中国西南典型森林土壤微生物在不同土壤深度下的变化特征  

Variation characteristics of microorganisms at different soil depths of typical forests in southwest China

作　　者：丁爽 魏圣钊 陈真亮 邵婧 段逢瑞 严禹 段兴武 DING Shuang;WEI Shengzhao;CHEN Zhenliang;SHAO Jing;DUAN Fengrui;YAN Yu;DUAN Xingwu(Institute of International River and Eco-security,Yunnan University,Kunming 650500,China;School of Life Sciences,Yunnan University,Kunming 650500,China;School of Earth Sciences,Yunnan University,Kunming 650500,China;School of Chemical Science and Technology,Yunnan University,Kunming 650500,China;School of Information Science and Engineering,Yunnan University,Kunming 650500,China)

机构地区：[1]云南大学国际河流与生态安全研究院,昆明650500 [2]云南大学生命科学学院,昆明650500 [3]云南大学地球科学学院,昆明650500 [4]云南大学化学科学与工程学院,昆明650500 [5]云南大学信息学院,昆明650500

出　　处：《应用生态学报》2023年第3期614-622,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金联合重点项目(U2002209);云南省杰出青年项目(202201AV070001);云南省科技厅-云南大学“双一流”建设联合基金项目(2019FY003009);云南大学研究生科研创新基金项目(2021Y362);国家级大学生创新创业训练计划项目(202110673070)资助。

摘　　要：微生物生物量与群落结构在碳循环过程中起着至关重要的作用。底层土存有大量有机碳,但有关微生物群落的研究多集中在表层土壤,深层土壤的微生物群落变化及影响机制尚不确定。本研究采用磷脂脂肪酸技术分析西南地区西双版纳热带雨林、哀牢山亚热带阔叶林和丽江温带针叶林3种森林生态系统不同土壤深度(0~20、20~40、40~60、60~80和80~100 cm)的土壤微生物生物量及群落结构,探讨其在不同森林类型及土壤深度下的变化特征及影响因素。结果表明:随土壤深度的增加,3种森林生态系统的有机碳和全氮逐渐降低,微生物生物量显著下降;真菌∶细菌比(F∶B)逐渐减小,革兰氏阳性菌∶革兰氏阴性菌比(G^(+)∶G^(-))显著增大,微生物群落结构由G^(-)为主的富营养型细菌结构逐渐转变为以G^(+)为主的寡营养型细菌结构。3种森林生态系统的土壤生物量没有显著差异,但微生物群落结构差异显著。哀牢山亚热带阔叶林与丽江温带针叶林0~20 cm的F∶B显著大于西双版纳热带雨林,而西双版纳热带雨林0~100 cm的G^(+)∶G^(-)显著大于丽江温带针叶林和哀牢山亚热带阔叶林。冗余分析发现,土壤有机碳、全氮和碳氮比(C∶N)等是影响微生物生物量的主要因素,共同解释度为78.3%。逐步回归分析表明,C∶N是影响F∶B和G^(+)∶G^(-)的最主要驱动因子。随着土壤深度的增加,微生物群落结构的改变和微生物生物量的下降可能强烈影响西南地区森林土壤有机碳的动态变化。Microbial biomass and community structure play a significant role in soil carbon cycling.There is a large amount of organic carbon in the subsoil,but most studies on soil microbial community have focused on the surface soil.The changes and influencing mechanisms of microbial community in subsoil are unclear.We analyzed soil microbial biomass and community structure at different soil depths(0-20,20-40,40-60,60-80,and 80-100 cm)in three typical forests in southwest China,Xishuangbanna tropical rain forest,Ailao Mountain subtropical broad-leaved forest,and Lijiang temperate coniferous forest,by using phospholipid fatty acid technology,to explore their variation characteristics and influencing factors in different forests and soil depths.The results showed that contents of soil organic carbon and total nitrogen decreased gradually,microbial biomass declined significantly.The ratio of Gram-positive bacteria to Gram-negative bacteria(G^(+):G^(-))reduced gradually,while the ratio of fungi to bacteria(F:B)increased with the increasing soil depth.Microbial community turned from G--dominated which adapted to eutrophic environment into G^(+)-dominated which adapted to oligotrophic environment.The three forest types differed little in soil microbial biomass,but different significantly in microbial community structure.Ailao Mountain subtropical broad-leaved forest and Lijiang temperate coniferous forest had much higher F:B at 0-20 cm than Xishuangbanna tropical rain forest,while significantly higher G^(+):G^(-)at 0-100 cm in Xishuangbanna tropical rain forest was observed.Results of the redundancy analysis showed that the contents of soil organic carbon and total nitrogen were the main factors determining microbial biomass,with combined explanation of 78.3%.Results of the stepwise regression analysis showed that C:N was the most important driving factor on F:B and G^(+):G^(-).The change in microbial community structure and the decrease in biomass along soil profile might strongly affect the dynamics of soil organic carbon in

关 键 词：垂直分布 土壤剖面 土壤层次 磷脂脂肪酸 微生物群落结构 

分 类 号：S714.3[农业科学—林学]