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1
Arney, James D. "A modeling strategy for the growth projection of managed stands". Canadian Journal of Forest Research 15, n.º 3 (1 de junio de 1985): 511–18. http://dx.doi.org/10.1139/x85-084.
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Using a large data base of permanent research plots in coastal Douglas-fir, a growth projection strategy is developed. The emphasis is on stratifying growth influences into potential and modifier functions for components of diameter and height growth within a stand table. Growth periods are defined as equal increments of top height through time. The model developed is an individual-tree, distance-independent, stand-projection model.
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Robinson, Andrew P. y William R. Wykoff. "Imputing missing height measures using a mixed-effects modeling strategy". Canadian Journal of Forest Research 34, n.º 12 (1 de diciembre de 2004): 2492–500. http://dx.doi.org/10.1139/x04-137.
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This paper proposes a method whereby heightdiameter regression from an inventory can be incorporated into a height imputation algorithm. Point-level subsampling is often employed in forest inventory for efficiency. Some trees will be measured for diameter and species, while others will be measured for height and 10-year increment. Predictions of these missing measures would be useful for estimating volume and growth, respectively, so they are often imputed. We present and compare three imputation strategies: using a published model, using a localized version of a published model, and using best linear unbiased predictions from a mixed-effects model. The bases of our comparison are four-fold: minimum fitted root mean squared error and minimum predicted root mean squared error under a 2000-fold cross-validation for tree-level height and volume imputations. In each case the mixed-effects model proved superior. This result implies that substantial environmental variation existed in the heightdiameter relationship for our data and that its representation in the model by means of random effects was profitable.
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Deng, Yun, Xiaobao Deng, Jinlong Dong, Wenfu Zhang, Tao Hu, Akihiro Nakamura, Xiaoyang Song, Peili Fu y Min Cao. "Detecting Growth Phase Shifts Based on Leaf Trait Variation of a Canopy Dipterocarp Tree Species (Parashorea chinensis)". Forests 11, n.º 11 (29 de octubre de 2020): 1145. http://dx.doi.org/10.3390/f11111145.
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Canopy species need to shift their adaptive strategy to acclimate to very different light environments as they grow from seedlings in the understory to adult trees in the canopy. However, research on how to quantitively detect ecological strategy shifts in plant ontogeny is scarce. In this study, we hypothesize that changes in light and tree height levels induce transitions in ecological strategies, and growth phases representing different adaptive strategies can be classified by leaf trait variation. We examined variations in leaf morphological and physiological traits across a vertical ambient light (represented by the transmittance of diffuse light, %TRANS) and tree height gradient in Parashorea chinensis, a large canopy tree species in tropical seasonal rainforest in Southwestern China. Multivariate regression trees (MRTs) were used to detect the split points in light and height gradients and classify ontogenetic phases. Linear piecewise regression and quadratic regression were used to detect the transition point in leaf trait responses to environmental variation and explain the shifts in growth phases and adaptive strategies. Five growth phases of P. chinensis were identified based on MRT results: (i) the vulnerable phase, with tree height at less than 8.3 m; (ii) the suppressed phase, with tree height between 8.3 and 14.9 m; (iii) the growth release phase, with tree height between 14.9 and 24.3 m; (iv) the canopy phase, with tree height between 24.3 and 60.9 m; and (v) the emergent phase, with tree height above 60.9 m. The suppressed phase and canopy phase represent “stress-tolerant” and “competitive” strategies, respectively. Light conditions drive the shift from the “stress-tolerant” to the “competitive” strategy. These findings help us to better understand the regeneration mechanisms of canopy species in forests.
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Carvalho, Marcia Eugenia Amaral, Paulo Roberto de Camargo e. Castro, Marcos Vinicius de Castro Ferraz Junior y Ana Carolina Cabrera Machado Mendes. "Are plant growth retardants a strategy to decrease lodging and increase yield of sunflower?" Comunicata Scientiae 7, n.º 1 (10 de mayo de 2016): 154. http://dx.doi.org/10.14295/cs.v7i1.1286.
