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Plant elemental content can vary up to 1,000-fold across grasslands, with implications for the herbivores the plants feed. We contrast the regulation, in grasses and forbs, of 12 elements essential to plants and animals (henceforth plant-essential), 7 essential to animals but not plants (animal-essential) and 6 with no known metabolic function (nonessential). Four hypotheses accounted for up to two thirds of the variation in grass and forb ionomes across 54 North American grasslands. Consistent with the supply-side hypothesis, the plant-essential ionome of both forbs and grasses tracked soil availability. Grass ionomes were more likely to harvest even nonessential elements like Cd and Sr. Consistent with the grazing hypothesis, cattle-grazed grasslands also accumulated a handful of metals like Cu and Cr. Consistent with the NP-catalysis hypothesis, increases in the macronutrients N and P in grasses were associated with higher densities of cofactors like Zn and Cu. The plant-essential elements of forbs, in contrast, consistently varied as per the nutrient-dilution hypothesis—there was a decrease in elemental parts per million with increasing local carbohydrate production. Combined, these data fit a working hypothesis that grasses maintain lower elemental densities and survive on nutrient-poor patches by opportunistically harvesting soil nutrients. In contrast, nutrient-rich forbs use episodes of high precipitation and temperature to build new carbohydrate biomass, raising leaves higher to compete for light, but diluting the nutrient content in every bite of tissue. Herbivores of forbs may thus be particularly prone to increases in pCO₂ via nutrient dilution.

Corn ( Zea mays ) biomass accumulation and nutrient uptake by the six-leaf collar (V6) growth stage are low, and therefore, synchronizing nutrient supply with crop demand could potentially minimize nutrient loss and improve nutrient use efficiency. Knowledge of corn’s response to nutrient stress in the early growth stages could inform such nutrient management. Field studies were conducted to assess corn recovery from when no fertilizer application is made until the V6 growth stage, and thereafter, applying fertilizer rates as those in non-stressed conditions. The early season nutrient stress and non-stress conditions received the same amount of nutrients. As the availability of nutrients for plant uptake is largely dependent on soil moisture, corn recovery from the early season nutrient stress was assessed under different soil moisture regimes induced via irrigation scheduling at 50% and 80% field capacity under overhead and subsurface drip irrigation (SSDI) systems. Peanut ( Arachis hypogaea ) was the previous crop under all conditions, and the fields were under cereal rye ( Secale cereale ) cover crop prior to planting corn. At the V6 growth stage, the nutrient concentrations of the early season-stressed crops, except for copper, were above the minimum threshold of sufficiency ranges reported for corn. However, the crops showed poor growth, with biomass accumulation being reduced by over 50% compared to non-stressed crops. Also, the uptake of all nutrients was significantly lower under the early season nutrient stress conditions. The recovery of corn from the early season nutrient stress was low. Compared to non-stress conditions, the early season nutrient stress caused 1.58 Mg ha -1 to 3.4 Mg ha -1 yield reduction. The percent yield reduction under the SSDI system was 37.6-38.2% and that under the overhead irrigation system was 11.7-13%. The high yield reduction from the early season nutrient stress under the SSDI system was because of water stress conditions in the topsoil soil layer. The findings of the study suggest ample nutrient supply in the early season growth stage is critical for corn production, and thus, further studies are recommended to determine the optimum nutrient supply for corn at the initial growth stages.

Feather pecking (FP) in laying hens remains an important economic and welfare issue. This paper reviews the literature on causes of FP in laying hens. With the ban on conventional cages in the EU from 2012 and the expected future ban on beak trimming in many European countries, addressing this welfare issue has become more pressing than ever. The aim of this review paper is to provide a detailed overview of underlying principles of FP. FP is affected by many different factors and any approach to prevent or reduce FP in commercial flocks should acknowledge that fact and use a multifactorial approach to address this issue. Two forms of FP can be distinguished: gentle FP and severe FP. Severe FP causes the most welfare issues in commercial flocks. Severe FP is clearly related to feeding and foraging behaviour and its development seems to be enhanced in conditions where birds have difficulty in coping with environmental stressors. Stimulating feeding and foraging behaviour by providing high-fibre diets and suitable litter from an early age onwards, and controlling fear and stress levels through genetic selection, reducing maternal stress and improving the stockmanship skills of the farmer, together offer the best prospect for preventing or controlling FP.

