冀北山地桦木林土壤细菌群落特征对坡向的响应

Response of soil bacterial community characteristics to slope aspect of birch forest in mountain area of northern Hebei Province

为了揭示冀北山地桦木林土壤细菌群落特征对坡向的响应规律,以冀北山地阴坡、半阴坡和半阳坡桦木林土壤为研究对象,采用高通量测序技术,分析了土壤细菌群落结构和多样性。结果表明:细菌群落组成主要包含41门、107纲,其中优势细菌门为变形菌门和酸杆菌门;土壤细菌群落α多样性指数在坡向间存在显著差异,阴坡>半阴坡>半阳坡;土壤含水量、容重、硝态氮和氨态氮均影响细菌微生物群落的结构组成,其中,土壤含水量与多种细菌门存在显著相关性,且与细菌α多样性存在极显著的正相关性。综上所述,不同坡向桦木林土壤细菌群落结构和多样性呈现出一定的变化规律,坡向和土层深度变化引起的土壤含水量变化是该地区桦木林土壤细菌群落结构和多样性差异的主要因素。

In order to reveal the response of soil bacterial community characteristics to slope aspect,high-throughput sequencing technology was used to analyze the soil bacterial community structure and diversity of birch forests on shady,semi-shady and semi-sunny slopes in mountain area of northern Hebei Province.The results showed that the bacterial community composition mainly included 41 phyla and 107 classes,among which the dominant bacterial phyla were Proteobacteria and Acidobacteria.There were significant differences in diversity index of soil bacterial communityαslope direction,and the shady slope>semi-shady slope>semi-sunny slope.Soil water content,bulk density,nitrate nitrogen and ammonia nitrogen all affected the structure and composition of bacterial microbial communities,and soil water content was significantly correlated with a variety of bacterial phyla,and there was a significant positive correlation with bacterialαdiversity.In conclusion,the soil bacterial community structure and diversity of birch forests with different slope orientations showed certain variations,and the changes of soil water content caused by slope orientation and soil depth were the main factors for the differences in soil bacterial community structure and diversity in birch forests in this area.