A survey of the reformulation of Australian child-oriented food products.

Changes in mass and nutrients in experimental logs of six tree species during 5 years of exposure in the three major forest production regions of southwest Western Australia were measured to determine how climate, substrate quality, and substrate size interact to regulate decomposition of woody debris in this Mediterranean-type climate. Branch (3–5 cm in diameter) and bole (10–15 cm in diameter) material of the six species was set out in representative areas of a regenerating clear-cut Eucalyptusdiversicolor F. Muell. wet sclerophyll forest, selectively cut Eucalyptusmarginata Donn ex Smith dry sclerophyll forest, and clear-cut areas of a former Pinuspinaster Aiton plantation. Experimental logs were collected at about 0.5, 2, and 5 years after placement and were separated into bark and wood components. Samples of initial material were analyzed for moisture content, water-soluble and NaOH-soluble extractives, and nutrient concentrations (N, P, K, Ca, and Mg). At each collection, moisture content and changes in mass and nutrient concentration were determined for the sample logs. Eucalyptuscalophylla R.Br, the major associate of the two native forests, lost the most mass during this time, up to 65% of the initial mass (decomposition coefficient k = 0.22 year−1). Decomposition was least in P. pinaster and E. marginata, at about 24–26% of original mass (k = 0.05 year−1 and 0.07 year−1, respectively). Mass losses were greatest in Manjimup, the wettest site, and least at Gnangara, the driest site, but differences in overall levels of decomposition were small despite the range in climatic moisture regimes. Small logs decomposed faster than large logs. Changes in nutrient concentrations occurred in all logs at all sites, indicating activity by decomposer organisms and (or) leaching losses. Nitrogen was the only element to be immobilized over the 5-year period. Mineralization rates were of the order P ≈ Ca < Mg < K. Concentrations of compounds extractable in cold water and NaOH decreased during the 5 years of exposure. Differences in decomposition rates were partly explained by initial concentrations of N only; there appeared to be no relationship between decomposition and concentration of the other elements and extractives.

Freshwater runoff during ebb flow and salt water intrusion during the flood may have a major effect on short‐term changes in nutrient (ammonium, nitrate+nitrite, phosphate, and silicate) concentrations along an estuary. Time series hourly measurements conducted in a mixed‐semidiurnal type estuary (i.e., characterized by two major lower and higher tidal levels) show that these changes are a strong function of both tidal state (e.g., low vs. high tide) and amplitude (e.g., neap vs. spring tide). In particular, the changes in nutrient concentrations are higher during ebb than during flood tide and largest between the lower low tide and the higher high tide of a spring tide. Finally, the importance of investigating simultaneously different stations along the estuarine spine is highlighted, in addition to studying the nutrient distribution based on selected salinity intervals which may reflect only the conditions at a particular tidal state.

Seasonal changes of mineral nutrients absorption and allocation in fruit of Zanthoxylum bungeanum ‘Hanyuan’ during the development

SummaryAn integrated study of changes in carbohydrates and nutrients in pecan was conducted and related to developmental changes during a growing season. Perennial woody plants exhibit marked seasonal changes in nutrient content, carbohydrate metabolism, and organ development. Information on nutrient changes may provide insight into seasonal demands and requirements and be useful in developing fertilisation regimes for this crop. Leaf and stem tissues collected at full bloom, leaf maturation, full cotyledon expansion, fruit maturation, and leaf abscission were analysed for starch, specific soluble sugars, and 11 other macro- and micro- nutrients. During leaf expansion, foliar levels of fructose and glucose declined from 12 mg g–1 DW to 5 mg g–1 DW and from 7 mg g–1 DW to 3 mg g–1 DW, respectively. After fruit maturation, stems exhibited an increase in sucrose, from 15 mg g–1 DW to 37 mg g–1 DW, and a marked decrease in starch, from 59 mg g–1 DW to 8 mg g–1 DW. Seasonal variations in elemental content indicated developmental stage-related nutrient movement. During leaf development, all nutrients accumulated in leaves, with more than a 70% increase in N, K, Ca, Mg, S, B and Fe content. During fruit development, the foliar content of many nutrients decreased, suggesting fruit are a strong sink for essential elements, as well as carbohydrates. However, nutrient changes differed with the stage of fruit development. For example, foliar concentrations of Mg and Zn decreased by 23% and 24%, respectively during cotyledon formation; while P, K, S, B, Cu and Mn levels decreased during reserve accumulation by 4, 15, 7, 12, 8 and 10%, respectively. During the period leading-up to leaf abscission, leaf nutrient resorption was observed with decreased contents of N (6%), P (14%), K (7%), Ca (7%), Mg (10%) and S (3%). Pecan leaf expansion and fruit development are critical periods, when nutrient movement can be appreciable. Maintaining adequate fertility levels during developmental periods of high nutrient demand may be important to optimise tree function. Management practices that promote late-season leaf retention would prevent nutrient losses associated with premature defoliation.

