Variations In Nutrient Concentrations Research Articles

“Wild barley serves as a source for biofortification of barley grains”

The continuing growth of the human population creates an inevitable necessity for higher crop yields, which are mandatory for the supply with adequate amounts of food. However, increasing grain yield may lead to a reduction of grain quality, such as a decline in protein and mineral nutrient concentrations causing the so-called hidden hunger. To assess the interdependence between quantity and quality and to evaluate the biofortification potential of wild barley, we conducted field studies, examining the interplay between plant development, yield, and nutrient concentrations, using HEB-YIELD, a subset of the wild barley nested association mapping population HEB-25. A huge variation of nutrient concentration in grains was obtained, since we identified lines with a more than 50% higher grain protein, iron, and zinc concentration in comparison to the recurrent parent ‘Barke’. We observed a negative relationship between grain yield and nutritional value in barley, indicated by predominantly negative correlations between yield and nutrient concentrations. Analyzing the genetic control of nutrient concentration in mature grains indicated that numerous genomic regions determine the final nutritional value of grains and wild alleles were frequently associated with higher nutrient concentrations. The targeted introgression of wild barley alleles may enable biofortification in future barley breeding.

杉木人工林下原生与引入树种叶性状变异特征

PDF HTML阅读 XML下载 导出引用 引用提醒 杉木人工林下原生与引入树种叶性状变异特征 DOI: 10.5846/stxb201809202054 作者: 作者单位: 中国林业科学研究院亚热带林业研究所,中国林业科学研究院亚热带林业研究所,中国林业科学研究院亚热带林业研究所,中国林业科学研究院亚热带林业研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家重点研发计划项目（2017YFC0505500，2017YFC0505502） Variations in leaf traits of native and introduced tree species in Cunninghamia lanceolata plantations Author: Affiliation: Research Institute of Subtropical Forestry,Chinese Academy of Forestry,Research Institute of Subtropical Forestry,Chinese Academy of Forestry,Research Institute of Subtropical Forestry,Chinese Academy of Forestry,Research Institute of Subtropical Forestry,Chinese Academy of Forestry Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:叶性状在表征植物资源利用和生存策略方面具有重要作用。构建异龄复层林是改造人工纯林的有效措施，探究引入与原生树种叶性状变异有利于林下伴生树种的筛选。研究了引入乔灌木树种（如闽楠、蚊母树等13个树种）与原生乔灌木树种（苦槠、红紫珠等6个树种）的叶片形态、光合色素、碳氮磷生态化学计量和非结构性碳水化合物特征。结果表明：（1）总体上引入与原生乔木和灌木树种的叶形态性状差异较小，原生乔木的叶长和比叶面积显著小于引入树种与原生灌木。引入与原生树种间光合色素具有显著差异，引入乔木叶绿素含量显著高于原生乔木，不同功能群植物的比叶面积.叶绿素关系格局存在策略位移现象。引入树种叶碳含量显著大于原生树种，叶氮和叶磷含量显著大于原生乔木；引入树种和原生灌木的碳、氮、磷养分含量的变异系数较大；引入与原生树种叶碳氮磷生态化学计量没有一致变化规律。引入灌木叶可溶性糖含量、原生灌木淀粉含量均显著高于乔木树种，灌木的非结构性碳水化合物总量也显著高于乔木。（2）引入与原生树种叶性状呈显著协同变化趋势。所有叶性状中，比叶面积、叶绿素含量、叶氮含量、叶磷含量在乔木和灌木中均呈极显著正相关关系。主成分分析显示，引入乔木和灌木树种的叶性状接近，引入树种与原生灌木之间叶性状差异相对较小，但与原生乔木间的叶性状差异较大。总体上引入树种的叶性状与原生树种具有趋同适应特征，但不同生活型植物叶性状在林下弱光环境中仍产生一定分异，引入灌木可能比引入乔木更适应杉木林下生境。 Abstract:Leaf traits of plants play crucial roles in determining resource utilization and survival strategies. Single-layered monoculture plantations are converted to multi-layered mixed plantations is an effective measure to improve plantation quality. To study the variation of the leaf traits of introduced and native species is beneficial to select the associated tree species under forest. This study assessed the traits of leaf morphology, photosynthetic pigments, carbon, nitrogen and phosphorus ecological stoichiometry, and non-structural carbohydrates of introduced arbors and shrubs species (such as Phoebe bournei and Distylium racemosum) and native arbors and shrubs species (such as Castanopsis sclerophylla and Callicarpa rubella). The results showed that leaf length and specific leaf area of native arbors were significantly smaller than those of the introduced species and native shrubs, and the other leaf morphological traits were little difference between introduced and native species. Photosynthetic pigment content differed markedly between the introduced and native species, and the chlorophyll content of native arbors was significantly lower than that of the introduced arbors. The relationship of specific leaf area and chlorophyll varied among different functional groups. The leaf carbon content of the introduced tree species was distinctly higher than that of the native tree species, and the leaf nitrogen and phosphorus contents were significantly higher than those of the native arbors. The coefficients of variation of nutrient contents of the introduced species and native shrubs were higher than that of the native arbors. The variations in leaf carbon, nitrogen, and phosphorus eco-stoichiometry differed in the introduced and native tree species. The soluble sugar content in the introduced shrubs and the starch content in the native shrubs were markedly higher than those of arbors, and the content of the non-structural carbohydrates in the shrubs was distinctly higher than that in the arbors. The leaf traits of the introduced and native tree species showed a significant synergistic change. For the arbor and shrub species, there was a marked positive correlation among the leaf area, chlorophyll content, and leaf nitrogen and phosphorus contents. Based on principal component analysis (PCA), the leaf traits were similar between the introduced arbors and shrubs. The differences of leaf traits were relatively smaller between introduced tree species and native shrubs, while there was a large difference between introduced tree species and native arbors. The leaf traits of introduced and native tree species showed convergent adaptation. However, the leaf traits of different life forms still had some differences in the low-light environment. The introduced shrubs may be more suitable for the understory environments in Cunninghamia lanceolata. 参考文献 相似文献 引证文献

