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林业科学 ›› 2019, Vol. 55 ›› Issue (10): 193-202.doi: 10.11707/j.1001-7488.20191019

• 研究简报 • 上一篇    下一篇

辽东栎林演替过程中的土壤细菌群落结构和多样性变化

张晓1,2,刘世荣2,*,黄永涛1,傅声雷1   

  1. 1. 河南大学环境与规划学院 黄河中下游数字地理技术教育部重点实验室 开封 475004
    2. 中国林业科学研究院森林生态环境与保护研究所 国家林业和草原局森林生态环境重点实验室 北京 100091
  • 收稿日期:2018-06-22 出版日期:2019-10-25 发布日期:2019-11-26
  • 通讯作者: 刘世荣
  • 基金资助:
    国家国际科技合作专项项目(2015DFA31440);国家自然科学基金项目(31700383)

Changes on Community Structure and Diversity of Soil Bacterial Community during the Succession of Quercus wutaishanica

Xiao Zhang1,2,Shirong Liu2,*,Yongtao Huang1,Shenglei Fu1   

  1. 1. Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education College of Environment and Planning, Henan University Kaifeng 475004
    2. Key Laboratory of Forest Ecology and Environment of National Forestry and Forestry Administration Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry Beijing 100091
  • Received:2018-06-22 Online:2019-10-25 Published:2019-11-26
  • Contact: Shirong Liu
  • Supported by:
    国家国际科技合作专项项目(2015DFA31440);国家自然科学基金项目(31700383)

摘要:

目的: 土壤微生物在维持森林生态系统功能中起着重要作用,研究辽东栎林演替过程中森林土壤微生物群落结构和多样性在演替过程中的变化规律,深入认识森林土壤细菌群落结构恢复和驱动机制。方法: 以太岳山地区皆伐后形成的30、80和150年生次生辽东栎林为对象,于2015年6月每个林型设置为20 m×20 m的森林动态监测样地20个,合计60个,用直径10 cm土钻采集0~10 cm表层土样,利用16S rRNA基因高通量测序技术,测定皆伐后自然恢复过程中森林土壤细菌群落的组成、结构和多样性变化。结果: 在辽东栎林自然恢复过程中,随演替阶段进行,变形菌门和绿弯菌门的相对丰度逐渐增加,而放线菌门和酸杆菌门的相对丰度逐渐降低,疣微菌门和浮霉菌门的相对丰度没有明显变化。拟杆菌门和厚壁菌门的相对丰度在80年生中龄林显著低于30年生幼龄林,而在150年生老龄林和80年生中龄林间却无显著差异。基于weighted UniFrac距离的主坐标分析表明,幼龄林、中龄林和老龄林的细菌群落结构有显著差异。基于OTU水平的Bray-Curtis相似性进一步证明,幼龄林与老龄林的平均细菌群落相似性为37.9%,中龄林与老龄林的相似性增加到47.2%,表明皆伐后自然恢复过程中不同演替阶段的细菌群落结构表现出逐渐向老龄林恢复的趋势。土壤细菌物种丰富度和系统发育多样性在自然恢复过程中呈递减趋势,幼龄林的土壤细菌物种丰富度和系统发育多样性显著高于老龄林,而中龄林和老龄林的土壤细菌多样性差异并不显著。Chao1指数和种系型多度则表现为幼龄林和中龄林间差异不显著,老龄林则显著降低。方差分解表明,皆伐后不同演替阶段的细菌群落变化和土壤有机质、可溶性碳、土壤总氮和有效氮含量等土壤因子显著相关,其中土壤碳和氮含量对细菌群落结构变化的解释量分别为20.2%和26.3%,未解释的部分为43.4%。结论: 皆伐后辽东栎林演替过程中不同恢复阶段土壤细菌群落结构具有显著差异,幼龄林和老龄林细菌群落结构差异最大,中龄林细菌群落结构与老龄林相似。土壤细菌多样性随着演替的进行呈逐步降低的趋势,幼龄林细菌多样性显著高于中龄林和老龄林,中林龄多样性则更加接近老龄林水平。这说明土壤细菌群落结构和多样性在次生演替过程中具有可预测性。

关键词: 森林演替, 细菌, 群落结构, 群落相似性, 多样性

Abstract:

Objective: Soil microorganisms play a critical role in maintaining forest ecosystem structure and function. This study aimed to investigate the structure and diversity of forest soil microbial community during succession, to understand the restoration and driving mechanism of soil bacterial community structure during succession. Method: A total of 60 (20 m×20 m) quadrats, 20 each for three forest types (30-year-, 80-year- and 150-year-old secondary forests of Quercus wutaishanica after clear cutting in Taiyue Mountains), were established in June 2015. Soil samples in the 0-10 cm layers were collected with a 10 cm diameter earth drill. High throughput sequencing of 16S rRNA gene was conducted to examine soil bacterial community composition, structure and diversity during natural restoration after clear cutting.Result: During the natural restoration of Q. wutaishanica forest, the relative abundances of Proteobacteria and Chloroflex gradually increased with the succession process, the relative abundances of Actinobacteria and Acidobacteria decreased gradually, while that of Verrucomicrobia and Planctomycetes did not change significantly. The relative abundance of Bacteroidetes and Firmicutes in 80-year-old forest was significantly lower than that in 30-year-old forest, but there was no significant difference between 150-year-old forest and 80-year-old forest. Principal coordinate analyses (PCoA) based on weighted UniFrac distance showed that there were significant differences in soil bacterial community structure among 30-year-old, 80-year-old, and 150-year-old forests. Bray-Curtis similarity based on OTU level further indicated that the average similarity of bacterial community structure between 30-year-old young growth forest and 150-year-old mature forest was 37.9%, and that between 80-year-old forest and 150-year-old forest was 47.2%. These findings suggested that soil bacterial communities at different succession stages in the natural restoration process after clear cutting showed a recovery trend to the old forest. Bacterial species richness and phylogenetic diversity showed a descending trend during natural recovery process. Species richness and phylogenetic diversity of bacterial communities in 30-year-old secondary forest were higher than those in 150-year-old growth forest, whereas there were no significant differences in soil bacterial diversity between middle-aged forest and old forest. Chao1 index and phylotype richness did not show obvious difference between 30-year-old young growth forest and 80-year-old secondary forest, but decreased significantly in 150-year-old mature forest. Variation partitioning analysis showed that bacterial community structure was significantly correlated with soil carbon and nitrogen content. Soil carbon and nitrogen explained 20.2% and 26.3% of variations on soil bacterial structure, respectively, and the unexplained part was 43.4%. Objective: Soil bacterial community structure changed significantly during the succession of oak secondary forest after clear cutting. The difference of bacterial community structure between 30-year-old secondary forest and 150-year-old secondary forest was obvious, and then the structure in 80-year-old secondary forest become more similar with communities in old growth forest during secondary succession. Bacterial diversity showed descending trend during succession. Bacterial diversity in young forest were higher than those in 80-year-old secondary and old growth forest, and the diversity in 80-year-old secondary forest was more close to the level in old growth forest. These findings suggest that bacterial community structure and diversity may be predictable during the secondary succession.

Key words: forest succession, bacteria, community structure, community similarity, diversity

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