Nitrogen fixation in freshwater, estuarine, and marine ecosystems. 1. Biogeochemical controls

Howarth, Robert W.; Marino, Roxanne; Lane, Julie; Cole, Jonathan J.

doi:10.4319/lo.1988.33.4_part_2.0688

Cited by 227 publications

(247 citation statements)

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“…As the root biomass increases in sediment, so also should the area that is enriched by available C. We found significant correlation between live root biomass and available C in both the upper and lower layers (r 2 = 0.53 and 0.83, respectively). The negative relationship between NA and the concentration of NH 4 -N in the interstitial water was in agreement with the widely accepted claim that the synthesis and/or NA is repressed by high levels of NH 4 -N/NO 3 -N (Yoch & Whiting, 1986;Howarth et al, 1988b;Hansen et al, 2000).…”

Section: Discussionsupporting

confidence: 70%

Heterotrophic nitrogen fixation in oligotrophic tropical marshes: changes after phosphorus addition

et al. 2009

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In order to determine the impact of nutrient enrichment on phosphorus (P) limited wetlands, we established experimental P additions in marshes throughout northern Belize. P significantly increased macrophyte primary production, which led to the rapid elimination of cyanobacterial mats. The replacement of cyanobacterial mats by macrophytes constrained autotrophic nitrogen (N) fixation, increased the quantity, and changed the quality of organic matter input to the sediments. We predicted that the activity of sediment heterotrophic N fixers will be impacted by these alterations in carbon input. We used the acetylene reduction technique to measure potential (glucose amended) nitrogenase activity (NA) in sediments from controls and treatment plots that have been P enriched for four years and dominated either by Eleocharis cellulosa, or Typha domingensis for two years. NA in P-enriched plots was 2-3 orders of magnitude higher than NA in controls. NA was positively correlated with the soil reactive P, both total organic and microbial carbon, live root biomass, and total phospholipid fatty acids (PLFA) as an indicator of active microbial biomass. It was negatively correlated with the concentration of ammonium-N. Path analysis revealed that the indirect effect of P on NA through the root biomass was more important than the direct effect of P. NA of the upper sediment layer was consistently higher in Eleocharis than in Typha dominated plots, despite the higher litter input by Typha. We feel that the higher levels of lignin and phenolics occurring in Typha litter, relative to Eleocharis, constrained NA in Typha plots.

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Section: Discussionsupporting

confidence: 70%

Heterotrophic nitrogen fixation in oligotrophic tropical marshes: changes after phosphorus addition

et al. 2009

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“…Measured N-fixation tends to follow a similar pattern as the prevalence of cyanobacteria [6,38,39]. Analyses using gene sequencing techniques have suggested that more organisms than we currently know may fix nitrogen in both lakes and marine systems [42].…”

Section: Cbmentioning

confidence: 88%

“…[38,39] found no data on N-fixing planktonic species in estuaries and coastal seas, except for the Baltic Sea and the PeelHarvey estuary, Australia. Also results from [40] support this general absence of N-fixing cyanobacteria in estuaries.…”

Section: Cb Versus Salinitymentioning

confidence: 99%

A New General Approach to Quantify Nitrogen Fixation Exemplified for the Baltic Proper

Håkanson¹,

Hytteborn²,

Bryhn³

2009

TOMBJ

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This work uses empirical data from the HELCOM database and a new empirically-based model to predict the concentration of cyanobacteria in the Baltic Proper. The aim has been to estimate nitrogen fixation. The inherent variabilities/patchiness in the variables regulating nitrogen fixation are great. This means that different approaches may provide complementary information so that several relatively uncertain estimates may together provide less uncertainty in the estimate for nitrogen fixation in a given system. We show that there is marked variability in nitrogen fixation among different years (a factor of 20 between the year 2001 with the smallest value and 2005 with the highest value of about 900 kt/yr of N-fixation). The mean value for the period from 1997 to 2005 was 190 kt/yr. TN/TP based on median monthly data has been higher than the Redfield ratio of 7.2 since 1994. 6.5% of all individual data (n = 3001) from the surface-water layer (44 m) in the Baltic Proper for samples with temperatures higher than 15°C (when risks of getting cyanobacteria blooms are favoured) have TN/TP lower than 7.2. The mean TN/TP is 20 for surface-water sites with temperatures higher than 15°C, indicating that the average trophic conditions in the Baltic Proper are likely more limited by phosphorus than nitrogen. Nitrogen fixation is an important contributor to the nitrogen concentration and we give overall budgets for nitrogen and phosphorus in the Baltic Proper, including nutrient data from land uplift, which is the most important contributor for nutrients and often neglected in discussions about sources of nutrients to the Baltic Sea.

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“…Unlike some marine organisms and plants, macroalgae are known to incorporate nutrients directly from the water column and store excess nutrients in their tissues, providing an integrated record of nutrient influx (Fong et al, 1994). Thus, macroalgae may better provide a history of nutrient influx to a site compared to other organisms that can: directly fix nitrogen (cyanobacteria; e.g., Howarth et al, 1988); primarily take up nutrients from sediments and interstitial water and not directly from the water column (rooted plants such as sea grasses; Paling and McComb, 1994;Erftenmeijer and Middleburg, 1995); or, incorporate nutrients from symbionts or ingested plants and/or other organisms (coral reef organisms; Mills et al, 2004).…”

mentioning

confidence: 99%

“…Thus, the history of available nutrients combined with the biochemistry of the macroalgae species drive the responses observed in the field (Fong et al, 2003). Whereas some macroalgae incorporate nutrients only from the water column, others can access nutrients in sediments, from adjacent heterotrophs (such as the scleractinian corals to which D. versluysii attaches; Larned and Stimson, 1996), or, in the case of some cyanobacteria, from fixation of nitrogen (Howarth et al, 1988). Halimeda and Dictyosphaeria (Division Chlorophyta) are rhizophytic algae and can access nutrients from the water as well as from sediment via holdfasts (Littler and Littler, 1990).…”

mentioning

confidence: 99%

Identifying nutrient sources to three lagoons at Ofu and Olosega, American Samoa using δ15N of benthic macroalgae

Garrison

Kroeger

Fenner

et al. 2007

Marine Pollution Bulletin

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Nitrogen fixation in freshwater, estuarine, and marine ecosystems. 1. Biogeochemical controls

Cited by 227 publications

References 0 publications

Heterotrophic nitrogen fixation in oligotrophic tropical marshes: changes after phosphorus addition

Heterotrophic nitrogen fixation in oligotrophic tropical marshes: changes after phosphorus addition

A New General Approach to Quantify Nitrogen Fixation Exemplified for the Baltic Proper

Identifying nutrient sources to three lagoons at Ofu and Olosega, American Samoa using δ15N of benthic macroalgae

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