scholarly journals A model for variable phytoplankton stoichiometry based on cell protein regulation

2013 ◽  
Vol 10 (6) ◽  
pp. 4341-4356 ◽  
Author(s):  
J. A. Bonachela ◽  
S. D. Allison ◽  
A. C. Martiny ◽  
S. A. Levin
Keyword(s):  
Physiological State ◽  
Single Point ◽  
Nutrient Content ◽  
Growth Conditions ◽  
Marine Phytoplankton ◽  
Cell Protein ◽  
Nitrogen And Phosphorus ◽  
Elemental Ratios ◽  
Regulatory Processes ◽  
Complex Interactions

Abstract. The elemental ratios of marine phytoplankton emerge from complex interactions between the biotic and abiotic components of the ocean, and reflect the plastic response of individuals to changes in their environment. The stoichiometry of phytoplankton is, thus, dynamic and dependent on the physiological state of the cell. We present a theoretical model for the dynamics of the carbon, nitrogen and phosphorus contents of a phytoplankton population. By representing the regulatory processes controlling nutrient uptake, and focusing on the relation between nutrient content and protein synthesis, our model qualitatively replicates existing experimental observations for nutrient content and ratios. The population described by our model takes up nutrients in proportions that match the input ratios for a broad range of growth conditions. In addition, there are two zones of single-nutrient limitation separated by a wide zone of co-limitation. Within the co-limitation zone, a single point can be identified where nutrients are supplied in an optimal ratio. When different species compete, the existence of a wide co-limitation zone implies a more complex pattern of coexistence and exclusion compared to previous model predictions. However, additional comprehensive laboratory experiments are needed to test our predictions. Our model contributes to the understanding of the global cycles of oceanic nitrogen and phosphorus, as well as the elemental ratios of these nutrients in phytoplankton populations.

scholarly journals A model for variable phytoplankton stoichiometry based on cell protein regulation

2013 ◽  
Vol 10 (2) ◽  
pp. 3241-3279
Author(s):  
J. A. Bonachela ◽  
S. D. Allison ◽  
A. C. Martiny ◽  
S. A. Levin
Keyword(s):  
Physiological State ◽  
Single Point ◽  
Nutrient Content ◽  
Growth Conditions ◽  
Marine Phytoplankton ◽  
Cell Protein ◽  
Nitrogen And Phosphorus ◽  
Elemental Ratios ◽  
Regulatory Processes ◽  
Complex Interactions

Abstract. The elemental ratios of marine phytoplankton emerge from complex interactions between the biotic and abiotic components of the ocean, and reflect the plastic response of individuals to changes in their environment. The stoichiometry of phytoplankton is, thus, dynamic and dependent on the physiological state of the cell. We present a theoretical model for the dynamics of the carbon, nitrogen and phosphorus contents of a phytoplankton population. By representing the regulatory processes controlling nutrient uptake, and focusing on the relation between nutrient content and protein synthesis, our model qualitatively replicates existing experimental observations for nutrient content and ratios. The population described by our model takes up nutrients in proportions that match the input ratios for a broad range of growth conditions. In addition, there are two zones of single-nutrient limitation separated by a wide zone of co-limitation. Within the co-limitation zone, a single point can be identified where nutrients are supplied in an optimal ratio. The existence of a wide co-limitation zone affects the standard picture for species competing for nitrogen and phosphorus, which shows here a much richer pattern. However, additional comprehensive laboratory experiments are needed to test our predictions. Our model contributes to the understanding of the global cycles of oceanic nitrogen and phosphorus, as well as the elemental ratios of these nutrients in phytoplankton populations.

scholarly journals Varying influence of phytoplankton biodiversity and stoichiometric plasticity on bulk particulate stoichiometry across ocean basins

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Michael W. Lomas ◽  
Steven E. Baer ◽  
Celine Mouginot ◽  
Kristina X. Terpis ◽  
Debra A. Lomas ◽  
...  
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Nutrient Content ◽  
Taxonomic Composition ◽  
Nitrogen And Phosphorus ◽  
Elemental Ratios ◽  
Carbon Cycles ◽  
The North ◽  
Suspended Particulate ◽  
Stoichiometric Ratios

