Pre-industrial and contemporary fluxes of nitrogen through rivers: a global assessment based on typology

Green, Pamela A.; Vörösmarty, Charles J; Meybeck, Michel; Galloway, James N.; Peterson, Bruce J.; Boyer, E. W.

doi:10.1023/b:biog.0000025742.82155.92

Cited by 272 publications

(281 citation statements)

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“…Assimilation rates increase with retention time and the availability of sunlight and nutrients [29][30][31]. NH 4 + and SRP are readily assimilated forms of inorganic N and P [32]. NH 4 + and SRP can also be retained through adsorption onto negatively charged soil particles.…”

Section: Stream Processes Driving Nutrient Cyclingmentioning

confidence: 99%

“…Another possible fate for N and P (that has been assimilated into biomass or adsorbed onto sediment particles) may be long-term burial in sediments. In contrast to P, N can be permanently removed through coupled nitrification-denitrification, a process that transforms inorganic compounds (NH 4 + , NO 2´, and NO 3´) into inert gaseous products (N 2 O and N 2 ) [36]. The first step, nitrification oxidizes ammonium to nitrite and then nitrate (NH 4 + Ñ NO 2 Ñ NO 3´) .…”

Section: Stream Processes Driving Nutrient Cyclingmentioning

confidence: 99%

“…Excess nitrogen (N) and phosphorus (P) from urban and agricultural areas contribute to these grand challenges [2,3]. Currently, the amount of N and P transported through streams and rivers to the ocean has increased by 2 to 20-fold [4,5]. This increase in aquatic N has resulted from the doubling of terrestrial N inputs from a mixture of fertilizer production, cultivation of N-fixing crops, and combustion of fossil fuels [6,7].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Nutrient Retention in Restored Streams and Rivers: A Global Review and Synthesis

Johnson

Kaushal

Mayer

et al. 2016

Water

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Excess nitrogen (N) and phosphorus (P) from human activities have contributed to degradation of coastal waters globally. A growing body of work suggests that hydrologically restoring streams and rivers in agricultural and urban watersheds has potential to increase N and P retention, but rates and mechanisms have not yet been analyzed and compared across studies. We conducted a review of nutrient retention within hydrologically reconnected streams and rivers, including 79 studies. We developed a typology characterizing different forms of stream and river restoration, and we also analyzed nutrient retention across this typology. The studies we reviewed used a variety of methods to analyze nutrient cycling. We performed a further intensive meta-analysis on nutrient spiraling studies because this method was the most consistent and comparable between studies. A meta-analysis of 240 experimental additions of ammonium (NH 4 + ), nitrate (NO 3´) , and soluble reactive phosphorus (SRP) was synthesized from 15 nutrient spiraling studies. Our results showed statistically significant relationships between nutrient uptake in restored streams and specific watershed attributes. Nitrate uptake metrics were significantly related to watershed surface area, impervious surface cover, and average reach width (p < 0.05). Ammonium uptake metrics were significantly related to discharge, velocity, and transient storage (p < 0.05). SRP uptake metrics were significantly related to watershed area, discharge, SRP concentrations, and chl a concentrations (p < 0.05). Given that most studies were conducted during baseflow, more research is necessary to characterize nutrient uptake during high flow. Furthermore, long-term studies are needed to understand changes in nutrient dynamics as projects evolve over time. Overall analysis suggests the size of the stream restoration (surface area), hydrologic connectivity, and hydrologic residence time are key drivers influencing nutrient retention at broader watershed scales and along the urban watershed continuum.

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Section: Stream Processes Driving Nutrient Cyclingmentioning

confidence: 99%

Section: Stream Processes Driving Nutrient Cyclingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Nutrient Retention in Restored Streams and Rivers: A Global Review and Synthesis

Johnson

Kaushal

Mayer

et al. 2016

Water

129

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“…Preindustrial CO 2 concentration assumed as 286 ppm was applied from 1704-1799, and changes in CO 2 concentrations were applied from 1800-2005 using reported data from NOAA's Earth System Research Laboratory. For 250 years , the estimated preindustrial N deposition (Dentener and Crutzen, 1944;Green et al, 2004;Gerber et al, 2010) was applied as a uniform annual rate. We then applied the 1985 reported …”

Section: Model Forcing and Simulationsmentioning

confidence: 99%

Capturing interactions between nitrogen and hydrological cycles under historical climate and land use: Susquehanna watershed analysis with the GFDL land model LM3-TAN

