Carbon dioxide assimilation potential and functional gene characteristics of autotrophic microorganisms of typical forest vegetations in Zhejiang
为研究亚热带不同森林植被类型土壤固碳微生物特征及其影响因子，选取毛竹林（Moso banboo groves）、阔叶林（Broad-leaved forest）、杉木林（Chinese fir forest）和马尾松林（Masson pine forest）等4种森林植被为研究对象，以cbbL为固碳细菌指示基因，利用实时荧光定量PCR（Real-time Quantitative PCR）和MiSeq高通量测序为研究手段。结果表明，4种林分土壤的细菌16S rRNA基因和固碳细菌cbbL基因丰度范围分别是5.40×1010～2.81×1011 copies·g-1干土和4.55×108～3.53×109 copies·g-1干土，其中毛竹林显著高于其他三种林分（P<0.05）；基因丰度显著关联的环境因子是阔叶林土壤的有效磷、不同土层的pH（P<0.05）。杉木林土壤固碳细菌多样性显著低于其他3种林分（P<0.05），其亚表层土壤高于表层（P<0.05）；双因子分析表明，林型、土层之间土壤固碳细菌多样性均存在显著或极显著差异。所有土壤具有相似的优势属但相对丰度不同，其中毛竹林和杉木林土壤的甲基化石油杆菌属（Methylibium）和诺卡菌属（Nocardia）占比明显高于阔叶林和马尾松林。冗余分析结果显示，不同林分土壤pH、土壤有机碳、有效磷、全氮差异是影响土壤固碳细菌群落特征形成的主要因素。综上，4种植被对土壤固碳微生物数量及群落结构多样性影响明显，从土壤理化性质、固碳细菌基因丰度、多样性以及结构特征等多维度结果证明，毛竹林对土壤肥力以及固碳细菌影响效果最好，固碳微生物对毛竹林土壤有机质积累贡献大于阔叶林，定量结论有待进一步研究。
[Objective] To alleviate the global climate change is one of the most important environmental challenges facing mankind. Autotrophic microorganisms, especially those in forest ecosystems, have been reported to have a strong ability to adapt to environmental changes and a high potential to sequestrate carbon. However, how their carbon-sequestrating effects vary with type of forests vegetation remains unclear. To explore this complex relationship, investigations were made of populations and community structures of soil carbon-sequestrating bacteria in the soils of four typical subtropical forests.[Method] Soil samples were collected from the surface (0-20 cm) and subsurface (20-40 cm) soil layers in the four types of forests, that is Moso banboo, Broad-leaved trees, Chinese fir and Masson pine for analysis of cbbL as indicator gene with the aid of quantitative PCR and MiSeq high-throughput sequencing technology.[Result] Abundance of the bacteria with 16S rRNA genes and those with cbbL genes varied in the range of 5.40×1010-2.81×1011 copies·g-1 dry soil and of 4.55×108to 3.53×109copies·g-1dry soil, respectively, in the four types of forest soils, and was the highest in the soil under bamboo groves (P<0.05); among soil physico-chemical properties, soil available P and soil pH was significantly related to the abundance of cbbL genes in the two soil layers under the broad-leaved forest (P<0.05). The soil under the Chinese fir forest was significantly lower than the others, and the subsurface soil was higher than the surface soil in diversity of carbon-sequestrating bacteria (P<0.05). Double factor variance analysis shows that the diversity of soil carbon-sequestrating bacteria varied significantly or ultra-significantly with forest type and soil layer. All the soils had similar dominant species of cbbL-carrying bacteria, which, however, differed in relative abundance beteween the four types of vegetations. The soil of the Moso bamboo groves and the Chinese fir forest was signiticantly higher than that of the Broad-leaved forest and Masson pine forest in proportion of Methylibium and Nocardia. Redundancy analysis (RDA) shows that soil pH, organic carbon, available P and total N were the main factors affecting the formation of community structure of the soil carbon-sequestrating bacteria in the soils.[Conclusion] To sum up, all the findings in this study indicate that population and community structure diversity of the soil carbonsequestrating microbes varied with type of the vegetation. Comparison of the four forest soils in soil physico-chemical property, and genetic abundance, diversity and community structure of the carbon-sequestrating bacteria shows Moso bamboo groves are the best type of vegetation benefitting soil fertility and carbon-sequestrating bacteria. Contribution of the bacteria to accumulation of organic matter was higher in the soil under bamboo groves than under broad-leaved forests, but as to how much, further investigations should be done.
刘茗,曹林桦,刘彩霞,梁辰飞,秦华,陈俊辉,邵帅,徐秋芳.亚热带4种典型森林植被土壤固碳细菌群落结构及数量特征[J].土壤学报,2021,58(4):1028-1039. DOI:10.11766/trxb202005110021 LIU Ming, CAO Linhua, LIU Caixia, LIANG Chenfei, QIN Hua, CHEN Junhui, SHAO Shuai, XU Qiufang. Characterization of Population and Community Structure of Carbon-Sequestration Bacteria in Soils under Four Types of Forest Vegetations Typical of Subtropical Zone[J]. Acta Pedologica Sinica,2021,58(4):1028-1039.复制