Does Nitrogen Cycle?: Changes in the Spatial Dynamics of Nitrogen with Industrial Nitrogen Fixation

Abstract. Both atmospheric deposition and benthic remineralization influence the marine nitrogen cycle, and hence ultimately also marine primary production. The biological and biogeochemical relations of the eastern tropical South Pacific (ETSP) to nitrogen deposition, benthic denitrification and phosphate regeneration are analysed in a prognostic box model of the oxygen, nitrogen and phosphorus cycles in the ETSP. In the model, atmospheric nitrogen deposition based on estimates for the years 2000–2009 is offset by half by reduced N2 fixation, with the other half transported out of the model domain. Both model- and data-based benthic denitrification are found to trigger nitrogen fixation, partly compensating for the NO3− loss. Since phosphate is the ultimate limiting nutrient in the model, enhanced sedimentary phosphate regeneration under suboxic conditions stimulates primary production and subsequent export production and NO3− loss in the oxygen minimum zone (OMZ). A sensitivity analysis of the local response to both atmospheric deposition and benthic remineralization indicates dominant stabilizing feedbacks in the ETSP, which tend to keep a balanced nitrogen inventory, i.e., nitrogen input by atmospheric deposition is counteracted by decreasing nitrogen fixation; NO3− loss via benthic denitrification is partly compensated by increased nitrogen fixation; enhanced nitrogen fixation stimulated by phosphate regeneration is partly removed by the stronger water-column denitrification. Even though the water column in our model domain acts as a NO3− source, the ETSP including benthic denitrification might become a NO3− sink.

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MOPS-1.0: modelling the regulation of the global oceanic nitrogen budget by marine biogeochemical processes

Geoscientific Model Development Discussions ◽

10.5194/gmdd-8-1945-2015 ◽

2015 ◽

Vol 8 (2) ◽

pp. 1945-2010 ◽

Cited By ~ 1

Author(s):

I. Kriest ◽

A. Oschlies

Keyword(s):

Nitrogen Fixation ◽

Nitrogen Cycle ◽

Nitrogen Budget ◽

Biogeochemical Processes ◽

Fixed Nitrogen ◽

Spatial And Temporal Scales ◽

Transient Behaviour ◽

Flux Profile ◽

Model Misfit ◽

The One

Abstract. Global models of the oceanic nitrogen cycle are subject to many uncertainties, among them type and form of biogeochemical processes involved in the fixed nitrogen cycle, and the spatial and temporal scales, on which the global nitrogen budget is regulated. We investigate these aspects using a global model of ocean biogeochemistry, that explicitly considers phosphorus and nitrogen, including pelagic denitrification and nitrogen fixation as sink and source terms of fixed nitrogen, respectively. The model explores different parameterizations of organic matter sinking speed, oxidant affinity of oxic and suboxic remineralization, and regulation of nitrogen fixation by temperature and different stoichiometric ratios. Examination of the initial transient behaviour of different model setups initialized from observed tracer distributions reveal changes in simulated nitrogen inventories and fluxes particularly during the first centuries. Millennial timescales have to be resolved in order to bring all biogeochemical and physical processes into a dynamically consistent steady state, for which global patterns of biogeochemical tracers and fluxes are reproduced quite well. Analysis of global properties suggests that particularly particle sinking speed, but also the parameterization of denitrification determines the extent of oxygen minimum zones, global nitrogen fluxes, and hence the oceanic nitrogen inventory. However, the ways and directions, in which different parameterizations of particle sinking, nitrogen fixation and denitrification affect the global diagnostics, are different, suggesting that these may, in principle, be constrained independently from each other. Analysis of the model misfit suggests a particle flux profile close to the one suggested by Martin et al. (1987). Simulated pelagic denitrification best agrees with the lower values between 59 and 84 Tg N yr−1 recently estimated by other authors.

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Asymbiotic nitrogen fixation in the phyllosphere of the Amazon forest: Changing nitrogen cycle paradigms

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.145066 ◽

2021 ◽

Vol 773 ◽

pp. 145066

Author(s):

Julio Cezar Fornazier Moreira ◽

Mauro Brum ◽

Lidiane Cordeiro de Almeida ◽

Silvia Barrera-Berdugo ◽

André Alves de Souza ◽

...

