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Kurppa, Sirpa. "Root parasitic nematodes in nursery plants imported to Finland in 1980." Agricultural and Food Science 57, no. 3 (September 1, 1985): 155–62. http://dx.doi.org/10.23986/afsci.72197.
Повний текст джерелаАнотація:
Injurious nematodes were found in 201 of the investigated 670 plant stocks of 42 imported consignments. Infections by quarantine nematodes appeared in 100 stocks of 26 consignments, 15 there of including 3 or more infected plant stocks each. Root knot nematode, Meloidogyne spp., appeared in 81 stocks, i.e. 12 % of the investigated material. The infections were found in 40 plant species, relatively often in barberry, Berberis sp., and in peony, Paeonia sp.. Among garden roses, 26 out of 167 stocks investigated were infected by root knot nematodes. Root lesion nematode, Pratylenchus penetrans (Cobb) Chitwood & Oteifa, of P. convallariae Seinhorst was found in 28 plant stocks, i.e. 4 % of the investigated material. Several Pratylenchus-infected stocks were found among roses, raspberry and barberry. Potato rot nematode, Ditylenchus destructor Thorne, was found in one rose stock and related D. myceliophagus J. B. Goodey in 12 stocks of various plants. Several ectoparasitic species were found in very low numbers. Virus vectors, Trichodorus primitivus (de Man) Micoletzky and T. viruliferus Hooper, were detected in a total of four stocks, but too few for virus transmission tests. The transmissability ofthe detected nematodes was discussed, and the risks of introduction of nematode pests to the country was re-assessed.
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Lima, Dayane de Souza, Laila Sirino de Araújo, Moacyr Cunha Filho, Francisco Sandro Rodrigues Holanda, Alceu Pedrotti, Victor Casimiro Piscoya, Thaiana Brunes Feitosa, et al. "Root biomass under different soil uses and native Cerrado in Tocantins, Brazil." Research, Society and Development 11, no. 1 (January 14, 2022): e53811125333. http://dx.doi.org/10.33448/rsd-v11i1.25333.
Повний текст джерелаАнотація:
Studies on the importance of root biomass and the effects that changes in vegetation coverage cause on carbon amount and stock are scarce, especially in the cerrado biome. Taking into account the scarcity of information about root biomass estimates, this work aimed to quantify root biomass under different land uses and native cerrado in Tocantins, Brazil. The research was conducted in different land uses: agriculture, pasture, eucalyptus and control with native cerrado forest. Six trenches with dimensions of 70 x 70 cm were opened and root biomass was collected at depths of 0-10, 10-20, 20-30, 30-40 and 40-50 cm. With the aid of a sieve, root biomass was collected and separated into fine and coarse roots. The amounts of fine and coarse root biomass showed the highest mean values of 7.7 and 12.9 g, respectively, in the eucalyptus area. Root biomass stocks were higher in the eucalyptus area, with maximum values above 3.68 Mg ha-1. Root biomass amounts and stocks were greater in eucalyptus areas, since forest areas, whether planted or native, manage to keep the environment in balance due to their long-term cycles, greater stability and low degree of disturbance.
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Shan, Fucheng, and Kevin Seaton. "Semi-sterilized Tissue Culture for Rapid Propagation of Grapevines (Vitis vinifera L.) Using Immature Cuttings." HortScience 49, no. 7 (July 2014): 949–54. http://dx.doi.org/10.21273/hortsci.49.7.949.
Повний текст джерелаАнотація:
Rapid expansion of grapevine plantings in many parts of the world has led to increased demand for desirable planting stocks. In countries that rely on importing new varieties and have strict quarantine rules, such as Australia, vines need to stay under quarantine for ≈2 years before they are released, at which time there is very limited wood available. Hence, rapid expansion of propagating stock after release is the key to multiplying up new varieties. A novel method, referred to as Semi-sterilized Tissue Culture (SSTC) using immature single-node cuttings, was established and evaluated as a way of rapid expansion of grapevine (Vitis vinifera L.) planting stock. In the SSTC method, immature single-node cuttings were surface-sterilized using methylated spirits and then cultured in the root pulsing medium [1/2 Murashige and Skoog (MS) medium supplemented with 40 μM indole-3-butyric acid (IBA)] for 24 hours. They were then planted in sterilized aerobic rooting medium (sphagnum peat:coarse river sand:perlite = 0.5:1:2) and cultured in a tissue culture room for ≈4 weeks for root initiation and development. The rooted immature single-node cuttings were then transferred to normal propagation beds in a greenhouse and potted on for acclimatization. Tube stock generated by SSTC easily acclimatized with a 15 times higher root strike rate than cutting propagation. It also took at least 50% less time than fully sterilized micropropagation methods to produce planting stocks. The advantages of the SSTC method are that it can be conducted under semisterilized conditions, avoiding degeneration and bacterial contamination problems encountered in micropropagation methods. By removing the time-consuming steps of the explant establishment, proliferation, and maintenance in vitro, the propagation process was simplified compared with conventional sterile tissue culture procedures. The SSTC procedure removed the need for high operator skill levels, reducing expense and allowing easier commercial adoption.
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Zielonka, Anna, Marek Drewnik, Łukasz Musielok, Marcin K. Dyderski, Dariusz Struzik, Grzegorz Smułek, and Katarzyna Ostapowicz. "Biotic and Abiotic Determinants of Soil Organic Matter Stock and Fine Root Biomass in Mountain Area Temperate Forests—Examples from Cambisols under European Beech, Norway Spruce and Silver Fir (Carpathians, Central Europe)." Forests 12, no. 7 (June 22, 2021): 823. http://dx.doi.org/10.3390/f12070823.
Повний текст джерелаАнотація:
Forest ecosystems significantly contribute to the global organic carbon (OC) pool, exhibiting high spatial heterogeneity in this respect. Some of the components of the OC pool in a forest (woody aboveground biomass (wAGB), coarse root biomass (CRB)) can be relatively easily estimated using readily available data from land observation and forest inventories, while some of the components of the OC pool are very difficult to determine (fine root biomass (FRB) and soil organic matter (SOM) stock). The main objectives of our study were to: (1) estimate the SOM stock; (2) estimate FRB; and (3) assess the relationship between both biotic (wAGB, forest age, foliage, stand density) and abiotic factors (climatic conditions, relief, soil properties) and SOM stocks and FRB in temperate forests in the Western Carpathians consisting of European beech, Norway spruce, and silver fir (32 forest inventory plots in total). We uncovered the highest wAGB in beech forests and highest SOM stocks under beech forest. FRB was the highest under fir forest. We noted a considerable impact of stand density on SOM stocks, particularly in beech and spruce forests. FRB content was mostly impacted by stand density only in beech forests without any discernible effects on other forest characteristics. We discovered significant impacts of relief-dependent factors and SOM stocks at all the studied sites. Our biomass and carbon models informed by more detailed environmental data led to reduce the uncertainty in over- and underestimation in Cambisols under beech, spruce, and fir forests for mountain temperate forest carbon pools.
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Jonas, KOALA, KAGAMBEGA O. Raymond, and SANOU Lassina. "Distribution des stocks de carbone du sol et de la biomasse racinaire dans un parc agroforestier à Prosopis africana (Guill., et Rich.) Taub au Burkina Faso, Afrique de l’Ouest." Journal of Applied Biosciences 160 (April 30, 2021): 16482–94. http://dx.doi.org/10.35759/jabs.160.5.
