scholarly journals A unified framework for herbivore-to-producer biomass ratio reveals the relative influence of four ecological factors

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Takehiro Kazama ◽  
Jotaro Urabe ◽  
Masato Yamamichi ◽  
Kotaro Tokita ◽  
Xuwang Yin ◽  
...  
Keyword(s):  
Ecological Factors ◽  
Nutrient Content ◽  
Volterra Equations ◽  
Unified Framework ◽  
Nutrient Contents ◽  
Multiple Factors ◽  
Biomass Ratio ◽  
Freshwater Plankton ◽  
Plankton Communities ◽  
Natural Communities

AbstractThe biomass ratio of herbivores to primary producers reflects the structure of a community. Four primary factors have been proposed to affect this ratio, including production rate, defense traits and nutrient contents of producers, and predation by carnivores. However, identifying the joint effects of these factors across natural communities has been elusive, in part because of the lack of a framework for examining their effects simultaneously. Here, we develop a framework based on Lotka–Volterra equations for examining the effects of these factors on the biomass ratio. We then utilize it to test if these factors simultaneously affect the biomass ratio of freshwater plankton communities. We found that all four factors contributed significantly to the biomass ratio, with carnivore abundance having the greatest effect, followed by producer stoichiometric nutrient content. Thus, the present framework should be useful for examining the multiple factors shaping various types of communities, both aquatic and terrestrial.

Marshland vegetation of the class Phragmito-Magnocaricetea in northwest Croatia (Krapina river valley)

Biologia ◽  
2010 ◽  
Vol 65 (1) ◽  
Author(s):  
Zvjezdana Stančić
Keyword(s):  
Plant Cover ◽  
Ecological Factors ◽  
Nutrient Content ◽  
Field Work ◽  
Life Forms ◽  
River Valley ◽  
Soil Reaction ◽  
Alien Plant ◽  
Invasive Alien Plant ◽  
Plant Life Forms

AbstractMarshland vegetation of the class Phragmito-Magnocaricetea in the Krapina river valley was investigated during 2006 and 2007, and some sporadic investigations were made earlier. Phytosociological studies were carried out in accordance with the standard Braun-Blanquet methodology. As a result of the field work, and a small amount of data from the literature, 120 relevés were collected and 18 communities were established. For the purposes of comparison, the relevés were also classified using numerical methods. The clusters obtained mostly correspond to specific associations, but do not confirm the division into traditional vegetation alliances and orders. In the analysis of the ecological factors it is established that separation of the relevés is influenced by nutrient content, soil reaction, soil moisture, depth of water, and type of management. Analysis of the plant life forms shows, in all marshland communities, a prevalence of hemicryptophytes, geophytes and hydrophytes. The most widespread marshland communities of the investigated area are: Phalaridetum arundinaceae, Phragmitetum australis and Galio palustris-Caricetum ripariae. Furthermore, Carex randalpina community is recorded for the first time in Croatia. The most threatened marshland communities could be considered to be: Carex randalpina community, Caricetum vesicariae, Leersietum oryzoidis and Oenantho-Rorippetum. They are selected because of their very small surfaces in the investigated area and the small number of known localities within the territory of Croatia. The most invasive alien plant species in the Krapina river valley is Solidago gigantea. It spreads in potential habitats of marshland vegetation, and it is recorded in the species composition of many marshland communities. For the preservation of marshland vegetation, and especially threatened types, it is necessary to maintain the water regime of the habitats, to not remove natural plant cover due to spreading of neophytes, and to provide occasional mowing and burning.

scholarly journals Effect of NPK fertilization on production and leaf nutrient content of eucalyptus minicuttings in nutrient solution

2011 ◽  
Vol 35 (1) ◽  
pp. 249-254
Author(s):  
José Pereira Carvalho Neto ◽  
Enilson de Barros Silva ◽  
Reynaldo Campos Santana ◽  
Paulo Henrique Grazziotti
Keyword(s):  
Experimental Design ◽  
Nutrient Solution ◽  
Plant Material ◽  
Management Practice ◽  
Dry Weight ◽  
Nutrient Content ◽  
Fractional Factorial ◽  
Nutrient Contents ◽  
Adequate Nutrient ◽  
Npk Fertilization

Adequate nutrient levels in plants vary according to the species or clone, age and management practice. Therefore, adjustments of the nutrient solution are often necessary according to the plant material for multiplication. This study aimed to evaluate the influence of NPK fertilization on production and leaf nutrient contents of eucalyptus cuttings in nutrient solution. The study was conducted from November 2008 to January 2009 in a greenhouse. The experimental design was completely randomized fractional factorial (4 x 4 x 4)½, with a total of 32 treatments with three replications. The treatments consisted of four doses of N (50, 100, 200 and 400 mg L-1) as urea, P (7.5, 15, 30 and 60 mg L-1) in the form of phosphoric acid and K (50, 100, 200 and 400 mg L-1) in the form of potassium chloride in the nutrient solution. Only the effect of N alone was significant for the number and dry weight of minicuttings per ministump, with a linear decreasing effect with increasing N levels. The highest number of cuttings was obtained at a dose of 50, 7.5 and 50 mg L-1 of N, P and K, respectively.

