DOI: 10.1002/2017GB005681
Scopus记录号: 2-s2.0-85021412658
论文题名: Basin scale variability of active diazotrophs and nitrogen fixation in the North Pacific, from the tropics to the subarctic Bering Sea
作者: Shiozaki T ; , Bombar D ; , Riemann L ; , Hashihama F ; , Takeda S ; , Yamaguchi T ; , Ehama M ; , Hamasaki K ; , Furuya K
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2017
卷: 31, 期: 6 起始页码: 996
结束页码: 1009
语种: 英语
英文关键词: iron
; nifH
; nitrogen fixation
; noncyanobacterial diazotrophs
; UCYN-A
Scopus关键词: bacterium
; coastal water
; community composition
; community structure
; cyanobacterium
; growth
; iron
; marine environment
; microbial activity
; microorganism
; nitrogen fixation
; subarctic region
; Alaska
; Bering Sea
; Pacific Ocean
; Pacific Ocean (Equatorial)
; Pacific Ocean (North)
; United States
; Cyanobacteria
英文摘要: Nitrogen-fixing microorganisms (diazotrophs) provide biologically available nitrogen to plankton communities and thereby greatly influence the productivity in many marine regions. Various cyanobacterial groups have traditionally been considered the major oceanic diazotrophs, but later noncyanobacterial and presumably heterotrophic diazotrophs were also found to be widespread and potentially important in nitrogen fixation. However, the distribution and activity of different diazotroph groups is still poorly constrained for most oceanic ecosystems. Here we examined diazotroph community structure and activity along a 7500 km south-north transect between the central equatorial Pacific and the Bering Sea. Nitrogen fixation contributed up to 84% of new production in the upper waters of the subtropical gyre, where the diazotroph community included the gammaproteobacterium γ-24774A11 and highly active cyanobacterial phylotypes (>50% of total nifH transcript abundance). Nitrogen fixation was sometimes detectable down to 150 m depth and extended horizontally to the edge of the gyre at around 35°N. Nitrogen fixation was even detected far north on the Bering Sea shelf. In the Alaskan Coastal Waters on the Bering Sea shelf, low nitrate together with high dissolved iron concentrations seemed to foster diazotroph growth, including a prominent role of UCYN-A2, which was abundant near the surface (1.2×105 nifH gene copies L−1). Our study provides evidence for nitrogen fixation in the Bering Sea and suggests a clear contrast in the composition of diazotrophs between the tropical/subtropical gyre and the separate waters in the cold northern regions of the North Pacific. ©2017. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/77731
Appears in Collections: 气候变化事实与影响
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作者单位: Atmosphere and Ocean Research Institute, University of Tokyo, Chiba, Japan; Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan; Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark; Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan; Faculty of Fisheries, Nagasaki University, Nagasaki, Japan; Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
Recommended Citation:
Shiozaki T,, Bombar D,, Riemann L,et al. Basin scale variability of active diazotrophs and nitrogen fixation in the North Pacific, from the tropics to the subarctic Bering Sea[J]. Global Biogeochemical Cycles,2017-01-01,31(6)