Повний текст джерелаАнотація:
Objectif : Cette présente étude visait à déterminer la distribution verticale des stocks de carbone organique du sol et de la biomasse racinaire dans un parc agroforestière à Prosopis africana (Guill., et Rich.) Taub au Burkina Faso. Méthodologie et Résultats : L’étude a été menée à Saria sur un dispositif factoriel avec 3 répétitions. L’échantillonnage des racines et du sol a été fait par l’extraction de monolithes sur 5 couches à une profondeur de 150 cm. Les résultats montrent que la profondeur a influencé les stocks de carbone. La couche 0-50 cm renferme 91% du stock total de carbone de la biomasse racinaire. Les stocks de Carbone Organique du Sol (COS) le plus élevé a été enregistré dans la couche 80-120 cm (26,59±7,94 tC ha-1), contre 8,74±6,05 tC ha-1 dans la couche 0-20 cm. Conclusion et implication des résultats : Les résultats montrent que les parcs agroforestiers étudiés ont un fort potentiel de séquestration de carbone. Cependant, les éventuels projets de carbone dans les parcs agroforestiers devront se focaliser sur la biomasse végétale aérienne et souterraine car le carbone organique du sol parait ne pas être influencé par les différents aménagements. Aussi pour une bonne gestion de ces stocks de carbone, des études complémentaires doivent être menées en vue de comprendre le cycle de de renouvellement des racines fines des parcs agroforestiers afin de de mesurer les flux de carbone organique du sol dans les parcs agroforestiers. Mots clés : Carbone organique du sol; Parc agroforestier, Prosopis africana, séquestration de carbone ; Biomasse racinaire 16482 Koala et al., J. Appl. Biosci. Vol.160 :2021 Distribution des stocks de carbone du sol et de la biomasse racinaire dans un parc agroforestier à Prosopis africana (Guill., et Rich.) Taub au Burkina Faso, Afrique de l’Ouest Distribution of carbon stocks from soil and root biomass in Prosopis africana (Guill., And Rich.) Taub agroforestry parkland in Burkina Faso, West Africa. ABSTRACT Objectives The aim of this study was to determine soil organic carbon stocks and root biomass carbon vertical distribution in an agroforestry parkland of Prosopis africana (Guill., And Rich.) Taub in Burkina Faso. Methodology and Results: The study was carried out in Saria on factorial design with 3 replicates. Root and soil sampling was done by extracting monoliths in 5-layer up to 150 cm depth. Results show that depth influenced carbon stocks. 0-50 cm layer contains 91% of root biomass total carbon stock. Highest soil Organic Carbon (SOC) stocks were recorded in 80-120 cm layer (26.59 ± 7.94 tC ha-1), compared to 8.74 ± 6.05 tC ha-1 in 0-20 cm layer. Conclusions and application of findings: Our results show that agroforestry parklands have a high carbon sequestration potential. However, any carbon projects in agroforestry parklands have to focus on trees above-ground and below-ground biomass because soil organic carbon does not influenced by management. Also for good management of these carbon stocks, additional studies must be carried out in order to understand the renewal cycle of fine roots in agroforestry parks in order to measure organic carbon flow from soil in agroforestry parklands. Keywords: Soil organic carbon; Agroforestry parklands, Prosopis africana, carbon sequestration; Root biomass INTRODUCTION L’agroforesterie est un système d’utilisation des terres traditionnel qui est toujours utilisé de nos jours par les populations (Santoro et al., 2020). Elle est considérée comme un système durable car contribuant à lutter contre la dégradation des terres. Sa contribution à l’amélioration à la productivité de l’agriculture est bien reconnue de nos jours (Montagnini and Nair, 2004). L’amélioration de la productivité est due à l’augmentation de la matière organique et au recyclage des éléments
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He, Jie, Quanhou Dai, Fengwei Xu, Xudong Peng, and Youjin Yan. "Variability in Carbon Stocks across a Chronosequence of Masson Pine Plantations and the Trade-Off between Plant and Soil Systems." Forests 12, no. 10 (September 30, 2021): 1342. http://dx.doi.org/10.3390/f12101342.
Повний текст джерелаАнотація:
Plantations sequester atmospheric carbon dioxide and positively respond to climate change, but the carbon (C) sequestration capacity and the trade-off between plant and soil systems in plantations may vary significantly across a chronosequence. Masson pine (Pinus massoniana Lamb.) plantations were selected to investigate the variability of C stocks in 7-, 14-, and 30-year-old stands. The total ecosystem C stock increased with stand age from 14.82 to 19.21 Mg C. Carbon stocks increased with stand age in the plant system but decreased in the soil system, with the ratio of plant-to-soil C stocks increasing from 0.06 in the 7-year-old plantation to 0.70 in the 30-year-old plantation. Carbon stocks in the first 20 cm of the soil accounted for 44.60%, 43.01%, and 30.18% of the total ecosystem carbon stock in 7-, 14-, and 30-year-old plantations, respectively. The variation trends for the proportions of C stock in soil decreased with soil depth as a result of tree and root growth regardless of stand age. Most C was stored in the stems, which contributed 1.36%, 6.85%, and 29.57% of total ecosystem C stock across the chronosequence. Results of structural equation model indicated that the effect of plant system C stock on ecosystem C stock was far larger than soil system C stock, and saturated hydraulic conductivity (ks) and fractal dimension (D) could be the primary parameters affecting ecosystem C stocks according to redundancy analysis (Variance explained by the variables selected). In summary, the plant system increased biomass C stocks by regulating soil properties to meet their growth requirements, the growth of plants in turn changed the soil organic carbon (SOC) stock, then both regulated ecosystem carbon sequestration in Masson pine plantations.
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Birhane, Emiru, Kbrom Fissiha Gebretsadik, Gebeyehu Taye, Ermias Aynekulu, Meley Mekonen Rannestad, and Lindsey Norgrove. "Effects of Forest Composition and Disturbance on Arbuscular Mycorrhizae Spore Density, Arbuscular Mycorrhizae Root Colonization and Soil Carbon Stocks in a Dry Afromontane Forest in Northern Ethiopia." Diversity 12, no. 4 (March 31, 2020): 133. http://dx.doi.org/10.3390/d12040133.
Повний текст джерелаАнотація:
We investigated arbuscular mycorrhizal fungi (AMF) spore density and root colonization in three distinct dry Afromontane forest plant communities, representing differing levels of disturbance and soil properties. Soil and root samples were collected from sixty-five 50 × 50-m plots from four plant communities. We collected data for AMF spore density, AMF root colonization and soil organic carbon stocks in 0–25 and 25–50 cm soil depth ranges. AMF spore density, and root colonization differed significantly among plant communities. The least disturbed Juniperus procera–Maytenus senegalensis (Jupr-Mase) plant community, which contained high tree and shrub density, had the highest AMF spore density, root colonization and soil carbon stocks. The most disturbed Cadia purpurea–Opuntia ficus-indica (Capu-Opfi) community which contained the lowest tree and shrub density supported the lowest AMF spore density, root colonization and soil carbon stocks. There was no significant difference in spore density between the two soil depths, but AMF root colonization was significantly higher in the upper soil than in the subsoil (p < 0.001). The difference in soil properties was not uniform between plant communities. Conserving remnant dry Afromontane forests and restoring the degraded forests are critical to improve and maintain forest ecosystem functioning and sustain ecosystem services.
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Lee, Sunjeoung, Seunghyun Lee, Joonghoon Shin, Jongsu Yim, and Jinteak Kang. "Assessing the Carbon Storage of Soil and Litter from National Forest Inventory Data in South Korea." Forests 11, no. 12 (December 10, 2020): 1318. http://dx.doi.org/10.3390/f11121318.
Повний текст джерелаАнотація:
Research Highlights: The estimation of soil and litter carbon stocks by the Land Use, Land-Use Changes, and Forestry (LULUCF) sectors has the potential to improve reports on national greenhouse gas (GHG) inventories. Background and Objectives: Forests are carbon sinks in the LULUCF sectors and therefore can be a comparatively cost-effective means and method of GHG mitigation. Materials and Methods: This study was conducted to assess soil at 0–30 cm and litter carbon stocks using the National Forest Inventory (NFI) data and random forest (RF) models, mapping their carbon stocks. The three main types of forest in South Kora were studied, namely, coniferous, deciduous, and mixed. Results: The litter carbon stocks (t C ha−1) were 4.63 ± 0.18 for coniferous, 3.98 ± 0.15 for mixed, and 3.28 ± 0.13 for deciduous. The soil carbon stocks (t C ha−1) were 44.11 ± 1.54 for deciduous, 35.75 ± 1.60 for mixed, and 33.96 ± 1.62 for coniferous. Coniferous forests had higher litter carbon stocks while deciduous forests contained higher soil carbon stocks. The carbon storage in the soil and litter layer increased as the forest grew older; however, a significant difference was found in several age classes. For mapping the soil and litter carbon stocks, we used four random forest models, namely RF1 to RF4, and the best performing model was RF2 (root mean square error (RMSE) (t C ha−1) = 1.67 in soil carbon stocks, 1.49 in soil and litter carbon stocks). Our study indicated that elevation, accessibility class, slope, diameter at breast height, height, and growing stock are important predictors of carbon stock. Soil and litter carbon stock maps were produced using the RF2 models. Almost all prediction values were appropriated to soil and litter carbon stocks. Conclusions: Estimating and mapping the carbon stocks in the soil and litter layer using the NFI data and random forest models could be used in future national GHG inventory reports. Additionally, the data and models can estimate all carbon pools to achieve an accurate and complete national GHG inventory report.
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Peumans, Willy J., Anthony K. Allen, Makuta Nsimba-Lubaki, and Maarten J. Chrispeels. "Related glycoprotein lectins from root stocks of wild cucumbers." Phytochemistry 26, no. 4 (January 1987): 909–12. http://dx.doi.org/10.1016/s0031-9422(00)82315-8.
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Shareef, S. "Ex-Situ Conservation and Multiplication of Garcinia Wightii T. And - A Rare, Endemic Species of the Southern Western Ghats." Indian Journal of Forestry 35, no. 1 (March 1, 2012): 85–88. http://dx.doi.org/10.54207/bsmps1000-2012-18wx91.
Повний текст джерелаАнотація:
As part of ex-situ consevation of Garcinia wightii, softwood grafting by cleft method was carried out using root stocks Garcinia gummi-gutta and G. hombroniana.The intra specific grafting carried out is found very successful in G. hombroniana and resulted 93% success, while G. gummi-gutta showed complete failure. All the saplings raised survived well in the field of Tropical Botanic Garden and Research Institute (TBGRI), Trivandrum. So, in G. wightii grafting, this method using the root stock of G. hombroniana can be adopted as an easy technique for its multiplication.
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Wilson, Chris H., Joao M. Vendramini, Lynn E. Sollenberger, and S. Luke Flory. "Root production in a subtropical pasture is mediated by cultivar identity and defoliation severity." Tropical Grasslands-Forrajes Tropicales 9, no. 2 (May 31, 2021): 144–58. http://dx.doi.org/10.17138/tgft(9)144-158.