Keyword(s):

Nitrogen Fixation ◽

Nitrogen Cycle ◽

Amazon Forest ◽

Asymbiotic Nitrogen Fixation

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Nitrogen utilization and transformation ofStenotrophomonas maltophiliaW-6 with nitrogen-fixing ability

10.1101/337386 ◽

2018 ◽

Author(s):

Shutong Wang ◽

Yi Xu ◽

Zhenlun Li

Keyword(s):

Nitrogen Fixation ◽

Nitrogen Cycle ◽

Biological Nitrogen Fixation ◽

Stenotrophomonas Maltophilia ◽

Inorganic Nitrogen ◽

Nitrate Removal ◽

Nitrogen Utilization ◽

Purple Soil ◽

Nitrogen Fixing ◽

Biological Nitrogen

AbstractStrain W-6 was isolated from the purple soil and successfully identifed asStenotrophomonas maltophiliaand used for the investigation on nitrogen utilization. Strain W-6 was monitored with the ability of biological nitrogen fixation when N2was used for the sole nitrogen source, and yet nitrogenase activity would be inhibited in the presence of extra nitrogen. Moreover, Strain W-6 could utilize NO3−, NO2−and NH4+for cell growth through assimilation, but unable to convert them to atmospheric nitrogen. Meantime, accumulation of nitrite was observed during the nitrate removal process, and the optimal conditions for nitrate removal were temperature of 20°C, shaking speed of 150 rpm, sodium succinate as the carbon source and C/N of 12. The experimental results indicate thatStenotrophomonas maltophiliautilize W-6 could utilize not only N2but also other nitrogen sources directly as its N substance. Therefore, heterotrophicAzotobactermay possess a great significance to nitrogen cycle except in biological nitrogen fixation.ImportanceAzotobacterspp. are found in soils worldwide, with features not simply for the nitrogen fixation, but for the energy metabolism relevant to agriculture. However, the role ofAzotobacterpotential in the function of nitrogen cycle except in biological nitrogen fixation is largely unknown. As such, whether bacteria utilize either inorganic nitrogen or organic nitrogen has remained obscure. The present studies indicate thatStenotrophomonas maltophiliaW-6 could highly efficient utilize nitrate, nitrite and ammonium etc. N substance and detect NH4+as final product. The transport velocities of nitrate-N to nitrite-N was quickly without gaseous nitrogen was produced. We probed the relationship between biological nitrogen fixation and N cycle via N conversion processes byS. maltophiliaW-6 with nitrogen-fixing ability

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Biological Nitrogen Fixation in CMIP6 Models

10.5194/bg-2021-290 ◽

2021 ◽

Author(s):

Taraka Davies-Barnard ◽

Sönke Zaehle ◽

Pierre Friedlingstein

Keyword(s):

Nitrogen Fixation ◽

Nitrogen Cycle ◽

Primary Productivity ◽

Biological Nitrogen Fixation ◽

Net Primary Productivity ◽

Explanatory Power ◽

Future Climate Change ◽

Tight Coupling ◽

Change Models ◽

Biological Nitrogen

Abstract. Biological nitrogen fixation is the main source of new nitrogen into natural terrestrial ecosystems and consequently in the nitrogen cycle in many earth system models. Representation of biological nitrogen fixation varies, and because of the tight coupling between the carbon and nitrogen cycles, previous studies have shown this affects net primary productivity. Here we present the first assessment of the performance of biological nitrogen fixation in models contributing to CMIP6 compared to observed and observation-constrained estimates of biological nitrogen fixation. We find that 9/10 models represent global total biological nitrogen fixation within the uncertainty of recent global estimates. However, 6/10 models overestimate the amount of fixation in the tropics, and therefore the extent of the latitudinal gradient in the global distribution. For the SSP3-7.0 scenario of future climate change, models project increases in fixation over the 21st century of up to 80 %. However, while the historical range of biological nitrogen fixation amongst models is large (up to 140 kg ha−1 yr−1 at the grid cell level and 43–208 TgN yr−1 globally) this does not have explanatory power for variations in net primary productivity or the coupled nitrogen-carbon cycle. Models with shared structures can have significant variations in both biological nitrogen fixation and other parts of the nitrogen cycle without differing in their net primary productivity. This points to systematic challenges in carbon-nitrogen model structures.

