杉木人工林土壤施用生物炭对细菌群落结构及多样性的影响

采集杉木人工林土壤，通过室内土壤培养实验，研究添加不同制备原料和制备温度的生物炭对土壤细菌群落结构及多样性的影响，为改善南方酸性红壤及合理应用生物炭提供科学依据。原土添加3%的300 ℃杉叶炭( BL300) 、600 ℃杉叶炭( BL600) 、300 ℃木屑炭( BW300) 及600 ℃木屑炭( BW600) ，与对照土壤进行对比，进行培养实验80 天，运用高通量测序技术对PCR 所扩增16S rDNA 序列的V3+V4 区域进行测定。OTU 韦恩图分析表明，添加BL300 的土壤细菌较对照丰度提高，其他生物炭处理丰度减小; 通过PCoA 分析和Beta多样性分析及UPGMA 聚类分析得出，添加杉叶炭后土壤细菌群落结构及多样性与对照土壤的差异显著，其中BL600 与对照差异最大，添加木屑炭结果与对照较相似; 添加生物炭对不同物种水平上的土壤细菌结构和功能产生一定影响，其中杉叶炭处理影响十分显著，使土壤优势菌丰度变化较大，木屑炭处理对优势菌的影响相对较小。添加BL300 生物炭提高了土壤细菌的丰度，而添加其他生物炭降低了细菌丰度; 不同制备原料和温度对生物炭存在影响，由于木屑炭可利用氮素不足，杉叶生物炭对土壤细菌结构和多样性的影响比木屑生物炭更显著，高温炭灰分含量较多，因此对细菌多样性的影响大于低温炭; 不同的土壤细菌种群生活习性与功能不同，对生物炭组分利用程度也不同，添加生物炭能够改变土壤中优势种群的相对丰度和土壤细菌群落的整体功能。

Soil samples were collected from a Chinese fir plantation, and an indoor soil incubation experiment was conducted to investigate the effects of biochars prepared with different raw materials and pyrolysis temperatures on soil bacterial community structure and diversity, providing scientific support for the amelioration of southern acidic red soil and the rational application of biochars. The collected soil samples were divided into five groups: four groups were amended with 3% of 300 ℃ fir leaf biochar (BL300), 600 ℃ fir leaf biochar (BL600), 300 ℃ wood sawdust biochar (BW300), and 600 ℃ wood sawdust biochar (BW600) respectively, while the fifth group served as the control soil without any biochar amendment. The incubation experiment lasted for 80 days, and the V3+V4 hypervariable region of 16S rDNA sequences amplified via PCR was analyzed using high-throughput sequencing technology. OTU Venn diagram analysis revealed that the abundance of soil bacteria in the BL300-amended group was higher than that in the control, while the abundances in the other biochar-amended groups were reduced. Principal Coordinates Analysis (PCoA), Beta diversity analysis and UPGMA cluster analysis showed that the soil bacterial community structure and diversity in the fir leaf biochar-amended groups differed significantly from those of the control, with BL600 exhibiting the largest difference from the control, while the results of the wood sawdust biochar-amended groups were relatively similar to the control. Biochar amendment exerted certain effects on soil bacterial structure and function at different taxonomic levels, among which fir leaf biochar treatments had extremely significant impacts, causing substantial changes in the abundance of dominant soil bacteria, whereas wood sawdust biochar treatments had relatively minor effects on dominant bacteria. Amendment with BL300 biochar increased the abundance of soil bacteria, while amendments with other biochars decreased bacterial abundance. Different preparation raw materials and pyrolysis temperatures affect biochars: due to the insufficient available nitrogen in wood sawdust biochars, fir leaf biochars exert more pronounced effects on soil bacterial structure and diversity than wood sawdust biochars. High-temperature biochars have higher ash content, thus having greater impacts on bacterial diversity than low-temperature biochars. Different soil bacterial populations have distinct living habits and functions, and differ in their utilization of biochar components. Biochar amendment can alter the relative abundance of dominant populations in soil and the overall function of the soil bacterial community.