scholarly journals Response of the mollusc communities to environmental factors along an anthropogenic salinity gradient

2019 ◽  
Vol 106 (11-12) ◽  
Author(s):  
Agnieszka Sowa ◽  
Mariola Krodkiewska ◽  
Dariusz Halabowski ◽  
Iga Lewin
Keyword(s):  
Alien Species ◽  
Nitrate Nitrogen ◽  
Salinity Gradient ◽  
Ammonium Nitrogen ◽  
Freshwater Ecosystems ◽  
Underground Coal Mining ◽  
Taxa Richness ◽  
Elevated Salinity ◽  
Large Gradient ◽  
Sand And Gravel

AbstractAnthropogenic salinisation of freshwater ecosystems is frequent across the world. The scale of this phenomenon remains unrecognised, and therefore, monitoring and management of such ecosystems is very important. We conducted a study on the mollusc communities in inland anthropogenic ponds covering a large gradient of salinity located in an area of underground coal mining activity. A total of 14 gastropod and 6 bivalve species were noted. No molluscs were found in waters with total dissolved solids (TDS) higher than 17.1 g L−1. The share of alien species in the communities was very high in waters with elevated salinity and significantly lower in the freshwaters. Canonical correspondence analysis (CCA) showed that TDS, pH, alkalinity, nitrate nitrogen, ammonium nitrogen, iron, the content of organic matter in sediments, the type of substrate and the content of sand and gravel in sediments were the variables that were significantly associated with the distribution of molluscs. The regression analysis revealed that total mollusc density was positively related to alkalinity and negatively related to nitrate nitrogen. The taxa richness was negatively related to TDS, which is consistent with previous studies which indicated that a high salinity level is a significant threat to freshwater malacofauna, causing a loss of biodiversity and contributing to the colonisation and establishment of alien species in aquatic ecosystems.

scholarly journals Observations on the mobilization of peat nitrogen in incubation experiments

1959 ◽  
Vol 31 (1) ◽  
pp. 268-281
Author(s):  
Jaakko Kivekäs ◽  
Erkki Kivinen
Keyword(s):  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
The Other ◽  
Incubation Experiments ◽  
Different Types ◽  
Working Out ◽  
Original Amount

60 peat samples from northern Finland representing different types of peat were incubated in a laboratory at a temperature of 17—18° C. The ammonium nitrogen, the nitrate nitrogen and the pH in the samples were determined after one month of incubation as well as after three months of incubation. The results were compared to results from determinations made before incubation. An attempt was made to elucidate the factors that influence the mobilization of nitrogen. On the basis of the above results it is evident that the differences between the various peat types as mobilizers of nitrogen are under these circumstances not very distinct, nor do these differences seem to be dependent on the types of peat. The following facts can, however, be established: In the amounts of ammonium nitrogen an increase takes place in most groups of samples during the first month. This increase is fairly big in the Sphagnum-dominated peats. The increase in ammonium nitrogen continues in the unlimed samples in most peat groups during all three months of incubation. After three months of incubation the amount of ammonium nitrogen in the limed samples is smaller than in the unlimed samples, although it is usually bigger than in the original samples. After the first month of incubation the amounts of nitrate nitrogen in all types of peat have decreased compared to the amounts in the original samples. In the limed samples the decrease is not as great as in the unlimed ones. After three months of incubation the amount of nitrate nitrogen has considerably increased as compared to the amount after one month of incubation. In the limed samples it might to some extent exceed the original amount of nitrate nitrogen, however, this is seldom the case in the unlimed samples. If the results are calculated on the basis of weight unit, it can be stated that the ability to mobilize nitrogen is greater in the Sphagnum peats than in the other peat groups. Working out the results in kg per ha it will be noted that somewhat more nitrogen is mobilized in the Carex-dominated than in the Sphagnum-dominated peats. The results obtained by experiments in the laboratory are not directly applicable to conditions in the field.

