汤旺河国家公园不同演替阶段森林土壤细菌多样性变化规律

Soil Bacterial Diversity between Different Forest Successional Stages in Tangwanghe National Park

为了解红松湿生演替系列过程中土壤生境及土壤细菌多样性的变化规律,以小兴安岭汤旺河国家公园的白桦次生林、人工针阔混交林和原始云冷杉红松林为研究对象,分别代表湿生演替系列的演替先锋群落、演替中期群落和演替顶级群落,采用高通量测序的方法分析森林土壤细菌的多样性变化规律.结果表明:汤旺河国家公园从先锋演替到顶级演替阶段,森林土壤中w(OC)、w(TN)、w (AN)、w (AP)和w (AK)升高,而p H降低.此次分析土壤细菌包括16门27纲52目60科75属,其中Acidobacteria、Proteobacteria、Actinobacteria、Bacteroidetes为共有的优势菌门(相对丰度> 1%).演替先锋阶段(白桦次生林)Proteobacteria相对丰度最高,然而演替后期(云冷杉红松林) Acidobacteria相对丰度最高.通过冗余分析和相关性分析发现,不同演替阶段的森林土壤细菌多样性与土壤中w(OC)呈显著负相关,与土壤中w(TK)呈显著负相关,与土壤中w(AK)呈极显著负相关.研究显示,土壤细菌群落结构和多样性在不同湿生演替阶段有明显差异,主要可能受到土壤中w(OC)、w(TK)和w(AK)的影响.

In order to understand the changes in soil habitats and soil bacterial diversity during the wet successional series of Pinus koraiensis,the secondary birch forests,artificial coniferous-broad-leaved mixed forests,and primary virgin Pinus koraiensis forests in the Tangwanghe National Park of Xiaoxing′anling Mountains were selected as the study objects.The three forest types represented the pioneer,the medium-term and the top-ranked community of succession series respectably.The high-throughout sequencing method was used to analyze the diversity of the bacteria in the forest soils.The results showed that the contents of soil organic carbon(OC),total nitrogen(TN),alkali-hydrolyzed nitrogen(AN),available phosphorus(AP)and available potassium(AK)increased from the pioneer succession to the top succession stage,while the soil pH value decreased.The community analysis of soil bacteria belonged to 16 families,27 orders,52 orders,60 families and 75 genera.Among them,Acidobacteria,Proteobacteria,Actinobacteria,and Bacteroidetes were the dominant phyla(relative abundance>1%).The relative abundance of Proteobacteria was the highest in the pioneer stage(secondary birch forest),but the relative abundance of Acidobacteria was highest in the late successional period(Pine and Pinus koraiensis).Based on the redundancy analysis and correlation analysis,it was found that the bacterial diversity in the forest soils at different successional stages was significantly negatively correlated with soil organic carbon(OC)content,significantly negatively correlated with the soil total potassium(TK)content,and significantly negatively correlated with the soil available potassium(AK)content.The soil bacterial community and diversity were significantly different between wet successional stages,and were mainly affected by soil organic carbon(OC),total potassium(TK)and available potassium(AK)contents.