小兴安岭大亮子河国家森林公园不同生境下土壤细菌多样性和群落结构

土壤细菌是森林生态系统的一个重要组成成分, 是生态系统中物质循环和能量流动的重要参与者, 细菌群落组成和生物多样性是反映土壤生态功能的重要指标。本文利用高通量测序技术分析了大亮子河国家森林公园内红松(Pinus koraiensis)林、落叶松(Larix gmelinii)林、蒙古栎(Quercus mongolica)林、枫桦(Betula costata)林、针阔混交林、灌木林和草甸等7种不同生境土壤细菌群落组成和多样性的差异性, 探讨该地区土壤细菌群落对不同生境的响应, 为地区森林生态系统的经营管理及生态系统稳定性的维护提供科学理论基础。在门的水平上, 各生境的细菌群落组成基本一致, 其中变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、酸杆菌门(Acidobacteria)和疣微菌门(Verrucomicrobia)在7种生境土壤中相对丰度均大于10.0%, 是细菌中的优势菌门。在属的水平上, 共测得245个菌属, 各样地共有属118个, 占总属数的48.2%, 占总相对丰度的97.8%; 优势菌属分别为Spartobacteria_ genera_incertae_sedis、Gaiella、Gp16、Gp4, 占总相对丰度的47.0%, Spartobacteria_genera_incertae_sedis在7种生境土壤中丰度均最高。7种生境下的土壤细菌多样性和土壤理化因子存在着显著的差异, 红松林的土壤细菌群落多样性和丰富度均高于其他生境。土壤pH是大亮子河森林公园影响土壤细菌多样性的关键因子。

Community structure and diversity of soil bacteria in different habitats of Da Liangzihe National Forest Park in the Lesser Khinggan Mountains

Soil bacteria are important participants in the material cycling and energy flows in forest ecosystems. Therefore, the composition and biodiversity of bacterial communities are major indicators of soil ecological function. The aim of this study was to investigate the structure and diversity of bacterial communities across seven different habitats (i.e. Pinus koraiensis, Larix gmelinii, Quercus mongolica, Betula costata, coniferous-broad-leaved mixed forests, shrubs and meadows) in Da liangzihe National Forest Park by using high throughput sequencing technology. At the phylum level, the bacterial community composition was basically the same in all habitats, with Proteobacteria, Actinobacteria, Acidobacteria and Verrucomicrobia dominating the bacterial phyla by having relative abundance of more than 10%. At the genus level, 245 genera were identified, with 118 common genera accounting for 48.2% of all genera and 97.8% of the total relative abundance. The dominant genera, Spartobacteria_genera_incertae_sedis, Gaiella, Gp16 and Gp4, made up 47.0% of the total relative abundance. Spartobacteria_genera_incertae_sedis was the most abundant genus in every habitat. In addition, the soil bacterial diversity and the soil physicochemical factors differed significantly among the habitats. Both the diversity and richness of the soil bacterial community were higher in Pinus koraiensis than the other habitats. Soil pH was found to be a key factor affecting soil bacterial community diversity in Da Liangzihe National Forest Park.