北京松山林地nirK型反硝化微生物群落立地及林型效应

doi:10.11707/j.1001-7488.LYKX20220629

摘要/Abstract

摘要：

目的: 探究北京松山林地土壤nirK型反硝化微生物群落特征及影响因子，为华北暖温带森林土壤生态系统氮循环过程和环境变化提供依据。方法: 在北京松山国家级自然保护区选择油松林、山杨林、蒙古栎林3种典型林型，分别设置3块（20 m× 20 m）标准地进行调查，采集0~20 cm表层混合土样，分析土壤性质并提取土壤微生物总DNA，PCR扩增反硝化过程关键酶亚硝酸盐还原酶的编码基因nirK片段，采用第2代高通量测序分析不同林型土壤nirK型反硝化微生物群落组成和多样性，探究林型和土壤性质对反硝化微生物群落特性的影响。结果: 1）从油松林、山杨林和蒙古栎林9个土壤样本中共得到nirK基因有效序列993401条、优质序列770328条。3种林型土壤nirK基因共检测出7门78属，在已鉴定的微生物中各林型优势菌为变形菌门，其相对丰度在3种林型中均达50%，在油松林中最高为58.2%；优势属主要为慢生根瘤菌属、中生根瘤菌属和红假单胞菌属，总相对丰度达50%以上，其中核心菌属为慢生根瘤菌属。2） nirK型反硝化微生物α多样性分析显示，油松林Shannon（7.59±0.56）、Simpson（0.98±0.01）、Chao1（2164.24±214.08）指数均显著高于山杨林（5.23±0.26、0.89±0.02、1650.56±136.69）和蒙古栎林（5.76±0.38、0.93±0.02、1621.36±156.70）（P<0.05）。基于Bray-Curtis距离算法并采用PCoA分析显示，不同林型土壤反硝化微生物群落组间差异大于组内。3）林分因子、土壤性质与土壤反硝化微生物的冗余分析结果表明，土壤碱解氮、硝态氮和有机质等土壤性质是影响nirK型反硝化微生物群落组成的关键因子（P<0.05）。结论: 北京松山油松林、山杨林和蒙古栎林土壤nirK型反硝化微生物群落组成、多样性存在明显差异，林型与碱解氮、硝态氮和有机质等土壤性质是影响土壤nirK型反硝化微生物群落特征的重要因素。

关键词: 华北暖温带, 林型, nirK基因, 反硝化微生物, 微生物群落组成, 微生物群落多样性

Abstract:

Objective: This work aims to explore the traits and influence factors of soil nirK-type denitrifying microbial community in different forests in Songshan, Beijing, providing novel insights into the nitrogen cycling process and environmental change of forest soil ecosystem in the warm temperate forest soil ecosystem of North China. Method: Three typical forest types of Pinus tabuliformis, Populus davidiana and Quercus mongolica were selected in the Songshan Nature Reserve of Beijing. Three standard sample plots (20 m×20 m) were set up in each forest type for investigation. The 0?20 cm surface mixed soil samples were collected to analyze soil properties, and extract total soil microbial DNA, PCR was used to amplify nirK gene coding the key enzyme, nitrate reductase, in the denitrification process. The second generation high-throughput sequencing was used to analyze the composition and diversity of soil denitrifying microbial communities in the different forest types, and to explore the effects of soil properties on the characteristics of denitrifying microbial communities. Pearson’s correlation analysis and redundancy analysis (RDA) were used to examine the soil properties factors influencing the trait of denitrifying microbial community. Result: 1) A total of 993 401 effective sequences with 770 328 high-quality sequences of nirK gene were obtained by high-throughput sequencing from 9 soil samples in P. tabuliformis forest, P. davidiana forest and Q. mongolica forest. There were 7 phyla and 78 genera of nirK gene detected in the soil of three different forest types. Among the identified microorganisms, the dominant bacteria of soil nirK denitrification microorganisms in the three forests were Proteobacteria, with the relative abundance of 50% in the three forest types, and the highest of 58.2% in the P. tabuliformis forest. The dominant genera were Bradyrhizobium, Mesorhizobium and Rhodopseudomonas, with a total relative abundance of more than 50%, among which the core genus was Bradyrhizobium. 2) The analysis of alpha diversity of nirK denitrifying microorganisms showed that the Shannon, Simpson and Chao1 diversity index of nirK-type denitrifying microorganisms in P. tabuliformis forest (7.59±0.56, 0.98±0.01, 2 164.24±214.08) were significantly higher than those in P. davidiana forest (5.23±0.26, 0.89±0.02, 1 650.56±136.69) and Q. mongolica forest (5.76±0.38, 0.93±0.02, 1 621.36±156.70) (P<0.05). Based on Bray-Curtis distance algorithm and PCoA analysis, the difference among soil denitrifying microbial communities in different forest types was greater than that within the community. 3) Redundancy analysis showed that soil alkali hydrolyzable nitrogen, nitrate nitrogen and soil organic matter were the key factors that significantly affected the composition of the nirK-type denitrifying microbial community (P<0.05). Conclusion: There are obvious differences in the composition and diversity of soil nirK-type denitrifying microbial communities among P. tabuliformis forest, P. davidiana forest and Q. mongolica forest in the warm temperate zone of North China. Forest types and soil properties such as alkali hydrolyzable nitrogen, nitrate nitrogen and soil organic matter are important factors affecting the traits of soil nirK-type denitrifying microbial communities.