Повний текст джерелаАнотація:
Grasslands occupy significant land area and account for a large proportion of the global soil carbon stocks, yet the direct effects of grazing and genotypic composition on relationships between shoot and root production are poorly resolved. This lack of understanding hinders the development of models for predicting root production in managed grasslands, a critical variable for determining soil carbon stocks. We quantified the effects of season-long defoliation treatments on both shoot and root production across 4 cultivars of a widely planted pasture grass species (Paspalum notatum Flüggé) in a common garden setting in South Florida, USA. We found that infrequently applied (4 weekly) severe defoliation (to 5 cm) substantially enhanced shoot production for all cultivars, while severe defoliation reduced root production across cultivars, regardless of frequency. Overall, there was no significant relationship between shoot and root production. Our results showed that above-ground and below-ground productivity are only weakly coupled, suggesting caution against use of simple above-ground proxies to predict variations in root production in grasslands. More broadly, our results demonstrated that improved modeling and management of grasslands for below-ground ecosystem services, including soil carbon sequestration/stocks, must account for intraspecific genetic variation and responses to defoliation management.
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Stocker, M., and D. J. Noakes. "Evaluating Forecasting Procedures for Predicting Pacific Herring (Clupea harengus pallasi) Recruitment in British Columbia." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 6 (June 1, 1988): 928–35. http://dx.doi.org/10.1139/f88-114.
Повний текст джерелаАнотація:
The ability of four forecasting methods to generate one-step-ahead forecasts of Pacific herring (Clupea harengus pillasi) recruitment is considered in this paper. Recruitment time series for five coastal stocks and various environmental time series are employed in the analyses. Information up to and including time t is employed to estimate the parameters of each model used to forecast recruitment in year t + 1. Parameter estimates are then updated after each time step with a total of seven one-step-ahead forecasts being generated by each model for each stock. The forecast errors are compared using the five criteria: (1) root mean squared error, (2) mean absolute deviation, (3) mean absolute percent error, (4) median absolute deviation, and (5) median absolute percent error. The results of the study indicate that time series models may provide better forecasts of recruitment for the Strait of Georgia/Johnstone Strait stocks than the other competing procedures. A Ricker stock–recruitment model that takes into account environmental data appears to produce marginally better forecasts for the Central Coast and Queen Charlotte Island stocks, while all models produced equally good/bad forecasts for the Prince Rupert district stocks.
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Hulugalle, N. R., T. B. Weaver, L. A. Finlay, N. W. Luelf, and D. K. Y. Tan. "Potential contribution by cotton roots to soil carbon stocks in irrigated Vertosols." Soil Research 47, no. 3 (2009): 243. http://dx.doi.org/10.1071/sr08180.
Повний текст джерелаАнотація:
The well-documented decline in soil organic carbon (SOC) stocks in Australian cotton (Gossypium hirsutum L.) growing Vertosols has been primarily analysed in terms of inputs from above-ground crop residues, with addition to soil C by root materials being little studied. Potential contribution by cotton roots to soil carbon stocks was evaluated between 2002 and 2008 in 2 ongoing long-term experiments near Narrabri, north-western New South Wales. Experiment 1 consisted of cotton monoculture sown either after conventional tillage or on permanent beds, and a cotton–wheat (Triticum aestivum L.) rotation on permanent beds; Experiment 2 consisted of 4 cotton-based rotation systems sown on permanent beds: cotton monoculture, cotton–vetch (Vicia villosa Roth.), cotton–wheat, and cotton–wheat–vetch. Roundup-Ready™ (genetically modified) cotton varieties were sown until 2005, and Bollgard™ II-Roundup Ready™-Flex™ varieties thereafter. Root growth in the surface 0.10 m was measured with the core-break method using 0.10-m-diameter cores. A subsample of these cores was used to evaluate relative root length and root C concentrations. Root growth in the 0.10–1.0 m depth was measured at 0.10-m depth intervals with a ‘Bartz’ BTC-2 minirhizotron video microscope and I-CAP image capture system (‘minirhizotron’). The video camera was inserted into clear, plastic acrylic minirhizotron tubes (50-mm-diameter) installed within each plot, 30° from the vertical. Root images were captured 4–5 times each season in 2 orientations, left and right side of each tube, adjacent to a furrow, at each time of measurement and the images analysed to estimate selected root growth indices. The indices evaluated were the length and number of live roots at each time of measurement, number of roots which changed length, number and length of roots which died (i.e. disappeared between times of measurement), new roots initiated between times of measurement, and net change in root numbers and length. These measurements were used to derive root C turnover between times of measurements, root C added to soil through intra-seasonal root death, C in roots remaining at end of season, and the sum of the last 2 indices: root C potentially available for addition to soil C stocks. Total seasonal cotton root C potentially available for addition to soil C stocks ranged between ~50 and 400 g/m2 (0.5 and 4 t/ha), with intra-seasonal root death contributing 25–70%. These values are ~10–60% of that contributed by above-ground crop residues. As soil organic carbon in irrigated Vertosols can range between 40 and 60 t/ha, it is unlikely that cotton roots will contribute significantly to soil carbon stocks in irrigated cotton farming systems. Seasonal root C was reduced by cotton monoculture, stress caused by high insect numbers, and sowing Bollgard II varieties; and increased by sowing non-Bollgard II varieties and wheat rotation crops. Permanent beds increased root C but leguminous rotation crops did not. Climatic factors such as cumulative day-degrees and seasonal rainfall were positively related to seasonal root C. Root C turnover was, in general, highest during later vegetative/early reproductive growth. Large variations in root C turnover and seasonal C indices occurred due to a combination of environmental, management and climatic factors.
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Mohapatra, Sabyasachi, Rohan Mukherjee, Arindam Roy, Anirban Sengupta, and Amit Puniyani. "Can Ensemble Machine Learning Methods Predict Stock Returns for Indian Banks Using Technical Indicators?" Journal of Risk and Financial Management 15, no. 8 (August 7, 2022): 350. http://dx.doi.org/10.3390/jrfm15080350.
Повний текст джерелаАнотація:
This paper develops ensemble machine learning models (XGBoost, Gradient Boosting, and AdaBoost in addition to Random Forest) for predicting stock returns of Indian banks using technical indicators. These indicators are based on three broad categories of technical analysis: Price, Volume, and Turnover. Various error metrics like Mean Absolute Error (MAE), Mean Squared Error (MSE), Mean Absolute Percentage Error (MAPE), Root-Mean-Squared-Error (RMSE) have been used to check the performance of the models. Results show that the XGBoost algorithm performs best among the four ensemble models. The mean of absolute error and the root-mean-square -error vary around 3–5%. The feature importance plots generated by the models depict the importance of the variables in predicting the output. The proposed machine learning models help traders, investors, as well as portfolio managers, better predict the stock market trends and, in turn, the returns, particularly in banking stocks minimizing their sole dependency on macroeconomic factors. The techniques further assist the market participants in pre-empting any price-volume action across stocks irrespective of their size, liquidity, or past turnover. Finally, the techniques are incredibly robust and display a strong capability in predicting trend forecasts, particularly with any large deviations.
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Gurgel, Antonio Leandro Chaves, Gelson dos Santos Difante, Alexandre Romeiro de Araujo, Denise Baptaglin Montagner, Valeria Pacheco Batista Euclides, and Manoel Gustavo Paranhos da Silva. "Carbon and Nitrogen Stocks and Soil Quality in an Area Cultivated with Guinea Grass under the Residual Effect of Nitrogen Doses." Sustainability 12, no. 22 (November 11, 2020): 9381. http://dx.doi.org/10.3390/su12229381.
Повний текст джерелаАнотація:
This study examines the residual effect of nitrogen (N) doses on the carbon (C) and N stocks and on soil quality in an area cultivated with guinea grass. The pastures received three annual doses of N (100, 200 and 300 kg ha−1) from 2015 to 2017. In 2018, N fertilization was not applied so the residual effect of the nutrient could be characterized. Soil chemical attributes, C and N stocks, density and penetration resistance and root system characteristics were evaluated at different depths. No difference was observed between the N doses for soil density, which averaged 1.22 and 1.25 g cm−3 under and between the tussocks of guinea grass, respectively. Penetration resistance was affected by the N doses post-grazing, with the highest value (1.9 MPa) observed in pastures that received 300 kg ha−1 of N for three consecutive years. Root dry mass was not affected by the N doses. There was no effect of N doses on the average (19.7 mg ha−1) or total (134.3 mg ha−1) C stock in the soil. The total N stock did not change (11.3 mg ha−1) in response to the N doses; however, the average N stock was higher in the soil cultivated with guinea grass under the N dose of 300 kg ha−1 (1.7 mg ha−1). The N doses had little interference with the soil chemical and physical aspects. Regardless of the dose, high C and N stocks were observed in the soil cultivated with guinea grass. Therefore, when properly managed, intensive pasture-based animal production systems become important allies of the environment.
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., M. A. Rahman, M. A. Rashid ., M. A. Salam ., M. A. T. Masud ., A. S. M. H. Masum ., and M. M. Hossain . "Performance of Some Grafted Eggplant Genotypes on Wild Solanum Root Stocks Against Root-Knot Nematode." Journal of Biological Sciences 2, no. 7 (June 15, 2002): 446–48. http://dx.doi.org/10.3923/jbs.2002.446.448.
