Excretion of Ammonia and Inorganic Phosphorus by Euphausia pacifica and Metridia pacifica at Different Concentrations of Phytoplankton

1975 ◽  
Vol 32 (11) ◽  
pp. 2189-2195 ◽  
Author(s):  
M. Takahashi ◽  
T. Ikeda
Keyword(s):  
Chlorophyll A ◽  
Uptake Rate ◽  
Excretion Rate ◽  
Inorganic Phosphorus ◽  
Euphausia Pacifica ◽  
Nutrient Excretion ◽  
Rapid Removal ◽  
Nutrient Uptake Rate ◽  
Zooplankton Excretion ◽  
Metridia Pacifica

Rates of excretion in the forms of ammonia and inorganic phosphorus were determined for Euphausia pacifica and Metridia pacifica at different phytoplankton concentrations. Nutrient uptake rate of the phytoplankton sample for each experiment was determined using Michaelis-Menten kinetics. The gross excretion of nutrients by zooplankton (Eg) was estimated by summing the apparent excretion (Ea) and nutrient removed by phytoplankton (Eu) as follows:[Formula: see text]Two significant effects of phytoplankton on zooplankton excretion were recognized: 1) rapid removal from the medium of nutrients excreted by zooplankton, and 2) increase in nutrient excretion of zooplankton. Phytoplankton could remove 0–100% of the nutrients excreted by zooplankton. The increase in nutrient excretion by zooplankton due to adding phytoplankton was proportional to the amount of phytoplankton ingested. Compared with the excretion rate at zero phytoplankton density, the estimated increase in excretion rate was as high as 5 times at 15 μg chlorophyll a/liter (optimum phytoplankton density) for M. pacifica and almost 9 times at 70 μg chlorophyll a/liter for E. pacifica.

scholarly journals Seasonal Nearshore Occurrence of the Neurotoxin β N methylamino L alanine (BMAA) in Lake Winnipeg, Canada

2016 ◽  
Vol 5 (1) ◽  
pp. 110 ◽  
Author(s):  
Eva Pip ◽  
Kimber Munford ◽  
Lindsay Bowman
Keyword(s):  
Chlorophyll A ◽  
Nutrient Management ◽  
Management Strategies ◽  
Seasonal Fluctuation ◽  
Inverse Correlation ◽  
Water Quality Monitoring ◽  
Inorganic Phosphorus ◽  
Lake Winnipeg ◽  
Nitrate N ◽  
Shading Effects

Seasonal fluctuation patterns of the neurotoxic amino acid β N methylamino L alanine (BMAA) were examined at four-day intervals during the ice-free season in water at three nearshore stations in the south basin of Lake Winnipeg, Canada. BMAA patterns were significantly exponentially correlated with concurrent phaeophytin, and inversely with chlorophyll a, indicating that free BMAA concentrations increased as blooms declined. BMAA was also significantly related to preceding microcystin concentrations, and as chlorophyll a declined, the proportion of BMAA relative to microcystin increased. Cross correlations identified significant relationships between BMAA and immediately preceding nitrate-N/inorganic phosphorus ratios, nitrate-N, rainfall, and a marginal inverse correlation with inorganic phosphorus. Total suspended solids levels were also significantly associated with BMAA, likely due to shading effects. A very high BMAA concentration was found under collapse of intense bloom conditions. These results have implications for water quality monitoring, nutrient management strategies and public health.

