摘要
在气候变暖及人类活动的双重干扰下,疏勒河上游冻土发生了显著退化,如活动层厚度加大、植被退化等,而冻土退化对微生物的影响一直是科研人员关注的热点话题。以疏勒河上游不同季节(4月、6月、9月)、不同退化程度冻土为研究对象,研究了可培养细菌多样性特征。通过16S r DNA基因测序及构建系统发育树表明,研究区域可培养细菌归类为27个属,分属于α-变形菌门,γ-变形菌门,放线菌门,厚壁菌门和拟杆菌门,其中放线菌门为优势类群。从属水平来讲,可培养细菌以节杆菌属和微球菌属为主,其含量随冻土退化程度加深分别呈下降和升高趋势。土壤细菌多样性与环境因子的相关性分析表明,可培养细菌多样性与土壤含水量、总氮极显著正相关,与有机碳显著正相关。这些结果表明,伴随着冻土退化而发生的地上植被逆向演替过程中,青藏高原不同类型冻土间已产生较大的环境异质性如土壤碳氮及含水量,进一步可能导致冻土微生物多样性分异。研究结果为利用微生物综合评价青藏高原不同类型冻土的生态环境提供了数据基础。
Owing to climate change and human activities,significant degradation of permafrost has happened in the upstream regions of the Shule River Basin,such as the increasing depth of the active layer and vegetation degradation. However,little is known about the consequent effects of permafrost degradation to the soil microbes. In this study,we analyzed the culturable bacterial diversity of 12 permafrost-affected soil samples from four principal permafrost types,sub-stable permafrost（ SSP）,transition permafrost（ TP）,unstable permafrost（ UP） and extremely unstable permafrost（ EUP） in different seasons,to investigate the effects of soil properties on bacterial community structure during the process of permafrost degradation. The results showed that the genera Arthrobacter and Micrococcus were the dominant bacteria in the upstream region of the Shule River. The genus Arthrobacter comprised 15. 6% - 50. 1% and the genus Micrococcus comprised 7. 5% - 48. 5% of the total culturable bacteria,and these percentages decreased and increased during the process of permafrost degradation,respectively. Based on 16 S rDNA gene sequences and the phylogenetic tree,the culturable bacteria in the study area belonged to 27 genera,and fell into five phylogenetic groups： α-Proteobacteria,γ-Proteobacteria,Actinobacteria,Firmicutes and Bacteroides,among which Actinobacteria was the dominate phylum. Such a culturable bacterial community structure was similar with previous studies of permafrost ecosystems. Bacterial diversity characteristics were different among different permafrost types,these results indicated that there existed huge environmental heterogeneity between different permafrost during the process of reverse vegetation succession along with permafrost degradation,and this heterogeneity has further affected the species diversity. Besides,correlation analysis showed that soil moisture,soil total nitrogen and organic carbon were important factors that affecting the culturable bacterial diversity. Hence,we can conclud
作者
张宝贵
刘晓娇
刘敏
张威
章高森
伍修琨
陈拓
刘光琇
ZHANG Baogui;LIU Xiaojiao;LIU Min;ZHANG Wei;ZHANG Gaosen;WU Xiukun;CHEN Tuo;LIU Guangxiu(Institute of Geographycial Science, Taiyuan Normal Univerisity, Jinzhong 030619, Shanxi, China;Key Laboratory of Inland Ecohydrology Northwest Institute of Eco-Environment and Resources, Lanzhou 730000, China;Key Laboratory of Desert and Desertification , Northwest Institute of Eco-Environment and Resources Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China)
出处
《冰川冻土》
CSCD
北大核心
2018年第1期156-165,共10页
Journal of Glaciology and Geocryology
基金
国家科技支撑计划项目(2014BAC05B02)
山西省面上青年基金项目(201701D221225)
山西省高等学校大学生创新创业训练项目(CXCY1772)资助
关键词
青藏高原
疏勒河上游
冻土退化
细菌多样性
环境因素
Qinghai-Tibet Plateau
the upstream of the Shule River
permafrost degradation
bacteria diversity
environmental factors