Nutrient patches are transient and unpredictable in an unproductive mountain grassland

While plant roots respond consistently to nutrient availability under experimental conditions, our understanding of the role of such response in the field is hindered by poor knowledge of size and duration of nutrient patches there. In particular, knowledge of patch duration is critically important for understanding types of root response. We determined spatial and temporal variations in phosphate-P, nitrate-N and ammonium-N concentrations, and pH in an unproductive mountain meadow for which extensive data on fine-scale root distribution exist. We sampled soil solution weekly over 2.5 growing seasons using suction cups to in a hierarchical spatial design with the smallest grain of 3.3 cm. Overall concentrations of all studied nutrients were fairly low with occasional and short-term, but large-in-magnitude peaks, with no pronounced spatial or temporal structure at any scale. Temporal variation was much stronger than spatial variation, with both interannual differences and within-season differences playing a role. Phosphate-P was consistently highest in spring, whereas ammonium-N increased during summers. The ammonium-N, the major nitrogen source at the site, was negatively correlated with phosphate-P. Our data suggest that repeated sampling of soil solution in fixed positions is necessary to cover the entire extent of nutrient variation in the field. It shows that there are no stable nutrient patches at the fine scale, and the duration and size of nutrient patches are smaller than usual growth responses of roots. This implies that under such conditions, the best rooting strategy is homogeneous space occupation linked with fast physiological response to varying nutrient concentrations.

Nutrients in Saltmarsh Soils Are Weakly Related to those in Adjacent Coastal Waters

Saltmarshes provide a broad range of high-value ecosystem services and can be sensitive to eutrophication, but elucidating such impacts at broad spatial scales demands a better understanding of the underlying nutrient linkages between saltmarsh soil and tidal waters. We used existing water quality data and field surveys of 15 saltmarshes across a broad trophic gradient of coastal waters, but similar biogeographic setting (in Ireland) to investigate if phosphorus and nitrogen pools in saltmarsh soils are related to those in tidal water across saltmarshes. We also investigated if the strength of such relationships is inversely related to ground elevation, which approximates the degree of tidal inundation. Plant-available phosphorus and nitrogen pools in soil were related to water nutrients, albeit only weakly. We did not find any support for the moderating influence of elevation, indicating that it may be obscured by internal cycling and external sources. We also found evidence for effect of birds on the saltmarsh nutrient pool. Saltmarsh soils are unlikely to serve as general sentinels of nutrient conditions in their corresponding water bodies and may need separate assessment criteria and management tools, which in turn require disentangling localised and whole-saltmarsh sources of variation in nutrient concentrations.