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One of the major disadvantages of sunflower cultivation is the increased plant height, making it prone to the lodging. The use of plant growth retardants can be an alternative strategy to reduce plant height; however, these compounds may affect productivity. The aim of this study was to evaluate the effects of plant growth retardants on sunflower development and yield. Four treatments were studied: 1- control; 2- gibberellic acid (GA) 10 mg L−1; 3- trinexapac-ethyl (TE) 5 mL L−1, and 4- maleic hidrazide (MH) 8 mL L−1. TE and MH decreased plant height (16.9 and 35.9%, respectively); however, only TE positively influenced capitulim diameter and dry mass (46.7 and 311%, when compared to control) at 60 days after planting (DAP). At 81 DAP, dry mass of capitulum did not differ among control and TE-treated plants. On the other hand, MH impaired diameter and dry mass of capitulum (92.9 and 74.7%, respectively). It can be concluded that the application of TE is a potential strategy to decrease lodging probability without affecting sunflower yield. Furthermore, although MH negatively affected sunflower development, its use on the crop cannot be excluded since other doses, frequencies and moment of application can be studied.
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Windyarini, Eritrina y Tri Maria Hasnah. "Identification and Seedlings Growth Evaluation of Shorea Species-Producing Tengkawang". Jurnal Wasian 2, n.º 1 (15 de marzo de 2015): 33. http://dx.doi.org/10.20886/jwas.v2i1.868.
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Most of non timber forest product (NTFP) utilization taken from natural forests which decrease on productivity annually, including tengkawang producer species which taken from West Kalimantan natural forests. This condition needs an effort to preserve those species from natural population utilization through plantation forest development that require spesific strategy. This study was part of breeding strategy of shorea species producing tengkawang which aimed to species identify and seedling growth evaluation used genetic material from 2 (two) population from West Kalimantan. The research was arranged in 2 (two) steps, i.e.1) species identification used morphology characteristic difference, and 2) seedling growth evaluation (height,diameter,sturdiness). Seedling growth evaluation was arranged in RCBD, with 5 plot (combination of species and source population), contained 25 seedlings and 4 replications (blocks). The result showed that seedlings of shorea species producing tengkawang, i.e. S.stenoptera, S.macrophylla, and S.gysbertsiana can be different from its stipulae morphology characteristic. Growth of 10 months shorea species producing tengkawang seedlings were significantly different on height and sturdiness. Seedlings height were 67,19 – 88,79 cm, seedlings diameter 9,65 – 10,33 mm and sturdiness 7 – 9,21 in range. The best seedling growth was S.stenoptera and S.macrophylla from Gunung Bunga, West Kalimantan.
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da Silva, Gilson Fernandes, Salvador Alejandro Gezan, Carlos Pedro Boechat Soares y Luciano Zumerle Zaneti. "Modeling Growth and Yield ofSchizolobium amazonicumunder Different Spacings". International Journal of Forestry Research 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/675137.
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This study aimed to present an approach to model the growth and yield of the speciesSchizolobium amazonicum(Paricá) based on a study of different spacings located in Pará, Brazil. Whole-stand models were employed, and two modeling strategies (Strategies A and B) were tested. Moreover, the following three scenarios were evaluated to assess the accuracy of the model in estimating total and commercial volumes at five years of age: complete absence of data (S1); available information about the variables basal area, site index, dominant height, and number of trees at two years of age (S2); and this information available at five years of age (S3). The results indicated that the 3 × 2 spacing has a higher mortality rate than normal, and, in general, greater spacing corresponds to larger diameter and average height and smaller basal area and volume per hectare. In estimating the total and commercial volumes for the three scenarios tested, Strategy B seems to be the most appropriate method to estimate the growth and yield of Paricá plantations in the study region, particularly because Strategy A showed a significant bias in its estimates.
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Strefeler, Mark S. "Growth Response of 20 Seed Geranium Cultivars to Three Day–Night Temperature Regimes". HortScience 30, n.º 7 (diciembre de 1995): 1465–66. http://dx.doi.org/10.21273/hortsci.30.7.1465.
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The influence of temperature and genotype on plant height, internode length, and morphological development of 20 cultivars of Pelargonium ×hortorum Bailey were determined by growing plants under one of three day–night temperature regimes (18/18C, 18/24C, and 24/18C). Temperature regime influenced internode length and plant height regardless of plant genotype. Internode length and plant height increased as the day–night temperature differential (DIF) increased from –6 to 6C. Average internode length increased from 5.3 ± 0.2 mm for –6C DIF to 6.3 ± 0.2 mm for +6C DIF. Genotypes differed for average internode length (4.2 to 8.7 mm) and plant height (54 to 95 mm). Node count increased as average daily temperature (ADT) increased. Node counts were 11.2 at 18/18C (ADT = 18), 11.9 at 24/18C (ADT = 20.3), and 12.1 at 18/24C (ADT = 21.8). Genotype × temperature interactions were not significant for the recorded traits. This study demonstrates that DIF is an effective height control strategy, regardless of geranium genotype, and that DIF combined with the selection of genetically short cultivars may eliminate the need for chemical height control in the commercial production of geraniums.
