气候变化领域集成服务门户(CCPortal): Low ratios of silica to dissolved nitrogen supplied to rivers arise from agriculture not reservoirs

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DOI	10.1111/ele.12689
	Low ratios of silica to dissolved nitrogen supplied to rivers arise from agriculture not reservoirs
	Downing J.A.; Cherrier C.T.; Fulweiler R.W.
发表日期	2016
ISSN	1461-023X
EISSN	1461-0248
卷号	19 期号:12
英文摘要	Coastal marine systems are greatly altered by toxic marine algae, eutrophication and hypoxia. These problems have been linked to decreased ratios of dissolved silica to inorganic nitrogen (Si : DIN) delivered from land. Two mechanisms for this decline under consideration are enhanced nitrogen (N) fertiliser losses from agricultural lands or Si sequestration in reservoirs. Here we examine these mechanisms via nutrient concentrations in impoundments receiving water from 130 watersheds in a landscape representative of the agriculture that often dominates coastal nutrient inputs. Decreased Si : DIN was correlated with agriculture, not impoundment. Watersheds with > 60% agricultural land yielded highest DIN, whereas Si was uncorrelated with agricultural intensity. Furthermore, eutrophic lakes were dominated by Cyanobacteria that use little Si, so reservoirs did not diminish Si : DIN. Instead, Si : DIN increased slightly as reservoir residence time increased. These data suggest that impoundments in agricultural watersheds may enhance the water quality of coastal ecosystems, whereas fertiliser losses are detrimental. © 2016 John Wiley & Sons Ltd/CNRS
英文关键词	Coastal; harmful algae blooms; landscape; marine ecology; nitrogen; reservoirs; silicon; watershed
学科领域	algae; Cyanobacteria; nitrogen; silicon dioxide; agriculture; chemistry; ecosystem; geographic and geological phenomena; river; Agriculture; Ecosystem; Geological Phenomena; Nitrogen; Rivers; Silicon Dioxide
语种	英语
scopus关键词	algae; Cyanobacteria; nitrogen; silicon dioxide; agriculture; chemistry; ecosystem; geographic and geological phenomena; river; Agriculture; Ecosystem; Geological Phenomena; Nitrogen; Rivers; Silicon Dioxide
来源期刊	Ecology Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/118461
作者单位	Minnesota Sea Grant College Program & Large Lakes Observatory, University of Minnesota Duluth, 31 W. College Street, Duluth, MN 55812-1198, United States; School of Science, Technology, Engineering & Mathematics, University of Washington, Bothell, WA 98011, United States; Department of Earth and Environment, Boston University, 685 Commonwealth Ave, Boston, MA 02215, United States; Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, United States
推荐引用方式 GB/T 7714	Downing J.A.,Cherrier C.T.,Fulweiler R.W.. Low ratios of silica to dissolved nitrogen supplied to rivers arise from agriculture not reservoirs[J],2016,19(12).
APA	Downing J.A.,Cherrier C.T.,&Fulweiler R.W..(2016).Low ratios of silica to dissolved nitrogen supplied to rivers arise from agriculture not reservoirs.Ecology Letters,19(12).
MLA	Downing J.A.,et al."Low ratios of silica to dissolved nitrogen supplied to rivers arise from agriculture not reservoirs".Ecology Letters 19.12(2016).