A nutrient dilution effect of diets high in added sugar has been reported in some older populations, but the evidence is inconsistent. The aim of this study was to investigate the association between added sugar intakes (according to recommended guidelines) and nutrient intake, food consumption, and body mass index (BMI). A cross-sectional analysis of data collected between 2007 and 2009 from participants of the Blue Mountains Eye study 4 was performed (n = 879). Dietary intake was assessed using a semiquantitative food frequency questionnaire. Added sugar content of foods was determined by applying a systematic step-wise method. BMI was calculated from measured weight and height. Food and nutrient intakes and BMI were assessed according to categories of percentage energy from added sugar (EAS% < 5%, EAS% = 5%–10%, and EAS% >10%) using analysis of covariance for multivariate analysis. Micronutrient intake including retinol equivalents, vitamins B6, B12, C, E, and D, and minerals including calcium, iron, and magnesium showed a significant inverse association with EAS% intakes (Ptrend < 0.05). In people with the lowest intake of added sugars (<5% energy) intake of alcohol, fruits, and vegetables were higher and intake of sugar sweetened beverages was lower compared to other participants (all Ptrend < 0.001). BMI was similar between the three EAS% categories. Energy intake from added sugar greater than the recommended level of 10% is associated with lower micronutrient intakes, indicating micronutrient dilution. Conversely, added sugar intakes <5% of energy intake are associated with higher micronutrient intakes. This information may inform dietary messages targeted at optimizing diet quality in older adults. •We assessed the association between added sugar, food, and nutrient intake in older Australians.•High added sugar consumers had higher energy intake than low added sugar consumers.•Consumers with higher added sugar intake had lower protein, vitamin C, vitamin E, and zinc intake.•Consumers with low added sugar intake had higher amounts of alcohol, fruit, vegetable, and fish.

Phenolic compounds represent a broad and structurally diverse class of plant secondary metabolites with importance for both plant biology and human health. This review provides a comprehensive overview of their biosynthesis, chemical diversity, multifaceted functions in plants, roles in the wider ecosystem, and significance in human nutrition and biotechnology. Primarily synthesized via the phenylpropanoid pathway, these compounds encompass major classes such as lignin, flavonoids, and tannins. Within the plant, they perform critical functions including providing structural support (lignin), defending against biotic stresses (e.g., pathogens, herbivores), mediating ecological interactions (pollination, symbiosis, allelopathy), and protecting against abiotic stresses like UV radiation and oxidative damage. Phenolic compounds extend their influence beyond the plant itself by shaping soil ecosystems through rhizodeposition, where they interact with microbial communities and nutrient cycles. At the same time, they play a central role in the health benefits of plant-rich diets, with strong epidemiological evidence linking their regular consumption to a reduced risk of chronic diseases such as cardiovascular disease, cancer, and obesity. The review further examines the significant variation of phenolic content in different food sources and explores the impact of processing methods, highlighting germination as a key strategy for enhancing the nutritional and bioactive value of cereals and legumes. Finally, the potential of phenolic compounds as a source for modern drugs and their targeted production through biotechnological approaches are discussed, underscoring their position as a cornerstone of phytochemical research with ongoing and future applications in health, agriculture, and industry. This paper employs a semi-systematic (or narrative) literature review methodology. A strategic search of key academic databases, including PubMed, Scopus, Web of Science, Google Scholar, was conducted to identify relevant literature and highly influential works. This review aims to synthesize the existing knowledge on phenolic compounds and to emphasize their undeniable impact on human health through an interdisciplinary approach.

Forage quality is a key property of grassland ecosystems. In this study, grassland forage qualities were measured at 373 sampling sites throughout Guizhou Province in the karst mountain region of Southwest China, and the factors affecting it were explored. The forage quality level of most plant species was categorized into four levels: (1) preferred forage species; (2) desirable forage species; (3) consumed but undesirable forage species; and (4) non-consumable or toxic forage species. High temperature and precipitation appeared to facilitate the growth of preferred forage species, but limited the growth of other plants. Increasing soil pH had a positive impact on the number and biomass of preferred forage plants, but a negative influence on other plants, especially non-consumable or toxic plants. Both GDP and population density had a positive correlation with the number and biomass of preferred forage species, while such correlations for other levels of forage species tended to be negative. Grazing could lead to a decrease in the preferred forage species. Therefore, it is suggested that by focusing on soil improvement in grassland and maintaining an appropriate grazing intensity, global warming and rapid economic growth in Guizhou Province will likely contribute to increase the forage quality of karst grasslands in Southwest China.

Phytoplankton functional groups have gained increasing attention in recent years. To understand the composition of phytoplankton functional groups in Poyang Lake and their drivers, field investigations were conducted over three years: 2013, 2014, and 2016. Phytoplankton were dominated by diatoms, contributing from 20.19% to 57.57% of the total biomass, followed by cyanobacteria, 9.81%–39.98%. Microcystis sp. and Anabaena sp. were the dominant species among cyanobacteria. Twenty-six functional groups were identified among 72 genera or species, and fiver groups (P, B, MP, H1, and G) were categorized dominant. All of dominant groups except H1 were tolerate highly fluctuating mixing intensities and showed a typical monthly succession variation. Water temperature, water level, and nutrients are key drivers for the variation of phytoplankton communities at taxonomic and functional levels. Both of redundancy and variation partitioning analyses showed that environmental variables might explain functional groups better than taxonomic communities, implying that the functional groups were more advantageous in showing the effects of environmental conditions than taxonomic compositions. Hydrological conditions have a crucial influence on phytoplankton assemblage dynamics in highly variable water regime lakes, but not in the largest ones. The functional groups method is suitable for identifying the spatial and seasonal characteristics of aquatic environments that significantly affected by water regimes.