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Singh, Sukhdip, Jatinder Singh, and Anis Mirza. "Evaluation of Mandarin Cultivars on Different Root Stocks-A Review." International Journal of Current Microbiology and Applied Sciences 8, no. 01 (January 10, 2019): 1213–22. http://dx.doi.org/10.20546/ijcmas.2019.801.128.
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Wang, Cunguo, Zhao Chen, Ivano Brunner, Zhen Zhang, Xianjin Zhu, Jiandong Li, Hong Yin, et al. "Global patterns of dead fine root stocks in forest ecosystems." Journal of Biogeography 45, no. 6 (April 10, 2018): 1378–94. http://dx.doi.org/10.1111/jbi.13206.
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M. T. Rahman, A. D. Adebayo, A. F. Adekoya,. "Predicting Stock Trends Using Tsk-fuzzy Rule Based System." Journal of Energy and Natural Resource Management 4, no. 1 (March 31, 2017): 48–55. http://dx.doi.org/10.26796/jenrm.v4i1.74.
Повний текст джерелаАнотація:
Stock investment is often regarded by investors as a green opportunity that is characterized by high rewards and its attendant risk. Consequently, investors are preoccupied with analysis and prediction of the future performance of stocks, and the direction and magnitude of future changes in the stock value. In this study, the Takagi-Sugueno-Kang - Fuzzy Rule Based System (TSK-FRBS) was used to analyzed the trend of stocks using historical data gathered over a period of five months between January and May 2015. The TSK-FRBS was implemented in R. The input data is split into training and testing data for experimentation, testing and further analysis. Predictive accuracy was evaluated using the root mean squared error (RMSE) and symmetric mean absolute percentage error (SMAPE). Final results showed consistency obtained from feeding the model with the data and hence provedthat patterns that allow for prediction can be deduced from the chaotic nature of the stock exchange market.
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Handri, Handri, Hendrati Dwi Mulyaningsih, Achmad Kemal Hidayat, Rudi Kurniawan, and Ani Wahyu Rachmawati. "The impact of Indonesian oil price (CPI) and macroeconomics on investments in the manufacturing sector in Indonesia." F1000Research 10 (May 4, 2021): 338. http://dx.doi.org/10.12688/f1000research.27958.1.
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Background: Indonesia consumes oil as the main energy source in the production process and as a result of the development of the manufacturing industry. Thus, investment in manufacturing stocks will be affected by oil price fluctuations and macroeconomic conditions. Changes in oil prices will affect the performance of the manufacturing sector which in turn affects manufacturing stock prices. This paper aims to examine the impact of Indonesia's oil price shocks and macroeconomic factors on stock price movements in the manufacturing sector. Methods: This study uses monthly data for the 2009-2016 period in the manufacturing sector, and 67 stocks were selected on the basis consistently available in the period of the research. The cointegration and causality technique was used in this paper; firstly we applied a unit-panel root test, Secondly, we performed a residual test to indicate whether there was cointegration among variables in the long run equilibrium, and short the short run, we used a Granger causality test. Results: The panel unit root test (both Shin and Fisher) and the Pedroni cointegration residual test show that the data is stationary at 1% level of significance, thus all variables simultaneously achieve long-run equilibrium, and in the short run, the Granger causality test shows that there is one way direction causality Conclusions: For long-term investment in manufacturing stocks, investors must consider the exchange rate, as it is also as a determining factor in influencing the movement of manufacturing stock prices, inflation, and the production index. Meanwhile, weakening of the rupiah in the short run will also determine investment conditions due to the dependency on raw materials for production from foreign sources. The price of oil as an energy source in the manufacturing sector does not have a long-term relationship with other variables.
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Tokareva, O. I. "Selection of seed stocks for propagation of apple trees in the Far East." Pomiculture and small fruits culture in Russia 62 (October 1, 2020): 91–97. http://dx.doi.org/10.31676/2073-4948-2020-62-91-97.
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The article presents the results of research on the selection of seed stocks aimed at the development of intensive horticulture in the Far Eastern region, which has great potential for growing apple fruits. There were summarized materials on the study of seed stocks of apple trees. In modern conditions in fruit growing, the most relevant direction is the creation of high-yielding apple varieties with high adaptive properties. Varieties must be early-growing, have high immunity and resistance to the most harmful pathogenic, and also have good compatibility with seed stocks that are resistant to the abiotic and biotic environmental factors of the Far Eastern region. The use of seed stocks makes it possible to propagate seedlings of the most promising varieties free from harmful viral infections without losing their genetic stability. Plantings planted with such planting material do not need expensive supports and require significantly fewer mineral fertilizers and water, because they have a powerful root system that penetrates into the deeper layers the soil. Seed stocks of the apple tree are initially free from viral infection, and, unlike the clonal stocks, do not require expensive recovery, which leads to significant material savings. High grafting on seed stock not only contributes to the accelerated entry of gardens into the productive period, but also helps protect trees from damage from sunburn and frost. The production and biological study of the seed stocks of the apple tree was carried out in the form of a collection variety study and production variety testing. The field method is used to evaluate seed stocks. The developed and scientifically substantiated methods for planting apple orchards on seed stocks make it possible to create stands that are resistant to the climate of the Far Eastern region and stably produce marketable fruits for several years. It was revealed that the Siberian berry apple tree, and the variety Ranetka Yantarnaya are the most highly adapted and can be used as a seed stock.
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Procop, A. "Zależność pokroju systemu korzeniowego podkładki od okulizowanej odmiany [Scion varieties determine root character of root-stocks]." Acta Agrobotanica 14 (2015): 199–203. http://dx.doi.org/10.5586/aa.1963.016.
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Gomes, Amândio L., Rasmus Revermann, Francisco M. P. Gonçalves, Fernanda Lages, Marcos P. M. Aidar, Graciela A. Sanguino Mostajo, and Manfred Finckh. "Suffrutex grasslands in south-central Angola: belowground biomass, root structure, soil characteristics and vegetation dynamics of the ‘underground forests of Africa’." Journal of Tropical Ecology 37, no. 3 (May 2021): 136–46. http://dx.doi.org/10.1017/s0266467421000298.
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AbstractDespite its importance for carbon stocks accounting, belowground biomass (BGB) has seldom been measured due to the methodological complexity involved. In this study, we assess woody BGB and related carbon stocks, soil properties and human impact on two common suffrutex grasslands (Brachystegia- and Parinari grasslands) on the Angolan Central Plateau. Data on BGB was measured by direct destructive sampling. Soil samples were analysed for select key parameters. To investigate vegetation dynamics and human impact, we used Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) and fire data retrieved via Google Earth Engine. Mean belowground woody biomass of sandy Parinari grasslands was 17 t/ha and 44 t/ha in ferralitic Brachystegia grasslands of which 50% correspond to carbon stocks. As such, the BGB of Brachystegia grasslands almost equals the amount of aboveground biomass (AGB) of neighbouring miombo woodlands. Almost the entire woody BGB is located in the top 30 cm of the soil. Soils were extremely acid, showing a low nutrient availability. Both grassland types differed strongly in EVI and fire seasonality. The Parinari grasslands burnt almost twice as frequent as Brachystegia grasslands in a 10-year period. Our study emphasizes the high relevance of BGB in suffrutex grasslands for carbon stock accounting.
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Dantas, Daniel, Marcela de Castro Nunes Santos Terra, Luiz Otávio Rodrigues Pinto, Natalino Calegario, and Sabrina Mandarano Maciel. "Above and belowground carbon stock in a tropical forest in Brazil." Acta Scientiarum. Agronomy 43 (November 5, 2020): e48276. http://dx.doi.org/10.4025/actasciagron.v43i1.48276.
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An increase in atmospheric CO2 levels and global climate changes have led to an increased focus on CO2 capture mechanisms. The in situ quantification and spatial patterns of forest carbon stocks can provide a better picture of the carbon cycle and a deeper understanding of the functions and services of forest ecosystems. This study aimed to determine the aboveground (tree trunks) and belowground (soil and fine roots, at four depths) carbon stocks in a tropical forest in Brazil and to evaluate the spatial patterns of carbon in the three different compartments and in the total stock. Census data from a semideciduous seasonal forest were used to estimate the aboveground carbon stock. The carbon stocks of soil and fine roots were sampled in 52 plots at depths of 0-20, 20-40, 40-60, and 60-80 cm, combined with the measured bulk density. The total estimated carbon stock was 267.52 Mg ha-1, of which 35.23% was in aboveground biomass, 63.22% in soil, and 1.54% in roots. In the soil, a spatial pattern of the carbon stock was repeated at all depths analyzed, with a reduction in the amount of carbon as the depth increased. The carbon stock of the trees followed the same spatial pattern as the soil, indicating a relationship between these variables. In the fine roots, the carbon stock decreased with increasing depth, but the spatial gradient did not follow the same pattern as the soil and trees, which indicated that the root carbon stock was most likely influenced by other factors.
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Adenomon, Monday Osagie, and Richard Adekola Idowu. "Modelling the Impact of the COVID-19 Pandemic on Some Nigerian Sectorial Stocks: Evidence from GARCH Models with Structural Breaks." FinTech 2, no. 1 (December 21, 2022): 1–20. http://dx.doi.org/10.3390/fintech2010001.