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Explore the Structural Changes of Nitrogen-fixing Microorganisms of Rhizosheath During the Growth of Stipagrostis Pennata in the Desert

10.21203/rs.2.19680/v1 ◽

2019 ◽

Author(s):

Yongzhi Tian ◽

Xiaolin Ma ◽

Yuanting Li ◽

Cong Cheng ◽

Dengdi An ◽

...

Keyword(s):

Nitrogen Fixation ◽

Nitrogen Cycle ◽

Structural Changes ◽

Nifh Gene ◽

Nitrogen Fixing ◽

Nifh Sequence ◽

Regulatory Changes ◽

Ecological Roles ◽

Abundance And Diversity ◽

And Function

Abstract Background: Rhizosheath is an adaptive feature of the survival of Stipagrostis pennata in desert systems. Although microorganisms play important ecological roles in promoting the nitrogen cycle of rhizosheath, the diversity and function of nitrogen-fixing microorganism communities have not been fully understood. Therefore, the aim of this study is to explore the nitrogen fixation ability of rhizosheaths and the changes of nitrogen-fixing microorganisms at different growth periods of Stipagrostis pennata. We sequenced the nifH gene through sequencing nifH gene to identify the structure and diversity of nitrogen-fixing microorganisms of Stipagrostis pennata at different growth periods of rhizosheaths.Results: A total of 1256 OTUs were identified by nifH sequence and distributed in different growth periods. There were 5 OTUs distributed in each sample at the same time, and the abundance and diversity of microorganisms in fruit period were much higher than those in other periods. Mainly 4 phyla were involved, among which Proteobacteria was the most abundant in all groups.Conclusions: In general, this study investigated the abundance and characteristics of nitrogen-fixing microorganisms of rhizosheaths in different growth periods of Stipagrostis pennata. It also elucidated the regulatory changes of the structure of nitrogen-fixing microorganisms of rhizosheaths in different growth periods of Stipagrostis pennata.

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Explore the Structural Changes of Nitrogen-fixing Microorganisms of Rhizosheath During the Growth of Stipagrostis Pennata in the Desert

Bioscience Reports ◽

10.1042/bsr20201679 ◽

2021 ◽

Author(s):

Yongzhi Tian ◽

Xiaolin Ma ◽

Yuanting Li ◽

Cong Cheng ◽

Dengdi An ◽

...

Keyword(s):

Nitrogen Fixation ◽

Nitrogen Cycle ◽

Structural Changes ◽

Nifh Gene ◽

Operational Taxonomic Unit ◽

Nitrogen Fixing ◽

Nifh Sequence ◽

Ecological Roles ◽

Abundance And Diversity ◽

And Function

Purpose: Rhizosheath is an adaptive feature of the survival of Stipagrostis pennata in desert systems. Although microorganisms play important ecological roles in promoting the nitrogen cycle of rhizosheath, the diversity and function of nitrogen-fixing microorganism communities have not been fully understood. Samples and methods :Therefore, the aim of this study is to explore the nitrogen fixation ability of rhizosheaths and the changes in abundance of nitrogen-fixing microorganisms at different growth periods of Stipagrostis pennata. We sequenced the nifH gene through sequencing to identify the structure and diversity of nitrogen-fixing microorganisms of Stipagrostis pennata at different growth periods of rhizosheaths. Results: A total of 1256 operational taxonomic unit (OTUs) were identified by nifH sequence and distributed in different growth periods. There were 5 OTUs distributed in each sample at the same time, and the abundance and diversity of microorganisms in fruit period were much higher than those in other periods. Mainly 4 phyla were involved, among which Proteobacteria was the most abundant in all groups. Conclusions: In general, this study investigated the abundance and characteristics of nitrogen-fixing microorganisms of rhizosheaths in different growth periods of Stipagrostis pennata. It also may elucidate indicate that the structure of nitrogen-fixing microorganisms of rhizosheaths in different growth periods of Stipagrostis pennata had changed.