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Zaitsev, Gleb, Alexander Davydychev, Alexey Kulagin, Rafak Giniyatullin, Ruslan Suleymanov, Andrey Kulagin, Natalya Egorova, Mikhail Komissarov, Ruslan Urazgildin y Olesya Tagirova. "Suppressed Undergrowth of Siberian Spruce (Picea obovata Ledeb.) in Early Ontogeny: One-Way Ticket or Survival Strategy?" Forests 12, n.º 7 (28 de junio de 2021): 851. http://dx.doi.org/10.3390/f12070851.
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The study examined the growth characteristics of the Siberian spruce (Picea obovata Ledeb.) under the canopy of coniferous forests in early ontogeny. We revealed that spruce undergrowth in adverse conditions is suppressed, is slow to grow and has xylorhizomes. The result is a significant difference in height, age and stage of ontogeny that affects the forest’s growth dynamics. The formation of xylorhizomes changes the relative dimensions of the above-ground part and the plant’s absolute height from 42 to 75%, depending on age. We identified two periods of growth intensity (slow and stable) and the critical age for spruce undergrowth to move from one stage of ontogeny to the next. If it does not make the transition, it will die. There are two strategies for developing spruce undergrowth: a “direct” path during rapid growth and a “waiting” path when the plants are suppressed. Such growth pathways in the pre-generative stage of the Siberian spruce’s ontogeny allow the undergrowth, even in a suppressed state, to survive in an adverse environment under the forest canopy.
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Mendley, Susan R., Fotios Spyropoulos y Debra R. Counts. "Short Stature in Chronic Kidney Disease Treated with Growth Hormone and an Aromatase Inhibitor". Case Reports in Pediatrics 2015 (2015): 1–4. http://dx.doi.org/10.1155/2015/738571.
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We describe an alternative strategy for management of severe growth failure in a 14-year-old child who presented with advanced chronic kidney disease close to puberty. The patient was initially treated with growth hormone for a year until kidney transplantation, followed immediately by a year-long course of an aromatase inhibitor, anastrozole, to prevent epiphyseal fusion and prolong the period of linear growth. Outcome was excellent, with successful transplant and anticipated complete correction of height deficit. This strategy may be appropriate for children with chronic kidney disease and short stature who are in puberty.
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Weber, John C., Carmen Sotelo Montes, Julio Ugarte y Tony Simons. "Phenotypic Selection of Calycophyllum spruceanum on Farms in the Peruvian Amazon: Evaluating a Low-Intensity Selection Strategy". Silvae Genetica 58, n.º 1-6 (1 de diciembre de 2009): 172–79. http://dx.doi.org/10.1515/sg-2009-0023.
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AbstractA low-intensity selection strategy was recommended for timber trees in the Peruvian Amazon to maintain genetic variation on farms and produce modest gains in tree growth. The effectiveness of this strategy was evaluated using Calycophyllum spruceanum. Farmers selected 66 mother trees of different ages on farms in seven locations (~20% of all trees in the locations) in one watershed, based on a visual assessment of growth, form and external disease symptoms. Another 66 mother trees were chosen at random. Tree height, stem diameter, stem bifurcations and mortality of progeny of the selected and random groups of mother trees were evaluated at 15, 26 and 38 months in a provenance/progeny test located on farms in the same watershed. Height was significantly greater (10%) in the selected group at 15 months, but it did not differ significantly between the selected and random groups at 26 and 38 months. There were no significant differences in diameter, bifurcations and mortality between the groups. There was significant variation in height and diameter at all measurement ages due to families, and results suggested that variation in bifurcations and mortality due to families was also significant. Based on approximate 95% confidenceintervals, family variances in height and diameter did not differ significantly between the selected and random groups at any measurement age, but evaluations should continue to confirm these tentative conclusions. Some practical implications for tree improvement programs are discussed.
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SUÁREZ-ISLAS, Alfonso, Juan CAPULÍN-GRANDE y José J. MATEO-SÁNCHEZ. "Performance of Dalbergia palo-escrito Rzed. & Guridi-Gómez, a valuable timber tree, in a coffee plantation in Hidalgo, Mexico". BOIS & FORETS DES TROPIQUES 344 (21 de julio de 2020): 47–57. http://dx.doi.org/10.19182/bft2020.344.a31899.
