QQ客服 官方微博 反馈留言

	Regional nitrogen budgets and riverine N&P fluxes for the drainages to the North Atlantic Ocean: Natural and human influences
	Howarth, RW; Billen, G; Swaney, D; Townsend, A; Jaworski, N; Lajtha, K; Downing, JA; Elmgren, R; Caraco, N; Jordan, T
刊名	BIOGEOCHEMISTRY
	1996-10-01
卷号	35期号:1页码:75-139
关键词	anthropogenic atmospheric deposition eutrophication fertilizer nitrogen nitrogen budget nitrogen fixation N:P ratio phosphorus pristine rivers temperate tropical
ISSN号	0168-2563
通讯作者	Howarth, RW()
英文摘要	We present estimates of total nitrogen and total phosphorus fluxes in rivers to the North Atlantic Ocean from 14 regions in North America, South America, Europe, and Africa which collectively comprise the drainage basins to the North Atlantic. The Amazon basin dominates the overall phosphorus flux and has the highest phosphorus flux per area. The total nitrogen flux from the Amazon is also large, contributing 3.3 Tg yr(-1) out of a total for the entire North Atlantic region of 13.1 Tg yr(-1). On a per area basis, however, the largest nitrogen fluxes are found in the highly disturbed watersheds around the North Sea, in northwestern Europe, and in the northeastern U.S., all of which have riverine nitrogen fluxes greater than 1,000 kg N km(-2) yr(-1). Non-point sources of nitrogen dominate riverine fluxes to the coast in all regions. River fluxes of total nitrogen from the temperate regions of the North Atlantic basin are correlated with population density, as has been observed previously for fluxes of nitrate in the world's major rivers. However, more striking is a strong linear correlation between river fluxes of total nitrogen and the sum of anthropogenically-derived nitrogen inputs to the temperate regions (fertilizer application, human-induced increases in atmospheric deposition of oxidized forms of nitrogen, fixation by leguminous crops, and the import/export of nitrogen in agricultural products). On average, regional nitrogen fluxes in rivers are only 25% of these anthropogenically derived nitrogen inputs. Denitrification in wetlands and aquatic ecosystems is probably the dominant sink, with storage in forests perhaps also of importance. Storage of nitrogen in groundwater, although of importance in some localities, is a very small sink for nitrogen inputs in all regions. Agricultural sources of nitrogen dominate inputs in many regions, particularly the Mississippi basin and the North Sea drainages. Deposition of oxidized nitrogen, primarily of industrial origin, is the major control over river nitrogen export in some regions such as the northeastern U.S. Using data from relatively pristine areas as an index of change, we estimate that riverine nitrogen fluxes in many of the temperate regions have increased from pre-industrial times by 2 to 20 fold, although some regions such as northern Canada are relatively unchanged. Fluxes from the most disturbed region, the North Sea drainages, have increased by 6 to 20 fold. Fluxes from the Amazon basin are also at least 2 to 5 fold greater than estimated fluxes from undisturbed temperate-zone regions, despite low population density and low inputs of anthropogenic nitrogen to the region. This suggests that natural riverine nitrogen fluxes in the tropics may be significantly greater than in the temperate zone. However, deforestation may be contributing to the tropical fluxes. In either case, projected increases in fertilizer use and atmospheric deposition in the coming decades are likely to cause dramatic increases in nitrogen loading to many tropical river systems.
收录类别	SCI
WOS关键词	NUTRIENT DYNAMICS ; PRECIPITATION CHEMISTRY ; COASTAL EUTROPHICATION ; NITRATE CONCENTRATIONS ; INORGANIC NITROGEN ; FOREST ECOSYSTEMS ; AMAZON BASIN ; WEST-AFRICA ; ST-LAWRENCE ; COSTA-RICA
WOS研究方向	Environmental Sciences & Ecology ; Geology
WOS类目	Environmental Sciences ; Geosciences, Multidisciplinary
语种	英语
出版者	SPRINGER
WOS记录号	WOS:A1996VU20000004
内容类型	期刊论文
URI标识	http://www.corc.org.cn/handle/1471x/2559087
专题	南京土壤研究所
通讯作者	Howarth, RW
作者单位	1.FREE UNIV BRUSSELS, GRP MICROBIOL MILIEUX AQUAT, B-1050 BRUSSELS, BELGIUM 2.US EPA, ENVIRONM RES LAB, NARRAGANSETT, RI 02882 USA 3.OREGON STATE UNIV, DEPT BOT & PLANT PATHOL, CORVALLIS, OR 97331 USA 4.IOWA STATE UNIV, AMES, IA 50011 USA 5.UNIV STOCKHOLM, DEPT SYST ECOL, S-10691 STOCKHOLM, SWEDEN 6.UNIV STOCKHOLM, CTR MARINE RES, S-10691 STOCKHOLM, SWEDEN 7.INST ECOSYST STUDIES, MILLBROOK, NY 12545 USA 8.SMITHSONIAN ENVIRONM RES CTR, EDGEWATER, MD 21037 USA 9.DLO, CABO, NL-6700 AA WAGENINGEN, NETHERLANDS 10.CSIRO, DIV PLANT IND, CANBERRA, ACT 2601, AUSTRALIA
推荐引用方式 GB/T 7714	Howarth, RW,Billen, G,Swaney, D,et al. Regional nitrogen budgets and riverine N&P fluxes for the drainages to the North Atlantic Ocean: Natural and human influences[J]. BIOGEOCHEMISTRY,1996,35(1):75-139.
APA	Howarth, RW.,Billen, G.,Swaney, D.,Townsend, A.,Jaworski, N.,...&Zhu, ZL.(1996).Regional nitrogen budgets and riverine N&P fluxes for the drainages to the North Atlantic Ocean: Natural and human influences.BIOGEOCHEMISTRY,35(1),75-139.
MLA	Howarth, RW,et al."Regional nitrogen budgets and riverine N&P fluxes for the drainages to the North Atlantic Ocean: Natural and human influences".BIOGEOCHEMISTRY 35.1(1996):75-139.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。