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The nitrogen cycle of an East Coast, U.K. saltmarsh: II. Nitrogen fixation, nitrification, denitrification, tidal exchange

Estuarine Coastal and Shelf Science ◽

10.1016/0272-7714(86)90093-4 ◽

1986 ◽

Vol 22 (6) ◽

pp. 689-704 ◽

Cited By ~ 42

Author(s):

S.Azni b Abd. Aziz ◽

D.B. Nedwell

Keyword(s):

Nitrogen Fixation ◽

Nitrogen Cycle ◽

East Coast ◽

Tidal Exchange

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The nitrogen cycle

10.1093/oso/9780198789406.003.0012 ◽

2018 ◽

Author(s):

David L. Kirchman

Keyword(s):

Nitrous Oxide ◽

Nitrogen Fixation ◽

Nitrogen Cycle ◽

Ammonia Oxidation ◽

Heterotrophic Bacteria ◽

Ammonium Nitrogen ◽

Gas Production ◽

Ammonia Oxidizing Bacteria ◽

Nitrogen Gas ◽

Chemolithoautotrophic Bacteria

Nitrogen is required for the biosynthesis of many cellular components and can take on many oxidation states, ranging from −3 to +5. Consequently, nitrogen compounds can act as either electron donors (chemolithotrophy) or electron acceptors (anaerobic respiration). The nitrogen cycle starts with nitrogen fixation, the reduction of nitrogen gas to ammonium. Nitrogen fixation is carried out only by prokaryotes, mainly some cyanobacteria and heterotrophic bacteria. The ammonium resulting from nitrogen fixation is quickly used by many organisms for biosynthesis, being preferred over nitrate as a nitrogen source. It is also oxidized aerobically by chemolithoautotrophic bacteria and archaea during the first step of nitrification. The second step, nitrite oxidation, is carried out by other bacteria not involved in ammonia oxidation, resulting in the formation of nitrate. Some bacteria are capable of carrying out both steps (“comammox”). This nitrate can then be reduced to nitrogen gas or nitrous oxide during denitrification. It can be reduced to ammonium, a process called “dissimilatory nitrate reduction to ammonium.” Nitrogen gas is also released by anaerobic oxidation of ammonium (“anammox”) which is carried out by bacteria in the Planctomycetes phylum. The theoretical contribution of anammox to total nitrogen gas release is 29%, but the actual contribution varies greatly. Another gas in the nitrogen cycle, nitrous oxide, is a greenhouse gas produced by ammonia-oxidizing bacteria and archaea. The available data indicate that the global nitrogen cycle is in balance, with losses from nitrogen gas production equaling gains via nitrogen fixation. But excess nitrogen from fertilizers is contributing to local imbalances and several environmental problems in drinking waters, reservoirs, lakes, and coastal oceans.

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Ammonia Volatilization in a Hypertrophic Prairie Lake

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f81-142 ◽

1981 ◽

Vol 38 (9) ◽

pp. 1035-1039 ◽

Cited By ~ 18

Author(s):

T. P. Murphy ◽

B. G. Brownlee

Keyword(s):

Nitrogen Fixation ◽

Nitrogen Cycle ◽

Nitrogen Limitation ◽

Ammonia Volatilization ◽

Algal Bloom ◽

Lake Surface ◽

High Ph ◽

Ammonia Uptake ◽

High Ammonia ◽

Prairie Lakes

During two periods of high pH and high ammonia concentrations, disappearance rates of ammonia of 20–30 μg N∙L−1∙h−1 were observed in Lake 885, a hypertrophic prairie lake. At these times, rates of ammonia uptake by phytoplankton were 2.6–4.3 μg N∙L−1∙h−1 as measured by a 15N method. The high excess rates of ammonia disappearance are best explained by volatilization of ammonia from the lake surface. The loss of ammonia induced nitrogen fixation; however, much larger quantities of ammonia were lost via ammonia volatilization after algal bloom collapsed than the algae could fix in one season.Key words: ammonia volatilization, prairie lakes, nitrogen limitation, nitrogen cycle

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