AbstractConcentrations and elemental ratios of suspended particulate organic matter influence many biogeochemical processes in the ocean, including patterns of phytoplankton nutrient limitation and links between carbon, nitrogen and phosphorus cycles. Here we present direct measurements of cellular nutrient content and stoichiometric ratios for discrete phytoplankton populations spanning broad environmental conditions across several ocean basins. Median cellular carbon-to-phosphorus and nitrogen-to-phosphorus ratios were positively correlated with vertical nitrate-to-phosphate flux for all phytoplankton groups and were consistently higher for cyanobacteria than eukaryotes. Light and temperature were inconsistent predictors of stoichiometric ratios. Across nutrient-rich and phosphorus-stressed biomes in the North Atlantic, but not in the nitrogen-stressed tropical North Pacific, we find that a combination of taxonomic composition and environmental acclimation best predict bulk particulate organic matter composition. Our findings demonstrate the central role of plankton biodiversity and plasticity in controlling linkages between ocean nutrient and carbon cycles in some regions.

scholarly journals Leaf Nutrient Relations of Cycads in a Common Garden

2021 ◽  
Vol 14 ◽  
pp. 194008292110365
Author(s):  
Thomas E. Marler ◽  
Anders J. Lindström
Keyword(s):  
Common Garden ◽  
Nutrient Content ◽  
Leaf Traits ◽  
Botanical Garden ◽  
Active Management ◽  
Nitrogen And Phosphorus ◽  
Representative Species ◽  
Nutrient Relations ◽  
Homogeneous Environment ◽  
Dry Combustion

Background and Aims Research required to clarify leaf nutrient relations of cycad species has been inadequate. Common garden studies are useful for determining the influence of genetics on leaf traits because of the homogeneous environment among experimental units. To date, there have been no common garden studies which included all ten genera of cycads. The full phylogenetic breadth has, therefore, not been included in this important area of study. Methods We examined macronutrient and micronutrient content of leaves from one representative species from each of the ten cycad genera at Nong Nooch Tropical Botanical Garden in Thailand. Nitrogen content was determined by dry combustion, and the remaining nutrients were quantified by spectrometry. Results The least variable elements were nitrogen and phosphorus, and the most variable elements were boron and sodium. Nutrient content based on leaflet area was more variable than based on leaflet mass, reflecting species differences in specific leaf area. There were no universal macronutrient or micronutrient signals indicating clear phylogenetic distinctions. Implications for Conservation: Active management of threatened cycad taxa requires research to develop the knowledge to enable evidence-based decisions. This common garden study inclusive of all 10 cycad genera creates a foundation to determine leaf nutrient sufficiency ranges to inform management decisions.

scholarly journals Phytoplankton community structure in Menjer Lake, Central Java

2021 ◽  
Vol 869 (1) ◽  
pp. 012037
Author(s):  
F Sulawesty ◽  
G P Yoga ◽  
L Subehi ◽  
R Rosidah
Keyword(s):  
Community Structure ◽  
Phytoplankton Community ◽  
Diversity Index ◽  
Nutrient Content ◽  
Cell Counting ◽  
Phytoplankton Community Structure ◽  
Nitrogen And Phosphorus ◽  
Central Java ◽  
Phytoplankton Communities ◽  
Ecological Pressure

Abstract The occurrence of land changes around Lake Menjer, Central Java Province will affect the condition of water quality subsequently will affect biota, including phytoplankton. The purposes of study was to analyze the composition and abundance of phytoplankton in Menjer Lake regarding to nutrient content i.e. nitrogen and phosphorus. Observations on the phytoplankton community were conducted in July and October 2019 at six locations in Menjer Lake. Water samples were taken at the water surface as much as 10 L filtered using plankton net. Identification was carried out under the inverted microscope Diaphot 300. The abundance was calculated using the Sedgwick Rafter cell counting (SRCC) method. Analysis of the phytoplankton community structure was derived by calculating the Diversity Index, Evenness Index, and Simpson Dominance Index. The nutrient content in Menjer Lake influences the structure of phytoplankton communities quantitatively and qualitatively. Observation showed that the diversity of phytoplankton was low and there was one species dominanted, the result explained that the phytoplankton community in Menjer Lake is unstable and there is ecological pressure on the community. It can be concluded that the improvement of environmental conditions around Menjer Lake is the basis for the sustainable management of Menjer Lake.

scholarly journals Influence of Height of Cane and Leaf Stage at Time of Sampling on Leaf-Nutrient Content of Sugarcane