The effects of ammonium and nitrate nitrogen on the growth of perennial rye grass

1936 ◽  
Vol 26 (2) ◽  
pp. 249-257 ◽  
Author(s):  
A. H. Lewis
Keyword(s):  
Nitrogen Content ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Early Stages ◽  
Rye Grass

The results show clearly a more rapid and greater uptake of ammonium than of nitrate nitrogen by perennial rye grass grown in a sand-bentonite medium of pH 7·61. The extent to which the extra uptake with added ammonia was reflected in increased yields was dependent upon the age of the grass.Except in the very early stages the percentage nitrogen content of the herbage was higher where nitrate nitrogen was applied than where ammonium nitrogen was applied. This indicates that any nitrate absorbed by the plant was less, efficient in increasing yields than was ammonium nitrogen.The percentage P205 content of the grass was higher where the nitrogen was applied in the ammoniacal form than where it was applied as nitrate, and it appears that this greater P205 uptake with ammonium nitrogen resulted in increased growth.

Influence of Photochemical Reactions on the Content and Transformation of Mineral Nitrogen in Sod-Podzol Soil

2018 ◽  
Vol 781 ◽  
pp. 195-199
Author(s):  
Sergey Novoselov
Keyword(s):  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Photochemical Reactions ◽  
Mineral Nitrogen ◽  
Light Energy ◽  
Second Stage ◽  
Humus Substances ◽  
Microbiological Oxidation ◽  
Two Stages

The article discusses the photochemical effects of sunlight on the soil. Under the influence of light energy the amount of mineral and easy hydrolysable nitrogen, as well as labile humus substances increased in the soil. The photochemical destruction of humus substances was accompanied by an increase in their mobility and loss of colour. The article shows that the process of mineral nitrogen formation in the soil during the photochemical destruction of humus substances has two stages. The first stage includes photochemical reactions with the formation of ammonium nitrogen. The second stage is the microbiological oxidation of ammonium nitrogen to the nitrate nitrogen.

Runoff characteristics of nutrients in the forest streams in Hyogo Prefecture, Japan

2001 ◽  
Vol 44 (7) ◽  
pp. 151-156 ◽  
Author(s):  
S. Umemoto ◽  
Y. Komai ◽  
T. Inoue
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Suspended Solids ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Stream Flows ◽  
The Difference ◽  
Hyogo Prefecture ◽  
Forest Streams ◽  
Precipitation Events

Nutrients and other pollutant runoffs from streams in artificial forest areas in central Hyogo Prefecture in southwest Japan have been investigated to estimate pollutant loads since 1995. The orthophosphate and ammonium nitrogen contents were usually low and constant during the investigation. When the flowrates of the streams were normal, the concentrations of suspended solids, CODMn, TOC and total phosphorus were very low, and did not change much. However, when stream flows were increased by rainstorms or other precipitation, higher concentrations of these parameters occurred. Otherwise, the average concentrations of nitrate nitrogen and total nitrogen were 0.26 mg/l and 0.31 mg/l, respectively, and they were often increased by precipitation events. They changed at the same time because the ratio of nitrate nitrogen per total nitrogen was high, about 80%. The fluctuation of concentrations of total phosphorus was similar to SS concentrations, which suggested that phosphorus was discharged in the types of suspended solids from forest areas. The specific loads of the nutrients and some other pollutants did not differ among the three watersheds investigated. However, the difference among them between fine days and rainy days was fairly large. It was presumed that pollutant runoff from forest areas is strongly dependent on precipitation events.

scholarly journals Effects of Grazing Pattern on Ecosystem Respiration and Methane Flux in a Sown Pasture in Inner Mongolia, China

Atmosphere ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 5
Author(s):  
Baoling Mei ◽  
Hongyu Yue ◽  
Xunhua Zheng ◽  
William McDowell ◽  
Qingshan Zhao ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Soil Temperature ◽  
Inner Mongolia ◽  
Nitrate Nitrogen ◽  
Ecosystem Respiration ◽  
Ammonium Nitrogen ◽  
Agricultural Practice ◽  
Ch4 Flux

