Modeling the Growth, Biomass, and Tissue Phosphorus Concentration of Cladophora glomerata in Eastern Lake Erie: Model Description and Field Testing

2005 ◽  
Vol 31 (4) ◽  
pp. 439-455 ◽  
Author(s):  
Scott N. Higgins ◽  
Robert E. Hecky ◽  
Stephanie J. Guildford
Keyword(s):  
Lake Erie ◽  
Field Testing ◽  
Model Description ◽  
Phosphorus Concentration ◽  
Cladophora Glomerata ◽  
Tissue Phosphorus

Nutrient Budgets for Lake Erie, 1970

1976 ◽  
Vol 33 (3) ◽  
pp. 520-536 ◽  
Author(s):  
N. M. Burns
Keyword(s):  
Lake Erie ◽  
Loss Rate ◽  
Inorganic Nitrogen ◽  
Phytoplankton Growth ◽  
Phosphorus Concentration ◽  
Nutrient Budgets ◽  
Eastern Basin ◽  
Phosphorus Budget ◽  
Upward Transport ◽  
Reactive Silica

Budgets for the quantities of water, chloride, and phosphorus entering and leaving Lake Erie during the year of 1970 have been developed. The phosphorus budget was broken down into basin budgets which were further subdivided into epilimnion budgets for the Central and Eastern basins. Epilimnion budgets for soluble inorganic nitrogen (SIN) and soluble reactive silica (SRS) were also developed. The average coefficients of elimination by sedimentation of the phosphorus within each basin were 4.0, 0.38, and 0.18%/day for the Western, Central, and Eastern basins, respectively. The phosphorus elimination was found to be inversely related to mean basin depth but directly related to the phosphorus concentration of the water. The epilimnion budgets showed that during the summer the internal loading of SRS to the epilimnion was greater than the uptake of SRS by phytoplankton growth. The epilimnion budget of SIN demonstrated a massive uptake of the material during the summer, which was only partially replenished. The loss rate of phosphorus from the Central and Eastern basin epilimnia decreased as the summer progressed, to the extent that there was a net gain of phosphorus in the Eastern basin epilimnion toward the end of the summer. It is believed that this resulted from significant upward transport of phosphorus from the hypolimnion to the epilimnion by flagellate species of phytoplankton.

scholarly journals Grass–Legume Forage Systems Effect on Phosphorus Removal from a Grassland Historically Irrigated with Reclaimed Wastewater

2020 ◽  
Vol 12 (6) ◽  
pp. 2256
Author(s):  
Everald Mclennon ◽  
Juan K. Q. Solomon ◽  
Jason Davison
Keyword(s):  
White Clover ◽  
Phosphorus Removal ◽  
Trifolium Pratense ◽  
Extended Period ◽  
Phosphorus Concentration ◽  
Reclaimed Wastewater ◽  
Seeding Rate ◽  
Main Station ◽  
Tissue Phosphorus ◽  
Response Variables

