1季节变化对喀斯特石山不同恢复阶段檵木群落土壤微生物群落的影响
Effects of seasonal changes on soil microbial community of Loropetalum chinense community in different recovery stages of Karst Plateau rocky mountains
[目的]探究季节变化对喀斯特石山不同恢复阶段檵木群落土壤微生物群落的影响,以期为深入解析喀斯特石山植被恢复过程中土壤生态环境对未来气候变化的反馈和响应机制提供科学依据。[方法]以雨季灌木林土壤(RS)、旱季灌木林土壤(DS)、雨季乔木林土壤(RA)和旱季乔木林土壤(DA)为研究对象,应用高通量测序技术测定土壤微生物群落结构,生理生化方法测定土壤化学性质和酶活性。研究不同季节和不同恢复阶段下土壤微生物群落结构特征、多样性变化及其与环境因子的关系。[结果](1)RS、DS、RA 和 DA 的优势真菌群为子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、被孢霉门(Mortierellomycota)和未被定义菌门(unclassified_k__Fungi);优势细菌群为放线菌门(Actinobacteria)、变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、绿弯菌门(Chloroflexi)。LEfSe分析表明RS、DS、RA和DA共有 41 个真菌和26个细菌相对丰度存在显著差异(LDA>2.0,P<0.05),季节变化对不同恢复阶段土壤真菌群落的物种差异影响更显著。(2)Shannon指数表明,无论旱雨季,真菌和细菌的多样性均为灌木林＜乔木林。同一恢复阶段下,从雨季到旱季,真菌多样性显著降低,细菌多样性显著增加。PCoA和NMDS分析表明季节变化对不同恢复阶段土壤细菌群落的组间差异影响更显著。(3)微生物网络分析表明,土壤真菌群落的微生物网络复杂性为DS＞RS和DA＞RA;土壤细菌群落的微生物网络复杂性为DS＞RS和DA＜RA.无论灌木林还是乔木林,从雨季到旱季过程中真菌和细菌各群落间的正相互作用增强,表明逐渐以共生关系为主导,竞争关系减弱来响应干旱胁迫。(4)CCA分析和相关性分析表明,驱动RS、DS、RA和DA的真菌群落发生变化的主要影响因子差异明显,分别对应为AK、URE,CEL,SUC、URE,pH、SWC;影响RS、DS、RA和DA的细菌群落发生变化的关键因子差异也明显,分别对应为CAT、SUC和SWC,AK、TN,pH、CAT,CAT、URE.从雨季到旱季,土壤微生物群落与环境因子的相互作用增强,表现为灌木林土壤真菌 Basidiomycota与CEL、TC、SOM都呈显著负相关;乔木林土壤真菌Calcarisporiellomyceyes与TN呈显著正相关。灌木林土壤细菌Acidimicrobiia与SOM、TC、CEL和TN呈显著正相关。[结论]不同恢复阶段土壤真菌群落对季节变化的敏感性强于细菌群落,但细菌群落的网络复杂性要强于真菌群落,群落结构更加稳定。
[Objective]To explore the impact of seasonal changes on soil microbial community of Loropetalum chinense community in different restoration stages of Karst Plateau rocky mountains,so as to provide scientific basis for in-depth analysis of the feedback and response mechanism of soil ecological environment to future climate change in the process of Karst Plateau rocky mountain vegetation restoration.[Method]The study focuses on the soil of rainy season shrub forests(RS),dry season shrub forests(DS),rainy season tree forests(RA),and dry season tree forests(DA).High throughput sequencing technology is used to determine the structure of soil microbial communities,and physiological and biochemical methods are used to determine soil chemical properties and enzyme activities.Study the structural characteristics and diversity changes of soil microbial communities under different seasons and recovery stages,as well as their relationship with environmental factors.[Result](1)The dominant fungal groups of RS,DS,RA and DA were Ascomycota,Basidiomycota,Mortierellomycota and unclassified_k__Fungi;The dominant bacteria are Actinomycetota,Pseudomonadota,Acidobacteriota and Chloroflexota.LEfSe analysis showed that there were significant differences in relative abundance of 41 fungi and 26 bacteria among RS,DS,RA,and DA(LDA>2.0,P<0.05),and seasonal changes had a more significant impact on species differences in soil fungal communities at different recovery stages.(2)The Shannon index indicates that regardless of the dry and rainy season,the diversity of fungi and bacteria in shrubland forests is lower than that in tree forests.During the same recovery phase,from the rainy season to the dry season,fungal diversity significantly decreases and bacterial diversity significantly increases.PCoA and NMDS analysis showed that seasonal changes had a more significant impact on the inter group differences of soil bacterial communities at different recovery stages.(3)The analysis of microbial network showed that the complexity of microbial network of soil fungal community was DS>RS and DA>RA;The complexity of microbial network of soil bacterial community is DS>RS and DA<RA.Whether in shrub or tree forests,the positive interaction between fungal and bacterial communities increases from the rainy season to the dry season,indicating a gradual dominance of symbiotic relationships and a weakening of competitive relationships in response to drought stress.(4)CCA analysis and correlation analysis showed that the main influencing factors driving the changes in fungal communities of RS,DS,RA,and DA were significantly different,corresponding to AK,URE,CEL,SUC,URE,pH,and SWC,respectively;The key factors affecting the changes in bacterial communities of RS,DS,RA,and DA are also significantly different,corresponding to CAT,SUC,and SWC,AK,TN,pH,CAT,CAT,URE.From the rainy season to the dry season,the interaction between soil microbial communities and environmental factors has increased,manifested as a significant negative correlation between the shrub soil fungus Basidiomycota and CEL,TC,SOM;There is a significant positive correlation between soil fungi Calcarisporiellomycoyes and TN in tree forests.There is a significant positive correlation between soil bacteria Acidimicrobia and SOM,TC,CEL,and TN in shrublands.[Conclusion]The sensitivity of soil fungal communities to seasonal changes during different recovery stages is stronger than that of bacterial communities,but the network complexity of bacterial communities is stronger than that of fungal communities,and the community structure is more stable.
王雅楠;马姜明;梁月明;杨皓;
珍稀濒危动植物生态与环境保护教育部重点实验室,广西 桂林 541006##广西漓江流域景观资源保育与可持续利用重点实验室,广西 桂林 541006;珍稀濒危动植物生态与环境保护教育部重点实验室,广西 桂林 541006##广西漓江流域景观资源保育与可持续利用重点实验室,广西 桂林 541006##广西师范大学可持续发展创新研究院,广西 桂林 541006;中国地质科学院岩溶地质研究所自然资源部广西壮族自治区岩溶动力学重点实验室,广西 桂林 541006;珍稀濒危动植物生态与环境保护教育部重点实验室,广西 桂林 541006##广西漓江流域景观资源保育与可持续利用重点实验室,广西 桂林 541006;
seasonal changes Soil microorganisms Karst Plateau Loropetalum chinense Recovery phase High throughput sequencing
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