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As a contribution to ex-situ conservation and production recovery of the valuable timber tree species Dalbergia palo-escrito Rzed. & Guridi-Gómez, enrichment planting was undertaken in a coffee plantation at 830 m above sea level in the east of the State of Hidalgo, Mexico. The purpose of this study was to assess the growth and health status of this species in order to put forward forest management recommendations. Average growth at 11 years of age (n = 56) was as follows: normal diameter, 13.2 ± 2.9 cm; total height, 10.9 ± 1.9 m. These values represent a mean annual increase of 1.2 cm/year in diameter and 1.0 m/year in height. Significant statistical differences in diameter growth (P = 0.0001) and height growth (P = 0.003) were observed as a function of crown position; growth, both in diameter and height, was highest in trees with emergent crowns in comparison with poorly lit trees. An association was also found concerning infestation by Struthanthus sp. mistletoe: differences in diameter growth (P = 0.002) were found between trees with mild infestation in comparison with healthy trees, which showed more growth. On the other hand, no height growth differences were detected (P = 0.102). Diameter and height growth were comparable to other commercially valuable species of fine Dalbergia timber on the international market, such as Dalbergia sissoo in India and Dalbergia retusa in mixed plantations in Costa Rica. The study suggests pruning out the mistletoe as a control strategy is a recommended forest management practice, as well as releasing poorly illuminated trees from competition and preserving the shade canopy of other native species.
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Weng, E. S., S. Malyshev, J. W. Lichstein, C. E. Farrior, R. Dybzinski, T. Zhang, E. Shevliakova y S. W. Pacala. "Scaling from individuals to ecosystems in an Earth System Model using a mathematically tractable model of height-structured competition for light". Biogeosciences Discussions 11, n.º 12 (19 de diciembre de 2014): 17757–860. http://dx.doi.org/10.5194/bgd-11-17757-2014.
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Abstract. The long-term and large scale dynamics of ecosystems are in large part determined by the performances of individual plants in competition with one another for light, water and nutrients. Woody biomass, a pool of carbon (C) larger than 50% of atmospheric CO2, exists because of height-structured competition for light. However, most of the current Earth System Models that predict climate change and C cycle feedbacks lack both a mechanistic formulation for height-structured competition for light and an explicit scaling from individual plants to the globe. In this study, we incorporate height-structured competition and explicit scaling from individuals to ecosystems into the land model (LM3) currently used in the Earth System Models developed by the Geophysical Fluid Dynamics Laboratory (GFDL). The height-structured formulation is based on the Perfect Plasticity Approximation (PPA), which has been shown to accurately scale from individual-level plant competition for light, water and nutrients to the dynamics of whole communities. Because of the tractability of the PPA, the coupled LM3–PPA model is able to include a large number of phenomena across a range of spatial and temporal scales, and still retain computational tractability, as well as close linkages to mathematically tractable forms of the model. We test a range of predictions against data from temperate broadleaved forests in the northern USA. The results show the model predictions agree with diurnal and annual C fluxes, growth rates of individual trees in the canopy and understory, tree size distributions, and species-level population dynamics during succession. We also show how the competitively optimal allocation strategy – the strategy that can competitively exclude all others – shifts as a function of the atmospheric CO2 concentration. This strategy is referred as an evolutionary stable strategy (ESS) in the ecological literature and is typically not the same as a productivity- or growth-maximizing strategy. Model simulations predict that C sinks caused by CO2 fertilization in forests limited by light and water will be down-regulated if allocation tracks changes in the competitive optimum. The implementation of the model in this paper is for temperate broadleaved forest trees, but the formulation of the model is general. It can be expanded to include other growth forms and physiologies simply by altering parameter values.
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Matsui, Naohiro y Fumio Takahashi. "Determination of Soil-Related Factors Controlling Initial Nipa (Nypa fruticans Wurmb.) Growth in an Abandoned Shrimp Pond". Environment and Natural Resources Research 6, n.º 1 (29 de febrero de 2016): 125. http://dx.doi.org/10.5539/enrr.v6n1p125.
