气候变化领域集成服务门户(CCPortal): High Rates of N2 Fixation in Temperate, Western North Atlantic Coastal Waters Expand the Realm of Marine Diazotrophy

CCPortal

DOI	10.1029/2018GB006130
	High Rates of N2 Fixation in Temperate, Western North Atlantic Coastal Waters Expand the Realm of Marine Diazotrophy
	Mulholland M.R.; Bernhardt P.W.; Widner B.N.; Selden C.R.; Chappell P.D.; Clayton S.; Mannino A.; Hyde K.
发表日期	2019
ISSN	0886-6236
EISSN	1944-9224
起始页码	826
结束页码	840
卷号	33 期号:7
英文摘要	Dinitrogen (N2) fixation can alleviate N limitation of primary productivity by introducing fixed nitrogen (N) to the world's oceans. Although measurements of pelagic marine N2 fixation are predominantly from oligotrophic oceanic regions, where N limitation is thought to favor growth of diazotrophic microbes, here we report high rates of N2 fixation from seven cruises spanning four seasons in temperate, western North Atlantic coastal waters along the North American continental shelf between Cape Hatteras and Nova Scotia, an area representing 6.4% of the North Atlantic continental shelf area. Integrating average areal rates of N2 fixation during each season and for each domain in the study area, the estimated N input from N2 fixation to this temperate shelf system is 0.02 Tmol N/year, an amount equivalent to that previously estimated for the entire North Atlantic continental shelf. Unicellular group A cyanobacteria (UCYN-A) were most often the dominant diazotrophic group expressing nifH, a gene encoding the nitrogenase enzyme, throughout the study area during all seasons. This expands the domain of these diazotrophs to include coastal waters where dissolved N concentrations are not always depleted. Further, the high rates of N2 fixation and diazotroph diversity along the western North Atlantic continental shelf underscore the need to reexamine the biogeography and the activity of diazotrophs along continental margins. Accounting for this substantial but previously overlooked source of new N to marine systems necessitates revisions to global marine N budgets. ©2019. The Authors.
英文关键词	diazotrophy; nitrogen fixation; North American continental shelf
语种	英语
scopus关键词	biogeography; coastal water; concentration (composition); continental shelf; cruise report; cyanobacterium; enzyme; genetic analysis; nitrogen fixation; nutrient limitation; oligotrophic environment; primary production; Atlantic Ocean; Atlantic Ocean (North); Canada; Cape Hatteras; Hatteras Island; North Carolina; Nova Scotia; United States; Cyanobacteria
来源期刊	Global Biogeochemical Cycles
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/129757
作者单位	Department of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, Norfolk, VA, United States; Now at Woods Hole Oceanographic Institute, Woods Hole, MA, United States; Goddard Space Flight Center, National Aeronautics and Space Administration, Greenbelt, MD, United States; Northeast Fisheries Science Center, National Oceanic and Atmospheric Administration, Narragansett, RI, United States
推荐引用方式 GB/T 7714	Mulholland M.R.,Bernhardt P.W.,Widner B.N.,et al. High Rates of N2 Fixation in Temperate, Western North Atlantic Coastal Waters Expand the Realm of Marine Diazotrophy[J],2019,33(7).
APA	Mulholland M.R..,Bernhardt P.W..,Widner B.N..,Selden C.R..,Chappell P.D..,...&Hyde K..(2019).High Rates of N2 Fixation in Temperate, Western North Atlantic Coastal Waters Expand the Realm of Marine Diazotrophy.Global Biogeochemical Cycles,33(7).
MLA	Mulholland M.R.,et al."High Rates of N2 Fixation in Temperate, Western North Atlantic Coastal Waters Expand the Realm of Marine Diazotrophy".Global Biogeochemical Cycles 33.7(2019).