa.The seasonal distribution in number of soil microorganism : The orderof seasonal distribution in number of bacteria is autumn>summer>spring ; The order of seasonal distribution in number of fungi is summer>autumn>spring, the number in summer was 1.98 times as much as that in autumn and 3.45 times as much as that in spring ; The order of seasonal distribution in number of actinomycetes is autumn>spring>summer. That reflects the quantity variation of each soil microorganism group has an obvious seasonal variation characteristic, moreover its quantity distribution obviously affected by the rainfall quantity.The stratification rate research indicated that : The microorganism quantity stratification ratio is 2.00 which may be used as the threshold value of soil quality appraisal. The total fungi quantity stratification rate of type is 2.31, indicated the soil quality is better ; The total fungus stratification rate of type④is 2.00, indicated the soil quality just in its healthy conditions ; The total fungi stratification rate of type①is the lowest about 0.66, each stratification rate of the variation is enormous between 0.87-5.08, which indicates the ecological condition is extremely frail of the type①, the soil has developed to the degenerated direction ; The total fungi stratification rate of type③is 1.61, indicated this type of vegetation is also bad, the manual repair to it must be carried on, the succession of soil quality can be faced to the healthy direction.The research proposed that : In the process of restoring and reconstruction the arid barren wilderness prairie, those tree seed、grass like bitter bean and also the leguminous plant which can formate actinomycetes nodule fungi and have strong resistance ability should be the main plant.

Mots clés : Prairie vegetation type; soil texture; microorganism biodiversity; stratification rate;

Présentation (CNKI)

Page publiée le 17 septembre 2014, mise à jour le 13 octobre 2017