et al. 2014

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Abstract.We developed a process model LM3-TAN to assess the combined effects of direct human influences and climate change on terrestrial and aquatic nitrogen (TAN) cycling. The model was developed by expanding NOAA's Geophysical Fluid Dynamics Laboratory land model LM3V-N of coupled terrestrial carbon and nitrogen (C-N) cycling and including new N cycling processes and inputs such as a soil denitrification, point N sources to streams (i.e., sewage), and stream transport and microbial processes. Because the model integrates ecological, hydrological, and biogeochemical processes, it captures key controls of the transport and fate of N in the vegetation-soil-river system in a comprehensive and consistent framework which is responsive to climatic variations and land-use changes. We applied the model at 1/8 • resolution for a study of the Susquehanna River Basin. We simulated with LM3-TAN stream dissolved organic-N, ammonium-N, and nitrate-N loads throughout the river network, and we evaluated the modeled loads for 1986-2005 using data from 16 monitoring stations as well as a reported budget for the entire basin. By accounting for interannual hydrologic variability, the model was able to capture interannual variations of stream N loadings. While the model was calibrated with the stream N loads only at the last downstream Susquehanna River Basin Commission station Marietta (40 • 02 N, 76 • 32 W), it captured the N loads well at multiple locations within the basin with different climate regimes, land-use types, and associated N sources and transformations in the sub-basins. Furthermore, the calculated and previously reported N budgets agreed well at the level of the whole Susquehanna watershed. Here we illustrate how point and non-point N sources contributing to the various ecosystems are stored, lost, and exported via the river. Local analysis of six sub-basins showed combined effects of land use and climate on soil denitrification rates, with the highest rates in the Lower Susquehanna Sub-Basin (extensive agriculture; Atlantic coastal climate) and the lowest rates in the West Branch Susquehanna Sub-Basin (mostly forest; Great Lakes and Midwest climate). In the re-growing secondary forests, most of the N from non-point sources was stored in the vegetation and soil, but in the agricultural lands most N inputs were removed by soil denitrification, indicating that anthropogenic N applications could drive substantial increase of N 2 O emission, an intermediate of the denitrification process.

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“…Accordingly, most modelling efforts to estimate the export of nitrogen from rivers worldwide have used attributes such as population density, land use, urbanisation and sanitation (Howarth et al, 1996;Seitzinger and Kroeze, 1998;Green et al, 2004;Bouwman et al, 2005;Dumont et al, 2005;Boyer et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Dissolved nitrogen in rivers: comparing pristine and impacted regions of Brazil

et al. 2010

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Riverine nitrogen distribution is increasingly controlled by anthropogenic activities in their watersheds, regardless of spatial scale, climate, and geographical zone. Consequently, modelling efforts to predict the export of nitrogen from rivers worldwide have used attributes such as population density, land use, urbanization and sanitation. These models have greatly enhanced our understanding of the sources and fate of nitrogen added to terrestrial systems and transported to rivers and streams, especially for developed countries of the North temperate zone. However, much of the world's population lives in developing countries of the tropics, where the effects of human activities on riverine N exports are still poorly understood. In an effort to close this gap, we compare riverine nitrogen data from 32 Brazilian rivers draining two contrasting regions in this tropical country in terms of economic development -the State of São Paulo and the Amazon. Our data include nitrogen in different dissolved forms, such as Dissolved Inorganic Nitrogen (DIN) and Dissolved Organic Nitrogen (DON). The results show that nitrogen concentrations decreased as river runoff increased in both study areas, and that concentrations were significantly higher in rivers draining the most economically developed region. The relationships between nitrogen concentrations and fluxes with demographic parameters such as population density were also determined and compared to those in temperate systems. In contrast to temperate watersheds, we found that nitrogen fluxes increased only after population densities were higher than 10 individuals per km 2 .Keywords: nitrogen, river, pollution, Piracicaba basin, Amazon basin, Brazil. Nitrogênio dissolvido em rios de regiões distintas do Brasil ResumoA carga do nitrogênio em rios é cada vez mais controlada por atividades humanas independentemente da escala espacial, do clima, ou da região geográfica. Consequentemente, esforços de modelagem que predizem exportação de nitrogênio usam atributos que refletem atividades humanas, tais quais, densidade populacional, uso do solo, urbanização e saneamento ambiental. Estes modelos têm aumentado significativamente nosso entendimento sobre as fontes e destino do nitrogênio adicionado ao sistema terrestre e transportado aos sistemas aquáticos, especialmente em países desenvolvidos localizados no Hemisfério Norte. Entretanto, a maioria da população mundial vive em países em desenvolvimento dos trópicos, onde os efeitos das atividades humanas sobre a carga de nitrogênio nos rios são pobremente entendidos. Em um esforço para aumentar nossa compreensão sobre este fenômeno, comparamos a distribuição de nitrogênio dissolvido em 32 rios brasileiros, drenando duas regiões contrastantes em termos de desenvolvimento econômico -rios do Estado de São Paulo e da região Amazônica. Nossos dados incluem nitrogênio em duas formas dissolvidas: inorgânica (NID) e orgânica (NOD

show abstract

Pre-industrial and contemporary fluxes of nitrogen through rivers: a global assessment based on typology

Cited by 272 publications

References 47 publications

Nutrient Retention in Restored Streams and Rivers: A Global Review and Synthesis

Nutrient Retention in Restored Streams and Rivers: A Global Review and Synthesis

Capturing interactions between nitrogen and hydrological cycles under historical climate and land use: Susquehanna watershed analysis with the GFDL land model LM3-TAN

Dissolved nitrogen in rivers: comparing pristine and impacted regions of Brazil

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