scholarly journals USE OF FISH OIL AS SUPPLEMENT TO RICE FLOUR FOR CHILDREN

2015 ◽  
Vol 2 (1) ◽  
pp. 136
Author(s):  
Ade Nugraheni ◽  
Fifi Retiaty ◽  
K Komari
Keyword(s):  
Fatty Acids ◽  
Fish Oil ◽  
Nutrient Content ◽  
Rice Flour ◽  
Food Supplement ◽  
Soy Flour ◽  
Equal Weight ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Nutrient Contents

Fish oil is a source of omega 3 fatty acids, especially DHA and EPA having health benefits, such as prevention of heart disease and improvement of brain development including vision. However, these components are susceptible to oxidative damage and its fishy smell may affect consumer acceptance. This study aimed to immobilize this oil in rice flour usually prepared for "sumsum" porridge, a traditional meals for children or mother. Some of type of polymer are mixture with oil and was sprayed on to the rice flour to ensure the oils were coated with these polymer. Hedonic test of "sumsum" porridge was performed for acceptability for 4% fish oil and 4% equal weight of polymer malto-dextrin and soy flour. The nutrient contents were also presented. The nutrient content of the sample could be use as food supplement for under-five year children and his mother. Keywords: fish oil, applement, omega 3 fatty acids 

scholarly journals Taste–nutrient relationships in commonly consumed foods

2011 ◽  
Vol 108 (1) ◽  
pp. 140-147 ◽  
Author(s):  
Mirre Viskaal van Dongen ◽  
Marjolijn C. van den Berg ◽  
Nicole Vink ◽  
Frans J. Kok ◽  
Cees de Graaf
Keyword(s):  
Cluster Analysis ◽  
Linear Regression ◽  
Protein Content ◽  
Nutrient Content ◽  
Processed Foods ◽  
Food Groups ◽  
Nutrient Contents ◽  
Sweet Foods

Taste is expected to represent a food's nutrient content. The objective was to investigate whether taste acts as nutrient-sensor, within the context of the current diet, which is high in processed foods. Intensities of the five basic tastes of fifty commonly consumed foods were rated by nineteen subjects (aged 21·0 (sd 1·7) years, BMI 21·5 (sd 2·0) kg/m2). Linear regression was used to test associations between taste and nutrient contents. Food groups based on taste were identified using cluster analysis; nutrient content was compared between food groups, using ANOVA. Sweetness was associated with mono- and disaccharides (R2 0·45, P < 0·01). Saltiness and savouriness were correlated, with r 0·92 (P < 0·01) and both were associated with Na (both: R2 0·33, P < 0·01) and protein (R2 0·27, P < 0·01 and R2 0·33, P < 0·01, respectively). Cluster analysis indicated four food groups: neutral, salty and savoury, sweet–sour and sweet foods. Mono- and disaccharide content was highest in sweet foods (P < 0·01). In salty and savoury foods, protein content (P = 0·01 with sweet–sour foods, not significant with neutral or sweet foods) and Na content (P < 0·05) were the highest. Associations were more pronounced in raw and moderately processed foods, than in highly processed foods. The findings suggest that sweetness, saltiness and savouriness signal nutrient content, particularly for simple sugars, protein and Na. In highly processed foods, however, the ability to sense nutrient content based on taste seems limited.

Development of an improved model estimating the nutrient content of the bole for four boreal tree species

1998 ◽  
Vol 28 (1) ◽  
pp. 37-43 ◽  
Author(s):  
P Rochon ◽  
D Paré ◽  
C Messier
Keyword(s):  
Populus Tremuloides ◽  
Tree Species ◽  
Picea Glauca ◽  
Nonlinear Models ◽  
Abies Balsamea ◽  
Nutrient Content ◽  
Forest Harvesting ◽  
Nutrient Concentrations ◽  
Nutrient Contents ◽  
Improved Model

An improved model for estimating nutrient contents of the commercial portion of tree boles was developed for four boreal tree species (Populus tremuloides Michx., Betula papyrifera Marsh., Picea glauca (Moench) Voss, and Abies balsamea (L.) Mill.). This model considers the spatial pattern of variation of nutrient concentrations inside the bole and its relationships with tree size. For all species-nutrient combinations, no significant pattern was found for vertical variations in nutrient concentrations, while two types of nonlinear models, using distance from the tree periphery as the independent variable, fit the pattern of horizontal (or radial) variations. These patterns of variability were used to estimate the global nutrient concentration of the bole by using mathematical integration. The values obtained with this method were generally lower, especially for large stems, than values obtained with traditional methods that do not consider the variability of nutrient concentrations inside the bole. This improved model would permit better estimates of the amounts of nutrients lost in biomass upon forest harvesting, as well as internal cycling of nutrients within the bole.

scholarly journals Quantification of nutrient content in the aboveground biomass of teak plantation in a tropical dry deciduous forest of Udaipur, India

