How Do Soil Organisms Affect Total Organic Nitrogen Storage and Substrate Nitrogen to Carbon Ratio in Soils? A Theoretical Analysis

Oikos ◽  
1999 ◽  
Vol 86 (3) ◽  
pp. 430 ◽  
Author(s):  
David W. Zheng ◽  
Goran I. Agren ◽  
Jan Bengtsson
Keyword(s):  
Theoretical Analysis ◽  
Organic Nitrogen ◽  
Nitrogen Storage ◽  
Soil Organisms ◽  
Total Organic Nitrogen

Partitioning of the nitrogen stock in the vicinity of a Fijian seagrass bed dominated by Syringodium isoetifolium (Ascherson) Dandy

1993 ◽  
Vol 44 (1) ◽  
pp. 101 ◽  
Author(s):  
M Yamamuro ◽  
I Koike ◽  
H Iizumi
Keyword(s):  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Minor Component ◽  
Adjacent Area ◽  
Bed Sediment ◽  
Seagrass Bed ◽  
Total Organic Nitrogen ◽  
Bare Area ◽  
Nitrogen Stock ◽  
Syringodium Isoetifolium

Partitioning of the nitrogen stock in a Fijian seagrass bed dominated by Syringodium isoetifolium (Ascherson) Dandy and in an adjacent area bare of macrophytic vegetation was assessed to evaluate the effect of the presence of seagrass on coral sediment. Concentrations of major nutrients, such as nitrogen and phosphate, were as low in the water column at the seagrass bed and the bare area as they were in the open ocean. Concentrations of ammonium and dissolved organic nitrogen, however, were higher in the water within the seagrass canopy than they were in other waters. In sediments at the seagrass bed and the bare area, interstitial nitrogen, such as nitrate and dissolved organic nitrogen, was a minor component of the total nitrogen (0.3-0.05%). On the other hand, concentrations of total organic nitrogen in seagrass-bed sediment (about 70% of which was in the form of amorphous organic nitrogen and the rest of which came from living and dead seagrass) were more than three times higher than those in bare-area sediment. Concentrations of organic carbon from amorphous organic materials in seagrass-bed sediment showed no large change with depth, resulting in an apparent decrease in the carbodnitrogen atom ratio from 60 to 10. These results suggest some mechanisms to minimize the loss of nitrogen stock from the sediment of tropical seagrass beds.

scholarly journals Impact of hydropower dam on total suspended sediment and total organic nitrogen fluxes of the Red River (Vietnam)

2020 ◽  
Vol 383 ◽  
pp. 367-374
Author(s):  
Nhu Da Le ◽  
Thi Phuong Quynh Le ◽  
Thi Xuan Binh Phung ◽  
Thi Thuy Duong ◽  
Orange Didier
Keyword(s):  
Suspended Sediment ◽  
Organic Nitrogen ◽  
Red River ◽  
Total Suspended Sediment ◽  
Wet Season ◽  
Annual Average ◽  
Total Organic Nitrogen ◽  
Sediment Loads ◽  
The Relationship ◽  
Experimental Equation

Abstract. The Red River is a typical example of the Southeast Asian rivers, which has been strongly affected by human activities. This paper analyses the change of total suspended sediment (TSS) load of the Red River from 1960 to 2015 in which numerous new dams in both China and Vietnam have been constructed. A strong decrease of TSS load of the whole Red River (from 79±26×106 t yr−1 in 1960s to 6±1×106 t yr−1 in 2010s) allocated to the dam impoundments in spite of population and deforestation increase. Base on the experimental equation describing the relationship between TSS and total organic nitrogen (TON) concentrations, and on the available data of TSS concentration and river discharge, the longterm TON concentrations and fluxes were calculated for the three tributaries and the whole Red River. The annual average of TON concentrations spatially varied from 0.41 to 3.19 mg L−1, averaging 0.98 mg L−1 for the whole period; the lowest was found for the Da River where the new dams have been impounded. The highest TON concentrations and fluxes occurred in the wet season in relationship with the highest sediment loads and river discharges. The riverine TON fluxes transferred to estuary significantly decreased from 141×103±38×103 t yr−1 (equivalent to 902±247 kg km−2 yr−1) in 1960s to 32×103±5×103 t yr−1 (equivalent to 207±35 kg km−2 yr−1) in 2010s. The TSS flux decrease has driven a clear reduction of associated elements like nitrogen, which let to hypothesis a change in biogeochemical processes in the coastal zone.