The establishment of sown pasture is an important agricultural practice in many landscapes. Although both native grassland and sown pasture play a key role in the global carbon cycle, due to lack of data and field experiments, our understanding of grassland CH4 fluxes and CO2 emissions remains limited, especially when it comes to sown pasture. We measured ecosystem respiration and CH4 fluxes in response to a variety of potential drivers (soil temperature, soil moisture, ammonium nitrogen, nitrate nitrogen and dissolved organic carbon) in CG (continuous grazing), RG (rotational grazing) and UG (ungrazed) plots in sown grassland for one year in Inner Mongolia. Fluxes of CH4 and ecosystem respiration were measured using static opaque chambers and gas chromatography. Grazing significantly reduced ecosystem respiration (p < 0.01), and grazing pattern significantly influenced respiration in CG and RG plots (p < 0.01). We find that the sown grassland is a net sink for atmospheric CH4. No influence of grazing pattern was observed on CH4 flux in CG, RG and UG (p > 0.05). Soil temperature is the most important factor influencing ecosystem respiration and CH4 flux in the sown grassland, with soil moisture playing a secondary role to soil temperature. Variation in levels of ammonium nitrogen, nitrate nitrogen and dissolved organic carbon had little influence on ecosystem respiration or CH4 flux (except in UG plots). The values obtained for ecosystem respiration of grasslands have a large uncertainty range, which may be due to spatial variability as well as differences in research methods. Mean CH4 fluxes measured only during the growing season were much higher than the annual mean CH4 fluxes.

scholarly journals Is nitrate a driver for pigments of phytoplankton (a case study from a small shallow European lake)?

2018 ◽  
Vol 54 ◽  
pp. 38
Author(s):  
Alexandra L. Rizhinashvili ◽  
Olga B. Maksimova
Keyword(s):  
Nitrogen Limitation ◽  
Nitrate Nitrogen ◽  
Close Correlation ◽  
Freshwater Ecosystems ◽  
Lake Ecosystem ◽  
Nitrate Anion ◽  
Production Potential ◽  
The Relationship ◽  
Drainage Ratio

The traditional view of biogenic limitation in freshwater ecosystems considers phosphorus as the primary limiting element, but this concept has recently been challenged. There are a number of studies that suggest that photosynthetic indices may depend on the levels of nitrogen (especially, nitrate-nitrogen). To test the hypothesis about the possibility of nitrogen limitation in the lake ecosystem, the present study analysed the water in the littoral zone of a shallow model lake for the relationship between the content of phytoplankton pigments (chlorophyll a and carotenoids) and nitrate. The nitrate-nitrogen was selected because it is the most chemically stable nitrogen species. The study was conducted in a small lake with a pronounced autochthonous regime (as indicated by its small drainage ratio) during a vegetation season with contrasting hydrological conditions. The relationship with the nitrate concentration was not confirmed for chlorophyll a, but the levels of nitrate anion and carotenoids were shown to be related. Chlorophyll a, which is regarded as a metabolically active component of phytoplankton cells, shows a close correlation with air temperature. The corresponding prognostic regression models were created. The data on nominal availability of nitrate-nitrogen for primary production show possible nitrogen limitation on some of the observation dates. If the production potential represented by certain levels of nitrate is not realised by phytoplankton, it can be used by filamentous algae. The results of the study provide first steps toward prediction of one of the indicators of phytoplankton growth, the content of two main types of pigment (chlorophyll a and carotenoids).

scholarly journals The effect of pulverising aeration on changes in the oxygen and nitrogen concentrations in water of Lake Starzyc

2015 ◽  
Vol 25 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Piotr Wesołowski ◽  
Adam Brysiewicz
Keyword(s):  
Dissolved Oxygen ◽  
Nitrate Nitrogen ◽  
Ecological Status ◽  
Ammonium Nitrogen ◽  
Abiotic Conditions ◽  
The Third ◽  
Long Period ◽  
Nitrogen Concentrations ◽  
Bottom Waters ◽  
Restoration Measures

