Increasing N Abundance in the Northwestern Pacific Ocean Due to Atmospheric Nitrogen Deposition

Kim, Tae Wook; Lee, Kitack; Najjar, Raymond G.; Jeong, Hee Dong; Jeong, Hoon Eui

doi:10.1126/science.1206583

Cited by 249 publications

(221 citation statements)

References 32 publications

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“…Over the past 150 years, the deposition of N compounds is estimated to have doubled [Duce et al, 2008], while the deposition of P species has remained relatively steady [Baker et al, 2003;Mahowald et al, 2008]. Consequently, recent modeling studies predict an atmospheric deposition-driven increase in P depletion in surface waters of some ocean regions relative to preindustrial times [Kanakidou et al, 2012;Kim et al, 2011;Krishnamurthy et al, 2007Krishnamurthy et al, , 2009Zamora et al, 2010]. However, the atmospheric fluxes of P to the ocean are poorly characterized compared to N deposition fluxes.…”

Section: Introductionmentioning

confidence: 99%

Atmospheric P deposition to the subtropical North Atlantic: sources, properties, and relationship to N deposition

et al. 2013

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[1] Biogeochemical studies show that the surface waters of the subtropical North Atlantic are highly phosphorus (P) stressed. Human activity may exacerbate phosphorus stress by enhancing atmospheric nitrogen (N) deposition and raising N/P ratios in deposition. However, the magnitude of this effect is unclear, in part, because atmospherically deposited phosphorus sources are not well known, particularly the contribution from organic phosphorus. Here we report measurements of phosphorus in aerosols and wet deposition at Miami and Barbados. African dust is the major aerosol P source at both Miami and Barbados, containing~880 ppm total phosphorus and~70 ppm soluble reactive phosphorus (SRP). Organic compounds contribute, on average, 28%-44% of soluble phosphorus in precipitation. Because of dust transport seasonality, phosphorus inputs to the North Atlantic are expected to be highly variable with 2-10 times more P deposition during summer than winter. Pollution is also an important contributor to total and soluble phosphorus in Miami aerosols and deposition. Estimated SRP deposition in Barbados and Miami is 0.21 and 0.13 mmol m À2 d À1 phosphorus, respectively. Inorganic nitrogen in excess of Redfield ratio expectations in deposition was very different between the sites, totaling 21-30 and 127-132 mmol m À2 d À1 nitrogen in Barbados and Miami, respectively; the high deposition rates at Miami are linked to pollutants. Including soluble organic nitrogen and phosphorus halved the estimates of excess nitrogen in Barbados wet deposition. Thus, the organic phosphorus fraction is important in the assessment of the magnitude of biogeochemical change of the North Atlantic caused by atmospheric deposition.Citation: Zamora, L. M., J. M. Prospero, D. A. Hansell, and J. M. Trapp (2013), Atmospheric P deposition to the subtropical North Atlantic: sources, properties, and relationship to N deposition,

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Section: Introductionmentioning

confidence: 99%

Atmospheric P deposition to the subtropical North Atlantic: sources, properties, and relationship to N deposition

et al. 2013

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“…diversity of the terrestrial ecosystems (Stevens et al, 2004;Clark and Tilman, 2008;Bobbink et al, 2010;Jiang et al, 2010;Kim et al, 2011). Both large-scale field survey and manipulated experiments to simulate N deposition have shown that N deposition has driven significant reductions in plant species richness in different grassland ecosystems (Stevens et al, 2004;Suding et al, 2005;Bai et al, 2010;Tilman, 2008, Dupre et al, 2010;Van Den Berg et al, 2011).…”

Section: Q-y Tian Et Al: Disruption Of Metal Ion Homeostasis In Soilsmentioning

confidence: 99%

Disruption of metal ion homeostasis in soils is associated with nitrogen deposition-induced species loss in an Inner Mongolia steppe