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This study provides evidence of the impact of COVID-19 on five (5) Nigerian Stock Exchange (NSE) sectorial stocks (NSE Insurance, NSE Banking, NSE Oil and Gas, NSE Food and Beverages, and NSE Consumer Goods). To achieve the goal of this paper, daily stock prices were obtained from a secondary source ranging from 2 January 2020 to 25 March 2021. Because of the importance of incorporating structural breaks in modelling stock returns, the Zivot–Andrews unit root test revealed 20 January 2021, 26 March 2020, 27 July 2020, 23 March 2020 and 23 March 2020 as potential break points for NSE Insurance, NSE Food, Beverages and Tobacco, NSE Oil and Gas, NSE Banking, and NSE Consumer Goods, respectively. This study investigates the volatility in daily stock returns for the five (5) Nigerian Stock Exchange (NSE) sectorial stocks using nine versions of GARCH models (sGARCH, girGARCH, eGARCH, iGARCH, aPARCH, TGARCH, NGARCH, NAGARCH, and AVGARCH); in addition, the half-life and persistence values were obtained. The study used the Student t- and skewed Student t-distributions. The results from the GARCH models revealed a negative impact of COVID-19 on the NSE Insurance, NSE Food, Beverages and Tobacco, NSE Banking, and NSE Consumer Goods stock returns; however, the NSE Oil and Gas returns showed a positive correlation with the COVID-19 pandemic. This study recommends that the shareholders, investors, and policy players in the Nigerian Stock Exchange markets should be adequately prepared in the form of diversification of investment in stocks that can withstand future possible crises in the market.
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Merezhko, O. E., A. A. Borisova, and E. V. Aminova. "Comparative study of apple plantations on seed and clonal stocks in the steppe zone of the Southern Urals." Horticulture and viticulture, no. 3 (June 29, 2021): 50–56. http://dx.doi.org/10.31676/0235-2591-2021-3-50-56.
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In recent years, Russian gardeners have become interested in apple seed stocks, since they are indispensable for growing planting material of the highest quality categories for the purpose of setting up mother-cuttings, nurseries of clonal stocks and intensive orchards intended for obtaining organic products. The advantage of apple seed stocks is not only in a powerful root system and resistance to biotic and abiotic stressors, but also in the absence of a harmful viral infection from which almost all clonal stocks in Russia suffer. The opinion that trees are more vigorous on seed stocks, and orchards later enter in the fruiting period is erroneous, since there are developed technologies that make it possible the establishment of intensive apple tree plantations that enter the fruiting period 2 years after grafting. Among the apple clonal stocks, the intensively propagated form 54-118 is characterized by good anchoring and winter hardiness. Due to the lack of scientific data on the comparative study of seed and clonal stocks in the context of scion/stock combinations, we have begun a long-term study in order to identify the most promising of them in terms of early fruitfulness and high productivity. Long-term studies were carried out on the basis of the Orenburg branch of the Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery from 2000 to 2020. The analysis of the results of the tests carried out shows that all the plantings on stocks 54-118 and 64-143 turned out to be early fruitfulness, and the stocks were suitable for intensive gardening, since the varieties grafted on them have a restrained growth force and a compact crown. The smallest height from 1.9 to 2.8 m was noted in trees on the 54-118 stock, on the 64-143 stock this parameter, depending on the variety, varied from 3.2 to 3.8 m. The largest crown diameter (over 3.0 m) and the largest projection area of the crown had plantings of all varieties on the seed stock of Purple Ranetka. The yield of apple tree plantations on stock 54-118 varied from 10.4 (Serebryanoe Kopitce variety) to 14.1 t/ha (Chudnoe variety), and revenue from the sale of products from 1 ha ranged from 263.1 to 356.7 thousand rubles. The highest profitability on clonal stock 54-118 was distinguished by perennial plantations of the Chudnoe variety (83.8 %). On stock 64-143, the yield of plantings varied from 10.2 t / ha (Serebryanoe Kopitce variety) to 13.5 t / ha (Chudnoe variety), the proceeds from the sale of products per hectare also varied from 258.1 thousand rubles. up to 341.5 thousand rubles. The highest profitability of production was noted in the plantations on the stock 64-143 of the variety Mechtatelnitsa (82.2 %). The average yield of apple varieties grafted on the seed stock of Purple Ranetka ranged from 8.2 (variety Letnee Polosatoe (K) to 9.3 t / ha (variety Serebryanoe Kopitce); high profitability of production was distinguished by plantings of the variety Mechtatelnitsa on ranetka purpurovaya (16.3 %).
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Bourne, Robert D., and Curt Rom. "PEACH ROOTSTOCK PERFORMANCE IN ARKANSAS." HortScience 28, no. 4 (April 1993): 265D—265. http://dx.doi.org/10.21273/hortsci.28.4.265d.
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Several trials were conducted to compare standard and potential peach rootstocks. The NC-140 trial, with 'Redhaven' as the scion, included 'Halford', 'Siberian-C', 'Bailey', 'GF-677', 'GF-655.2', 'Damas', 'Citation', 'Lovell' and 'GF-43' rootstocks. All trees with 'Citation' as the rootstock died in the first three years. while 'CF-43' and 'Siberian-C' had low survivability and productivity. 'Damas' and 'GF-43' suckered profusely. 'Lovell' trees bloomed an average of one-to-three days later than all other entries. 'Halford'. 'GF-677', 'Bailey' and 'Lovell' had the highest yields. A trial comparing 'Loring' own-root and on 'Tennessee Natural' resulted in similar yields among stocks, but larger fruit and tree size with the own-root trees. 'Redskin' own-root and on 'Lovell' also resulted in similar yields among stocks, and larger tree and fruit size with own-root trees. A trial using the processing peach selection A-219 as the scion on `S-37' 'Chum Li Tao', AR-78118, 'Yarbrough Cling' and 'Lovell' resulted in highest yields and yield efficiency with 'Yarbrough Cling', 'Lovell' and 'S-37' rootstocks.
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Mohammed, A. M., J. S. Robinson, A. Verhoef, and D. J. Midmore. "Nutrient Stocks and Distribution in Ghanaian Cocoa Ecosystems." International Journal of Agronomy 2020 (October 29, 2020): 1–9. http://dx.doi.org/10.1155/2020/8856314.
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There is a paucity of information on nutrient stocks and distribution in the cocoa ecosystem for the management of production sites to improve its productivity. Apart, sites with long histories of cocoa production could differ in nutrient stocks and distribution relative to recent production regions. Therefore, some existing cocoa farms in Ghana were sampled on the basis of shade management (shaded and unshaded) and production site longevity (Eastern region > Western North region) to determine the nutrient stock and distributions in them. Over 93% of the total ecosystems’ elementary nutrients were stored in the soil. Higher nutrient stocks occurred under shaded cocoa ecosystem. Nutrient element concentrations in cocoa tree biomasses followed the order: N > Ca > K > Mg > P > S > Al = Fe > Zn = Mn, and mostly concentrated in leaf > root = husk > branch > stem. On average, region as a main factor affected nutrient distributions. There was a sharp distinction between macronutrient and micronutrient accumulations in favour of Eastern region and Western North region, respectively. Therefore, the regional distinction with respect to macro- and micronutrients could be used as a guide to fertilizer recommendation for cocoa systems in the two regions.
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Setianto, Rahmat Heru, and Turkhan Ali Abdul Manap. "The Behavior of Indonesian Stock Market: Structural Breaks and Nonlinearity." Gadjah Mada International Journal of Business 13, no. 3 (September 12, 2011): 209. http://dx.doi.org/10.22146/gamaijb.5480.
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This study empirically examines the behaviour of Indonesian stock market under the efficient market hypothesis framework by emphasizing on the random walk behaviour and nonlinearity over the period of April 1983 - December 2010. In the first step, the standard linear unit root test, namely the augmented Dickey-Fuller (ADF) test, Phillip-Perron (PP) test and Kwiatkowski-Philllips-Schmidt-Shin (KPSS) test identify the random walk behaviour in the indices. In order to take account the possible breaks in the index series Zivot and Adrews (1992) one break and Lumsdaine and Papell (1997) two breaks unit root test are employed to observe whether the presence of breaks in the data series will prevent the stocks from randomly pricing or vice versa. In the third step, we employ Harvey et al. (2008) test to examine the presence of nonlinear behaviour in Indonesian stock indices. The evidence of nonlinear behaviour in the indices, motivate us to use nonlinear unit root test procedure recently developed by Kapetanios et al. (2003) and Kruse (2010). In general, the results from standard linear unit root test, Zivot and Adrews (ZA) test and Lumsdaine and Papell (LP) test provide evidence that Jakarta Composite Index characterized by a unit root. In addition, structural breaks identified by ZA and LP test are corresponded to the events of financial market liberalization and financial crisis. The nonlinear unit root test procedure fail to rejects the null hypothesis of unit root for all indices, suggesting that Jakarta Composite Index characterized by random walk process supporting the theory of efficient market hypothesis.