scholarly journals The estimation of the total organic nitrogen in water by the Kjeldahl process

The Analyst ◽  
1889 ◽  
Vol 14 (September) ◽  
pp. 168
Author(s):  
Henry Leffmann ◽  
William Beam
Keyword(s):  
Organic Nitrogen ◽  
Total Organic Nitrogen

scholarly journals The Effect of Habitat Structural Complexity on Gastropods in Anarid Mangrove Wetland

2021 ◽  
Author(s):  
Haniyeh Ebadzadeh ◽  
Mehdi Ghodrati Shojaei ◽  
Jafar Seyfabadi
Keyword(s):  
Community Structure ◽  
Habitat Complexity ◽  
Organic Nitrogen ◽  
Linear Models ◽  
Structural Complexity ◽  
Mangrove Ecosystem ◽  
Mangrove Forests ◽  
Total Organic Nitrogen ◽  
The Persian Gulf ◽  
Local Habitat

Abstract Structural complexity of mangrove forests are thought to provide critical habitats for a variety of invertebrates. We studied the influence of mangrove structure and seasonality on the gastropod diversity in the extreme mangrove ecosystem of the Persian Gulf. Sampling was conducted in two successive years (February and June 2018, February and June 2019) at two mangrove habitats i.e., pneumatophore zone and mudflats. The communities were characterized by the dominance of specific taxa and the comparably low species richness. In total, 18 taxa were identified, including 14 species occurring in the mangrove forest and 16 species in the mudflats. Assimineidae dominated the community in both mangrove habitats. Mean density of gastropods was 1.5-fold higher in the pneumatophore zone (86.12±135.21 ind.m-2) than in the mudflats (54.33±108.69 ind.m-2). Species such as Haminoea vitrea, Peronia verruculata, Assiminea mesopotamica and Platevindex tigrinus were found to benefit from the presence of pneumatophores, which highlights the importance of local habitat complexity. Gastropod communities varied significantly between the habitats, but there was little difference in the community structure between seasons. Distance-based linear models revealed that total organic carbon and total organic nitrogen best explained the variation in gastropods community structure.

scholarly journals Effect of lead on nitrate reductase activity and nitrate assimilation in pea leaves

2014 ◽  
Vol 57 (4) ◽  
pp. 457-463 ◽  
Author(s):  
S. K. Sinha ◽  
H. S. Srivastava ◽  
S. N. Mishra
Keyword(s):  
Enzyme Activity ◽  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
Organic Nitrogen ◽  
Reductase Activity ◽  
Total Organic Nitrogen ◽  
Intact Leaf ◽  
Leaf Tissues

The effect of Pb on nitrate reductase activity, protein, total organic nitrogen and on the chlorophyll content in excised and intact leaf tissues of <em>Pisum sativum</em> was examine. Enzyme activity assayed in vitro or in vivo in the excised leaves showed marked increase at lower concentrations of Pb while being inhibited at higher concentrations. In intact leaf tissues, the enzyme activity (in vivo or in vitro) was unaffected at lower concentrations but was inhibited at higher concentrations of Pb. Chlorophyll, carotenoids (non-nitrogenous pigments), soluble protein and organic nitrogen contents remained almost unaffected at all concentrations of Pb tested. It seems that nitrate reductase has a different response towards Pb pollution in this species, which is more tolerant to heavy metal pollution, especially Pb.