Cd enrichment and nutrient variation in pine willow

Heavy metals can be enriched by some vegetables. However, it is not well known about their impacts on nutritional quality of vegetables. In this study, a kind of vegetable, pine willow (Lathyrus quinquenervius) grown hydroponically in simulated Cd contaminated culture was used to investigate both metal accumulation and its influences on nutrient content variation and growth. The results show that under Cd stress, the biomass, K, Ca, Zn and β-carotene of pine willow sprouts decreased significantly, while vitamin E and vitamin C increased slightly. Cd can be sharply enriched by pine willow shoots rather than roots. This study implies that it is absolutely necessary to remove Cd from irrigation water in order to avoid problems of both food safety and nutritional quality of pine willow sprouts.

Exploring the factors affecting carbon and nutrient concentrations in tree biomass components in natural forests, forest plantations and short rotation forestry

BackgroundCoupling biomass models with nutrient concentrations can provide sound estimations of carbon and nutrient contents, enabling the improvement of carbon and nutrient balance in forest ecosystems. Although nutrient concentrations are often assumed to be constant for some species and specific tree components, at least in mature stands, the concentrations usually vary with age, site index and even with tree density. The main objective of this study was to evaluate the sources of variation in nutrient concentrations in biomass compartments usually removed during harvesting operations, covering a range of species and management conditions: semi-natural forest, conventional forest plantations and short rotation forestry (SRF). Five species (Betula pubescens, Quercus robur, Eucalyptus globulus, Eucalyptus nitens and Populus spp.) and 14 genotypes were considered. A total of 430 trees were sampled in 61 plots to obtain 6 biomass components: leaves, twigs, thin branches, thick branches, bark and wood. Aboveground leafless biomass was pooled together for poplar. The concentrations of C, N, K, P, Ca, Mg, S, Fe, Mn, Cu, Zn and B were measured and the total biomass of each sampled tree and plot were determined. The data were analysed using boosted regression trees and conventional techniques.ResultsThe main sources of variation in nutrient concentrations were biomass component > > genotype (species) ≈ age > tree diameter. The concentrations of Ca, Mg and K were most strongly affected by genotype and age. The concentrations of P, K, Ca, Mg, S and Cu in the wood component decreased with age, whereas C concentrations increased, with a trend to reach 50% in the older trees. In the SRF, interamerican poplar and P. trichocarpa genotypes were comparatively more efficient in terms of Ca and K nutrient assimilation index (NAI) (+ 65–85%) than eucalypts, mainly because leafless biomass can be removed. In the conventional eucalypt plantations (rotation 15 years), debarking the wood at logging (savings of 225% of Ca and 254% of Mg for E. globulus) or the use of selected genotypes (savings of 45% of P and 35% of Ca) will provide wood at a relatively lower nutrient cost. Considering all the E. globulus genotypes together, the management for pulp with removal of debarked wood shows NAI values well above (× 1.7–× 3.9) the ones found for poplar or eucalypt SRF and also higher (× 1.6–× 4.0) than the ones found for oak and birch managed in medium or long rotations. The annual rates of nutrient removal were low in the native broadleaved species but the rates of available soil nutrients removed were high as compared to poplar or eucalypts. Management of native broadleaved species should consider nutrient stability through selection of the biomass compartments removed.ConclusionsThe nutrient assimilation index is higher in poplar grown under short rotation forestry management than in the other systems considered. Nutrient management of fast growing eucalyptus plantations could be improved by selecting efficient genotypes and limiting removal of wood. The values of the nutrient assimilation index are lower in the natural stands of native broadleaved species than in the other systems considered.

