不同气候带森林土壤微生物多样性和群落构建特征

Diversity and Community Assembly of Forest Soil Microorganisms in Different Climatic Zones

【目的】研究不同气候带森林土壤微生物的多样性特征和分布模式,为认识其多样性形成机制及加强森林生态系统管理提供依据。【方法】以温带针叶林(新疆喀纳斯,新疆库尔德宁)、暖温带针阔混交林(甘肃小陇山)、亚热带常绿落叶阔叶混交林(湖北木林子)和热带雨林(海南霸王岭)4种不同气候带森林为对象,在已经建立的固定样地采集土壤样品,利用Illumina测序技术分析不同气候带森林土壤细菌和真菌的多样性以及群落构建特征。【结果】土壤细菌多样性在暖温带针阔混交林中最高,即在沿气候梯度的5个地点样地中呈单峰分布;土壤真菌的香农指数在温带针叶林中最高,土壤真菌丰富度在热带雨林中最高。基于零模型数学框架分析发现,土壤细菌的群落构建主要由确定性过程主导,土壤真菌群落结构受随机性过程影响较大。典范对应分析(CCA)和Mantel test分析表明,土壤pH值(r=0.826,P<0.001)和植物多样性(r=0.474,P<0.001)与土壤细菌和真菌群落具有显著相关性。【结论】不同气候带的森林土壤细菌和真菌的多样性和群落结构都存在显著差异,土壤细菌和真菌具有不同的群落构建特征,土壤pH值和植物多样性是影响不同气候带森林土壤微生物多样性的重要因素。

【Objective】This study aimed to investigate the diversity characteristics and distribution patterns of forest soil microorganisms to provide a basis for the understanding soil microbial diversity and its response to environmental changes,as well as forest ecosystem management.【Method】This study was conducted in different climate zones,including temperate coniferous forest(Kanas,Xinjiang,KNS;Ku’erdening,Xinjiang,KEDN),warm temperate coniferous and broad-leaved mixed forest(Xiaolong Mountain,Gansu),subtropical evergreen deciduous broad-leaved mixed forest(Mulinzi,Hubei),and tropical rain forest(Bawangling,Hainan).Soil samples were collected from the established six hm^(2) permanent plots,and the distribution patterns of bacterial and fungal diversity were analyzed by using Illumina sequencing technology.【Result】The results showed that the diversity of soil bacteria was the highest in the warm temperate coniferous and broad-leaved mixed forest.It exhibited a single peak distribution in the five sample plots along the climate gradient.The Shannon index of soil fungi was the highest in temperate coniferous forest,and the richness of soil fungi was the highest in tropical rain forest.The null model revealed that the soil bacterial community was mainly dominated by deterministic processes,while the fungal community was mainly dominated by stochastic processes.Canonical correlation analysis(CCA)and Mantel test indicated that soil pH(r=0.826,P<0.001)and plant diversity(r=0.474,P<0.001)were significantly correlated with soil bacterial and soil fungal community structure.【Conclusion】There are significant differences in the diversity and community structure of forest soil bacteria and fungi in different climatic zones.Soil bacteria and fungi have different community assembly characteristics.Soil pH and plant diversity are important factors affecting forest soil microbial diversity in different climate zones.