聚湫和淤地坝地土壤微生物生物量和群落结构垂直分布特征及其影响因素

发布时间：2018-03-15 20:38

本文选题：微生物　切入点：群落结构　出处：《南京农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：土壤微生物种类和生物量可以反映土壤生态环境所发生的变化。目前对淤地坝地土壤微生物的研究主要集中在表层土壤,对微生物在土壤剖面中分布规律的研究较少。为了弄清黄土高原土壤微生物生物量和群落结构特征的主要影响因素,本文以天然聚湫坝地和人工淤地坝地为实例,研究了微生物生物量和群落结构在土壤剖面中的垂直分布特征,讨论了它们与化学成分和机械组成之间的相关性。在此基础上,得出以下初步结论:(1)根据机械组成数据,聚漱坝地土壤剖面在垂直方向上可划分出5个沉积旋回,而淤地坝地土壤剖面可划分出25个沉积旋回。聚湫坝地土壤以砂粒为主(平均含量56.62%),淤地坝地土壤以粉砂粒为主(平均含量46.39%)。(2)聚湫坝地SOC、TN、MBC和MBN含量在垂直方向上的分布与粘粒含量基本一致,在水平方向上呈现A剖面B剖面C剖面的分布规律。淤地坝地的SOC、TN、MBC和MBN含量均呈现细颗粒层粗颗粒层的规律。(3)在聚揪坝地和淤地坝地土壤样品中分别检测出17种和20种PLFA。无论是聚湫坝地还是淤地坝地,土壤微生物均以细菌为主(分别占微生物总量的65%～75%和60%～7-J%),其次为放线菌(分别为15%～25%和10%～25%)和真菌(分别为5%-10%和12%～20%)。(4)从微生物生物量来看,聚湫坝地土壤在垂直方向上可区分出3个高值区(分别位于0-50cmm、120-140cm和220-260cm段)和3个低值区,在水平方向上则表现为A剖面B剖面C剖面。淤地坝地土壤微生物总量、细菌、真菌和放线菌生物量均呈现细颗粒层粗颗粒层的规律。(5)聚湫坝地土壤微生物多样性指数(Shannon指数、Simpson指数和Pielou指数)的变化趋势基本一致。在垂直方向上,微生物生物量高值区的Shannon指数、Simpson指数和Pielou指数基本上都高于其下的低值区。在水平方向上,三个指数均表现为A剖面B剖面C剖面。淤地坝地土壤的三个微生物多样性指数均表现为细颗粒层粗颗粒层。(6)粘粒组分是影响聚湫和淤地坝地土壤微生物生物量和群落结构的主要因素。土壤微生物总量、细菌生物量和真菌生物量与粘粒含量均具有显著的正相关关系。对于聚湫,相关性系数r分别为 0.58、0.57 和 0.62(P0.05);对于淤地坝,r 则分别为 0.94、0.97 和 0.98(P0.001)。
[Abstract]:The species and biomass of soil microorganisms can reflect the changes of soil ecological environment. In order to find out the main influencing factors of soil microbial biomass and community structure, this paper takes natural accumulation and artificial silt dam field as examples. The vertical distribution characteristics of microbial biomass and community structure in soil profile were studied, and their correlation with chemical composition and mechanical composition were discussed. In the vertical direction of soil profile, five sedimentary cycles can be divided. The soil profile of silt dam can be divided into 25 sedimentary cycles. The soil of Qiqiu dam land is mainly composed of sand (average content is 56.62%), and the soil of silt sand is the main content of silt grain (average content is 46.39%) and the content of MBN is in the vertical direction. The distribution is basically the same as the clay content. In horizontal direction, the distribution law of section C in section A, section B, and the contents of MBN and MBN in silt dam are the same as those of coarse granular layer in fine grained layer, respectively. 17 species were detected in soil samples of Ju-Pu dam area and silt dam field respectively. And 20 kinds of PLFA. whether it's the Puqiu dam or the silt dam, Most of the soil microbes were bacteria (65% and 60% of the total amount of microbes, respectively), followed by actinomycetes (15% and 10%) and fungi (5% -10% and 12% respectively) from the microbial biomass point of view. In the vertical direction, three high value areas (located between 0-50 cm ~ 140 cm and 220-260 cm) and three low value areas can be distinguished from the soil of Puqiu dam land. In the horizontal direction, they can be seen as section A, section B, section C, the total amount of soil microbes and bacteria in the silt dam. The biomass of fungi and actinomycetes showed the rule of coarse granular layer in fine grained layer. The variation trend of soil microbial diversity index Shannon index Simpson index and Pielou index was basically the same in vertical direction. The Shannon index and Pielou index in the high value area of microbial biomass are basically higher than those in the low value area under them. The three indices are all A profile B section C section and the three microbial diversity indices of silt dam soil are all shown as fine granular layer coarse granular layer. 6) the clay component is the influence of accumulation and silt dam soil microbial biomass. Major factors in community structure. Total soil microbes, There was a significant positive correlation between bacterial biomass and fungal biomass and clay content, the correlation coefficient r was 0. 58 0. 57 and 0. 62% P 0. 05, respectively, and for silt dam, r was 0. 94 0. 97 and 0. 98 P0. 001, respectively.
【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S154.3

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