Nutrient dynamics and eutrophication assessment in the tropical river system of Saigon – Dongnai (southern Vietnam)

Saigon-Dongnai Rivers in Southern Vietnam is a complex lowland hydrological network of tributaries that is strongly influenced by the tidal cycles. The increasing economic, industrial and domestic developments in and around Ho Chi Minh City (HCMC) have led to serious impacts on water quality due to lack of appropriate wastewaters treatment. Drinking water production is impacted and the large aquaculture production areas may also be affected. We analyzed spatial and seasonal variability of nutrient concentrations (Phosphorus, Nitrogen and Silica) and eutrophication indicators (Organic Carbon, Chlorophyll-a and Dissolved Oxygen) based on bi-monthly monitoring during two hydrological cycles (July 2015–December 2017). Four monitoring sites were selected to assess the impact of HCMC: two upstream stations on the Saigon River and Dongnai River branches to provide the reference water quality status before reaching the urbanized area of HCMC; one monitoring station in the city center to highlight Saigon River water quality within the heart of the megacity; the fourth station downstream of the confluence to evaluate the impact of HCMC on the estuarine waters. This study points to excess nutrients in HCMC's water body with concentrations of NH4+ and PO43− averaging to 0.7 ± 0.6 mgN L−1 and 0.07 ± 0.06 mgP L−1, respectively in mean over the monitored period and rising up to 3 mgN L−1 and 0.2 mgP L−1, in extreme conditions. During the dry season, we evidenced that untreated domestic discharges leads to degradation of the Saigon River's water quality with extreme values of algal biomass (up 150 μChl-a L−1) and hypoxic conditions occurring episodically (DO < 2 mg L−1) in the heart of the megacity. Until now, eutrophication in the urban center has had no clear effect downstream because eutrophic water mass from the Saigon River is efficiently mixed with the Dongnai River and sea water masses during the successive semi-diurnal tidal cycles.

Predators buffer the effects of variation in prey nutrient content for nutrient deposition

Predator feeding behavior and digestion regulate the flow of nutrients through ecosystems by determining the fate of prey nutrients. Most predators feed on a diversity of prey items, which differ widely in traits including their nutrient content. Yet, relatively little is known of the mechanisms through which variation in prey nutrient content affects the form by which nutrients are deposited into the environment. The overall goal of this study was to test how variation in the nutrient content of prey affected the fate of nutrients following predation by an arthropod carnivore, the Carolina wolf spider Hogna carolinensis. We manipulated the macronutrient content of prey by varying the diet on which crickets were fed to produce prey treatments that differed in lipid and protein content. Nutrients were measured as both macronutrients and elements in prey and elements in excreta. We found that there was no effect of diet treatment on the amounts of elements or macronutrients in prey carcasses and excreta despite significant variation in the nutrient content of those prey. This is in contrast to studies of some aquatic systems where mass balance by consumers results in variation in excreta content depending on the nutrient content of food. Wolf spiders assimilated the majority of prey nutrients and deposited relatively small and similar amounts of nutrients following feeding. Hence, while prey can vary widely in nutrient content, our findings suggest that this variation has little effect on the amounts of nutrients deposited by predators.

Spatio-temporal dynamics in the dissolved nutrient waste plume from Norwegian salmon cage aquaculture