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<p class="1Body">In an abandoned shrimp pond, the spatial variability of the height of nipa (<em>Nypa fruticans</em> Wurmb.) plants 5 years after their planting was evaluated to elucidate the determining factors for height. Soil properties were evaluated in 20 points in an area of 0.48 ha. Physical (e.g., hardness, water content) and chemical (e.g., pH and EC) properties were determined using surface soil samples collected at each point. Nipa height was moderately variable, showing a CV value of 31.2%. Soil conditions were considered to affect nipa height; therefore, principal component analysis (PCA) was conducted to elucidate the relationships among soil properties. As a result, three factors were extracted. PC1 correlated positively with relative ground level and Eh, and negatively with moisture. Because these properties were closely related to topography, PC1 was referred to as the topography factor. PC3 showed the second important contribution, a high K content contributed to a large nipa height. Multivariate analysis was also performed to examine the spatial property of nipa height (H), and as a result, the following equation was obtained: H = 423.94 - 0.39 x PC1 - 0.57 x PC3 (r<sup>2</sup>=0.53). Results of this study indicate that 53% of nipa height variation was explained by soil properties, which is larger than the nipa height variation explained solely by topography (23%). Site-specific management to regulate soil properties could be a practical strategy for nipa plantation.</p>
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de Zegher, Francis, Nele Reynaert, Lien De Somer, Carine Wouters y Mathieu Roelants. "Growth Failure in Children with Systemic Juvenile Idiopathic Arthritis and Prolonged Inflammation despite Treatment with Biologicals: Late Normalization of Height by Combined Hormonal Therapies". Hormone Research in Paediatrics 90, n.º 5 (2018): 337–43. http://dx.doi.org/10.1159/000489778.
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Background: Biologicals targeting the interleukin (IL)-1β or IL-6 pathway are becoming prime choices for the treatment of children with systemic juvenile idiopathic arthritis (sJIA). Up to 1 in 3 sJIA children receiving such treatment continues to have inflammatory activity and to require supra-physiological glucocorticoid doses which may reduce growth velocity for years and may lead to an extremely short stature for age, if not for life. Currently, there is no long-term proposal to normalize the adult height of these children with sJIA. Methods and Results: We present long-term (up to 10 years), proof-of-concept evidence that the adult stature and adipose body composition of short sJIA children can be normalized with a hormonal combination strategy: (i) pubertal onset is postponed with a gonadotropin-releasing hormone analog (triptorelin) until a minimum height is reached, or until prepubertal growth is exhausted, and (ii) height gain is promoted with growth hormone (≈50 μg/kg/day), once inflammation is under control and high glucocorticoid doses are no longer needed. The latter treatment takes advantage of the window of relative glucocorticoid deficiency, which is known to open after prolonged glucocorticoid administration, and to be uniquely favorable to height gain. Conclusion: A long-term combination of biological and hormonal treatments for short sJIA children can be guided by a simple concept that involves (i) postponement of pubertal development and (ii) growth-promoting therapy after the episodes of major inflammation and high-dose glucocorticoid treatment. Limited long-term experience in short sJIA children suggests that this strategy leads consistently – albeit late – to a normal adult stature.
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Yagi, Takanobu. "Ontogenetic strategy shift in sapling architecture of Fagus crenata in the dense understorey vegetation of canopy gaps created by selective cutting". Canadian Journal of Forest Research 39, n.º 6 (junio de 2009): 1186–96. http://dx.doi.org/10.1139/x09-056.
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Ontogenetic architectural variation is a key aspect of the light foraging of saplings under canopy gaps, where the interactions with the surrounding understorey plants are intense and change as saplings grow. Therefore, relationships between the allometry of 58 Fagus saplings (15–184 cm tall) and both the surrounding vegetation and light environment were investigated in the dense understorey of canopy gaps. The light available to the saplings exhibited a positive exponential relationship to their height, and at a given sapling height, it was inversely related to the height of the surrounding understorey. The slenderness of the saplings' stems increased as their height increased, and their crown architecture shifted from horizontally spread monolayer to vertically extended multilayer forms, indicating an ontogenetic strategy shift from shade tolerance to shade avoidance. These changes in sapling architecture were independent of the height of the surrounding understorey and, therefore, light availability, although the length of their current-year shoots (reflecting the rate of architectural development) was inversely related to the surrounding understorey height. Thus, ontogenetic architectural variation in Fagus saplings probably has the character of a developmentally programmed growth trajectory preadjusted to the most likely environments; the surrounding environments mainly affect the rate at which saplings move along this trajectory.
