间伐措施对松材线虫病疫区马尾松林土壤微生物多样性的影响

Effects of Thinning Measures on Soil Microbial Diversity of Pinus massoniana Forest in Pine Wilt Disease Endemic Areas

松材线虫病作为世界检疫性病害严重危害松属植物并威胁森林生态安全,至今没有行之有效的措施对其进行控制和除杀。为满足人们对森林提供多种生态服务的需要,通过对马尾松林进行高强度(采伐强度60%)和低强度(采伐强度15%)2种间伐措施采伐松材线虫病疫木后,采用高通量测序手段对松材线虫病疫区马尾松林土壤的细菌和真菌结构变化进行分析,旨在探究间伐对松材线虫病疫区马尾松林土壤微生物群落结构的变化,分析对土壤微环境的影响。采用高通量测序法对间伐抚育后的马尾松林土壤细菌和真菌群落进行研究,结果表明,3种林分土壤细菌和真菌群落表现出明显的差异,高间伐措施林分组(H-CK)的Shannon多样性指数和Chao1指数最高,H-CK组的土壤微生物群落多样性和丰富度显著高于低间伐措施林分组(L-CK)和对照组(CK)。L-CK组中标志细菌群落为Actinobacteriota(放线菌门),标志真菌群落为Leotiomycetes(锤舌菌纲);H-CK组中标志细菌群落为Chloroflexi(绿弯菌门),标志真菌群落为Dothideomycetes(座囊菌纲)。结合土壤理化性质分析表明,与对照组相比,高强度间伐H-CK组的土壤有机质含量上升13%,在增加土壤有机质积累的同时,H-CK组的全氮含量达1.12 g/kg,碱解氮的含量为64.15 mg/kg,可显著提高土壤全氮含量和有效氮含量的积累(P<0.05),从而提升林地地力。稳步提升森林质量,逐步将现有发生松材线虫病的马尾松纯林培育成复层异龄针阔混交林,使其抗病能力增加,生态功能增强。

Pine wilt disease,as a world quarantine disease,seriously endangers pine plants and threatens forest ecological security.However,there are currently no effective measures to control and eliminate it.To suit people′s needs for supplying diverse ecological services to the forest,high-intensity(60%logging intensity)and low-intensity(15%logging intensity)thinning measures were used in Pinus massoniana forests to harvest wood infected with pine wilt disease.The alterations in bacterial and fungal composition in the soil of P.massoniana forests impacted by the disease were analyzed using high-throughput sequencing.The objective was to investigate the alterations in the organization of the soil microbial community in P.massoniana forests impacted by thinning-induced pine wilt disease and assess the effects on the soil microenvironment.The soil bacterial and fungal populations of P.massoniana woods were investigated using the high-throughput sequencing technique.The findings demonstrated that the bacterial and fungal populations in the soil varied significantly among the three stands.The high thinning measure forest group(H-CK)had the greatest Shannon diversity index and Chao1 index,and the diversity and richness of the soil microbial community in the H-CK group were considerably higher than those in the low thinning measure forest group(L-CK)and control group(CK).Actinobacteriota was the marker bacterial community and Leotiomycetes was the marker fungus community in the L-CK group.In the H-CK group,Chloroflexi was the marker bacterial community and Dothideomycotes was the marker fungal community.The high-intensity thinning H-CK group′s soil organic matter content rose by 13%as compared to the control group,according to an analysis of soil physical and chemical properties.The H-CK group′s total nitrogen content increased to 1.12 g/kg and its alkaline nitrogen content was 64.15 mg/kg as soil organic matter buildup increased.The forest′s soil fertility was enhanced as a result,with a significant increase in both the total and accessible nitrogen content of the soil(P<0.05).Steadily impoving forest quality,strengthening the disease resistance and boosting the ecological function of the current,pure Pinus massoniana forest that has been harmed by pine wilt disease by progressively transforming it into a multilayer,unevenly aged needle broad-leaved mixed forest.