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 10:385-399 (2018) - DOI: https://doi.org/10.3354/aei00276 Spatio-temporal dynamics in the dissolved nutrient waste plume from Norwegian salmon cage aquaculture H. M. Jansen1,2,*, O. J. Broch3, R. Bannister1, P. Cranford4, A. Handå3, V. Husa1, Z. Jiang5, T. Strohmeier1, Ø. Strand1 1Institute of Marine Research, Nordnesgaten 50, 5005 Bergen, Norway 2Wageningen University and Research, Wageningen Marine Research (WMR), PO Box 77, 4400 AB Yerseke, The Netherlands 3SINTEF Ocean, Postboks 4762 Torgarden, 7465 Trondheim, Norway 4Fisheries and Oceans Canada, St. Andrews Biological Station, 125 Marine Science Dr., Saint Andrews, New Brunswick E5B 0E4, Canada 5Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, 106 Nanjing Road, Qingdao, Shandong Province, PR China *Corresponding author: henrice.jansen@wur.nl ABSTRACT: The aim of this study was to define the waste plume dynamics around a salmon farm in Norway. Systematic water sampling and numerical modeling were implemented to define nutrient concentrations in the upper water column at long-term (seasonal) and short-term (between and within days) time scales. Nutrient enhancement was observed for ammonium only, while the concentrations of orthophosphate and organic wastes were never higher than the background values. The spatial magnitude of cage effluent dispersion was limited. Empirical results detected enhanced concentrations up to 100 m down-current of the farm when fish biomass was high. Model results showed that the zone of influence could occasionally reach to >1000 m. In the first year of production, when fish biomass was low, no enhancement was detected, and in April and September of the following year, average ammonium concentrations were respectively 0.2 and 0.8 µM above the background concentrations. Taking the ambient seasonal variability into account, this resulted in 1.6 times higher concentrations for both sampling months. The measured short-term temporal variability in nutrient concentrations near the cages varied up to 2 times from day to day and were 3.5 times higher in the evening compared to the morning. As seasonal investigations were performed in the morning, maximum enhancement was likely underestimated. The rapid decrease in nutrient concentrations with increasing distance from the cages suggests that the farm studied here is currently not causing significant degradation of surface water quality. Results of this study contribute to evaluating the potential for ecological mitigation of waste nutrients and provide directions for design of optimized integrated multi-trophic aquaculture facilities. KEY WORDS: Atlantic salmon · Farm scale · Nutrients · Nitrogen · Integrated multi-trophic aquaculture · IMTA · Pelagic · Environmental impact Full text in pdf format Supplementary material PreviousNextCite this article as: Jansen HM, Broch OJ, Bannister R, Cranford P and others (2018) Spatio-temporal dynamics in the dissolved nutrient waste plume from Norwegian salmon cage aquaculture. Aquacult Environ Interact 10:385-399. https://doi.org/10.3354/aei00276 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 10. Online publication date: September 27, 2018 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2018 Inter-Research.

How various concentrations of nutrients affect basal redox homeostasis of fruit flies according to gender and aging.

We evaluated the effects of type of nutrients on redox status according to age and gender in Drosophila melanogaster. Flies were raised on different dose of sucrose and fixed concentration of protein containing media and separated according to their gender and age. Redox status biomarkers such as protein carbonyl groups, dityrosine, kynurenine, lipid hydroperoxides, advanced glycation end products, and Cu,Zn superoxide dismutase were assessed. We found that all of the males had higher levels of basal oxidative stress biomarkers except protein carbonyl. On the other hand, Cu,Zn-superoxide dismutase activity was elevated. We found that high concentration of sucrose leads to impaired redox status. We also observed that high protein content in sucrose-based media fecundity rate was increased and also transition to adult flies and survival ratio were decreased. Further studies are needed to focus on evaluation of the relation between median life span, nutritional mechanisms, and redox status biomarkers. PRACTICAL APPLICATIONS: Aging is characterized by functional decline in whole body system. Unfortunately, many of the life span extension strategies may lead to age-related disorders. It is widely accepted that impaired redox homeostasis is one of the signs of age-related pathophysiological changes. Due to difficulties in the establishment and validation of mimetic aging models in rodents, D. melanogaster is becoming/getting widely used model organism in gerontological studies. Currently, high protein and low carbohydrate-based nutrition regimes have become one of the most popular nutritional choice in aging population. Favorable nutrition type is considered one of the important factors for preventing age-related pathologies and promote healthy aging. In this study, we aimed to evaluate redox modulatory effects of different nutrition types as combination of various sucrose and constant protein concentration on basal redox status in D. melanogaster. Due to evolutionally conservation, we hypothesize that similar findings may be observed in aging population. Favorable nutrition type may ameliorate or postpone age-related degenerative processes and promote healthy aging.

Effect of elevated CO2 on the interaction between invasive thrips, Frankliniella occidentalis, and its host kidney bean, Phaseolus vulgaris.