RADIOPHOSPHORUS METABOLISM IN ZOOPLANKTON AND MICROORGANISMS

1957 ◽  
Vol 35 (6) ◽  
pp. 769-782 ◽  
Author(s):  
Eugene Harris
Keyword(s):  
Particulate Matter ◽  
Uptake Rate ◽  
Inorganic Phosphorus ◽  
Turnover Time ◽  
The Other ◽  
Lag Period ◽  
The One ◽  
Time Required

The exchange of radiophosphonis between water on the one hand and Artemia, Gammarus, and microorganisms on the other was observed. Results are expressed as turnover time, which is related to the rate at which phosphorus moves back and forth, being defined as the time required for as much material as is present to enter or leave a phase of the system. Tt for Arlemia is 14 hours; for Gammarus 43 hours; the equilibrium between organic and inorganic phosphorus in the presence of microorganisms has a Tt of 19 hours. In Gammarus there is a lag period of a few hours before they reach a maximal uptake rate. Gammarus, treated with terramycin to kill bacteria, do not remove appreciable quantities of radiophosphorus from water. Evidently they must acquire their phosphorus from particulate matter, such as bacteria.

scholarly journals Potassium chloride fertilization of potatoes: nutrient uptake rate and tuber yield of cultivars Ágata and Atlantic

2020 ◽  
Vol 38 (4) ◽  
pp. 400-406
Author(s):  
José Magno Q Luz ◽  
Roberta C Oliveira ◽  
Regina Maria Q Lana ◽  
João Ricardo R Silva ◽  
Tiyoko Nair H Rebouças
Keyword(s):  
Experimental Design ◽  
Uptake Rate ◽  
Tuber Yield ◽  
Application Rate ◽  
Potassium Fertilizer ◽  
Fertilizer Use ◽  
Use Efficiency ◽  
Nutrient Uptake Rate ◽  
Cultivar Atlantic ◽  
The Relationship

ABSTRACT Potassium (K) is the nutrient taken up in the greatest quantity by the potato plant. Obtaining information about the relationship between tuber yield and K application rate allows improvements in fertilizer use efficiency. We aimed to evaluate the variation in potassium fertilizer doses in uptake rate of other nutrients and in potato tuber yield. The experiments were carried out in Unaí-MG testing cultivars Ágata and Atlantic and in Mucugê-BA evaluating cultivar Ágata. The experimental design used was randomized blocks. We studied the rates of 0; 70; 110; 220, and 450 kg ha-1 K2O. The increase in K rate reduced the levels of S, Ca, Mg and B in Atlantic-Unaí, Ca, Mg, Zn and B in Ágata-Unaí and S, Fe and B in Ágata-Mucugê. The cultivar Atlantic-Unaí did not respond to the increase of potassium fertilizer dose, with a total of 32.3 to 37 t ha-1. Cultivars Ágata-Unaí and Ágata-Mucugê responded to rates estimated at 225 and 166 kg ha-1 K2O with the highest productivities of 53.9 and 56.2 t ha-1, respectively.

Exploitation of Nutrient-Rich Soil Patches by Invasive Annual and Native Perennial Grasses

2010 ◽  
Vol 3 (2) ◽  
pp. 169-177 ◽  
Author(s):  
Jeremy J. James ◽  
L. Ziegenhagen ◽  
Z. T. Aanderud
Keyword(s):  
Nutrient Uptake ◽  
Uptake Rate ◽  
Native Species ◽  
Perennial Grasses ◽  
Nutrient Distribution ◽  
Common Time ◽  
Heterogeneous Soils ◽  
Nitrogen Uptake Rate ◽  
Nutrient Uptake Rate ◽  
Slow Growing

AbstractInvasion of nutrient-poor habitats might be related to the ability of a species to exploit nutrient-rich microsites. Recent research suggests fast-growing species might have a greater ability to allocate root biomass to nutrient-rich microsites (root foraging precision) than slow-growing species. We examined if differences in relative growth rate (RGR) between invasive and native species were related to differences in foraging precision. We hypothesized that invasive species would: (1) have greater foraging precision than native species but (2) greater foraging precision would come at a cost in terms of root nutrient uptake rate. Foraging precision was evaluated on plants growing in soils with uniform or patchy nutrient distribution. Plants were harvested at a common time and a common developmental stage to separate indirect effects of RGR on foraging. Nutrient uptake rate was examined by exposing plants to a low or high nitrogen pulse. Invasives foraged more precisely than natives but had lower nitrogen uptake rate. Although these results support the idea of a positive relationship between RGR and foraging precision, biomass production in heterogeneous soils showed no relationship to foraging precision. Instead, species with greater RGR produced more biomass and root length across all treatments, allowing greater nutrient capture in heterogeneous soils. Although these results do not exclude a role for proliferation in influencing invasion of nutrient-poor systems or the potential for heterogeneity to influence population processes, these results suggest other traits may have an overriding importance in determining invader success in these systems.