Key words: warm temperate zone of north China, forest type, nirK gene, denitrifying microorganism, microbial community composition, microbial community diversity

中图分类号:

S718.43

祝琳,聂立水,史策,黄梦遥,牛鑫,张润哲,张兆德,魏一凡,王登芝,杨昊,聂浩亮,王江,薄慧娟. 北京松山林地nirK型反硝化微生物群落立地及林型效应[J]. 林业科学, 2024, 60(5): 139-150.

Lin Zhu,Lishui Nie,Ce Shi,Mengyao Huang,Xin Niu,Runzhe Zhang,Zhaode Zhang,Yifan Wei,Dengzhi Wang,Hao Yang,Haoliang Nie,Jiang Wang,HuiJuan Bo. Effects of Soil Properties and Stand Factors on nirK-Denitrifying Microbial Community in Songshan, Beijing[J]. Scientia Silvae Sinicae, 2024, 60(5): 139-150.

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林分类型 Forest stands	海拔 Altitude/m	坡度 Slope/(°)	坡向 Aspect	凋落物厚度 Litter depth/cm	林分密度 Stand density/ (plant·hm^?2)	平均树高 Average height/m	平均胸径 Average DBH/cm	郁闭度 Canopy density
油松林Pinus tabuliformis forest	941	18	东East	7.0	894	18	32	0.80
山杨林Populus davidiana forest	869	21	北North	1.0	992	9	14	0.80
蒙古栎林Quercus mongolica forest	856	23	东北Northeast	3.5	985	7	12	0.80

林型 Forest stands	pH	有机质 SOM/(g?kg^?1)	总氮 TN/(g?kg^?1)	碱解氮 AN/(mg?kg^?1)	有效磷 AP/(mg?kg^?1)	速效钾AK/ (mg?kg^?1)	铵态氮NH₄⁺/ (mg?kg^?1)	硝态氮NO₃^?/ (mg?kg^?1)
油松林Pinus tabuliformis forest	6.3 ± 0.3a	70.3 ± 2.8a	1.6 ± 0.1a	247.0 ± 10.1a	2.8 ± 0.1c	378.0 ± 15.4a	24.4 ± 2.9a	28.7 ± 0.2a
山杨林Populus davidiana forest	5.7 ± 0.2a	12.3 ± 0.4c	0.4 ± 0.01c	158.1 ± 4.5b	8.0 ± 0.2a	110.0 ± 3.1c	18.7 ± 0.5b	8.7 ± 0.3b
蒙古栎林Quercus mongolica forest	5.9 ± 0.2a	33.2 ± 1.4b	0.9 ± 0.03b	68.0 ± 2.8c	3.8 ± 0.2b	174.0 ± 7.1b	21.4 ± 1.1b	10.7 ± 2.2b

林型 Forest stands	Shannon指数Shannon index	Simpson指数Simpson index	Chao1指数Chao1 index
油松林 Pinus tabuliformis forest	7.59 ± 0.56a	0.98 ± 0.01a	2164.24 ± 214.08a
山杨林 Populus davidiana forest	5.23 ± 0.26b	0.89 ± 0.02b	1650.56 ± 136.69b
蒙古栎林 Quercus mongolica forest	5.76 ± 0.38b	0.93 ± 0.02b	1621.36 ± 156.70b

土壤性质 Soil properties	Shannon指数 Shannon index	Simpson指数 Simpson index	Chao1指数 Chao1 index	β多样性 β diversity
pH	0.68*	?0.33	0.47	0.48
有机质 SOM	0.78*	?0.85**	0.70*	0.58
碱解氮 AN	0.40	?0.85**	0.72*	0.46
全氮 TN	0.78*	?0.42	0.70*	0.58
有效磷 AP	?0.85**	0.86**	?0.70*	?0.52
速效钾 AK	0.75*	?0.86**	0.67*	0.52
铵态氮 NH₄⁺-N	0.90**	?0.71*	0.67*	0.30
硝态氮 NO₃^?-N	0.77*	?0.77*	0.70*	0.44

土壤性质 Soil properties	R²	P
pH	0.37	0.25
有机质 SOM	0.46	0.17
全氮 TN	0.44	0.19
碱解氮 AN	0.92	0.001
有效磷 AP	0.13	0.65
速效钾 AK	0.63	0.06
铵态氮 NH₄⁺-N	0.27	0.38
硝态氮 NO₃^?-N	0.71	0.03