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Urooj, Syeda Faiza, Nosheen Zafar, and Muzammil Illyas Sindhu. "Overconfidence Bias: Empirical Examination of Trading Turnover and Market Returns." Global Social Sciences Review IV, no. II (June 30, 2019): 384–90. http://dx.doi.org/10.31703/gssr.2019(iv-ii).50.
Повний текст джерелаАнотація:
Theory of overconfidence states that investors are highly overconfident when valuing the stocks. Self-attribution has been found by the researchers as the root cause for overconfidence bias in investors. Investors attribute the high stock prices and returns with their own art of picking up the stocks, and thus they trade more frequently. In order to test overconfidence and self-attribution Vector Autoregressive (VAR) model has been employed to find out the long-term relationship between endogenous variables: market return and market turnover and exogenous variables: volatility and dispersion. Results revealed that there exists a strong positive relationship between market returns and trading turnover. Also, the crosssectional standard deviation in market prices i-e volatility and the cross-sectional variation in stock returns i-e dispersion has a very strong impact on trading pattern and returns. Since investment decisions made by Pakistani investor largely depend upon psychological factors, giving less weightage to all the fundamentals, the trading pattern exhibited may collectively tend the market behave in an irrational manner.
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Tripathi, Vanita, and Arnav Kumar. "Relationship between Inflation and Stock Returns – Evidence from BRICS markets using Panel Co integration Test." International Journal of Accounting and Financial Reporting 1, no. 1 (January 14, 2015): 647. http://dx.doi.org/10.5296/ijafr.v4i2.6671.
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Stocks are generally considered to be a good hedge against inflation because of their tendency to move together. This paper examines long term relationship between inflation and stock returns in BRICS markets using panel data for the period from March 2000 to September 2013. Correlation results reveal a significant negative relationship between stock index and inflation rate for Russia and a significantly positive relationship for India & China. ADF, PP and KPSS unit root tests indicate non-stationary characteristic of the data. Further we find no long term co-integrating relationship between stock index values and inflation rates using Pedroni panel co integration test. These findings have important implications for policy makers, regulators and investment community at large. There may seem to be short term contemporaneous relationship between inflation and equity returns but in the long run they do not seem to be significantly integrated. Changes in inflation may bring some short run movement in stock return but certainly equity does not seem to be a good hedge against inflation in long run at least in emerging BRICS markets. Keywords: BRICS, Stock Index, Inflation, Unit root test, Pedroni Panel Co integration Test, Johansen Co integration Test.
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Jin, Jiankang, Chen Jie, and Quanda Zhang. "Analysis on the Impact of the Fluctuation of the International Gold Prices on the Chinese Gold Stocks." Discrete Dynamics in Nature and Society 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/308626.
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Five gold stocks in Chinese Shanghai and Shenzhen A-share and Comex gold futures are chosen to form the sample, for the purpose of analysing the impact of the fluctuation of the international gold prices on the gold stocks in Chinese Shanghai and Shenzhen A-share. Using the methods of unit root test, Granger causality test, VAR model, and impulse response function, this paper has analysed the relationship between the price change of the international gold futures and the price fluctuation of gold stocks in Chinese Shanghai and Shenzhen comprehensively. The results suggest the fluctuation of the international gold futures has a strong influence on the domestic futures.
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Morais, Vinícius Augusto, José Roberto Soares Scolforo, Carlos Alberto Silva, José Marcio de Mello, Lucas Rezende Gomide, and Antônio Donizette de Oliveira. "Carbon and biomass stocks in a fragment of cerradão in Minas Gerais state, Brazil." CERNE 19, no. 2 (June 2013): 237–45. http://dx.doi.org/10.1590/s0104-77602013000200007.
Повний текст джерелаАнотація:
This study aimed at quantifying carbon (C) and biomass stocks in shoot portion, leaf litter, roots and soil within a fragment of dense savanna 'cerradão', 158.5 ha in area, located in Minas Gerais state. Measures were quantified using dendrometric parameters obtained during the forest inventory and collection of leaf litter, root and soil samples. Furrows were dug in the soil each 100 cm long, 50 cm wide and 100 cm deep in order to collect root samples at depths of 0-30 cm, 30-50 cm and 50-100 cm, and soil samples from the layers 0-10 cm, 10-20 cm, 20-40 cm, 40-60 cm and 60-100 cm, as well as any leaf litter from the surrounding surface. Analyses were performed in the Organic Matter Study Laboratory (DCS/UFLA) to determine C contents in the above matrices, using an Elementar analyzer model Vario TOC Cube. Higher C contents and stocks and lower density were noted in topmost soil layers. In cerradão, shoot portion was found to be the matrix contributing the most to biomass production, followed by roots and leaf litter. Carbon stock in the fragment was 139.7 Mg ha-1. Soil was the matrix contributing the most to stocked C (64.8%), followed by the shoot portion (26.3%), roots (5.2%) and leaf litter (3.7%).
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Ma, Li, Chang Wei Hou, Xin Zhong Zhang, Hong Li Li, De Guo Han, Yi Wang, and Zhen Hai Han. "Seasonal Growth and Spatial Distribution of Apple Tree Roots on Different Rootstocks or Interstems." Journal of the American Society for Horticultural Science 138, no. 2 (March 2013): 79–87. http://dx.doi.org/10.21273/jashs.138.2.79.
Повний текст джерелаАнотація:
Understanding of root growth patterns and architecture of apple (Malus ×domestica Borkh.) trees is very important for commercial apple production. Most commercial apple trees are usually a grafted complex consisting of the scion and the rootstock, each of which is a different genotype. Recently, rootstocks of dwarf tree species have been used extensively to meet the convenience in management; however, this practice appears to negatively impact root development. Using minirhizotrons, we investigated root dynamics, root spatial distribution, and shoot growth in ‘Red Fuji’ scion grown: 1) directly on dwarf and vigorous root stocks and 2) on a dwarf root stock placed in between the non-dwarf scion and non-dwarf rootstock (hereinafter referred to as an interstem). The results showed that: 1) one or two peaks in total root length density (TRLD) were observed in each scion/rootstock combinations every year; 2) the greatest TRLD peaks were always observed in between May and December. The peaks of shoot growth were always asynchronous with that of white root length density; 3) compared with scion/vigorous rootstock combinations, inserting a dwarfing interstem between the scion and vigorous seedling rootstock reduced the TRLD; 4) scion/vigorous rootstock combinations had a relatively deep, widespread and large root system. Scion/dwarfing rootstock combinations had a root system distributed in a small region; and the root systems of scion/dwarfing interstem/vigorous rootstock combinations tended to be intermediate between those of scion/vigorous rootstock and scion/dwarfing rootstock. This implies that the insertion of interstems altered the root architecture by not only the quantity of roots, but also the spatial distribution.
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Aysanov, T. S., E. S. Romanenko, M. V. Selivanova, N. A. Esaulko, E. A. Mironova, and M. S. German. "Improving the technology of obtaining clonal root stocks of stone fruit crops." IOP Conference Series: Earth and Environmental Science 315 (August 23, 2019): 022017. http://dx.doi.org/10.1088/1755-1315/315/2/022017.
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Neumann, Mathias, Douglas L. Godbold, Yasuhiro Hirano, and Leena Finér. "Improving models of fine root carbon stocks and fluxes in European forests." Journal of Ecology 108, no. 2 (January 10, 2020): 496–514. http://dx.doi.org/10.1111/1365-2745.13328.
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Gamble, Joshua D., Gregg A. Johnson, Dean A. Current, Donald L. Wyse, Diomides S. Zamora, and Craig C. Sheaffer. "Alley cropping affects perennial bioenergy crop root distribution, carbon, and nutrient stocks." Agronomy Journal 112, no. 5 (August 22, 2020): 3718–32. http://dx.doi.org/10.1002/agj2.20350.
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Gautam, Tilak Prasad, and Tej Narayan Mandal. "Storage and Flux of Nutrients in Disturbed and Undisturbed Tropical Moist Forest of Eastern Nepal." International Journal of Forestry Research 2018 (October 18, 2018): 1–12. http://dx.doi.org/10.1155/2018/8516321.
Повний текст джерелаАнотація:
The disturbance activities in tropical forests shrink the nutrient cycling between the vegetation and soil. To understand the nutrient cycling in undisturbed and disturbed stands of mixed deciduous tropical forest of eastern Nepal, plant biomass was estimated within seventy randomly established sampling plots. The biomass values were multiplied with nutrient concentration of respective parts to estimate the nutrient stocks. The nutrient concentrations varied widely amongst components. In trees, concentrations of all nutrients were highest in leaves followed in decreasing order by fine roots (<5 mm) and twigs and then by branches, bole, and coarse roots. The contribution of different components to total nutrient stocks was in the following order: tree > stand fine root > shrub > herb, in both stands. The relative contribution of different components of trees to total nutrient stocks was in the following order: bole > coarse root > branch > leaf > twig > fine roots. In trees, leaves and fine roots had greater gross uptake of nutrients than other components. The concentrations of different nutrients in the plants are in the following order: nitrogen > potassium > phosphorus. Total nutrient return to the soil through the litterfall is almost 1.5 times greater than that from fine roots in both forests. In conclusion, various types of forest disturbances had adverse effect on the nutrient stocks and nutrient dynamics.