Bi-decadal changes in nutrient concentrations and ratios in marine coastal ecosystems: The case of the Arcachon bay, France

Time series changes in sea surface temperature (SST), chlorophyll a (Chl a), nutrients (PO4, NO3), and sea winds, which correlated with the passage of Typhoon Shanshan in the East/Japan Sea (EJS), are illustrated using satellite data for Chl a, SST, sea winds, and in situ data for nutrients and water temperature. The sea-surface cooling (SSC) effect by the passage of the typhoon was higher at stations nearer to the center compared to stations further from the center. The SSC effect at stations in the colder water region (on the left side of the typhoon’s track) was higher than at stations in the Tsushima Warm Current region (on the right side of the typhoon). The SSC effect continued for approximately 10 days after the passage of the typhoon. The Chl a concentration at all stations increased after the passage of the typhoon. This increase continued for a period of approximately 10 days, but the duration period at each station varied with distance from the typhoon center. Changes in Chl concentrations at stations within a 2° distance on both sides from the typhoon’s center were higher than that at other stations. The changes in Chl a by the passage of the typhoon were measured at approximately 0.3–1.0 mg/m3 along the moving path of the typhoon. Phosphate and nitrate changes were inversely correlated with the water temperature changes; the nutrient concentration increased with the passage of the typhoon. Like the changes in SST, changes in nutrient concentrations on the left side of the typhoon’s track were higher compared to those at the center and the right side.

It has been shown that perennial woody plants exhibit marked seasonal changes in nutrient content, carbon metabolism, and organ development. A knowledge of seasonal nutrient allocation and temporal accumulation patterns can be useful in the development of fertilization regimes that reflect the biology of a tree crop. Maintenance of optimum leaf nutrient status is an important priority in pecan cultural practice. However, a systematic evaluation of nutrient resorption is lacking in pecan. In this work, seasonal changes in nutrients and carbohydrates were evaluated in pecan trees grown under orchard conditions. In addition, resorption efficiencies of eight pecan cultivars were evaluated. Significant levels of resorption were observed in all essential elements, but cultivar differences were not significant. Seasonal patterns of nutrient and carbohydrate content in leaf, stem, and shoot tissue, will be presented as well as a structural evaluation of abscission zone formation.

The frequency of large wildfires in western North America has been increasing in recent decades, yet the geochemical impacts of these events are poorly understood. The multidecadal timescales of both disturbance-regime variability and ecosystem responses make it challenging to study the effects of fire on terrestrial nutrient cycling. Nonetheless, disturbance-mediated changes in nutrient concentrations could ultimately limit forest productivity over centennial to millennial time scales. Here, we use a novel approach that combines quantitative elemental analysis of lake sediments using x-ray fluorescence to assess the geochemical impacts of high-severity fires in a 6200 year long sedimentary record from a small subalpine lake in Rocky Mountain National Park, Colorado, USA. Immediately after 17 high-severity fires, the sedimentary concentrations of five elements increased (Ti, Ca, K, Al, and P), but returned to pre-fire levels within three decades. Multivariate analyses indicate that erosion of weathered mineral material from the catchment is a primary mechanism though which high-severity fires impact element cycling. A longer-term trend in sediment geochemistry was also identified over millennial time scales. This decrease in the concentrations of six elements (Al, Si, K, Ti, Mn, and Fe) over the past 6200 years may have been due to a decreased rate of high-severity fires, long-term ecosystem development, or changes in precipitation regime. Our results indicate that high-severity fire events can determine elemental concentrations in subalpine forests. The degree of variability in geochemical response across time scales suggests that shifting rates of high-severity burning can cause significant changes in key rock-derived nutrients. To our knowledge, these results are the first to reveal repeated loss of rock-derived nutrients from the terrestrial ecosystem due to high-severity fires. Understanding the future of fire-prone coniferous forests requires further documentation and quantification of this important mechanism linking fire regimes and biogeochemical cycles.

