scholarly journals Limited progress in nutrient pollution in the U.S. caused by spatially persistent nutrient sources

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0258952
Author(s):  
Rebecca J. Frei ◽  
Gabriella M. Lawson ◽  
Adam J. Norris ◽  
Gabriel Cano ◽  
Maria Camila Vargas ◽  
...  
Keyword(s):  
Spatial Patterns ◽  
Nutrient Removal ◽  
Nutrient Balance ◽  
Temporal Trends ◽  
Nutrient Concentrations ◽  
Nutrient Pollution ◽  
Nutrient Inputs ◽  
Nutrient Sources ◽  
Removal Capacity ◽  
The U.S

Human agriculture, wastewater, and use of fossil fuels have saturated ecosystems with nitrogen and phosphorus, threatening biodiversity and human water security at a global scale. Despite efforts to reduce nutrient pollution, carbon and nutrient concentrations have increased or remained high in many regions. Here, we applied a new ecohydrological framework to ~12,000 water samples collected by the U.S. Environmental Protection Agency from streams and lakes across the contiguous U.S. to identify spatial and temporal patterns in nutrient concentrations and leverage (an indicator of flux). For the contiguous U.S. and within ecoregions, we quantified trends for sites sampled repeatedly from 2000 to 2019, the persistence of spatial patterns over that period, and the patch size of nutrient sources and sinks. While we observed various temporal trends across ecoregions, the spatial patterns of nutrient and carbon concentrations in streams were persistent across and within ecoregions, potentially because of historical nutrient legacies, consistent nutrient sources, and inherent differences in nutrient removal capacity for various ecosystems. Watersheds showed strong critical source area dynamics in that 2–8% of the land area accounted for 75% of the estimated flux. Variability in nutrient contribution was greatest in catchments smaller than 250 km2 for most parameters. An ensemble of four machine learning models confirmed previously observed relationships between nutrient concentrations and a combination of land use and land cover, demonstrating how human activity and inherent nutrient removal capacity interactively determine nutrient balance. These findings suggest that targeted nutrient interventions in a small portion of the landscape could substantially improve water quality at continental scales. We recommend a dual approach of first prioritizing the reduction of nutrient inputs in catchments that exert disproportionate influence on downstream water chemistry, and second, enhancing nutrient removal capacity by restoring hydrological connectivity both laterally and vertically in stream networks.

Nitrogen and Phosphorus Removal-capacity of Four Chosen Aquatic Macrophytes in Tropical Freshwater Ponds

1991 ◽  
Vol 18 (2) ◽  
pp. 143-147 ◽  
Author(s):  
Brahma D. Tripathi ◽  
Jaya Srivastava ◽  
Kiran Misra
Keyword(s):  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Water Hyacinth ◽  
Aquatic Macrophytes ◽  
Field Experiments ◽  
Phosphate Removal ◽  
Pistia Stratiotes ◽  
Reproductive Capacity ◽  
Nutrient Concentrations ◽  
Removal Capacity

The nutrient removal-capacity of four chosen aquatic macrophytes was tested in both natural and laboratory conditions. Laboratory experiments were performed under controlled conditions using ‘microcosm’ methods wherein the plants were grown in three different nutrient concentrations. For field experiments, three ponds were selected that had different levels of plant nutrient concentrations and accordingly were treated as polluted, moderately polluted, and relatively unpolluted, respectively, the object being to study the nutrient removal-capacity of chosen aquatic macrophytes living in ‘natural’ conditions. For the present investigation, four common and widespread aquatic plants growing in all three ponds were chosen: Water-hyacinth (Eichhornia crassipes [Mart.] Solms), Water-lettuce (Pistia stratiotes L.), Round-leafed Water-fern (Salvinia rotundifolia Willd.), and Lesser Duckweed (Lemna minor L.). These plants were selected also because of their frequent presence in aquatic bodies in the region and their high reproductive capacity.From the results it is revealed that, during the summer and rainy seasons, the highest content of nitrogen was removed by the Eichhornia, followed by the Pistia > Lemna > Salvinia, while during winter the highest content of nitrogen was removed by the Eichhornia followed by the Lemna > Pistia > Salvinia. Higher phosphorus removal was found in summer than in the rainy or the winter season. Phosphorus removal by the macrophytes was in the order of the Eichhornia > Pistia > Lemna > Salvinia, during the summer and rainy seasons, whereas the highest content of phosphorus was removed by Lemna in the winter months.The nutrient removal-capacity was rated to be highest by the Water-hyacinth, followed by the Pistia, then the Lemna, and lowest by the Salvinia. It was also evident that the nutrient removal increased with increasing nutrient concentration in the wastewater. The removal of nitrate by the selected macrophytes ranged from 42.0% to 96.2%, while phosphate removal ranged from 36.3% to 70.2%. A positive and significant correlation was obtained between the concentration of nitrate and phosphate in the waters and plant tissues that were studied, and it is thought that a useful strategy to employ might be to grow the Eichhornia and the Lemna together at least where winter temperatures were likely to be low enough to favour the Lemna at that season, though at other times it is apt to be a nuisance.

