title: Changes of the Bacterial Abundance and Communities in Shallow Ice Cores from Dunde and Muztagata Glaciers, Western China.
abstract: In this study, six bacterial community structures were analyzed from the Dunde ice core (9.5-m-long) using 16S rRNA gene cloning library technology. Compared to the Muztagata mountain ice core (37-m-long), the Dunde ice core has different dominant community structures, with five genus-related groupsBlastococcussp./Propionibacterium,Cryobacterium-related.,Flavobacteriumsp.,Pedobactersp., andPolaromassp. that are frequently found in the six tested ice layers from 1990 to 2000. Live and total microbial density patterns were examined and related to the dynamics of physical-chemical parameters, mineral particle concentrations, and stable isotopic ratios in the precipitations collected from both Muztagata and Dunde ice cores. The Muztagata ice core revealed seasonal response patterns for both live and total cell density, with high cell density occurring in the warming spring and summer months indicated by the proxy value of the stable isotopic ratios. Seasonal analysis of live cell density for the Dunde ice core was not successful due to the limitations of sampling resolution. Both ice cores showed that the cell density peaks were frequently associated with high concentrations of particles. A comparison of microbial communities in the Dunde and Muztagata glaciers showed that similar taxonomic members exist in the related ice cores, but the composition of the prevalent genus-related groups is largely different between the two geographically different glaciers. This indicates that the micro-biogeography associated with geographic differences was mainly influenced by a few dominant taxonomic groups.
authors.affiliation: School of Life Science, Lanzhou University, Lanzhou China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.affiliation: School of Life Science, Lanzhou University, Lanzhou China.
authors.forename: Xiang-Kai
authors.initials: XK
authors.lastname: Li
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou China.
authors.forename: Jing
authors.initials: J
authors.lastname: Si
authors.affiliation: Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, BeijingChina; Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, LanzhouChina.
authors.forename: Guang-Jian
authors.initials: GJ
authors.lastname: Wu
authors.affiliation: Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, BeijingChina; Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, LanzhouChina.
authors.forename: Li-De
authors.initials: LD
authors.lastname: Tian
authors.affiliation: School of Life Science, Lanzhou University, LanzhouChina; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, BeijingChina; Laboratory of Ice Core and Cold Regions Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, LanzhouChina.
authors.forename: Shu-Rong
authors.initials: SR
authors.lastname: Xiang
keywords: Tibet Plateau; glacier; live cell density; micro-biogeography; taxonomic group