Changes in pasture nutrients over the growing season are typically not monitored but doing so may help farmers improve how effectively they utilise forage. The aim of this research was to assess the use of real-time near-infrared spectroscopy (NIRS) for monitoring seasonal changes in nutrient concentrations of different pasture types used for grazing and silage production. Three permanent pastures and three temporary ley pastures (3 years old) grazed by cattle or sheep and/or used for silage production were monitored weekly for 20 weeks from April to August 2017 in the UK. Five pasture samples per field were obtained per week for NIRS analysis and estimation of fresh and dry matter herbage cover (both kg per hectare). Herbage height was also measured each week. Permanent pastures included a diverse range of native UK grass species, and temporary ley pastures were predominantly perennial ryegrass (Lolium perenne) with either white (Trifolium repens) or red clover (Trifolium pretense). Effects of pasture type (permanent or temporary), phase of production (grazed or rested for regrowth) and month of year (April to August) on pasture nutrients (dry matter, crude protein, acid detergent fibre (ADF), neutral detergent fibre (NDF), water soluble carbohydrate (WSC), ash, digestible organic matter (DOMD) and dry matter digestibility (DMD)) were assessed by fitting a linear mixed model. Considerable variation was observed in pasture production and in the concentrations of dry matter, crude protein and WSC in pastures. This study suggests that grazing pastures to a mean height of below 7 cm results in a significantly reduced concentration of crude protein, DOMD and DMD, which may be detrimental to the grass intake and protein intake of the grazing animal. The DOMD and DMD of pasture were positively correlated with herbage height and herbage cover crude protein concentration. An approach of real-time nutrient monitoring will facilitate more timely adaptive pasture management than currently feasible for farmers. This should lead to productivity gain.

Little information on fine roots that play an important role in nutrient cycling was available in tropical rainforests. Distribution of fine root production and effects of selective logging on root biomass and nutrient content change were studied in the tropical rainforests of south-western Cameroon. Twenty five root samples were excavated in each of two soil depths (0-10 and 10-25 cm) and in each of three undisturbed forests (Ebom, Ebimimbang and Nyangong) and one disturbed forest by logging, using a square metallic frame of 25 x 25 cm and 30 cm high. Root samples were categorized in three diameter classes: fine (<2 mm), small (2-5 mm) and medium roots (5-20 mm). Root biomass of three diameter classes and nutrients (N, Ca, Mg, K, Na and P) of the two first diameter classes were determined. Results have shown that total root biomass varied from 9.62 (Ebom) to 29.88 t ha-1 (Ebimimbang); those of fine roots decreased from Nyangong (7.43 t ha-1) to Ebom (1.74 t ha-1). In the top soil, the fine root biomass was 2 to 4 time lower in Ebom (1.43 t ha-1) than in other undisturbed forests (3.28 and 5.87 t ha-1). From 70 to 80% of fine root biomass were produced in the first 10 centimeters of soil depth. Nutrient amount in fine root biomass were also lower in Ebom than in Ebimimbang and Nyangong, except the P amount (kg ha-1) which remained high in Ebom. On the contrary, no pattern of nutrient content (g kg-1) changes among forest were found, except N and P that decreased from Ebom to Nyangong. Six years after logging, its effects on root biomass and nutrient changes were not significant and during this period, root production of disturbed forest was high due to rapid regeneration of forest particularly heliophilous tree species.

