覆盖经营对雷竹林土壤细菌群落结构演变及多样性的影响

发布时间：2018-06-09 02:38

本文选题：雷竹 + 林地覆盖　；参考：《林业科学》2017年09期

【摘要】：【目的】研究覆盖对雷竹林土壤细菌群落结构及多样性的影响,为科学评价该种植模式的生态风险提供科学依据。【方法】调查并采集不同覆盖年限(0、3、6、9、12年)雷竹林土样,采用Illumina Miseq高通量测序技术分析16S rDNA土壤细菌基因V3-V4区域,鉴定细菌类群,并结合测定土壤的N、P和有机质等化学指标分析覆盖经营土壤细菌群落结构演变及多样性影响。【结果】1)测序共获得598个OTUs,计280 548条读数,平均读长453.5 bp。调查林地土壤细菌优势门为变形菌门、酸杆菌门和放线菌门(平均相对丰度分别为30.80%、22.0%和13.9%)。2)不同覆盖年限土样的多样性指数及丰度指数存在较大差异。覆盖初期,随着覆盖物的投入,林分土壤细菌的多样性指数及丰度指数均呈增加趋势,在覆盖6年时达到最大值,之后则呈现一定程度的下降,覆盖12年与覆盖初期无较大差别。3)覆盖对土壤微生物群落结构造成一定影响,未覆盖林地土壤细菌群落结构与覆盖后林地出现差异;变形菌门丰度由17.60%(对照)上升为37.77%(覆盖12年),酸杆菌门丰度呈现下降的趋势,而放线菌门丰度变化很小。4)覆盖造成的土壤理化性质的改变在一定程度上对细菌群落结构可造成影响,随着覆盖时间的增加,细菌菌落结构与土壤环境的关系也趋于复杂化,覆盖造成土壤严重酸化,对照和覆盖12年的p H值分别为5.23和3.42,但土壤中的嗜酸菌群落酸杆菌门的丰度反而出现下降的趋势。5)RDA分析排序轴前两轴解释了覆盖竹林土壤微生物群落变异的88.5%,土壤中各细菌种群对土壤环境因子变化的适应性不同,土壤中速效K、全N和有机质的积累会提高Proteobacteria、Bacteroidetes的相对丰度,土壤酸化会降低Chloroflexi的相对丰度。【结论】竹林覆盖经营对土壤细菌群落结构和多样性产生较大的影响,短期覆盖(小于6年)能增加土壤细菌的丰度和多样性,但随着覆盖时间增加,土壤细菌的丰度和多样性下降,土壤各环境因子的变化会对覆盖竹林土壤微生物群落结构造成影响,对土壤中微生物多样性的研究能够从微生物角度分析土壤退化程度,为竹林土壤修复提供理论依据。
[Abstract]:[objective] to study the effect of mulching on the structure and diversity of soil bacterial community in the forest of Phyllostachys praecox, so as to provide a scientific basis for the scientific evaluation of the ecological risk of the planting model. [methods] soil samples of different mulching years were investigated and collected. The V3-V4 region of 16s rDNA soil bacterial gene was analyzed by Illumina Miseq high-throughput sequencing technique. The changes of bacterial community structure and the influence of diversity on soil microbial community were analyzed by using chemical indexes such as NNP and organic matter. [results] 1) A total of 598 OTUs were obtained by sequencing, with 280,548 readings and an average reading length of 453.5 BP. The dominant phylum of bacteria in forest soil was Proteus, and the diversity index and abundance index of soil samples with different mulching years were different between acidobacterium and actinomycetes (average relative abundance was 30.80% and 13.990%, respectively). In the early stage of mulching, the diversity index and abundance index of soil bacteria increased with the mulch input, and reached the maximum value after 6 years of mulching, and then decreased to a certain extent. There was no significant difference between 12 years and the initial period of mulching. 3) the soil microbial community structure was affected to some extent by mulching, but there was a difference between the bacterial community structure of uncovered forest land and the forestland after mulching. The abundance of Proteus increased from 17.60 to 37.77 (covering 12 years). However, the change of soil physical and chemical properties caused by actinomycetes is very small. The relationship between bacterial colony structure and soil environment tends to be complicated with the increase of mulching time, and the change of soil physical and chemical properties can affect the structure of bacterial community to a certain extent, and with the increase of mulching time, the relationship between bacterial colony structure and soil environment is becoming more and more complicated. Soil cover results in severe acidification of the soil, The pH values of control and mulching for 12 years were 5.23 and 3.42, respectively, but the abundance of acidophilus community in soil decreased. The first two axes of RDA analysis explained the variation of soil microbial community in covered bamboo forest. The adaptability of bacterial populations to soil environmental factors was different. The accumulation of available K, total N and organic matter in soil increased the relative abundance of Proteobacteria Bacteroidetes, and soil acidification decreased the relative abundance of Chloroflexi. [conclusion] Bamboo forest cover management has a great effect on the structure and diversity of soil bacterial community. Short-term mulching (less than 6 years) can increase the abundance and diversity of soil bacteria, but with the increase of mulching time, the abundance and diversity of soil bacteria decrease. The change of soil environmental factors will affect the structure of soil microbial community in covered bamboo forest. The study of microbial diversity in soil can analyze the degree of soil degradation from the point of view of microorganism and provide theoretical basis for soil remediation of bamboo forest.
【作者单位】：国家林业局竹子研究开发中心;
【基金】：林业公益性行业科研专项(201504407)
【分类号】：S714.3

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