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Yang, Bin, Wenhui Zhang, Yanlei Lu, Weiwei Zhang, and Yanan Wang. "Carbon Storage Dynamics of Secondary Forest Succession in the Central Loess Plateau of China." Forests 10, no. 4 (April 17, 2019): 342. http://dx.doi.org/10.3390/f10040342.
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Research Highlights: This study comprehensively revealed the carbon sequestration characteristics of secondary forests in the central Loess Plateau during vegetation succession. Background and Objectives: The secondary succession of Loess Plateau forests is of great significance in global climate change, but their carbon storage dynamics are poorly understood. The study objectives were to clarify the pattern of changes and contribution level of carbon stocks in various components of ecosystem during succession. Materials and Methods: We selected 18 plots for Pinus tabuliformis Carr. forest at the early stage of succession, 19 for pine-broadleaved mixed forest at the middle stage, and 12 for Quercus-broadleaved mixed forest at the climax stage to determine the tree, shrub, herb, fine root, litter, coarse wood debris (CWD), and soil carbon stocks. Results: Ecosystem carbon stocks increased from 160.73 to 231.14 Mg·ha−1 with the succession stages. Vegetation (including tree, shrub and herb) and soil were the two largest carbon pools, and carbon was mainly sequestrated in tree biomass and shallow soil (0–50 cm). In the early stage, soil contributed more carbon stocks to the ecosystem than vegetation, but with succession, the soil contribution decreased while vegetation contribution increased, finally reaching a balance (46.78% each) at the climax stage. Fine root, litter, and CWD contributed little (average 6.59%) to ecosystem carbon stocks and were mainly involved in the turnover of vegetation biomass to soil carbon. Conclusions: Our results provide direct evidence for carbon sequestration of secondary forests on the Loess Plateau. The dynamic results of carbon storage provide an important basis for forest restoration management under climate change.
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Tang, YM, Ka-Yin Chau, Wenqiang Li, and TW Wan. "Forecasting Economic Recession through Share Price in the Logistics Industry with Artificial Intelligence (AI)." Computation 8, no. 3 (August 3, 2020): 70. http://dx.doi.org/10.3390/computation8030070.
Повний текст джерелаАнотація:
Time series forecasting technology and related applications for stock price forecasting are gradually receiving attention. These approaches can be a great help in making decisions based on historical information to predict possible future situations. This research aims at establishing forecasting models with deep learning technology for share price prediction in the logistics industry. The historical share price data of five logistics companies in Hong Kong were collected and trained with various time series forecasting algorithms. Based on the Mean Absolute Percentage Error (MAPE) results, we adopted Long Short-Term Memory (LSTM) as the methodology to further predict share price. The proposed LSTM model was trained with different hyperparameters and validated by the Root Mean Square Error (RMSE). In this study, we found various optimal parameters for the proposed LSTM model for six different logistics stocks in Hong Kong, and the best RMSE result was 0.43%. Finally, we can forecast economic recessions through the prediction of the stocks, using the LSTM model.
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Sinlapates, Parichat, and Surachai Chancharat. "Contrarian Profits in Thailand Sustainability Investment-Listed versus in Stock Exchange of Thailand-Listed Companies." Risks 10, no. 12 (December 1, 2022): 229. http://dx.doi.org/10.3390/risks10120229.
Повний текст джерелаАнотація:
In contrarian trading, investors buy and sell loser stocks (lowest average historical prices) and winner stocks (highest average historical prices), respectively. This study examines whether (a) Thailand Sustainability Investment-listed companies outperform Stock Exchange of Thailand (SET)-listed companies (from 1 January 2016 to 31 December 2019) in contrarian profits, (b) the five-factor model outperforms their 1993 three-factor model in explaining contrarian profits, and (c) risk drives the earnings of contrarians. Companies were divided into portfolios of winners and losers based on the average of the daily historical prices held in various eras. The SET-listed companies perform better in generating profits. The root mean squared error and mean absolute error—measurements of model accuracy—report that the error from the three-factor model is smaller than the one from the five-factor model. Thus, the three-factor model is applied to estimate the risk-adjusted return. Zero contrarian profits after risk adjustment confirms that they are risk-driven.
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Jarrett, Jeffrey E., and Janne Schilling. "DAILY VARIATION AND PREDICTING STOCK MARKET RETURNS FOR THE FRANKFURTER BÖRSE (STOCK MARKET)." Journal of Business Economics and Management 9, no. 3 (September 30, 2008): 189–98. http://dx.doi.org/10.3846/1611-1699.2008.9.189-198.
Повний текст джерелаАнотація:
In this article we test the random walk hypothesis in the German daily stock prices by means of a unit root test and the development of an ARIMA model for prediction. The results show that the time series of daily stock returns for a stratified random sample of German firms listed on the stock exchange of Frankfurt exhibit unit roots. Also, we find that one may predict changes in the returns to these listed stocks. These time series exhibit properties which are forecast able and provide the intelligent data analysts’ methods to better predict the directive of individual stock returns for listed German firms. The results of this study, though different from most other studies of other stock markets, indicate the Frankfurt stock market behaves in similar ways to North American, other European and Asian markets previously studied in the same manner.
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Purnomo, Dwi Tjahjo. "APAKAH SAHAM FARMASI DI BURSA EFEK INDONESIA MENGIKUTI HIPOTESIS RANDOM WALK SAAT PANDEMI COVID-19?" Jurnal Riset Ekonomi dan Bisnis 14, no. 1 (April 30, 2021): 18. http://dx.doi.org/10.26623/jreb.v14i1.3170.
Повний текст джерелаАнотація:
<p><em><span lang="EN-US">Berbeda dengan saham lain yang turun cukup tajam saat dimulainya pandemi Covid-19, pergerakan harga saham farmasi justru mengalami peningkatan. Kenaikan harga saham farmasi sejalan dengan ekspektasi investor terhadap peningkatan permintaan obat dan suplemen kesehatan yang berdampak pada kenaikan harga saham di pasar. Penelitian ini secara empiris bertujuan untuk menguji perilaku rantai jual beli di Bursa Efek Indonesia (BEI) yaitu PT Indo Farma Tbk (INAF), PT Kimia Farma Tbk (KAEF), PT Kalbe Farma Tbk (KLBF), PT Phapros Tbk (PEHA), PT Pyridam Farma Tbk (PYFA), dan PT Tempo Scan Pacific Tbk (TSPC). Secara khusus, penelitian ini menyelidiki apakah akan melaporkan apakah saham farmasi selama Pandemi Covid-19 mengikuti Random Walk Hypothesis (RWH) atau sebaliknya apakah pergerakan harga dapat diprediksi. Data yang digunakan dalam penelitian ini adalah harga penutupan saham harian dari tanggal 2 Januari 2020 sampai dengan 2 Februari 2021. Data dianalisis menggunakan uji Augmented Dickey-Fuller untuk adanya Uji Unit Root, uji Variance Ratio, dan Autoregressive Moving Average. (ARMA). Hasilnya, berdasarkan Uji Akar Unit, semua data stasioner di tingkat. Pengujian lebih lanjut menggunakan Variance Ratio, baik secara stand alone intersep maupun trend dan antar semua data juga tidak bergerak secara acak dan tidak mengikuti Hipotesis Random Walk. Terakhir, dengan menggunakan model ARMA, pergerakan log return saham farmasi di BEI dapat diprediksi.</span></em></p><p><em><span lang="EN-US"><em><span>In contrast to other stocks that fell quite sharply at the start of the Covid-19 pandemic, pharmaceutical stock price movements have increased. The increase in the price of pharmaceutical stocks is in line with investors' expectations of an increase in demand for medicines and health supplements, which will have an impact on the increase in stock prices in the market. This study empirically aims to examine the behavior of the chain buying and selling on the Indonesia Stock Exchange (IDX), namely PT Indo Farma Tbk (INAF), PT Kimia Farma Tbk (KAEF), PT Kalbe Farma Tbk (KLBF), PT Phapros Tbk (PEHA), PT Pyridam Farma Tbk (PYFA), and PT Tempo Scan Pacific Tbk (TSPC). Specifically, this study investigates whether to report whether pharmaceutical stocks during the Covid-19 Pandemic followed the Random Walk Hypothesis (RWH) or vice versa whether the price movements were predictable. The data used in this study are daily stock closing prices from January 2, 2020, to February 2, 2021. The data were analyzed using the Augmented Dickey-Fuller test for the existence of the Unit Root Test, Variance Ratio test, and Autoregressive Moving Average (ARMA). The result, based on the Unit Root Test, all data is stationary at the level. Further testing using the Variance Ratio, both by stand-alone intercept and trend and between all data also does not move randomly and does not follow the Random Walk Hypothesis. Finally, using the ARMA model, the log return movement of pharmaceutical stocks in IDX can be predicted.</span></em></span></em></p>
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WELLER, DAVID L., and JOSEPH F. COSTANTE. "PEROXIDASE ZYMOGRAMS OF 16 APPLE ROOTSTOCKS." Canadian Journal of Plant Science 66, no. 3 (July 1, 1986): 647–52. http://dx.doi.org/10.4141/cjps86-085.
