寒温带兴安落叶松林土壤细菌微生物量和群落组成研究

Study on soil microbial biomass and community composition of Larix gmelinii in cold temperate zone

为了研究不同林型兴安落叶松林土壤细菌微生物量和土壤细菌群落结构特征,探讨微生物量和群落组成变化的分布规律及影响因子,选择了4个典型兴安落叶松林:藓类兴安落叶松林、杜香兴安落叶松林、草类兴安落叶松林和杜鹃兴安落叶松林,采用磷脂脂肪酸(PLFAs)和高通量测序的方法,分析了4个林型土壤细菌的微生物量和群落组成。结果表明:PLFA法检测出4个林型中C12~C20 8种类型共44种不完全分布的PLFAs生物标记,4个林型中的兴安落叶松林细菌生物量最高,草类兴安落叶松林最低;高通量共检测出19门35纲55目87科92属细菌,其中变形菌纲Alphaproteobacteria、γ-变形菌纲Gammaproteobacteria、酸杆菌纲Acidobacteria、β变形菌纲Betaproteobacteria、放线菌纲Actinobacteria丰度较高。通过冗余分析分析发现,有效磷对土壤细菌生物量的影响较大,土壤pH值、土壤含水率和土壤养分对土壤细菌的群落组成影响比较明显。本研究表明寒温带兴安落叶松林中不同土壤环境的土壤细菌微生物量和群落组成存在差异,且与土壤环境因子之间具有相关性。

In order to study the distribution characterizes and influencing factors of soil microbial biomass and soil bacterial community structure in different Larix gmelinii forest types, we analyzed the soil bacterial biomass and community structure of four different Larix gmelinii forest types： mosses- Larix gmelinii forest, Ledum palustre- Larix gmelinii forest, grass- Larix gmelinii forest and Rhododendron dauriczcm- Larix gmelinii forest by using the phospholipid fatty acids and high-throughput sequencing. The result showed that a total of 44 species belong to 8 types（C12-C20）, which were no-fully distributions PLFA biomarker types, were detected in this study, of which Larix gmelinii forest was highest and grass- Larix gmelinii forest was lest. Moreover, 92 genus, 87 families, 55 orders, 35 classes and 19 phylum were investigated, in those, the more abundance were Alphaproteobacteria, Gammaproteobacteria, Acidobacteria and Betaproteobacteria. The results showed that there were no significant differences between the two groups （P 〈 0.05） Actinobacteria has a higher abundance. The redundancy analysis indicated that available phosphor was key factor to affect the soil bacterial biomass, but soil pH, soil moisture and nutrition were key factors to affect the soil bacterial community structures. This study showed that there were significant different in the soil bacterial biomass and community structure between different Larix gmelinii forest types, and were correlated with soil environmental factors.