【作者】 曾敏；

【导师】 谢锦升；

【作者基本信息】 福建师范大学 ， 水土保持与荒漠化防治， 2018， 硕士

【摘要】 南方红壤侵蚀区水土流失严重,生态环境脆弱。通过近三十年的水土保持生态恢复,植被逐步恢复,林下芒萁群落大量生长,土壤肥力得到改善,但植被恢复过程芒萁覆盖对土壤微生物群落结构的变化以及土壤微生物的影响因素缺乏了解。本研究选取福建省长汀县河田镇红壤侵蚀退化地为研究区,选择未治理地(Y0)、恢复13年(Y13)和恢复31年(Y31)的马尾松林为实验地,进行3种处理:保留芒萁覆盖(NRD)、芒萁去除(RD)和林下裸地(CK)。利用Illumina Miseq高通量测序技术对细菌16S rDNA和真菌ITS进行测序,结果表明:(1)植被恢复和芒萁覆盖对土壤含水量无显著影响,土壤pH随植被恢复和芒萁覆盖降低。土壤有机碳、全氮、全磷、速效磷、土壤碳氮比、铵态氮和土壤微生物生物量含量随植被恢复显著增加;恢复年限对铵态氮和土壤微生物生物量碳有显著影响,硝态氮的含量随植被恢复年限的增加先降低后上升。芒萁覆盖导致土壤有机碳、全磷、土壤碳氮比、速效磷和土壤微生物量含量有增加的趋势,降低了硝态氮含量。(2)本研究共得到土壤细菌优化序列1710503条,细菌群落42门、100纲、209目、387科、700属、1232种和4987个OTU;土壤真菌优化序列1675385条,真菌群落6门、24纲、72目、162科、293属、453种和1544个OTU。测序数据量合理,能够反映绝大多数土壤微生物群落的多样性和物种。土壤细菌群落丰富度随植被恢复年限的增加而显著增加(P<0.05),细菌多样性随植被恢复增加但恢复年限对多样性没有显著影响;真菌丰富度和多样性亦随植被恢复显著增加(P<0.05),但恢复年限对真菌丰富度和多样性没有显著影响。这说明土壤微生物群落多样性在一定时间内达到稳定,真菌丰富度比细菌丰富度先达到稳定。芒萁覆盖在未治理地对土壤细菌真菌的丰富度有显著影响;对未治理样地的真菌多样性显著增加,对细菌多样性没有显著影响。这表明芒萁覆盖在未治理侵蚀地对微生物的影响更显著,同时芒萁对真菌多样性的影响大于细菌。土壤微生物Beta多样性表明植被恢复和芒萁覆盖对土壤细菌真菌有显著影响。冗余分析结果表明土壤pH、土壤有机碳、全氮、全磷、碳氮比、速效磷、硝态氮、铵态氮和地上凋落量是微生物群落丰富度和多样性的影响因子,其中全氮、速效磷和地上凋落量是主要的影响因子。(3)本研究中土壤细菌优势门为变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、放线菌门(Actinobacteria)、酸杆菌门(Acidobacteria)、浮霉菌门(Planctomycetes)、后壁菌门(Firmicutes)、疣微菌门(Verrucomicrobia)、GAL 15、拟杆菌门(Bacteroidetes)和Thaumarchaeota,相对丰度占土壤细菌群落组成的97.00%以上。植被恢复增加了变形菌门、放线菌门、酸杆菌门、浮霉菌门和疣微菌门的相对丰度,降低了绿弯菌门、后壁菌门、GLA15、拟杆菌门和Thaumarchaeota的相对丰度。土壤真菌群落门水平是子囊菌门(Ascomycota)、担子菌门(Basidiomycota)、接合菌门(Zygomycota)、壶菌门(Chytridiomycota),优势菌门为子囊菌门、担子菌门。植被恢复和芒萁覆盖对子囊菌门没有显著影响,担子菌门的相对丰度随芒萁覆盖显著下降。冗余分析表明地上凋落量和速效磷含量是土壤微生物群落组成的主要影响因子。更多还原