Повний текст джерелаАнотація:
Shoot bark and root extracts of 16 different apple (Malus domestica Borkh.) root-stocks were analyzed for multiple electrophoretic forms of peroxidase (EC 1.11.1.7) using polyacrylamide gel electrophoresis (PAGE). Thirteen bands were seen in the peroxidase zymograms of shoot bark extracts and eight in the peroxidase zymograms of root extracts. The root peroxidase bands corresponded to ones in the shoot bark peroxidase zymograms. Two of the bands were common to all 16 rootstock patterns. The other 11 bands formed six patterns which were characterized by the presence of specific peroxidase bands. The 16 rootstocks were grouped according to banding characteristics.Key words: Apple, Malus domestica Borkh., apple rootstocks, PAGE-peroxidase zymograms
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Friggens, Nina L., Thomas J. Aspray, Thomas C. Parker, Jens-Arne Subke, and Philip A. Wookey. "Spatial patterns in soil organic matter dynamics are shaped by mycorrhizosphere interactions in a treeline forest." Plant and Soil 447, no. 1-2 (December 26, 2019): 521–35. http://dx.doi.org/10.1007/s11104-019-04398-y.
Повний текст джерелаАнотація:
Abstract Aims In the Swedish sub-Arctic, mountain birch (Betula pubescens ssp. czerepanovii) forests mediate rapid soil C cycling relative to adjacent tundra heaths, but little is known about the role of individual trees within forests. Here we investigate the spatial extent over which trees influence soil processes. Methods We measured respiration, soil C stocks, root and mycorrhizal productivity and fungi:bacteria ratios at fine spatial scales along 3 m transects extending radially from mountain birch trees in a sub-Arctic ecotone forest. Root and mycorrhizal productivity was quantified using in-growth techniques and fungi:bacteria ratios were determined by qPCR. Results Neither respiration, nor root and mycorrhizal production, varied along transects. Fungi:bacteria ratios, soil organic C stocks and standing litter declined with increasing distance from trees. Conclusions As 3 m is half the average size of forest gaps, these findings suggest that forest soil environments are efficiently explored by roots and associated mycorrhizal networks of B. pubescens. Individual trees exert influence substantially away from their base, creating more uniform distributions of root, mycorrhizal and bacterial activity than expected. However, overall rates of soil C accumulation do vary with distance from trees, with potential implications for spatio-temporal soil organic matter dynamics and net ecosystem C sequestration.
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Dangler, James M. "Alabama's Foundation Sweetpotato Program Maintains Root Quality." HortTechnology 4, no. 3 (July 1994): 224b—227. http://dx.doi.org/10.21273/horttech.4.3.224b.
Повний текст джерелаАнотація:
Many sweetpotato growers produce their own transplants to control quality, assure timely availability, and reduce production costs. The Alabama Crop Improvement Association, Inc., maintains Foundation, Registered, and Certified stocks to provide sweetpotato producers with high-quality sweetpotatoes. These sweetpotato roots are available to growers in any state to improve the quality of their rootstock. Sweetpotatoes produced in the crop improvement program are examined in the bed and the field. They are inspected by the Alabama Dept. of Agriculture and Industries, stored in approved facilities, graded, and shipped in clean crates that are tagged prior to transport and delivery to producers. As a result of the program, sweetpotatoes are produced free of serious diseases and pests, and exhibit the characteristics of the variety.
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Ko, Ching-Ru, and Hsien-Tsung Chang. "LSTM-based sentiment analysis for stock price forecast." PeerJ Computer Science 7 (March 11, 2021): e408. http://dx.doi.org/10.7717/peerj-cs.408.
Повний текст джерелаАнотація:
Investing in stocks is an important tool for modern people’s financial management, and how to forecast stock prices has become an important issue. In recent years, deep learning methods have successfully solved many forecast problems. In this paper, we utilized multiple factors for the stock price forecast. The news articles and PTT forum discussions are taken as the fundamental analysis, and the stock historical transaction information is treated as technical analysis. The state-of-the-art natural language processing tool BERT are used to recognize the sentiments of text, and the long short term memory neural network (LSTM), which is good at analyzing time series data, is applied to forecast the stock price with stock historical transaction information and text sentiments. According to experimental results using our proposed models, the average root mean square error (RMSE ) has 12.05 accuracy improvement.
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Li, Boran, Xiao Gui, and Qianyi Zhou. "Construction of Development Momentum Index of Financial Technology by Principal Component Analysis in the Era of Digital Economy." Computational Intelligence and Neuroscience 2022 (June 28, 2022): 1–12. http://dx.doi.org/10.1155/2022/2244960.
Повний текст джерелаАнотація:
The purpose is to study applying mathematical analysis in financial technology (FinTech) development in the era of digital economy. An Evaluation Index System (EIS) for the current situation of Chinese FinTech enterprises is established by considering the impact of the era of the digital economy on the development of FinTech. Specifically, the Principal Component Analysis (PCA) is introduced to construct the principal component prediction model based on functional data. Then, six Chinese State-owned Enterprises (SOEs) are selected. Their stock prices are predicted using the proposed model through an empirical study. The results show that selecting three principal components to evaluate the financial situations of six SOEs is reasonable. The accumulated variance values of the first three principal components of the stock’s closing price and opening price are all greater than 85%. Thus, the selected three principal components can obtain the potential information of the original data. The gap between the actual value and the proposed model-predicted value of the stocks of the six SOEs is relatively small. The Root Mean Square Error (RMSE) of China National Petroleum Corporation (CNPC) is 0.105, more than 10%. The predicted values of Huadian Energy and China Shenhua are 9.4% and 8.5%, respectively, second only to CNPC. Therefore, the proposed principal component prediction model based on functional data can predict the closing price of stocks well. The accuracy is relatively high and matches well with financial data analysis. This research has important implications for the development of FinTech.
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Firdaus, Mohamad, Nur Arina Bazilah Kamisan, Nur Arina Bazilah Aziz, and Chan Weng Howe. "MODELLING STOCK MARKET EXCHANGE BY AUTOREGRESSIVE INTEGRATED MOVING AVERAGE, MULTIPLE LINEAR REGRESSION AND NEURAL NETWORK." Jurnal Teknologi 84, no. 5 (July 26, 2022): 137–44. http://dx.doi.org/10.11113/jurnalteknologi.v84.18487.
Повний текст джерелаАнотація:
Stocks, sometimes known as equities, are fractional ownership shares in a firm, and the stock market is a venue where investors may purchase and sell these investible assets. Because it allows enterprises to quickly get funds from the public, a well-functioning stock market is critical to economic progress. The purpose of this study is to model Bursa Malaysia using autoregressive integrated moving average (ARIMA), multiple linear regression (MLR), and neural network (NN) model. To compare the modelling accuracy of these models for intraday trading, root mean square error (RMSE) and mean absolute percentage error (MAPE) as well as graphical plot will be used. From the results obtained from these three methods, the NN model provides the best trade signal.
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Lima, Augusto Miguel Nascimento, Ivo Ribeiro da Silva, Jose Luis Stape, Eduardo Sá Mendonça, Roberto Ferreira Novais, Nairam Félix de Barros, Júlio César Lima Neves, et al. "Modeling changes in organic carbon stocks for distinct soils in southeastern brazil after four eucalyptus rotations using the century model." Revista Brasileira de Ciência do Solo 35, no. 3 (June 2011): 833–47. http://dx.doi.org/10.1590/s0100-06832011000300018.
Повний текст джерелаАнотація:
Soil organic matter (SOM) plays an important role in carbon (C) cycle and soil quality. Considering the complexity of factors that control SOM cycling and the long time it usually takes to observe changes in SOM stocks, modeling constitutes a very important tool to understand SOM cycling in forest soils. The following hypotheses were tested: (i) soil organic carbon (SOC) stocks would be higher after several rotations of eucalyptus than in low-productivity pastures; (ii) SOC values simulated by the Century model would describe the data better than the mean of observations. So, the aims of the current study were: (i) to evaluate the SOM dynamics using the Century model to simulate the changes of C stocks for two eucalyptus chronosequences in the Rio Doce Valley, Minas Gerais State, Brazil; and (ii) to compare the C stocks simulated by Century with the C stocks measured in soils of different Orders and regions of the Rio Doce Valley growing eucalyptus. In Belo Oriente (BO), short-rotation eucalyptus plantations had been cultivated for 4.0; 13.0, 22.0, 32.0 and 34.0 years, at a lower elevation and in a warmer climate, while in Virginópolis (VG), these time periods were 8.0, 19.0 and 33.0 years, at a higher elevation and in a milder climate. Soil samples were collected from the 0-20 cm layer to estimate C stocks. Results indicate that the C stocks simulated by the Century model decreased after 37 years of poorly managed pastures in areas previously covered by native forest in the regions of BO and VG. The substitution of poorly managed pastures by eucalyptus in the early 1970´s led to an average increase of C of 0.28 and 0.42 t ha-1 year-1 in BO and VG, respectively. The measured C stocks under eucalyptus in distinct soil Orders and independent regions with variable edapho-climate conditions were not far from the values estimated by the Century model (root mean square error - RMSE = 20.9; model efficiency - EF = 0.29) despite the opposite result obtained with the statistical procedure to test the identity of analytical methods. Only for lower soil C stocks, the model over-estimated the C stock in the 0-20 cm layer. Thus, the Century model is highly promising to detect changes in C stocks in distinct soil orders under eucalyptus, as well as to indicate the impact of harvest residue management on SOM in future rotations.