The utilization of reclaimed wastewater is a suitable and sustainable approach to agriculture production in water-scarce regions. However, even though the wastewater is treated to reduce nutrient concentration such as phosphorus, the 10,600 to 14,006 m3 of water applied ha−1 year−1 on grass and alfalfa hay crops in Nevada can lead to soil phosphorus buildup over an extended period. This study evaluated the effectiveness of forage systems (FS) of monoculture grass, monoculture legume, and their mixtures on herbage accumulation, tissue phosphorus concentration, and quantity of phosphorus removed from a grassland under wastewater irrigation. The study was carried out at the Main Station Field laboratory in Reno, Nevada, USA. A total of 23 FS using tall fescue (Schedonorus arundinaceus (Schreb.) Dumort), alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.) and white clover (Trifolium repens L.) in monocultures or grass–legume mixtures (25:75, 50:50, and 75:25) based on seeding rate were used. The response variables were herbage accumulation (HA), tissue phosphorus concentration, and phosphorus removal. Forage systems means were considered different P ≤ 0.05. Herbage accumulation, tissue phosphorus concentration, and phosphorus removal differed among FS and year. Herbage accumulation was similar for the grass monocultures (10.5 Mg ha−1; SE = 1.1) and the majority of the grass–legume mixtures (9.0 Mg ha−1; SE = 1.1) but both systems had greater HA than legumes monoculture (4.3 Mg ha−1; SE = 1.1). The legume monocultures of alfalfa and white clover had the greatest phosphorus concentrations (10.9 g kg−1 dry matter; SE = 0.44) among all FS. Total phosphorus removed was least among legume monocultures (34.0 kg P ha−1; SE = 6.2) in this study and generally similar for grass monocultures (67.4 kg P ha−1; SE = 6.2) and grass–legume mixtures of 75:25 (61.7 kg P ha−1; SE = 6.2). Based on the response variables, agronomic, and environmental considerations a grass–legume mixture that includes 75:25 or even a 50:50 seeding rate ratio will be suitable options for phosphorus removal from phosphorus enriched grasslands in semiarid ecosystems that utilized wastewater for irrigation.

scholarly journals Increases in Great Lake winds and extreme events facilitate interbasin coupling and reduce water quality in Lake Erie

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aidin Jabbari ◽  
Josef D. Ackerman ◽  
Leon Boegman ◽  
Yingming Zhao
Keyword(s):  
Water Quality ◽  
Lake Erie ◽  
Southern Oscillation ◽  
Flow Analysis ◽  
Atlantic Multidecadal Oscillation ◽  
Phosphorus Concentration ◽  
Wave Power ◽  
Central Basin ◽  
Total Phosphorus Concentration ◽  
Western Basin

AbstractClimate change affects physical and biogeochemical processes in lakes. We show significant increases in surface-water temperature (~ 0.5 °C decade−1; > 0.2% year−1) and wave power (> 1% year−1; the transport of energy by waves) associated with atmospheric phenomena (Atlantic Multidecadal Oscillation and Multivariate El Niño/Southern Oscillation) in the month of August between 1980 and 2018 in the Laurentian Great Lakes. A pattern in wave power, in response to extreme winds, was identified as a proxy to predict interbasin coupling in Lake Erie. This involved the upwelling of cold and hypoxic (dissolved oxygen < 2 mg L−1) hypolimnetic water containing high total phosphorus concentration from the seasonally stratified central basin into the normally well-mixed western basin opposite to the eastward flow. Analysis of historical records indicate that hypoxic events due to interbasin exchange have increased in the western basin over the last four decades (43% in the last 10 years) thus affecting the water quality of the one of the world’s largest freshwater sources and fisheries.

Identification of Critical Nutrient Levels through Field Verification of Models for Phosphorus and Phytoplankton Growth

1986 ◽  
Vol 43 (2) ◽  
pp. 379-388 ◽  
Author(s):  
Martin T. Auer ◽  
Mark S. Kieser ◽  
Raymond P. Canale
Keyword(s):  
Growth Rate ◽  
Total Phosphorus ◽  
Lake Erie ◽  
Trophic State ◽  
Lake Ontario ◽  
Phytoplankton Growth ◽  
Phosphorus Concentration ◽  
Conceptual Foundation ◽  
Green Bay ◽  
Phosphorus Levels