【Abstract】 Red soil erosion area in Subtropical China is the serious soil erosion area and fragile ecological environment.Ecological restoration of soil and water conservation in recent 30 years,the gradual recovery of vegetation,forest biomass growth,improve soil fertility,but Dicranopteris dichotoma in the process of vegetation restoration change on soil microbial community structure and influencing factors of soil microbial lack of understanding.In this study,the eroded land of red soil in Hetian Town,Changting County,Fujian province is selected as the research area,and without building measures of vegetation restoration(YO),13 years of vegetation restoration(Y13)and 31 years of vegetation restoration(Y31)were selected as experimental sites.We implemented three kinds of treatment(NRd-Not removed Dicranopteris dichotoma;Rd-Removed Dicranopteris dichotoma;CK-Control)at experimental plots.The bacterial 16S rDNA and fungal ITS were sequenced using Illumina Miseq sequencing technology.The results showed that:(1)The effect of vegetation restoration and Dicranopteris dichotoma on soil moisture is little,The value of soil pH decreased with the vegetation restoration and Dicranopteris dichotoma.The concentration of soil organic carbon,total nitrogen,total phosphorus,available phosphorus,soil carbon and nitrogen ratio,ammonium nitrogen and soil microbial biomass increased significantly with vegetation recovery;the increase in recovery years has a significant effect on ammonium nitrogen and soil microbial biomass carbon;the content of nitrate nitrogen is low to high with the restoration of vegetation.Dicranopteris dichotoma lead the contents of soil organic carbon,total phosphorus,soil carbon nitrogen ratio,instant phosphorus and soil microbial content increased respectively,which reduced the nitrate content.(2)A total of 1710503 optimization sequences of soil bacteria were obtained,and soil bacterial communities were identified as 42 phylums,100 classes,209 orders,387 families,700 genera,1232 species and 4987 OTUs respectively;the optimum sequence of soil fungi is 1675385,and fungi Community has 6 Phylums,24 classes,72 orders,162 families,293 genera,453 species and 1544 OTUs.The amount of sequencing data is reasonable and can reflect the diversity and species of the vast majority of soil microbial communities.The richness of soil bacterial community increased significantly with the increase of vegetation restoration years(P<0.05),bacterial diversity increased with vegetation recovery but restoration years had no significant impact on diversity;the richness and diversity of the fungal community also increased significantly with the restoration of vegetation(P<0.05),but the recovery years had no significant effect on the richness and diversity of fungi.This shows that the diversity of soil microbial community is stable in a certain time,and the richness of fungi is more stable than the richness of bacteria.Dicranopteris dichotoma in the control has a significant influence on the richness of soil microbial;the control sample of the fungal diversity increased significantly,had no significant effect on bacterial diversity.Dicranopteris dichotoma in the control plots more significant effect on soil microbial,while the impact of the fungal diversity is greater than bacteria.Soil microbial diversity of Beta showed that vegetation restoration and Dicranopteris dichotoma have significant effect on soil bacteria and fungi.The results of redundancy analysis showed that soil pH,soil organic carbon,total nitrogen,total phosphorus,carbon and nitrogen ratio,available phosphorus,nitrate nitrogen,ammonium nitrogen and aboveground litter were the influencing factors of microbial community richness and diversity,among them,total nitrogen,available phosphorus and aboveground litter are the main influencing factors.(3)The level of soil bacterial community relative abundance is greater than 1%,which are Proteobacteria,veronicus,actinomycetes,Actinobacteria,floating mold,posterior wall,verruca,microphylum,GAL 15,Bacteroides and Thaumarchaeota,accounting for more than 97%of the total number of soil bacteria.Vegetation restoration increased the relative abundance of Proteobacteria,Actinomycetes,Actinobacteria,Planctomycetes and Verrucomicrobia,reduced the relative abundance of Chloroflexi,Firmicutes,GLA15,Bacteriomonas and Thaumarchaeota.The Phylum level of soil fungal community are Ascomycota,Basidiomycota,Zygomycota and Chytridiomycota,the dominant fungal of phylum level are Ascomycota,basidiomycota.The vegetation restoration and Dicranopteris dichotoma have no significantly influence on the relative abundance of Ascomycota,and the relative abundance of Basidiomycota decreased significantly with Dicranopteris dichotoma.Redundancy analysis showed that aboveground litter and available phosphorus content made the main influencing factors of soil microbial community.更多还原