et al. 2015

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Abstract. Enhanced deposition of atmospheric nitrogen (N) resulting from anthropogenic activities has negative impacts on plant diversity in ecosystems. Several mechanisms have been proposed to explain the species loss. Ion toxicity due to N deposition-induced soil acidification has been suggested to be responsible for species loss in acidic grasslands, while few studies have evaluated the role of soil-mediated homeostasis of ions in species loss under elevated N deposition in grasslands with neutral or alkaline soils. To determine whether soil-mediated processes are involved in changes in biodiversity induced by N deposition, the effects of 9-year N addition on soil properties, aboveground biomass (AGB) and species richness were investigated in an Inner Mongolia steppe. Low to moderate N addition rate (2, 4, 8 g N m −2 yr −1 ) significantly enhanced AGB of graminoids, while high N addition rate (≥ 16 g N m −2 yr −1 ) reduced AGB of forbs, leading to an overall increase in AGB of the community under low to moderate N addition rates. Forb richness was significantly reduced by N addition at rates greater than 8 g N m −2 yr −1 , while no effect of N addition on graminoid richness was observed, resulting in decline in total species richness. N addition reduced soil pH, depleted base cations (Ca 2+ , Mg 2+ and K + ) and mobilized Mn 2+ , Fe 3+ , Cu 2+ and Al 3+ ions in soils. Soil inorganic-N concentration was negatively correlated with forb richness and biomass, explaining 23.59 % variation of forb biomass. The concentrations of base cations (Ca 2+ and Mg 2+ ) and metal ions (Mn 2+ , Cu 2+ and, Fe 3+ ) showed positively and negatively linear correlation with forb richness, respectively. Changes in the metal ion concentrations accounted for 42.77 % variation of forb richness, while reduction of base cations was not associated with the reduction in forb richness. These results reveal that patterns of plant biodiversity in the temperate steppe of Inner Mongolia are primarily driven by increases in metal ion availability, particularly enhanced release of soil Mn 2+ .

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“…As inferred from extremely high organic matter inputs to the bottom layer, a 'micro reducing environment̓ may be formed in the bottom layer (Wolgast et al 1998), enabling an upward extension of denitrifying bacterial activity from the sediments to the bottom waters above. Recent increases in atmospheric nitrogen deposition flux to the EJS (Kim et al 2011), warming of the water column (Gamo et al 2001;Kim et al 2001Kim et al , 2004Min and Kim 2006), oxygen content decreases (Kim and Kim 1996;Chen et al 1999;Gamo 1999;Kang et al 2004), and high deposition rates of organic matter (Cha et al 2007;Tishchenko et al 2007;Lee et al 2008Lee et al , 2010Hyun et al 2010) might have created a favorable environment for denitrification in the bottom layer at the two basins in the EJS in recent years.…”

Section: Extended Benthic Denitrification To Bottom Waters Vs 'Aerobmentioning

confidence: 99%

Deep Nitrate Deficit Observed in the Highly Oxygenated East/Japan Sea and Its Possible Cause

Kim¹,

Min²,

Lee³

2012

Terr. Atmos. Ocean. Sci.

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We present evidence of denitrification on the continental slopes of the Ulleung Basin (UB) and the Eastern Japan Basin (EJB) near the Tatar Strait (TtS) in the East/Japan Sea (EJS), despite its high water column dissolved oxygen concentrations. Some nutrient concentration data deviate significantly from the fitted regression line of nitrate (N) vs. phosphate (P) in deep waters, indicating a loss of nitrate in the region. The EJS has a lower N/P ratio (ca. 12.4 below 300 dbar) than a traditional Redfield ratio (16). The N/P ratio and oxygen concentration are substantially lower at several locations whose depths are close to the sediment-water interface, near TtS (500 -1100 dbar) and in UB (1100 -2200 dbar). The decreased nitrate concentration is smaller than the expected nitrate level (a low N/P ratio of < 12.4), and a secondary nitrite peak near the bottom of these two regions: taken collectively, both indicate the presence of denitrification in the bottom layer. It is speculated that active re-mineralization and denitrification may occur simultaneously along the rich organic matter bottom layer on the slope environment. Denitrification rates are estimated at ~3 -33 μmol N m -2 d -1 . Current estimates do not support the previous idea of basin-wide denitrification in EJS, although the N/P ratio is low like in other hypoxic/anoxic seas. A better understanding of the denitrification process is necessary for predicting future changes of nitrogen cycle in the well-oxygenated EJS considering the decadal-scale physical and biogeochemical changes that have occurred.

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Increasing N Abundance in the Northwestern Pacific Ocean Due to Atmospheric Nitrogen Deposition

Cited by 249 publications

References 32 publications

Atmospheric P deposition to the subtropical North Atlantic: sources, properties, and relationship to N deposition

Atmospheric P deposition to the subtropical North Atlantic: sources, properties, and relationship to N deposition

Disruption of metal ion homeostasis in soils is associated with nitrogen deposition-induced species loss in an Inner Mongolia steppe

Deep Nitrate Deficit Observed in the Highly Oxygenated East/Japan Sea and Its Possible Cause

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