Ground-level ozone (O3) pollution has been widely concerned in the world, particularly in the cities of Asia, including China. Elevated O3 concentrations have potentially influenced growth and nutrient cycling of trees in urban forest. The decomposition characteristics of urban tree litters under O3 exposure are still poorly known. Ginkgo biloba is commonly planted in the cities of northern China and is one of the main tree species in the urban forest of Shenyang, where concentrations of ground-level O3 are very high in summer. Here, we hypothesized that O3 exposure at high concentrations would alter the decomposition rate of urban tree litter. In open-top chambers (OTCs), 5-year-old G. biloba saplings were planted to investigate the impact of elevated O3 concentration (120 ppb) on changes in nutrient contents and decomposition rate of leaf litters. The results showed that elevated O3 concentration significantly increased K content (6.31 ± 0.29 vs 17.93 ± 0.40, P < 0.01) in leaves of G. biloba, significantly decreased the contents of total phenols (2.82 ± 0.93 vs 1.60 ± 0.44, P < 0.05) and soluble sugars (86.51 ± 19.57 vs 53.76 ± 2.40, P < 0.05), but did not significantly alter the contents of C, N, P, lignin and condensed tannins, compared with that in ambient air. Furthermore, percent mass remaining in litterbags after 150 days under ambient air and elevated O3 concentration was 56.0% and 52.8%, respectively. No significant difference between treatments was observed in mass remaining at any sampling date during decomposition. The losses of the nutrients in leaf litters of G. biloba showed significant seasonal differences regardless of O3 treatment. However, we found that elevated O3 concentration slowed down the leaf litter decomposition only at the early decomposition stage, but slightly accelerated the litter decomposition at the late stage (after 120 days). This study provides our understanding of the ecological processes regulating biogeochemical cycles from deciduous tree species in high-O3 urban area.

Nutrient allocation is an important aspect of plant resource uptake and use, which is related to life‐history strategies. Although to date considerable attention has focused on plant allocation of nitrogen and phosphorus, comparatively little information is available on the allocation of various other nutrients and their up‐scaling from the species to community level. We measured 10 nutrient elements in the leaves, branches and fine roots of 551 plant species growing in eight forest ecosystems in China, ranging from cold temperate to subtropical forests. We estimated the scaling relationship of multiple nutrients among plant organs at the species level and scaled‐up the relationship to the community level by combining this information with that of community structure. Nutrient allocation among plant organs was conserved in different functional groups and biomes across broad environmental gradients. Nutrient partitioning between organs with similar function tended to be isometric, whereas partitioning between organs with distinct functions tended to be allometric. The scaling relationship between above‐ and below‐ground organs remained consistent, whereas the scaling relationship within above‐ground organs changed after scaling up from the species to the community level, with the relative change in nutrients being consistently smaller in the more active organs. Synthesis. The pattern of multiple nutrient allocation among organs showed a degree of conservatism across plant functional groups and biomes, with disproportional changes in nutrient content between functionally distinct organs and a lower relative change in more active organs. This conservative strategy implies the existence of general rules that constrain plant nutrient allocation.