Elevated CO2 can alter the leaf damage caused by insect herbivores. Frankliniella occidentalis (Pergande) is highly destructive invasive pest of crop production worldwide. To investigate how elevated CO2 affects F. occidentalis fed with Phaseolus vulgaris and, in particular, the interaction between plant defense and thrips anti-defense, nutrient content and antioxidant enzyme activity of P. vulgaris were measured, as well as the detoxifying enzyme activity of adult thrips. Elevated CO2 increased the soluble sugar, soluble protein and free amino acid content in non thrip-infested plants, and decreased superoxide dismutase (SOD) and peroxidase (POD) activity in these plants. Feeding thrips reduced the nutrient content in plants, and increased their SOD, catalase and POD activity. Variations in nutrient content and antioxidant enzyme activity in plants showed an opposite tendency over thrip feeding time. After feeding, acetylcholinesterase, carboxylesterase, and mixed-function oxidase activity in thrips increased to counter the plant defenses. Greater thrip densities induced stronger plant defenses and, in turn, detoxifying enzyme levels in thrips increased over thrip numbers. Our study revealed that F. occidentalis can induce not only an antioxidant-associated plant defense, but also detoxifying enzymes in thrips. Elevated CO2 might both enhance plant defense against thrip attack, and increase thrip anti-defense against plant defenses. © 2018 Society of Chemical Industry.

Nutrient Accumulation in Faba Bean Varieties

ABSTRACT Increasing the amount of nutrients in plant-based foods will help to improve the nutritional status of people in the World. Faba bean (Vicia faba L.) as a staple food in developing countries has the potential to provide many nutrients in human diets. The objective of this study was to characterize the nutrient concentrations in leaf, pod, and seed of faba bean varieties. A field study was conducted with six faba bean varieties. Variation in the elemental concentrations of nutrients and protein occurred among varieties and different parts of the plants. The highest concentrations of nitrogen, phosphorus, potassium, zinc, or copper and protein were in the seeds. However, the highest accumulation of calcium, magnesium, iron, or manganese was in the leaves. We recommend that faba bean can be considered as a valuable crop in the diet of nutrient-deficient consumers due to high concentration nutrients in edible parts of the plant.

Elevated nutrient concentrations in headwaters affected by drained peatland

Nutrient export from drained peatland has significant impacts on aquatic environments in Nordic catchments. Spatial information on variations in nutrient concentrations across different landscapes and land uses is needed to design measures for achieving the good ecological status of the EU Water Framework Directive. In this study we determined background concentrations in natural peatland-dominated streams and examined effects of peatland use practices on water quality in headwater catchments. We quantified sources for different elements by joint analysis of water chemistry, isotopes, and hydrology for 62 small catchments in North Ostrobothnia, Finland. Concentrations of nutrients and suspended solids were relatively high in catchments containing drained peatland. In particular, dissolved nitrogen and phosphorus concentrations were elevated during baseflow conditions when flow likely originated from deeper soil layers. Total concentrations of nutrients, suspended solids, and loss on ignition also showed elevated values, and changes in the ratio of dissolved and particulate forms, especially the C/N ratio, were observed. Past drainage had a stronger effect on organic matter and nutrients concentrations than local hydroclimate conditions. These results strongly indicate that current water protection methods are not sufficient to capture all seasonal variations in nutrient and suspended solid loads from drained peatland. Thus, more effort and actions are needed for water protection in such areas.

Interannual and seasonal effects of environmental factors on the zooplankton distribution in the solar saltern of Sfax (south-western Mediterranean sea)

Understanding interannual variation of zooplankton communities is a mean for assessment and monitoring of aquatic ecosystems. For this reason, we monitored the zooplankton community of the Sfax saltern (Tunisia) during four years (2000–2003). A multivariate method, the “STATICO analysis” was used to investigate the effect of environmental parameters on the abundance, distribution and composition of the zooplankton community according to time, in three ponds with different salinity values. The results revealed some seasonal and interannual variations of the zooplankton community. Copepods, which were the most abundant zooplankton species, were clearly influenced by the nutrient content variation (higher in spring and autumn) and the anthropogenic pollution level in each pond but their distribution was mainly related to salinity changes. In autumn, Oithona nana (Cyclopoida) proliferated in the least salty pond, Microsetella sp. (Harpacticoida) was abundant at intermediate salinity; and Harpacticus littoralis and Bryocamptus sp. (Harpacticoida) proliferated in the saltiest pond.