2009 ◽  
Vol 55 (No. 6) ◽  
pp. 251-256 ◽  
Author(s):  
I. Nirmal Kumar J ◽  
N. Kumar R ◽  
R. Kumar Bhoi ◽  
R. Sajish P
Keyword(s):  
Aboveground Biomass ◽  
Dry Matter ◽  
Deciduous Forest ◽  
Nutrient Content ◽  
Total Biomass ◽  
Nutrient Contents ◽  
Teak Plantation ◽  
Dry Deciduous Forest ◽  
Crown Biomass

This study was designed to evaluate the quantification of the nutrient content of aboveground biomass of teak plantation in a tropical dry deciduous forest of Udaipur, Rajasthan, India. The nutrient contents in the total biomass of teak in the plantation were 165.47 kg/ha N, 20.96 kg/ha P, 35.06 kg/ha K, 49.29 kg/ha Ca, 31.52 kg/ha Mg, 4.27 kg/ha Na, 4.06 kg/ha S and 3.21 kg/ha Cl. In total, 42.93% of the dry matter accounted for crown biomass (leaves, branches, twigs and reproductive parts), which in turn accounts for 60.93% N, 58.63% P, 54.30% K, 51.40% Ca, 62.5% Mg, 53.62% Na, 59.85% S and 60.74% Cl of the aboveground biomass, whereas 57.07% of the dry matter account for trunk biomass (bole bark and bole wood), which in turn accounts for 39.07% N, 41.37% P, 45.70% K, 48.6% Ca, 37.5% Mg, 46.38% Na, 40.15% S and 39.26% Cl.

scholarly journals Nutritional contents in Myrciaria dubia plants in function of in Potassium doses applied through fertigation

2020 ◽  
Vol 68 (4) ◽  
pp. 291-298
Author(s):  
Carlos Abanto-Rodríguez ◽  
Edvan Alves Chagas ◽  
Wellintong Farias Araújo ◽  
João Luiz Lopes Monteiro Neto ◽  
Eduardo Medeiros de Oliveira ◽  
...  
Keyword(s):  
Dry Matter ◽  
Nutrient Content ◽  
First Year ◽  
Nutrient Contents ◽  
Myrciaria Dubia ◽  
The Mean ◽  
Cu And Zn ◽  
Leaf N

The objective in this study was to determine the nutrient contents in Myrciaria dubia plants in function of five K2O doses (0, 40, 80, 120 and 160 kg ha-1) applied through fertigation.  Leaf dry matter (LDM), total dry matter (TDM), and leaf nutrient contents were evaluated.  The LDM and TDM were higher in plants subjected to the dose of 160 kg ha-1 of K2O, with 52.44 g and 302.69 g, respectively.  Leaf N and K contents were 22.15 and 9.48 g kg-1 in response to 160 kg ha-1 of K2O.  The mean P, Ca and S contents were 1.6, 17.89 and 1.61 g kg-1, respectively, and the content of Mg2 + decreased from 5.62 to 2.74 g kg-1 at the dose of 0 and 160 kg ha-1 of K2O, respectively.  The B, Mn and Fe contents decreased from 136.5 to 100.0, 346.24 to 248, and from 142.06 to 97.35 mg kg-1 at the dose of 0 and 160 kg ha-1 of K2O, respectively.  The mean Cu and Zn contents were 3.81 and 40,54 mg kg-1, respectively, at the K2O doses.  The nutrient content determined in the leaves of M. dubia were adequate for the development of the species in the first year of cultivation, presenting the following decreasing order: N> Ca> K> Mg> P = S> Mn> B> Fe > Zn> Cu.

scholarly journals Complex Analyses of Plankton Structure and Function

2001 ◽  
Vol 1 ◽  
pp. 119-132 ◽  
Author(s):  
Karl E. Havens
Keyword(s):  
Size Structure ◽  
Experimental Studies ◽  
Structure And Function ◽  
Size Spectrum ◽  
Phytoplankton Productivity ◽  
Resource Managers ◽  
Carbon Transfer ◽  
And Function ◽  
Freshwater Plankton ◽  
Plankton Communities

This paper critically evaluates some complex methods that have been used to characterize the structure and function of freshwater plankton communities. The focus is on methods related to plankton size structure and carbon transfer. The specific methods reviewed are 1) size spectrum analysis, 2) size-fractionated phytoplankton productivity, 3) size-fractionated zooplankton grazing, 4) plankton ecological transfer efficiency, and 5) grazer effects on phytoplankton community structure. Taken together, these methods can provide information on community ecological properties that are directly related to practical issues including water quality and fisheries productivity. However, caution is warranted since application without a complete understanding of assumptions and context of the manipulations could lead to erroneous conclusions. As an example, experimental studies involving the addition or removal of zooplankton, especially when coupled with nutrient addition treatments, could provide information on the degree of consumer vs. resource control of phytoplankton. Resource managers subsequently could use this information in developing effective measures for controlling nuisance algal biomass. However, the experiments must be done critically and with sufficient safeguards and other measurements to ensure that treatments (e.g., zooplankton exclosure by screening of water) actually are successful and do not introduce other changes in the community (e.g., removal of large algae). In all of the methods described here, the investigator must take care when generalizing results and, in particular, carry out a sufficient number of replications to encompass both the major seasonal and spatial variation that occurs in the ecosystem.

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