Physiological responses of seagrasses used to identify anthropogenic nutrient inputs

1997 ◽  
Vol 48 (7) ◽  
pp. 605 ◽  
Author(s):  
James W. Udy ◽  
William C. Dennison
Keyword(s):  
Amino Acid ◽  
Nutrient Availability ◽  
Nutrient Content ◽  
Physiological Characteristics ◽  
Nutrient Concentrations ◽  
Nutrient Load ◽  
Nutrient Inputs ◽  
Nutrient Sources ◽  
Moreton Bay ◽  
Amino Acid Concentrations

Fertilization experiments have established that seagrass growth in Moreton Bay can be limited by the supply of both N and P. In the present study, morphological and physiological characteristics (canopy height, shoot density, biomass, growth, tissue nutrient content, amino acid concentrations and δ15N ratios) of Zostera capricorni Aschers. in Moreton Bay, close to and distant from nutrient sources, were compared. Z. capricorni at the four sites close to nutrient sources (sewage, septic or prawn-farm effluent, or river discharge), had physiological characteristics representative of high nutrient availability and at the five sites distant from nutrient sources had physiological characteristics representative of low nutrient availability. Differences in sediment nutrient concentrations (NH4+ and PO43- ), seagrass morphology and growth were not related to proximity to nutrient sources. However, the nutrient content of the seagrasses and their amino acid concentrations were consistently higher at sites close to a nutrient source. The amino acids glutamine and asparagine were the most responsive to elevated nutrient availability, and δ15N values of seagrasses reflected the source of N rather than the nutrient load. These results demonstrate that physiological characteristics of seagrasses can be used to identify the nutrient load and source affecting marine ecosystems.

scholarly journals Grape Pomace Ingestion by Dry Cows Does Not Affect the Colostrum Nutrient and Fatty Acid Composition

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1633
Author(s):  
Michal Rolinec ◽  
Daniel Bíro ◽  
Milan Šimko ◽  
Miroslav Juráček ◽  
Ondrej Hanušovský ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Late Pregnancy ◽  
Grape Pomace ◽  
Farm Animals ◽  
Nutrient Concentrations ◽  
Nutrient Sources ◽  
Negative Effect

The utilisation of different by-products from the food industry as nutrient sources for farm animals is both possible and beneficial. Grape pomace is a by-product that contains polyphenols and fatty acids, both of which have the potential to improve the nutritional quality of cow colostrum. This study aimed to explore how the addition of grape pomace to the diet of dry cows affects the concentration of nutrients and fatty acids of colostrum. Sixteen Slovak spotted cows in late pregnancy were used in this study. From the seventh day before expected calving to the day of calving, cows in the grape pomace group received a diet supplemented with dried grape pomace, at 0.116 kg/cow/day. Colostrum samples were analysed for basal nutrients and fatty acid concentrations. Between the control and experimental groups, the nutrient and fatty acid concentrations of all the colostrum samples did not show significant differences. The nutrient levels in the colostrum from both groups of cows were typical, as related to the time from calving. The addition of the grape pomace into the diet of dry cows had no effect on nutrient concentrations and the fatty acid composition of the colostrum. The somatic cell score of the colostrum sampled at the 12th hour after calving (4.2 versus 2.6) was positively affected by grape pomace addition. The results of this study revealed that grape pomace (fed in an amount of 0.116 kg/cow/day) had no positive or negative effect on the base nutrients and fatty acids of cow colostrum, and, therefore, grape pomace can be used as a nutrient source for dry cows in small amounts.

Spatial patterns and temporal trends of daily precipitation indices in Iran

2014 ◽  
Vol 124 (1-2) ◽  
pp. 239-253 ◽  
Author(s):  
Tayeb Raziei ◽  
Jamal Daryabari ◽  
Isabella Bordi ◽  
Reza Modarres ◽  
Luis S. Pereira
Keyword(s):  
Spatial Patterns ◽  
Daily Precipitation ◽  
Temporal Trends ◽  
Precipitation Indices

Spatial Patterns and Drivers of Soil Chemical Properties in a Typical Hickory Plantation

2021 ◽  
Author(s):  
Mengjiao Sun ◽  
Enqing Hou ◽  
Jiasen Wu ◽  
Jianqin Huang ◽  
Xingzhao Huang
Keyword(s):  
Random Forest ◽  
Soil Nutrients ◽  
Spatial Patterns ◽  
Abiotic Factors ◽  
Soil Nutrient ◽  
Parent Material ◽  
Mean Annual Precipitation ◽  
Nutrient Concentrations ◽  
Available Phosphorus ◽  
Mean Annual Temperature