Determinants and constraints of fruit and vegetable consumption in Uzbekistan

Since 1991, fruit and vegetable production has been expanding in Uzbekistan. Although national supply exceeds the recommended amounts, individual-level fruit and vegetable intake remains inadequate with a strong seasonal pattern. The supply of horticultural products in Uzbekistan is characterized by seasonal fluctuations, which influence decisions on consumption via prices and other factors. Data for this paper are drawn from a food consumption survey conducted in Tashkent province. A total of 931 persons were interviewed twice - in summer 2014 and again in winter 2015. The seasonality of individual-level fruit and vegetable intake was confirmed by the survey data. Such fluctuations resulted in variations of nutrient content of consumed fruit and vegetables derived from food composition tables. Multiple linear regression analysis examined the relationships between various factors and the consumption of fruit and vegetables. Regression results showed that income, food knowledge and household size had a strong positive effect on fruit and vegetable intake among the adult population. Across all population groups, the winter season was positively associated with consumption, while age and prices had a strong negative effect. Food knowledge positively influenced nutrient intake for all the population. High income elasticity of demand was observed for children for derived nutrients. This paper adds to the discussion on the benefits of food and nutrition education among all population groups.

Construction of lake reference conditions for nutrient criteria based on system dynamics modelling

Assessment of ecological status is crucial for establishing well-defined reference conditions for a lake. In this study, a model based on System Dynamics was developed to simulate the production, transport and distribution of the nutrients in Lake Chenghai, Yunnan Province, China. Application of the proposed model with a system retrieval technique yielded the variations in nutrient concentrations and eutrophication levels under different hydraulic conditions during the past several decades. Results showed that the proposed model is capable of describing the historical process of the lake’s eutrophication after calibrating with the experimental data. The reference conditions for Lake Chenghai were proposed as follows: 0.0074–0.0091 mg/L for the total phosphorus concentration, 0.112–0.128 mg/L for the total nitrogen concentration, 0.859–1.081 ug/L for the chlorophyll a concentration, and 6.327–5.557 m for the Secci depth transparency. It provided an effective way to establish the nutrient reference conditions for the foundation of a lake’s nutrient criteria, as well as the eutrophication control standards in China.

Phytoplankton Size Structure in Association with Mesoscale Eddies off Central-Southern Chile: The Satellite Application of a Phytoplankton Size-Class Model

Understanding the influence of mesoscale and submesoscale features on the structure of phytoplankton is a key aspect in the assessment of their influence on marine biogeochemical cycling and cross-shore exchanges of plankton in Eastern Boundary Current Systems (EBCS). In this study, the spatio-temporal evolution of phytoplankton size classes (PSC) in surface waters associated with mesoscale eddies in the EBCS off central-southern Chile was analyzed. Chlorophyll-a (Chl-a) size-fractionated filtration (SFF) data from in situ samplings in coastal and coastal transition waters were used to tune a three-component (micro-, nano-, and pico-phytoplankton) model, which was then applied to total Chl-a satellite data (ESA OC-CCI product) in order to retrieve the Chl-a concentration of each PSC. A sea surface, height-based eddy-tracking algorithm was used to identify and track one cyclonic (sC) and three anticyclonic (ssAC1, ssAC2, sAC) mesoscale eddies between January 2014 and October 2015. Satellite estimates of PSC and in situ SFF Chl-a data were highly correlated (0.64 &lt; r &lt; 0.87), although uncertainty values for the microplankton fraction were moderate to high (50 to 100% depending on the metric used). The largest changes in size structure took place during the early life of eddies (~2 months), and no major differences in PSC between eddy center and periphery were found. The contribution of the microplankton fraction was ~50% (~30%) in sC and ssAC1 (ssAC2 and sAC) eddies when they were located close to the coast, while nanoplankton was dominant (~60–70%) and picoplankton almost constant (&lt;20%) throughout the lifetime of eddies. These results suggest that the three-component model, which has been mostly applied in oceanic waters, is also applicable to highly productive coastal upwelling systems. Additionally, the PSC changes within mesoscale eddies obtained by this satellite approach are in agreement with results on phytoplankton size distribution in mesoscale and submesoscale features in this region, and are most likely triggered by variations in nutrient concentrations and/or ratios during the eddies’ lifetimes.