scholarly journals Relationship between the Weekly Nutrient Uptake Rate during Fruiting Stages and Fruit Weight of Tomato (Lycopersicon esculentum Mill.) Grown Hydroponically

2004 ◽  
Vol 73 (4) ◽  
pp. 324-329 ◽  
Author(s):  
Satoshi Terabayashi ◽  
Isao Muramatsu ◽  
Seiji Tokutani ◽  
Masaaki Ando ◽  
Eriko Kitagawa ◽  
...  
Keyword(s):  
Lycopersicon Esculentum ◽  
Nutrient Uptake ◽  
Uptake Rate ◽  
Fruit Weight ◽  
Lycopersicon Esculentum Mill ◽  
Nutrient Uptake Rate

Responses of Stream Periphyton and Benthic Insects to Increases in Dissolved Inorganic Phosphorus in a Mesocosm

1991 ◽  
Vol 48 (11) ◽  
pp. 2061-2072 ◽  
Author(s):  
J. H. Mundie ◽  
K. S. Simpson ◽  
C. J. Perrin
Keyword(s):  
Chlorophyll A ◽  
Inorganic Phosphorus ◽  
Size Distributions ◽  
Size Selection ◽  
Periphytic Algae ◽  
Benthic Insects ◽  
Stream Periphyton ◽  
Dissolved Inorganic Phosphorus ◽  
Emerging Insects

Responses of stream periphytic algae and benthic insects to increases in dissolved inorganic phosphorus (P) were assessed in a streamside mesocosm. Controls and treatments were colonized continuously in summer by biota from the stream. P was maintained in the treatments at 10 μg∙L−1, [Formula: see text] times the concentration in the controls. In the treatments the biomass of chlorophyll a reached 3.5 times that of the controls, accompanied by an increase in Cyanophyta relative to diatoms. No difference was detectable in the numbers of insects drifting from controls and treatments. Numbers of individuals emerging (> 40 species) from the treatments over 7 wk were 2.2 times those from the controls. In both controls and treatments, 77% or more of emerging insects were Chironomidae. After week 7 the density of benthic insects in the treatments, determined without size selection, was 1.75 times that of the controls; size distributions in treatments and controls were similar. Addition of P, therefore, increased the food of insects and resulted in a doubling of their survival to emergence.

Using the Williams Equation to Evaluate Nutrient Uptake Rate by Intact Plants

1994 ◽  
Vol 86 (1) ◽  
pp. 107-110 ◽  
Author(s):  
Moshe Silberbush ◽  
Edward E. Gbur
Keyword(s):  
Nutrient Uptake ◽  
Uptake Rate ◽  
Intact Plants ◽  
Nutrient Uptake Rate

scholarly journals Plant development and nutrient uptake rate in Dendrobium nobile Lindl

2018 ◽  
Vol 41 (15) ◽  
pp. 1937-1945
Author(s):  
Juliana Garcia dos Santos Ichinose ◽  
Cibele Mantovani ◽  
Renata Bachin Mazzini-Guedes ◽  
Kathia Fernandes Lopes Pivetta ◽  
Ricardo Tadeu de Faria ◽  
...  
Keyword(s):  
Nutrient Uptake ◽  
Plant Development ◽  
Uptake Rate ◽  
Dendrobium Nobile ◽  
Nutrient Uptake Rate ◽  
Dendrobium Nobile Lindl
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