Abstract Background: Soil nutrients play critical roles in regulating and improving the sustainable development of economic forests. Consequently, an elucidation of the spatial patterns and drivers of soil nutrients in these forests is fundamental to their management. For this study, we collected 314 composite soils at a 0-30 cm depth from a typical hickory plantation in Lin 'an, Zhejiang Province, China. We determined the concentrations of macronutrients (i.e., soil organic carbon, hydrolyzed nitrogen, available phosphorus, and available potassium) and micronutrients (i.e., iron, manganese, zinc, and copper.) of the soils. We employed random forest analysis to quantify the relative importance of soil-forming factors to predict the soil nutrient concentrations, which could then be extrapolated to the entire hickory region. Results: Random forest models explained 61%–88% of the variations in soil nutrient concentrations. The mean annual temperature and mean annual precipitation were the most important predictor of soil macronutrient and micronutrient concentrations. Moreover, parent material was another key predictor of soil available phosphorus and micronutrient concentrations. Mapping results demonstrated the importance of climate in controlling the spatial distribution of soil nutrient concentrations at finer scales, as well as the effect of parent material, topography, stand structure, and management measures of hickory plantations. Conclusions: Our study highlights the biotic factors, abiotic factors, and management factors control over soil macronutrient and micronutrient concentrations, which have significant implications for the sustainability of soil nutrients in forest plantations.

scholarly journals High-resolution monitoring of nutrients in groundwater and surface waters: process understanding, quantification of loads and concentrations, and management applications

2016 ◽  
Vol 20 (9) ◽  
pp. 3619-3629 ◽  
Author(s):  
Frans C. van Geer ◽  
Brian Kronvang ◽  
Hans Peter Broers
Keyword(s):  
High Resolution ◽  
High Frequency ◽  
Temporal Trends ◽  
Surface Water Quality ◽  
Mitigation Measures ◽  
Nutrient Concentrations ◽  
Special Issue ◽  
Monitoring Strategies ◽  
Frequency Monitoring ◽  
Water Quality And Quantity

Abstract. Four sessions on "Monitoring Strategies: temporal trends in groundwater and surface water quality and quantity" at the EGU conferences in 2012, 2013, 2014, and 2015 and a special issue of HESS form the background for this overview of the current state of high-resolution monitoring of nutrients. The overview includes a summary of technologies applied in high-frequency monitoring of nutrients in the special issue. Moreover, we present a new assessment of the objectives behind high-frequency monitoring as classified into three main groups: (i) improved understanding of the underlying hydrological, chemical, and biological processes (PU); (ii) quantification of true nutrient concentrations and loads (Q); and (iii) operational management, including evaluation of the effects of mitigation measures (M). The contributions in the special issue focus on the implementation of high-frequency monitoring within the broader context of policy making and management of water in Europe for support of EU directives such as the Water Framework Directive, the Groundwater Directive, and the Nitrates Directive. The overview presented enabled us to highlight the typical objectives encountered in the application of high-frequency monitoring and to reflect on future developments and research needs in this growing field of expertise.

Mosses as biomonitors of atmospheric heavy metal deposition: Spatial patterns and temporal trends in Europe

2010 ◽  
Vol 158 (10) ◽  
pp. 3144-3156 ◽  
Author(s):  
H. Harmens ◽  
D.A. Norris ◽  
E. Steinnes ◽  
E. Kubin ◽  
J. Piispanen ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Spatial Patterns ◽  
Temporal Trends ◽  
Metal Deposition ◽  
Heavy Metal Deposition

scholarly journals Did the COVID-19 Pandemic Crisis Affect Housing Prices Evenly in the U.S.?

2021 ◽  
Vol 13 (21) ◽  
pp. 12277
Author(s):  
Xinba Li ◽  
Chuanrong Zhang
Keyword(s):  
Real Estate ◽  
Spatial Patterns ◽  
Price Change ◽  
Housing Prices ◽  
Housing Price ◽  
Real Estate Market ◽  
Moran’S I ◽  
Moran's I ◽  
Price Changes ◽  
The U.S

While it is well-known that housing prices generally increased in the United States (U.S.) during the COVID-19 pandemic crisis, to the best of our knowledge, there has been no research conducted to understand the spatial patterns and heterogeneity of housing price changes in the U.S. real estate market during the crisis. There has been less attention on the consequences of this pandemic, in terms of the spatial distribution of housing price changes in the U.S. The objective of this study was to explore the spatial patterns and heterogeneous distribution of housing price change rates across different areas of the U.S. real estate market during the COVID-19 pandemic. We calculated the global Moran’s I, Anselin’s local Moran’s I, and Getis-Ord’s statistics of the housing price change rates in 2856 U.S. counties. The following two major findings were obtained: (1) The influence of the COVID-19 pandemic crisis on housing price change varied across space in the U.S. The patterns not only differed from metropolitan areas to rural areas, but also varied from one metropolitan area to another. (2) It seems that COVID-19 made Americans more cautious about buying property in densely populated urban downtowns that had higher levels of virus infection; therefore, it was found that during the COVID-19 pandemic year of 2020–2021, the housing price hot spots were typically located in more affordable suburbs, smaller cities, and areas away from high-cost, high-density urban downtowns. This study may be helpful for understanding the relationship between the COVID-19 pandemic and the real estate market, as well as human behaviors in response to the pandemic.

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