1969 ◽  
Vol 44 (1) ◽  
pp. 11-15
Author(s):  
G. Samuels ◽  
S. Alers-Alers ◽  
P. Landrau, Jr.
Keyword(s):  
Nutrient Content ◽  
Leaf Nitrogen ◽  
Sampling Time ◽  
Nitrogen And Phosphorus ◽  
Leaf Sample ◽  
Leaf Stage ◽  
Fertilizer Experiment ◽  
Significant Difference ◽  
Leaf Sampling ◽  
Number Of Leaves

Leaf samples of sugarcane were taken from a fertilizer experiment at Río Piedras with varieties B. 41227 and M. 336 to determine whether the height of cane or the number of leaves present at leaf-sampling time influenced the nutrient content of the leaf sample. It was found that: 1. There was no significant difference in leaf nitrogen or potassium from cane tillers aged 3 months with heights of 12, 24, and 36 inches. 2. Variations in cane height at time of sampling did influence leaf-phosphorus values; there were increases in cane height. 3. The number of leaves present at time of sampling (7-13 weeks) did not influence leaf-nutrient values in general, except for nitrogen and phosphorus at 9 weeks of age. Here the trends of this influence with the two varieties studied were contrary.

scholarly journals Yield and Nutritional Quality of Cabbage as Affected by Nitrogen and Phosphorus Fertilization

1970 ◽  
Vol 41 (1) ◽  
pp. 41-46
Author(s):  
KMF Haque ◽  
AA Jahangir ◽  
ME Haque ◽  
RK Mondal ◽  
MAA Jahan ◽  
...  
Keyword(s):  
Block Design ◽  
Growth Yield ◽  
Nutrient Content ◽  
Phosphorus Fertilization ◽  
Fertilizer Treatment ◽  
P Fertilization ◽  
Nitrogen And Phosphorus ◽  
Titrable Acidity ◽  
Nitrogen Phosphorus

An experiment was conducted in field condition to study the effect of nitrogen-phosphorus fertilization on growth, yield and nutrient content of cabbage. The experiment was laid out in randomize block design with three replications. The yield and yield components were maximized by N3P2 fertilizer treatment. Nutrient content of cabbage varied with fertilizer treatment. The maximum amount of reducing sugar, ascorbic acid, phosphorus were found at the highest rate of N - P fertilization whereas accumulation of titrable acidity, iron, calcium were maximum at the rate of N2P2 treatment. However pH, ash content were more or less same throughout the experiment. Bangladesh J. Sci. Ind. Res. 41(1-2), 41-46, 2006

A Parsimonious Number of Growth Curves

1993 ◽  
Vol 10 (3) ◽  
pp. 132-136 ◽  
Author(s):  
Boris Zeide
Keyword(s):  
Growth Pattern ◽  
Ecological Factors ◽  
Growth Curves ◽  
Site Index ◽  
Growth Conditions ◽  
Growth Patterns ◽  
Construction Methods ◽  
Complex Interactions ◽  
Site Index Curve ◽  
Index Curve

Abstract Construction of new site index curves is often justified by a lack of growth information for a given species and site. This justification presumes that there is a one-to-one correspondence between growth pattern and stand conditions which are determined by numerous genetic and ecological factors together with their complex interactions. Because these factors are combined in an infinite number of ways, each stand is unique and needs its own site index curve. The effort required for collecting growth information would be prohibitive. This effort is also unnecessary because many existing curves coincide with each other and are, therefore, redundant. Differences in species, site, and construction methods do not prevent the appearance of the same growth patterns. These facts indicate that unique growth conditions do not mean that each stand has a unique growth pattern. Therefore, a more productive approach to growth modeling consists of distilling these patterns from existing curves and yield tables rather than piling up more new site index curves. Earlier investigations showed that the diversity in growth curves can be reduced to a small number (15-30) of growth types. The present study demonstrates that the number of types can be further reduced to 3-5 without sacrificing accuracy of growth predictions. North. J. Appl. For. 10(3):132-136.

