气候变化领域集成服务门户(CCPortal): Diatom Physiology Controls Silicic Acid Leakage in Response to Iron Fertilization

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DOI	10.1029/2019GB006460
	Diatom Physiology Controls Silicic Acid Leakage in Response to Iron Fertilization
	Holzer M.; Pasquier B.; DeVries T.; Brzezinski M.
发表日期	2019
ISSN	0886-6236
EISSN	1944-9224
起始页码	1631
结束页码	1653
卷号	33 期号:12
英文摘要	We explore how the iron dependence of the Si:P uptake ratio RSi:P of diatoms controls the response of the global silicon cycle and phytoplankton community structure to Southern Ocean iron fertilization. We use a data-constrained model of the coupled Si-P-Fe cycles that features a mechanistic representation of nutrient colimitations for three phytoplankton classes and that is embedded in a data-assimilated global ocean circulation model. We consider three parameterizations of the iron dependence of RSi:P, all of which are consistent with the available field data and allow equally good fits to the observed nutrient climatology but result in very different responses to iron fertilization: Depending on how sharply RSi:P decreases with increasing iron concentration, iron fertilization can either cause enhanced silicic acid leakage from the Southern Ocean or strengthened Southern Ocean silicon trapping. Enhanced silicic acid leakage occurs if decreases in RSi:P win over increases in diatom growth, while the converse causes strengthened Southern Ocean silicon trapping. Silicic acid leakage drives a floristic shift in favor of diatoms in the subtropical gyres and stimulates increased low-latitude opal export. The diatom contribution to global phosphorus export increases, but the lower diatom silicon requirement under iron-replete conditions reduces the global opal export. Regardless of RSi:P parameterization, the global response of the biological phosphorus and silicon pumps is dominated by the Southern Ocean. The Si isotope signature of opal flux becomes systematically lighter with increasing iron-induced silicic acid leakage, consistent with sediment records from iron-rich glacial periods. ©2019. American Geophysical Union. All Rights Reserved.
英文关键词	biological pump; iron fertilization; phosphorus cycle; silicic acid leakage; silicon cycle; silicon isotopes
语种	英语
scopus关键词	biological pump; climatology; community structure; concentration (composition); data assimilation; diatom; floristics; iron; parameterization; phytoplankton; silicon; Southern Ocean; Bacillariophyta
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/129689
作者单位	Department of Applied Mathematics, School of Mathematics and Statistics, University of New South Wales, Sydney, NSW, Australia; Department of Earth System Sciences, University of California, Irvine, CA, United States; Earth Research Institute and Department of Geography, University of California, Santa Barbara, CA, United States; Department of Ecology, Evolution and Marine Biology, The Marine Science Institute, University of California, Santa Barbara, CA, United States
推荐引用方式 GB/T 7714	Holzer M.,Pasquier B.,DeVries T.,et al. Diatom Physiology Controls Silicic Acid Leakage in Response to Iron Fertilization[J],2019,33(12).
APA	Holzer M.,Pasquier B.,DeVries T.,&Brzezinski M..(2019).Diatom Physiology Controls Silicic Acid Leakage in Response to Iron Fertilization.Global Biogeochemical Cycles,33(12).
MLA	Holzer M.,et al."Diatom Physiology Controls Silicic Acid Leakage in Response to Iron Fertilization".Global Biogeochemical Cycles 33.12(2019).