The effects of phylogeny, life-history traits and altitude on the carbon, nitrogen, and phosphorus contents of seeds across 203 species from an alpine meadow

Seed reserves are very important to the earlier growth and survival of plants, and its variation in nutrient contents might make species to form different germination or seedlings growth strategies. Here, 203 species collected from an alpine meadow on the northeastern Qinghai-Tibet plateau were used to test the effects of phylogenetic groups, life-history traits, and altitude on carbon (C), nitrogen (N) and phosphorus (P) contents of seeds across species. The results showed that (1) seeds of Brassicaceae had the highest C content, those of Fabaceae had the highest N content, and Asteraceae had the highest P content, and family explained independently 32.7%, 46.4%, and 17.9% of the variation in C, N, and P contents of seeds, respectively; (2) the smaller seeds tended to have higher C and P contents, and seed mass explained independently 2.5% of variation in C, 4.3% in N, and 8.1% in P contents; (3) N content was explained 1% independently by life form, seeds N content of perennials was significantly higher than that of annals, but seeds C and P contents had non-significant difference between them; (4) seeds of wind-adapted species had higher N and P contents, and dispersal mode explained independently 1.7% of variation in C, 1.6% in N, and 5.6% in P contents; (5) seeds from high altitude had the highest N and P contents, and altitude explained independently 4.3% of the variation in N and 4% in P contents.

Effects of Ambient Ozone on Soybean Biophysical Variables and Mineral Nutrient Accumulation

The effects of increasing ambient ozone (O3) concentrations on food security has become a major concern as the demand for agricultural productivity is projected to increase significantly over the next several decades. In this contribution, the responses of common soybean genotypes (AK-HARROW, PI88788, DWIGHT, PANA, and WILLIAMS82) to ambient O3 are characterized using hyperspectral data and foliar biophysical, mineral nutrient concentrations and soybean yield. Specifically, leaf reflectance spectra measured at different growth stages and canopy layers were used to examine the spectral indices that were most strongly correlated with leaf physiological status. The effects of elevated O3 on six important nutrients (K, Ca, Mg, Fe, Mn and Cu) were evaluated by analyzing the variations in nutrient concentrations at two critical growth stages with increasing ambient O3 concentration using Partial Least Square Regression (PLSR). Lastly, the identified best spectral indices and the robust nutrient prediction models were extrapolated to the entire growth period to explore their ability to track the effects of ambient O3 concentrations on soybean physiology and nutrient uptake. The results showed that fluorescence yield (ΔF/Fm’) and photochemical quenching (qP) appear to be good indicators of soybean physiological responses to O3 stress that are echoed by the harvest index (HI). Newly identified normalized difference spectral index (NDSI) [R416, R2371] always had the highest correlation (R2 &gt; 0.6) with ΔF/Fm’, qP and electron transport rate (ETR, μmol m−2 s−1) compared to the published indices. Additionally, there were significant and broad spectral regions in visible and near infrared region that were well-correlated with ΔF/Fm’ and selected NDSIs that were applicable to satellite observations. The results of nutrient modeling using PLSR explained 54–87% of the variance in nutrient concentrations, and the predicted mineral nutrient accumulation throughout the growing season reflected the responses of ozone tolerant and sensitive genotypes well. NDSI [R416, R2371] demonstrated great potential in regard to its sensitivity in tracking plant physiological responses to changing ambient O3 concentrations. The outcome of this research has potential implications for development of space-based observation of large-scale crop responses to O3 damage, as well as for biotechnological breeding efforts to improve ozone tolerance under future climate scenarios.

Calcium plus magnesium indicates digestibility: the significance of the second major axis of plant chemical variation for ecological processes.

Plant variation in nutrient concentrations encompasses two major axes. The first is connected to nitrogen (N) and phosphorus (P), reflects growth rate and has been designated as the leaf economics spectrum (LES) while the second follows the gradient in calcium (Ca) and magnesium (Mg) and mirrors cell structural differences. Here, we tested in grasslands whether the sum Ca+Mg concentrations is a better indicator of digestibility than LES constituents. Structural equationmodelling revealed that the total effect size of N (0.30) on digestibility was much lower than that of Ca+Mg (0.58). The N effect originated predominantly from sampling date (biomass ageing), while the Ca+Mg effect largely from phylogenetic composition (proportion of monocots). Thus, plant variation in partially substitutable divalent cations seems to play a significant role in biomass digestion by ruminants. This finding contests, together with litter decomposition studies, the prominent role of the LES for understanding both fundamental ecological processes.