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Weng, E. S., S. Malyshev, J. W. Lichstein, C. E. Farrior, R. Dybzinski, T. Zhang, E. Shevliakova y S. W. Pacala. "Scaling from individual trees to forests in an Earth system modeling framework using a mathematically tractable model of height-structured competition". Biogeosciences 12, n.º 9 (7 de mayo de 2015): 2655–94. http://dx.doi.org/10.5194/bg-12-2655-2015.
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Abstract. The long-term and large-scale dynamics of ecosystems are in large part determined by the performances of individual plants in competition with one another for light, water, and nutrients. Woody biomass, a pool of carbon (C) larger than 50% of atmospheric CO2, exists because of height-structured competition for light. However, most of the current Earth system models that predict climate change and C cycle feedbacks lack both a mechanistic formulation for height-structured competition for light and an explicit scaling from individual plants to the globe. In this study, we incorporate height-structured competition for light, competition for water, and explicit scaling from individuals to ecosystems into the land model version 3 (LM3) currently used in the Earth system models developed by the Geophysical Fluid Dynamics Laboratory (GFDL). The height-structured formulation is based on the perfect plasticity approximation (PPA), which has been shown to accurately scale from individual-level plant competition for light, water, and nutrients to the dynamics of whole communities. Because of the tractability of the PPA, the coupled LM3-PPA model is able to include a large number of phenomena across a range of spatial and temporal scales and still retain computational tractability, as well as close linkages to mathematically tractable forms of the model. We test a range of predictions against data from temperate broadleaved forests in the northern USA. The results show the model predictions agree with diurnal and annual C fluxes, growth rates of individual trees in the canopy and understory, tree size distributions, and species-level population dynamics during succession. We also show how the competitively optimal allocation strategy – the strategy that can competitively exclude all others – shifts as a function of the atmospheric CO2 concentration. This strategy is referred to as an evolutionarily stable strategy (ESS) in the ecological literature and is typically not the same as a productivity- or growth-maximizing strategy. Model simulations predict that C sinks caused by CO2 fertilization in forests limited by light and water will be down-regulated if allocation tracks changes in the competitive optimum. The implementation of the model in this paper is for temperate broadleaved forest trees, but the formulation of the model is general. It can be expanded to include other growth forms and physiologies simply by altering parameter values.
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Jobidon, Robert. "Light threshold for optimal black spruce (Piceamariana) seedling growth and development under brush competition". Canadian Journal of Forest Research 24, n.º 8 (1 de agosto de 1994): 1629–35. http://dx.doi.org/10.1139/x94-211.
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Light threshold is suggested as a method for quantifying brush competition in black spruce (Piceamariana (Mill.) B.S.P) plantations and predicting losses in tree growth as measured by the relative growth rate (RGR). The severity of the competing vegetation (expressed in terms of density and height) around 300 planted tree seedlings, and the growth status of the seedlings (expressed in terms of total height and current height growth increment), were analyzed simultaneously with multivariate analysis of variance (MANOVA), with one level of light quantity (photosynthetically active radiation) reaching the upper one-half of the tree seedlings as the predictor variable. This study showed that it is possible to establish a competitive status based on light interception, thus allowing a grouping of seedlings with similar growth characteristics and severity of competition. Canonical analysis showed that 60% of full sunlight reaching the upper one half of spruce seedlings can be defined as a threshold to significantly discriminate between stressed and unstressed tree seedlings, based on the above-mentioned variables and also based on spruce basal stem diameter. For spruce total height, current height increment, and basal stem diameter, significant differences were found between plots above and below this threshold, averaging 18.5, 44.7, and 23.2%, respectively. Measuring the intensity of light reaching the upper one half of the spruce seedlings also significantly explains spruce relative growth rates, expressed in terms of height growth increment and basal stem diameter growth increment over the following two growing seasons. The light threshold used in the MANOVA and the ANOVA showed significant differences between plots above and below the threshold, averaging 70 and 58% for spruce height and basal stem diameter RGRs, respectively. Instead of measuring competing vegetation variables and relative height of a crop species to infer light interception, this study demonstrated that a direct measure of light attenuation at the tree seedling level can be used to assess the competitive status and predict losses in tree growth for the period of time required by the seedlings to emerge from the vegetation cover. Moreover, this study demonstrated that canonical relations, rather than linear relations, explain the pattern of competition for light between young spruce seedlings and brushlike vegetation. The light threshold suggested in this study has potential for assessing interspecific competition problems in young black spruce plantations and is proposed as a tool to support a containment strategy of vegetation management.
