DOI: 10.1002/2014GB005050
Scopus记录号: 2-s2.0-84939256474
论文题名: On the influence of "non-Redfield" dissolved organic nutrient dynamics on the spatial distribution of N<inf>2</inf> fixation and the size of the marine fixed nitrogen inventory
作者: Somes C ; J ; , Oschlies A
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2015
卷: 29, 期: 7 起始页码: 973
结束页码: 993
语种: 英语
英文关键词: dissolved organic matter
; N2 fixation
; nitrogen
; nutrient
; Redfield ratio
Scopus关键词: air-sea interaction
; bacterium
; biogeochemistry
; data set
; denitrification
; dissolved organic matter
; dissolved organic phosphorus
; global ocean
; inventory
; nitrogen fixation
; nutrient dynamics
; oligotrophic environment
; phosphorus
; phytoplankton
; Redfield ratio
; sea ice
; spatial distribution
; surface layer
; uncertainty analysis
; Atlantic Ocean
; Pacific Ocean
英文摘要: Dissolved organic nitrogen (DON) and phosphorus (DOP) represent the most abundant form of their respective nutrient pool in the surface layer of the oligotrophic oceans and play an important role in nutrient cycling and productivity. Since DOP is generally more labile than DON, it provides additional P that may stimulate growth of nitrogen-fixing diazotrophs that supply fixed nitrogen to balance denitrification in the ocean. In this study, we introduce semirecalcitrant components of DON and DOP as state variables in an existing global ocean-atmosphere-sea ice-biogeochemistry model of intermediate complexity to assess their impact on the spatial distribution of nitrogen fixation and the size of the marine fixed nitrogen inventory. Large-scale surface data sets of global DON and Atlantic Ocean DOP are used to constrain the model. Our simulations suggest that both preferential DOP remineralization and phytoplankton DOP uptake are important "non-Redfield" processes (i.e., deviate from molar N:P=16) that need to be accounted for to explain the observed patterns of DOP. Additional non-Redfield DOP sensitivity experiments testing dissolved organic matter (DOM) production rate uncertainties that best reproduce the observed spatial patterns of DON and DOP stimulate additional nitrogen fixation that increases the size of the global marine fixed nitrogen inventory by 4.7±1.7% compared to the simulation assuming Redfield DOM stoichiometry that underestimates the observed nitrogen inventory. The extra 8Tgyr-1 of nitrogen fixation stimulated in the Atlantic Ocean is mainly responsible for this increase due to its large spatial separation from water column denitrification, which buffers any potential nitrogen surplus in the Pacific Ocean. Our study suggests that the marine fixed nitrogen budget is sensitive to non-Redfield DOP dynamics because access to the relatively labile DOP pool expands the ecological niche for nitrogen-fixing diazotrophs. ©2015. 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/77967
Appears in Collections: 气候变化事实与影响
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作者单位: GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Recommended Citation:
Somes C,J,, Oschlies A. On the influence of "non-Redfield" dissolved organic nutrient dynamics on the spatial distribution of N<inf>2</inf> fixation and the size of the marine fixed nitrogen inventory[J]. Global Biogeochemical Cycles,2015-01-01,29(7)