Distribution of cellular amino acids, protein, and total organic nitrogen during fruit body development in Flammulina velutipes. II. Growth on potato–glucose solution

1982 ◽  
Vol 60 (8) ◽  
pp. 1342-1351 ◽  
Author(s):  
Hans E. Gruen ◽  
William M. Wong
Keyword(s):  
Amino Acids ◽  
Organic Nitrogen ◽  
Glucose Solution ◽  
Fruit Body ◽  
Amino Nitrogen ◽  
Dry Weight ◽  
Early Growth ◽  
Flammulina Velutipes ◽  
Total Organic Nitrogen ◽  
Rapid Elongation

In Flammulina velutipes grown on potato–glucose solution the dry weight of mycelium decreased when fruitbodies elongated rapidly. Loss of dry weight by aborted primordia and stunted fruitbodies paralleled gains by large fruitbodies. These gains exceeded the losses by the rest of the colony and indicate that large fruitbodies derived their substrates both from the medium and from materials stored in the rest of the colony. Close to 43% of the organic nitrogen in the medium was consumed before fruitbodies formed and only 8% remained at the end of their growth. Concentrations of total nitrogen, α-amino nitrogen, and alkali-soluble protein declined in the mycelium during most of the growth of the fruitbodies and then remained constant except for a slight final increase in protein. Concentrations of these fractions also decreased in the small fruitbodies and stipes of large fruitbodies but increased in the pilei. Changes in total amounts of these fractions show that gains by all fruitbodies during elongation exceeded the losses by the mycelium and that part of their nitrogen continues to be derived from the medium. Changes in 18 free and 17 protein amino acids were followed quantitatively in the colony. Free arginine, glutamic acid, ornithine, and alanine predominated in the mycelium and small fruitbodies during early growth of the latter, but arginine and ornithine decreased steeply thereafter. During rapid elongation of the large fruitbodies the concentration of arginine increased strongly in the pilei. The increase was much less in the stipes, but successive changes in the rest of the colony suggest that arginine is translocated into the large pilei from the mycelium and possibly the small fruitbodies. Aspartic and glutamic acids, leucine, and alanine predominated in protein of the whole colony until the early growth of fruitbodies, but protein composition changed during rapid elongation. The proportion of valine increased in the mycelium and it became the most abundant bound amino acid in large stipes. [14C]Leucine was fed in replacement medium and incorporation of the label was determined in nitrogenous fractions of different colony portions at the onset and termination of fruitbody growth. Most of the label transported into fruitbodies was in the ethanol-soluble free amino acids.

Effects of Different Fertilization Methods on Organic Nitrogen Components in Paddy Soil

2014 ◽  
Vol 955-959 ◽  
pp. 1116-1119
Author(s):  
Ji Wang ◽  
Yun Jiang Liang ◽  
Min Jie Fu ◽  
Ze Yu Guan
Keyword(s):  
Significant Influence ◽  
Paddy Field ◽  
Organic Nitrogen ◽  
Organic Fertilizer ◽  
Total Acid ◽  
Total Organic Nitrogen ◽  
Total N ◽  
Soil Organic Nitrogen ◽  
Hydrolysable N

In order to reveal characteristics of soil organic nitrogen components under long-term different fertilization methods on paddy field, selected 7 typical paddy field of Korean Autonomous Prefecture of Yanbian of Jilin Province, collected soil samples of 0 to 10 cm and 10 to 20 cm, analyzed total nitrogen content of soil and each component of organic nitrogen. Results showed that effects of different fertilization methods on content of soil total acid hydrolysable N (TAHN), amino acid N (AAN), ammonia sugar N (ASN), acid-hydrolysable unknown N (AUN) in 0 to 10 cm soil had significant influence or more, and non hydrolysable N (NHN), AAN and ASN accounted for proportion of total N (TN) had significant influence. Effects soil organic nitrogen components in 10 to 20 cm soil had not significant influence. Applying organic fertilizer was beneficial to improve soil total organic nitrogen, mainly by improving content of AAN and ASN; Long-term application inorganic fertilizer led to NHN accumulation, but applying organic fertilizer was beneficial to NHN transformation, increase content of AAN; TAHN, NHN, AN, AAN, ASN content in 0 to 10 cm soil were slightly higher than that in 10 to 20 cm soil, and content of HUN had no obvious regularity between two soil layers.

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