Abstract Due to poor ecological status of Lake Starzyc, lake restoration measures were undertaken in 2003 to improve aerobic conditions of near-bottom waters and to decrease phosphorus concentrations. To do this, a wind-driven pulverising aerator was installed in the lake. The aim of this study was to analyse variability of oxygen and nitrogen concentrations in lake water near the aerator in the third year of its operation and later on in the three-year-long period of the years 2008–2010. It was found that concentrations of ammonium-nitrogen, nitrate-nitrogen and dissolved oxygen near the aerator did not differ from those in sites 4 and 5, which evidenced similar abiotic conditions in analysed waters. Higher concentrations of dissolved oxygen and lower concentrations of nitrate-nitrogen were found in the years 2008–2010 than in 2005.

scholarly journals Climate change and freshwater ecosystems in Oceania: an assessment of vulnerability and adaptation opportunities.

2011 ◽  
Vol 17 (3) ◽  
pp. 201 ◽  
Author(s):  
K M Jenkins ◽  
R T Kingsford ◽  
G P Closs ◽  
B J Wolfenden ◽  
C D Matthaei ◽  
...  
Keyword(s):  
Climate Change ◽  
New Zealand ◽  
Sea Level ◽  
Pacific Islands ◽  
Environmental Flows ◽  
Freshwater Ecosystems ◽  
Freshwater Wetlands ◽  
Snow Melt ◽  
Mountainous Regions ◽  
Elevated Salinity

Human-forced climate change significantly threatens the world’s freshwater ecosystems, through projected changes to rainfall, temperature and sea level. We examined the threats and adaptation opportunities to climate change in a diverse selection of rivers and wetlands from Oceania (Australia, New Zealand and Pacific Islands). We found common themes, but also important regional differences. In regulated floodplain rivers in dry regions (i.e. Australia), reduced flooding projected with climate change is a veneer on current losses, but impacts ramp up by 2070. Increasing drought threatens biota as the time between floods extends. Current measures addressing water allocations and dam management can be extended to adapt to climate change, with water buy-back and environmental flows critical. Freshwater wetlands along coastal Oceania are threatened by elevated salinity as sea level rises, potentially mitigated by levee banks. In mountainous regions of New Zealand, the biodiversity of largely pristine glacial and snow melt rivers is threatened by temperature increases, particularly endemic species. Australian snow melt rivers face similar problems, compounding impacts of hydro-electric schemes. Translocation of species and control of invasive species are the main adaptations. Changes to flow regime and rising water temperatures and sea levels are the main threats of climate change on freshwater ecosystems. Besides lowering emissions, reducing impacts of water consumption and protecting or restoring connectivity and refugia are key adaptations for conservation of freshwater ecosystems. Despite these clear imperatives, policy and management has been slow to respond, even in developed regions with significant resources to tackle such complex issues.

Study on the Effects of Nitrogen Pollution to the Soil and Groundwater

2013 ◽  
Vol 437 ◽  
pp. 1019-1022 ◽  
Author(s):  
Xiao Hui Lu ◽  
Yang Wang
Keyword(s):  
Nitrogen Content ◽  
Nitrate Nitrogen ◽  
Flow Direction ◽  
Ammonium Nitrogen ◽  
Nitrogen Pollution ◽  
Monitoring Point ◽  
River Bank ◽  
The North ◽  
Geological Conditions ◽  
Nitrite Nitrate

Xuzhou city lies on the north of Jiangsu province, which geological conditions are complex, water resources are deficient and environment is vulnerable. At present, water pollution in Kui river area is very serious; Kui River nitrogen pollution had affected Coastal soil and chemical environment of groundwater. The monitoring sections are elected in the seriously polluted river, and downstream at the banks of river decorates with six monitoring sections. Each section from the river bank of 50m, 100m, 200m, 500m, 1000m, 1500m is arranged of monitoring points respectively, and each monitoring point is monitored for sampling test at different depths. The monitoring results of surface water showed that the content of ammonia-nitrite-nitrate was a decreasing trend along the flow direction. The nitrate nitrogen content would decrease further in December while the ammonium nitrogen content was on the rise, showing that the supplement of nitrogen pollution resources was still insufficient when the denitrification was stronger. The content of ammonium and nitrate nitrogen in soil was higher, and had some regular change features with the change of depth.

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