Sulfonolipid content of Cytophaga and Flexibacter species isolated from soil and cultured under different nutrient and temperature regimes

1994 ◽  
Vol 40 (2) ◽  
pp. 132-139 ◽  
Author(s):  
R. A. Drijber ◽  
W. B. McGill
Keyword(s):  
Biochemical Marker ◽  
Narrow Range ◽  
Growth Conditions ◽  
Lipid Biomarkers ◽  
Cell Protein ◽  
G Cell ◽  
Temperature Regimes ◽  
Cell Components ◽  
Lipid Phosphate ◽  
Soil Batch

Gliding bacteria of the genera Cytophaga and Flexibacter contain an unusual sulfonolipid in their outer membrane that may be a potential biochemical marker for these organisms in soil. The precision with which a marker provides information about biomass varies with the range in marker content within the cells of the taxon under study. To evaluate this, Cytophaga and Flexibacter spp. were isolated from earthworm fecal pellets and soil, batch cultured with [35S]sulfate, and extracted for lipids. Sulfonolipid S was measured using isotope dilution techniques and lipid phosphate was determined by colorimetry. Ratios of sulfonolipid S to protein and to phospholipid P were compared among isolates grown under various conditions. Ratios of sulfonolipid S to phospholipid P from 0.22 to 0.98 confirmed sulfonolipids as major cell components of Cytophaga and Flexibacter spp. Two criteria essential to the success of sulfonolipids as a biomarker for these organisms in soil were met: (i) sulfonolipid concentration among the noncellulolytic isolates, with one exception, spanned a narrow range (40–60 μmol S/g cell protein), and (ii) this range in sulfonolipid concentration was maintained under the range of growth conditions studied here. Cellulolytic cytophagas, however, could be clearly differentiated from other Cytophaga and Flexibacter spp. on the basis of sulfonolipid content, 85–164 μmol S/g cell protein. This dichotomy in sulfonolipid content between cellulolytic and noncellulolytic isolates must be considered when interpreting data where sulfonolipids are used as a quantitative biomarker for Cytophaga and Flexibacter spp. in habitats where cellulolytic cytophagas are dominant.Key words: lipid biomarkers, cellulolytic cytophagas, Cytophaga, Flexibacter, sulfonolipids.

scholarly journals Self-Organized Superlattices in GaInAsSb Grown on Vicinal Substrates

2003 ◽  
Vol 794 ◽  
Author(s):  
C.A. Wang ◽  
C.J. Vineis ◽  
D.R. Calawa
Keyword(s):  
Deposition Temperature ◽  
Alloy Composition ◽  
Growth Conditions ◽  
Composition Modulation ◽  
Compositional Modulation ◽  
Complex Interactions ◽  
Self Organized ◽  
Natural Superlattice ◽  
Lateral Extent ◽  
Lattice Matched

ABSTRACTSelf-organized superlattices are observed in GaInAsSb epilayers grown lattice matched to vicinal GaSb substrates. The natural superlattice (NSL) is oriented at a slight angle of about 4° with respect to the vicinal (001) GaSb substrate. This vertical composition modulation is detected at the onset of growth. Layers in the NSL are continuous over the lateral extent of the substrate. Furthermore, the NSL persists throughout several microns of deposition. The NSLs have a period ranging from 10 to 30 nm, which is dependent on deposition temperature and GaInAsSb alloy composition. While the principle driving force for this type of phase separation is chemical, the mechanism for the self-organized microstructure is related to local strains associated with surface undulations. By using a substrate with surface undulations, the tilted NSL can be induced in layers with alloy compositions that normally do not exhibit this self-organized microstructure under typical growth conditions. These results underscore the complex interactions between compositional modulation and morphological perturbations.

The Effects of Estuary Dredging on Removing Nitrogen and Phosphorus in Dianchi Lake, China

2012 ◽  
Vol 518-523 ◽  
pp. 2895-2899 ◽  
Author(s):  
Ju Hong Zhan ◽  
Sha Deng ◽  
Zhao Xin Li ◽  
Yu Luo ◽  
Ting Ting Zhao ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nutrient Loading ◽  
Nutrient Content ◽  
Dianchi Lake ◽  
Nitrogen And Phosphorus ◽  
Eutrophic Lakes ◽  
Available Nitrogen ◽  
Sediment Dredging ◽  
Internal Nutrient Loading

Sediment dredging is currently the most commonly selected option for getting rid of contaminated sediments. In this study, the effects of estuary dredging on removing nitrogen and phosphorus were investigated by comparing the different vertical nutrient content between the dredged and un-dredged areas in Dianchi Lake. The results showed that the contents of total nitrogen and total phosphorus in the un-dredged areas were relatively higher than that in dredged areas. Besides, the contents of bio-available nitrogen and phosphorus represented the similar results, only a few dredged spots showed a higher potential releasing capacity. Therefore, with the reduction of internal nutrient loading, it indicated that sediment dredging might be an effective and reliable way to improve such eutrophic lakes.

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