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Válio, Ivany Ferraz Marques. "Seedling growth of understorey species of a Southeast Brazilian tropical forest". Brazilian Archives of Biology and Technology 46, n.º 4 (diciembre de 2003): 697–703. http://dx.doi.org/10.1590/s1516-89132003000400024.
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Thirteen understorey species of a mesophyllous tropical forest were studied under two different photosynthetic photon flux densities (PPFD). Seedlings were grown in the glasshouse under 51% and 2.6% solar PPFD. Growth of the seedlings was evaluated by 1-) total height; 2-) leaf number; 3-) leaf dry mass;4-) stem dry mass; 5-) root dry mass; 6-) stem length/mass; 7-)shoot/root mass; 8-) percent allocation to leaf, stem and roots. For most of the parameters recorded, low PPFD drastically reduced growth. It seemed that the strategy of these understorey species was a reduction of growth under low PPFD saving energy for survival.
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Kabzems, Richard, Philip G. Comeau, Cosmin N. Filipescu, Bruce Rogers y Amanda F. Linnell Nemec. "Creating boreal mixedwoods by planting spruce under aspen: successful establishment in uncertain future climates". Canadian Journal of Forest Research 46, n.º 10 (octubre de 2016): 1217–23. http://dx.doi.org/10.1139/cjfr-2015-0440.
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Planting white spruce (Picea glauca (Moench) Voss) under established aspen (Populus tremuloides Michx.) stands has substantial potential for regenerating mixedwood ecosystems in the western Canadian boreal forest. The presence of an aspen overstory serves to ameliorate frost and winter injury problems and suppresses understory vegetation that may compete with white spruce. Under future climatic regimes with more frequent and severe drought episodes, underplanting may be a cost-effective strategy for lowering the risk of mortality in mixedwood regeneration. We examine the growth of white spruce during the first 18 years after being planted beneath a 39-year-old stand of trembling aspen. Treatments included thinning from over 6000 stems·ha−1 to 3000, 2000, and 1000 stems·ha−1 and fertilization. Initial stimulation of understory vegetation by fertilization had no measureable effect on spruce heights or diameters at year 18. Aspen thinning treatments did not have a significant effect on spruce height growth rates after spruce crowns had emerged above the understory shrub layer due to rapid aspen basal area increases after thinning. Small, but significant, increases for spruce height and diameter were present in the 1000 and 2000 stem·ha−1 aspen thinnings. A much wider range of aspen stand conditions may be suitable for planting spruce to create mixedwood ecosystems than has been previously considered.
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Zhao, Qianqian, Mei Zhang, Yuntian Chu, Hailing Sun, Hui Pan y Bo Ban. "A Retrospective Analysis of Patients with Short Stature in Eastern China between 2013 and 2019". BioMed Research International 2021 (20 de abril de 2021): 1–8. http://dx.doi.org/10.1155/2021/6640026.
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Objective. To identify the aetiology of growth and development diseases and assess the long-term effectiveness of recombinant human growth hormone (rhGH) therapy in a real-life clinical setting and provide better guidance in clinical strategy and decision making. Methods. This retrospective study included 1145 children and adolescents with short stature admitted to the Department of Endocrinology, Affiliated Hospital of Jining Medical University, from January 2013 to December 2019, of whom 484 received rhGH treatment. The related anthropometrics and laboratory examinations were assessed in all participants. Results. A total of 1145 children and adolescents with short stature aged 10.5 ± 3.3 years, including 740 boys and 405 girls, were analysed in this study. The number of children and adolescents with short stature gradually increased per year from 2013 to 2019. The mean pretreatment height standard deviation score (SDS) and insulin-like growth factor-1 SDS were − 2.93 ± 1.05 and -1.01 (-1.83--0.16), respectively. The majority of the children (658, 57.47%) were prepubescent. In total, 484 subjects aged 10.6 ± 3.2 years received rhGH and were followed up, and among them, 292 children were treated for more than one year. As the treatment time increased, the children’s height SDS gradually increased, and most of them attained a height SDS within the normal range. The mean height SDS in children who were treated for more than one year was − 3.0 ± 1.0 at baseline and gradually increased to − 0.8 ± 0.3 by year 6. The results were consistent across subgroups of different aetiologies of short stature. Conclusions. Increasing attention has been given to the height of children during the period of 2013–2019 in eastern China. The present findings indicate that children with short stature need to be referred to a specialist centre to diagnose the cause of growth failure and that short children receiving rhGH therapy show a significant increase in height over time.