This analysis aimed to examine the association between intake of sugars (total or added) and nutrient intake with data from a recent Australian national nutrition survey, the 2007 Australian National Children’s Nutrition and Physical Activity Survey (2007ANCNPAS). Data from participants (n 4140; 51 % male) who provided 2×plausible 24-h recalls were included in the analysis. The values on added sugars for foods were estimated using a previously published ten-step systematic methodology. Reported intakes of nutrients and foods defined in the 2007ANCNPAS were analysed by age- and sex-specific quintiles of %energy from added sugars (%EAS) or %energy from total sugars (%ETS) using ANCOVA. Linear trends across the quintiles were examined using multiple linear regression. Logistic regression analysis was used to calculate the OR of not meeting a specified nutrient reference values for Australia and New Zealand per unit in %EAS or %ETS. Analyses were adjusted for age, sex, BMI z-score and total energy intake. Small but significant negative associations were seen between %EAS and the intakes of most nutrient intakes (all P<0·001). For %ETS the associations with nutrient intakes were inconsistent; even then they were smaller than that for %EAS. In general, higher intakes of added sugars were associated with lower intakes of most nutrient-rich, ‘core’ food groups and higher intakes of energy-dense, nutrient-poor ‘extra’ foods. In conclusion, assessing intakes of added sugars may be a better approach for addressing issues of diet quality compared with intakes of total sugars.

Objectives: To investigate the association between added sugar and macronutrient and micronutrient intakes, and to assess whether added sugar intake is related to biochemical indices of nutritional status, Mini-Nutritional Assessment (MNA) score, body mass index (BMI) and performance on physical function tests. Design: A cross-sectional, analytical study. Setting and subjects: Convenient sample of 285 institutionalised and community-dwelling black South African men and women aged 60+ y. Methods: An interviewer-administered 24-h dietary recall and MNA were performed. Serum albumin, vitamin B 12 , ferritin, cholesterol, haemoglobin, red blood cell (RBC) folate and plasma vitamin C were measured. Handgrip strength, BMI, ‘sit-to-stand’ and ‘get-up-and-go’ tests were measured. Outcome variables were analysed according to tertiles of added sugar, in grams and as a percentage of total energy (% E). Results: In each tertile of sugar intake, mean MNA score fell in the ‘at-risk’ classification. In women, energy, protein, % E protein, fibre, thiamin, riboflavin, niacin, vitamin B6, folate, pantothenic acid, biotin, vitamin C, calcium, iron, magnesium, phosphorus, zinc, copper and selenium intake were significantly lowest in subjects in the highest % E sugar tertile. In men, no differences were found for micronutrient intake according to tertiles of total added sugar or % E added sugar. Physical function declined with increasing sugar intake, and suboptimal RBC folate and plasma ascorbic acid status was associated with increasing sugar intake (in women). No relationship was found between added sugar intake and the very high prevalence (65%) of obesity in women. Conclusion: A nutrient-diluting effect of added sugars intake was demonstrated in elderly black South African women. Further studies in this population are required in order to develop food-based dietary guidelines, which include messages on added sugar intake.

Alternative assumptions about the utilization of stored nitrogen are used to derive two different models for predicting how the growth rate of both the whole plant and its shoot vary with their respective total-N concentrations following interruption of the external N supply. Model 1 predicts that plant growth should follow monomolecular kinetics after the supply is interrupted, with the resulting relative growth rates linearly related to total-N concentration. Model 2 predicts that plants grow logistically once N is withheld, with their relative growth rates varying linearly with the reciprocal of total-N concentration. The versions of the models derived for the shoot are similar to those for the whole plant, but include an additional term to allow for transfer of N to the roots as deficiency increases. Tests of the models were carried out using data from N interruption experiments with young cabbage and lettuce plants (containing either high or low nitrate concentrations) which were grown hydroponically in nutrient recirculating units. The results showed that there was little statistical difference between the fits of the two models to the growth data over the range tested, but that model 1 was unsatisfactory because the estimates of its parameters were inconsistent with assumptions about the physiological processes controlling growth, and because its predictions became unrealistic when extrapolated to conditions of acute N deficiency. Model 2 did not suffer from either of these problems and provided a better mechanistic interpretation of the data, yielding predictions that were in close agreement with the observed relationship between relative growth rate and total-N concentration for both the whole plant and its shoot. The curvilinear form of this relationship for model 2 differs from the linear form of other models derived from measurements in experiments where there was a continuing but restricted supply of external N to plants. This implies that the relationship between relative growth rate and total-N concentration may vary depending on whether or not a plant has to rely entirely on its internal reserves of N in times of shortage. The results also showed that the size of these reserves governed the amounts of N transferred to the roots as deficiency developed. Transfer of N was greater in cabbage than lettuce because of a greater capacity to adapt by increasing root growth at the expense of the shoot.Copyright 1994, 1999 Academic Press