【作者】 李梦莎；

【导师】 穆立蔷；

【作者基本信息】 东北林业大学 ， 森林植物资源学， 2020， 博士

【摘要】 中国东北温带的地带性植被(或称显域植被、显性植被,Zonal vegetation)是落叶阔叶林,紫椴是其中具有代表性的植被类型。森林中物质资源丰富,在人类发展中提供了大量的物质基础。在长时间的生态环境演变与人类活动的共同作用下,地带性的紫椴被其他类型的森林取代,自身面积在不断减少,如何恢复紫椴分布区的温带地区森林植被是许多学者目前研究重点。森林土壤理化性质以及土壤肥力主要由微生物的种群分布与其数量相关。森林土壤微生物的多样性和变异性反映了它们对生境质量的适应性,因此,不同地带或者不同地区植被下土壤微生物群落的结构和多样性,即不同紫椴分布区土壤微生物群落的结构和多样性的变化和分异,是维持东北森林生态系统可持续发展的关键因素之一。为此,本研究以东北地区紫椴分布区-不同海拔梯度和不同纬度带土壤微生物为研究对象,分析了土壤理化性质和土壤酶活性的地带性差异、土壤微生物组成和多样性的差异,利用高通量测序技术分析在不同海拔和纬度土壤中形成的微生物群落差异,从而阐明东北地区紫椴分布区中微生物群落及土壤养分的影响,为促进森林生态系统的微生物维持循环及森林功能的维持提供理论依据,结果如下:(1)土壤化学成分、土壤酶活性发现,不同海拔和纬度紫椴分布区土壤理化存在显著差异。低海拔土壤有机碳、全氮显著高于高海拔;长白山地区的土壤有机碳、全氮高于其它地区。不同海拔土壤FDA水解酶,过氧化物酶,脲酶,酸性蛋白酶,脱氢酶差异不显著,但是土壤蔗糖酶差异显著。不同纬度下FDA水解酶,过氧化物酶,脲酶,酸性蛋白酶,脱氢酶,蔗糖酶差异显著。FDA水解酶和过氧化氢酶随着纬度由南向北逐渐增加,脱氢酶和脲酶呈现中间纬度高,两边低的趋势,酸性蛋白酶和蔗糖酶呈现随着由北向南逐渐增加。土壤酶活性在纬度地带性呈现出不同的地带性规律。(2)不同海拔土壤真菌群落结构及多样性分析发现,土壤真菌群落主要门为担子菌门(Basidiomycota)、子囊菌门(Ascomycota)、被孢霉门(Mortierellomycota)。不同海拔土壤alpha多样性差异不显著,但是海拔梯度改变了土壤真菌beta多样性。从土壤真菌群落结构及多样性角度分析发现,不同海拔的植被通过调整真菌丰度的方式来调节植被对土壤养分的吸收利用,而且易受土壤pH、有机碳、土壤含水量的调控。(3)不同海拔土壤细菌群落结构及多样性分析发现,土壤细菌群落主要门为变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)。不同海拔土壤Shannon多样性差异不显著但是ACE,Chao1指数差异显著。海拔梯度改变了土壤细菌beta多样性,细菌海拔分布上呈现了出700m和800m细菌相似度高,而900m和1000m相似度高。从土壤细菌群落结构及多样性角度分析发现,不同海拔的土壤细菌群落结构的影响因素不同,低海拔主要调控环境因子为土壤化学养分,而高海拔主要调控因子是土壤pH和土壤含水量。(4)不同纬度紫椴分布区土壤真菌群落结构及多样性分析发现,担子菌门(Basidiomycota)、子囊菌门(Ascomycota)、被孢霉门(Mortierellomycota)为优势菌门,占了全部序列80%。纬度差异显著改变了土壤中的真菌群落结构,纬度由北向南显著提高了紫椴分布区中土壤中真菌群落丰度及beta多样性。不同纬度紫椴分布区土壤的铵态氮、总磷、总钾、微生物碳是解释土壤真菌群落结构变异的主要因素。(5)不同纬度紫椴分布区土壤细菌群落结构及多样性分析发现,变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、放线菌门(Actinobacteria)、绿弯菌门(Chloroflexi)。纬度差异显著改变了土壤中的细菌群落结构,纬度由北向南紫椴分布区中土壤中细菌群落丰度及beta多样性显著升高。北部地区嫩江和胜山细菌群落相似度较高、勃利和凤凰山和凉水和宁安细菌群落相似度较高。不同纬度紫椴分布区土壤的pH、速效钾、土壤含水量、微生物量碳氮是解释土壤细菌群落结构变异的主要因素。综上所述,东北地区紫椴分布区土壤真菌和细菌在空间部分上出现了一定的分异,驱动微生物产生差异的因子主要来自于土壤中pH、有机质、全氮,还有一些速效养分。在小尺度上,微生物的alpha多样性差异小或者没有差异,随着尺度的增加,微生物alpha多样性变化增加。但是不同纬度,不同海拔微生物的丰富并未发生改变。因此维持着紫椴分布区主要土壤微生物组成并未发生改变。更多还原