BackgroundDendrocalamus latiflorus is widely distributed in southern China and has high ornamental and edible value. The growth dynamics and the associations between growth and the distribution of nutrients or chemical components across various parts and stages of shoot development remain inadequately understood. In this study, tender shoots of D. latiflorus from Guangxi, China, were used to conduct experiments. During the edible growth period, the height, ground diameter, and morphology of the tender shoots were investigated, and the growth stages were classified by conducting ordered sample cluster analysis. The internal internode anatomy and nutritional/chemical components of the tender shoots at different growth stages and parts were measured and analyzed. The optimal harvesting stages and parts were determined by conducting a comprehensive analysis using the technique for order preference by similarity to the ideal solution (TOPSIS).ResultsThe height growth of D. latiflorus tender shoots lasted for 21 days and can be divided into four stages: I (0–9 d), II (10–13 d), III (14–17 d), and IV (18–21 d), while thickening growth lasted about 19 days. The moisture content of D. latiflorus tender shoots decreased as growth increased. Cell division and elongation increased the height of tender shoots. Among the four stages, cell division dominated in Stages I and II, whereas cell elongation dominated in Stages III and IV. The changes in nutrients and chemical components in different parts and stages of tender shoot development have distinct characteristics, and the differences are significant. The starch and reducing sugar contents reached a maximum value in the lower part of Stage II (10.19 mg·g–1, 18.87 mg·g–1), whereas the soluble sugar content reached a maximum value in the middle of Stage III (2.15 mg·g–1). The protein and fat contents were the highest in the upper part of Stage IV (3.84% and 4.8%). The contents of the chemical components of flavonoids and vitamin C were the highest in the middle of Stage IV (5.51 mg·g–1, 33.58 mg·100 g–1), whereas the contents of cellulose and lignin in the later part of Stage IV were the highest (9.43% and 13.67%, respectively). Stage II (10–13 d) was the best harvest stage for D. latiflorus tender shoots, according to the comprehensive TOPSIS analysis, and the comprehensive quality of the upper part was the best in this stage. Additionally, the middle part of Stage III and the lower part of Stage IV were also high quality and could also be harvested.ConclusionsThis study revealed the growth patterns of the tender shoots of D. latiflorus from morphological, anatomical, and physiological perspectives, as well as the dynamic changes in nutrient content during their growth. Within the 21-day edible stage, Stage II (10–13 days) was identified as the optimal harvesting stage, with the upper part of the shoot being the best section for harvest. This study provided a theoretical basis for further cultivating high-quality D. latiflorus for shoot production and has significant potential for increasing economic benefits.

The accumulation of nutrients in rivers is a major cause of eutrophication, and the change in nutrient content is affected by a variety of factors. Taking the River Yi as an example, this study used wavelet analysis tools to examine the periodic changes in nutrients and environmental factors, as well as the relationship between nutrients and environmental factors. The results revealed that total phosphorus (TP), total nitrogen (TN), and ammonia nitrogen (NH4+-N) exhibit multiscale oscillation features, with the dominating periods of 16-17, 26, and 57-60 months. The continuous wavelet transform revealed periodic fluctuation laws on multiple scales between nutrients and several environmental factors. Wavelet transform coherence (WTC) was performed on nutrients and environmental factors, and the results showed that temperature and dissolved oxygen (DO) have a strong influence on nutrient concentration fluctuation. The WTC revealed a weak correlation between pH and TP. On a longer period, however, pH was positively correlated with TN. The flow was found to be positively correct with N and P, while N and P were found to be negatively correct with DO and electrical conductance (EC) at different scales. In most cases, TP was negatively correlated with 5-day biochemical oxygen demand (BOD5) and permanganate index (CODMn). The correlation between TN and CODMn and BOD5 was limited, and no clear dominant phase emerged. In a nutshell, wavelet analysis revealed that water temperature, pH, DO, flow, EC, CODMn, and BOD5 had a pronounced influence on nutrient concentration in the River Yi at different time scales. In the case of the combination of environmental factors, pH and DO play the largest role in determining nutrient concentration.

This research aims to determine the nutritional content and the best treatment for the addition of Lemna sp. fermented for the growth of sangkuriang catfish. The research was conducted from February to August 2022, in Aquaculture Laboratory of the Fisheries and Marine Science Faculty, Universitas Padjadjaran. The method used in this research is experimental, and is of a Completely Randomized Design (CRD). It consists of four treatments and four repetitions, namely treatment A (control) treatment B (10% fermented lemna + 90% commercial feed), Treatment C (20% fermented lemna + 80% commercial feed), and Treatment D (30% fermented lemna + 70% commercial feed). Parameters observed were changes in nutrient content of lemna, daily growth rate, feed conversion ratio, survival rate, and water quality. Data were analyzed using ANOVA analysis of variance and if there was a significant difference, Duncan test was performed with a 95% confidence level, while changes in nutrients in lemna and water quality were analyzed descriptively. The results of the proximate analysis showed that the fermented lemna using BIOM-S probiotics experienced changes in the nutritional content, namely an increase in protein content from 25.24% to 33.66% and a decrease in crude fiber from 11.93 to 9.13%. Based on the results of this research, the treatment C (20% fermented lemna + 80% commercial feed) the best results in a daily growth rate at 1.92%/day, a feed conversion ratio at 1.41, and a survival rate of up to 97.5%.