海南岛尖峰岭热带雨林土壤固碳微生物群落特征

Soil Carbon Sequestering Microbial Communities in Jianfengling Tropical Rainforests of Hainan Island

采集海南岛尖峰岭地区低地雨林次生林、山地雨林次生林和山地雨林原始林土壤,基于绝对定量PCR和高通量测序技术,探讨了热带雨林土壤中固碳微生物群落结构的多样性与组成及其影响因素。结果表明:固碳微生物的Alpha多样性与基因丰度均表现为低地雨林次生林高于山地雨林原始林;尖峰岭热带雨林土壤固碳微生物优势菌门为假单胞菌门(Pseudomonadota,44.28%~70.60%)和放线菌门(Actinomycetota,11.95%~33.73%),优势菌属为慢生根瘤菌属(Bradyrhizobium,11.53%~31.06%)、诺卡氏菌属(Nocardia,4.97%~17.07%)、中慢生根瘤菌属(Mesorhizobium, 4.44%~12.97%)、分枝杆菌属(Mycobacterium, 2.62%~9.20%)、芽绿菌属(Blastochloris,4.34%~10.12%)、固氮弧菌属(Aromatoleum,1.97%~5.39%)、分枝菌酸杆形菌属(Mycolicibacterium,1.71%~3.78%)、固氮螺菌属(Azospirillum,1.97%~2.65%)、Methylibium (1.22%~3.77%),且以兼性自养菌为主。PCoA与LEfSe分析表明,热带雨林3个林型土壤固碳微生物群落存在差异,其标志物种分属放线菌纲、γ-变形菌纲、α-变形菌纲和β-变形菌纲。RDA分析表明,全氮、全磷、有机碳、易氧化有机碳是驱动尖峰岭热带雨林固碳微生物群落差异的重要影响因素。

Soil samples were collected from the lowland rainforest secondary forests,montane rainforest secondary forests,and montane rainforest primary forests in the Jianfengling of Hainan Island,absolute quantification PCR and high-throughput sequencing technology were used to explore the diversity and composition of carbon sequestering microbial community structure in soil and its influencing factors.The results showed that bothαdiversity and gene quantity of carbon-fixing microorganisms were higher in lowland rainforest secondary forest than in montane rainforest primary forest.The dominant phyla of soil carbon-fixing microorganisms in the Jianfengling rainforest were Actinomycetota(11.95%–33.73%)and Pseudomonadota(44.28%–70.60%),the dominant genera were Bradyrhizobium(11.53%–31.06%),Nocardia(4.97%–17.07%),Mesorhizobium(4.44%–12.97%),Mycobacterium(2.62%–9.20%),Blastochloris(4.34%–10.12%),Aromatoleum(1.97%–5.39%),Mycolicibacterium(1.71%–3.78%),Azospirillum(1.97%–2.65%)and Methylibium(1.22%–3.77%),and facultative autotrophs were predominant.PCoA and LEfSe analyses revealed the differences in soil carbon sequestration microbial communities among the three forest types of tropical rainforest,with marker species belonging to Actinomycetes,γ-Proteobacteria,α-Proteobacteria andβ-Proteobacteria,respectively.RDA analysis showed that total nitrogen,total phosphorus,organic carbon and readily oxidizable carbon were important soil factors for the differences.