【Abstract】 The zonal vegetation in the temperate zone of northeast China(also known as dominant area vegetation,dominant vegetation,and zonal vegetation)is a deciduous broad-leaved forest,and Tilia amurensis Rupr is one of the typical vegetation types.In the long history of human development,forests have provided an important material basis for human survival and production.Under long-term human effects and changes in the ecological environment,the area of zonal Tilia amurensis has been declining and replaced by other types of forest.The restoration and reconstruction of the forest vegetation in temperate areas with aster distribution areas has a long way to go.The quantity and population of forest soil microorganisms directly affect the physical and chemical properties of the forest soil and soil fertility,and then affect the growth and development of the forest.The diversity and variability of forest soil microorganisms reflect their adaptability to habitat quality,and they are the most sensitive biological indicators.Therefore,the structure and diversity of soil microbial communities under different zones or regions of vegetation,that is,the distribution of different Tilia amurensis the change and differentiation of the structure and diversity of soil microbial communities in the area is one of the key factors to maintain the sustainable development of forest ecosystems in Northeast China.To this end,this study takes the Tilia amurensis’s distribution area of Northeast China-soil microorganisms at different altitude gradients and different latitudes as research objects,and analyzes the zonal differences in soil physical and chemical properties and soil enzyme activities,and the differences in soil microbial composition and diversity.High-throughput sequencing technology analyzes the differences in microbial communities formed in soils at different altitudes and latitudes,thereby clarifying the effects of microbial communities and soil nutrients in the Tilia amurensis distribution area in Northeast China,in order to promote the maintenance of microorganisms in the forest ecosystem and the maintenance of forest functions.Provide theoretical basis,the results are as follows:(1)It was found that the soil chemical composition and soil enzyme activity showed significant differences in soil physical and chemical properties at different altitudes and latitudes.Soil organic carbon and total nitrogen in low altitude were significantly higher than those in high altitude;soil organic carbon and total nitrogen in Changbai Mountain area were higher than those in other areas.The differences in soil FDA hydrolase,peroxidase,urease,acid protease,and dehydrogenase were not significant at different altitudes,but the soil invertase was significantly different.At different latitudes,FDA hydrolase,peroxidase,urease,acid protease,dehydrogenase,and sucrase have significant differences.FDA hydrolase and catalase gradually increase with the latitude from south to north,dehydrogenase and urease show a trend of high middle latitude and low on both sides,and acid protease and sucrase gradually increase from north to south.The soil enzyme activity showed different zonal patterns at the latitude.(2)Analysis of the structure and diversity of soil fungal communities at different altitudes revealed that the main families of soil fungal communities were Basidiomycota,Ascomycota,and Mortierellomycota.There was no significant difference in soil alpha diversity at different altitudes,but altitude gradients changed the beta diversity of soil fungi.From the perspective of soil fungal community structure and diversity,it was found that vegetation at different altitudes adjusted the absorption and utilization of soil nutrients by adjusting the fungal abundance,and was susceptible to the regulation of soil pH,organic carbon,and soil moisture.(3)Analysis of the structure and diversity of soil bacterial communities at different altitudes revealed that the main phytophyte communities of soil are Proteobacteria,Acidobacteria,and Actinobacteria.Shannon diversity at different altitudes was not significantly different but ACE and Chao 1 indices were significantly different.Altitude gradient changed the beta diversity of soil bacteria.The altitude distribution of bacteria showed a high degree of similarity of bacteria at 700m and 800m,and a high degree of similarity at 900m and 1000m.From the perspective of soil bacterial community structure and diversity,it was found that the factors affecting soil bacterial community structure at different altitudes are different.The main regulating environmental factors at low altitudes are soil chemical nutrients,while the major regulating factors at high altitudes are soil pH and soil moisture content.(4)Analysis of the structure and diversity of soil fungal communities in the distribution areas of Tilia amurensis in different latitudes revealed that Basidiomycota,Ascomycota,and Mortierellomycota are the dominant phyla,accounting for 80%of the total%.The latitude difference significantly changed the fungal community structure in the soil,and the latitude from north to south significantly increased the fungal community abundance and beta diversity in the soil in the Aster distribution area.The ammonium nitrogen,total phosphorus,total potassium,and microbial carbon in the soils of Tilia amurensis at different latitudes are the main factors explaining the structural variation of soil fungal communities.(5)Analysis of the structure and diversity of soil bacterial communities in the distribution areas of Tilia amurensis in different latitudes revealed that Proteobacteria,Acidobacteria,Actinobacteria,and Chloroflexi.The latitude difference significantly changed the bacterial community structure in the soil,and the abundance and beta diversity of the bacterial community in the soil in the area of laziness from north to south increased significantly.The bacterial communities of Nenjiang and Shengshan in the northern region have higher similarity,and the similarities of bacterial communities in Boli and Fenghuangshan and Liangshui and Ning’an.Soil pH,available potassium,soil water content,and microbial biomass carbon and nitrogen are the main factors that explain the variation of soil bacterial community structure in different latitudes.To sum up,the soil fungi and bacteria in the aster distribution area of Northeast China have some differences in space.The factors that drive the difference of microorganisms mainly come from soil pH,organic matter,total nitrogen,and some quick-acting nutrients.On a small scale,there is little or no difference in the alpha diversity of microorganisms.As the scale increases,the change in alpha diversity of microorganisms increases.However,the abundance of microorganisms at different latitudes and altitudes did not change.Therefore,the main soil microbial composition in the aster distribution area was not changed.更多还原