Two models for phosphorus and phytoplankton growth were field verified along a marked gradient in trophic conditions in Green Bay (Lake Michigan): one, the Monod model, relates growth rate to external (dissolved) phosphorus concentration, and the other, the Droop model, describes growth rate as a function of internal (stored) phosphorus levels. The verification provided through a satisfactory fit of model output to field measurements of phosphorus and gross photosynthesis established a conceptual foundation for empirical models relating phosphorus and trophic state parameters. Phosphorus concentrations corresponding to boundary conditions for trophic state categories were developed based on the verified models by defining oligotrophy as the region of linear response by growth rate to increases in phosphorus (<1.2 μg soluble reactive phosphorus (SRP)∙L−1, <11.5 μg total phosphorus (TP)∙L−1), mesotrophy as the transitional state (1.2–8.0 μg SRP∙L−1, 11.5–37.5 μg TP∙L−1), and eutrophy as the region where growth rate is saturated, i.e. insensitive to changes in phosphorus concentration (>8.0 μg SRP∙L−1, >37.5 μg TP∙L−1). We applied the trophic state classification scheme to several Great Lakes basins to examine their sensitivity to changes in phosphorus levels. The oligotrophic waters of Lakes Superior, Huron, and Michigan and northern Green Bay and Georgian Bay have the greatest sensitivity to increases in total phosphorus concentration. The eutrophic waters of southern Green Bay, western Lake Erie, and nearshore Lake Ontario are nutrient saturated and relatively insensitive to initial reductions in phosphorus levels. Offshore Lake Ontario, eastern and central Lake Erie, Saginaw Bay, and mid Green Bay lie in the transitional phase for sensitivity to phosphorus management.

Trends in nutrient concentrations in Hatchery Bay, western Lake Erie, before and after Dreissena polymorpha

1995 ◽  
Vol 52 (6) ◽  
pp. 1202-1209 ◽  
Author(s):  
Ruth E. Holland ◽  
Thomas H. Johengen ◽  
Alfred M. Beeton
Keyword(s):  
Total Phosphorus ◽  
Dreissena Polymorpha ◽  
Lake Erie ◽  
Soluble Reactive Phosphorus ◽  
Water Clarity ◽  
Nutrient Concentrations ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration ◽  
Western Lake ◽  
Western Lake Erie

Concentrations of soluble reactive phosphorus, ammonium-nitrogen, nitrate-nitrogen, silica, and chloride have all increased since the establishment of the zebra mussel (Dreissena polymorpha) in Hatchery Bay, western Lake Erie, in 1988. Total phosphorus concentrations have changed little. These results are from 188 samples collected weekly and year round before the establishment of Dreissena (1984–1987) and 192 samples post-Dreissena (1990–1993). The mean annual total phosphorus concentration for the three complete post-Dreissena years was 35 μg∙L−1 strikingly similar to the concentration of 36 μg∙L−1, which in 1959 helped to define the waters of Lake Erie as eutrophic. The relative steadiness in total phosphorus may reflect sediment reflux, because Hatchery Bay is a polymictic system. The slight increase in the biologically conservative ion, chloride, in the 1990s, is probably due to the increased precipitation and runoff in the western Lake Erie watershed. Decreased phytoplankton and associated increased water clarity caused by efficient filtering by D. polymorpha, have lessened symptoms of eutrophication and produced a situation where nutrients are not fully utilized, i.e., biological oligotrophy.

Physiological responses of semiarid grasses. III.* Growth in relation to temperature and soil water deficit

1975 ◽  
Vol 26 (3) ◽  
pp. 447 ◽  
Author(s):  
EK Christie
Keyword(s):  
Soil Water ◽  
Growth Rates ◽  
Soil Water Potential ◽  
Dry Weight ◽  
Phosphorus Concentration ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Ample Supply ◽  
Net Assimilation ◽  
Tissue Phosphorus

The optimum temperature for vegetative growth of mulga grass was about 25°C, and for Mitchell and buffel grasses 30°. Buffel grass had the highest yield at all temperatures, partly because of its higher growth rate which in turn can be ascribed to both a higher net assimilation rate and the diversion of a greater proportion of dry weight into leaf area. Seedlings with an ample supply of phosphate had higher relative growth rates than phosphorus-deficient seedlings at the commencement of the soil drying cycle, but their growth rates declined more rapidly as the soil water potential fell. This decline was associated with a reduction in the rate of phosphate absorption as well as a decrease in the tissue phosphorus concentration. *Part II, Aust. J. Agric. Res., 26: 437 (1975).

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