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Agehara, Shinsuke y Daniel I. Leskovar. "Growth Reductions by Exogenous Abscisic Acid Limit the Benefit of Height Control in Diploid and Triploid Watermelon Transplants". HortScience 49, n.º 4 (abril de 2014): 465–71. http://dx.doi.org/10.21273/hortsci.49.4.465.
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Height control is important to produce compact vegetable transplants that are suitable for shipping and transplanting. Although abscisic acid (ABA) inhibits stem elongation, it can also induce other growth modifications. To optimize its application timing for effective height control, we examined age-dependent sensitivity of various growth variables to ABA in diploid ‘Summer Flavor 800’ and triploid ‘Summer Sweet 5244’ watermelon [Citrullus lanatus (Thunb.) Matsum & Nakai]. Seedlings were sprayed once with 1.9 mm ABA at 25, 18, or 11 days before transplanting (DBT) or twice with 0.95 mm ABA at 25 and 18 DBT. The application rate was 0.55 mg ABA per plant with a spray volume of 0.61 L·m−2 (1.1 mL/plant). Only the single-spray treatment at 25 DBT (cotyledon stage) suppressed plant height by inhibiting petiole elongation. This effect was similar in both cultivars with 13% to 14% reductions at the transplanting stage compared with the untreated control. Undesirable growth modifications were also induced by ABA. In both cultivars, all ABA treatments caused 16% to 23% shoot biomass reductions mainly by inhibiting leaf expansion. Additionally, ABA treatments reduced stem diameter and root biomass in ‘Summer Flavor 800’. The double-spray treatment had similar growth-modulating effects as the single-spray treatments, except that it induced cotyledon abscission in ‘Summer Flavor 800’. These results suggest that although ABA applied at the cotyledon stage can reduce watermelon transplant height, the benefit is limited because of overall growth reductions, which can occur regardless of application timing. On the other hand, in triploid ‘Summer Sweet 5244’, moderate shoot growth delay by ABA may be of value as a growth-holding strategy when transplanting is delayed because of inclement weather at the time of field establishment. Importantly, field evaluations demonstrated that the growth modulation by ABA is only transient with no negative impact on marketable yield and fruit quality.
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Wu, Su, Qian-qi Liu, Wei Gu, Shi-ning Ni, Xing Shi y Zi-yang Zhu. "A Retrospective Analysis of Patients with Short Stature in the South of China between 2007 and 2015". BioMed Research International 2018 (20 de diciembre de 2018): 1–8. http://dx.doi.org/10.1155/2018/5732694.
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Objective. To describe the demographic features of children with short stature and poor growth in the south of China and provide better guidance on clinical strategy and decisions. Study Design. This retrospective, chart review study analyzed children with short stature and poor growth admitted to the Department of Endocrinology of Children’s Hospital of Nanjing Medical University from Jan 2007 to Dec 2015. Results. The chart review yielded 4142 patients, including 2546 boys and 1596 girls (P < 0.001); the number of patients gradually increased per year from 2007 to 2015. There was an upward trend in the average levels of height standard deviations (SDs) during the study period (P < 0.001), both in males (P < 0.001) and females (P < 0.001). Mean height SDs were smaller in females (-2.42±1.09) than males (-2.33±1.03; P = 0.01). The percentage of females admitted at normal height (33.83%) was lower than that of males (37.20%; P = 0.028). The peak age range of hospitalization in males was 10–12 years of age, while females were generally admitted earlier—8–10 years. Conclusions. There was an increasing tendency to focus on children’s height. Parents and pediatricians were recommended to pay more attention to the treatment needs of girls while avoiding excessive treatment of those who merely appear not to be tall enough without a clear medical issue related to growth, especially for boys.
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Wawrzyniak, Mikołaj, Artur Szwengiel, Marta Stelmach-Mardas y Roman Hołubowicz. "Effect of Chlorocholine Chloride (CCC) on the Plants’ Height and Inulin Content in Jerusalem Artichoke (Helianthus tuberosus L.)". Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Horticulture 73, n.º 2 (30 de noviembre de 2016): 210. http://dx.doi.org/10.15835/buasvmcn-hort:11957.
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Jerusalem artichoke (Helianthus tuberosus L.) is herbaceous perennial plant rich in inulin and useful source of biomass. Due to its low agricultural requirements and high adaptability, it can provide very high biomass yields even on low quality sites. The plant is used in food industry, bio-fuel production, forage, pharmacy and nutrition. Its tubers accumulate approx. 10-20% of inulin in fresh weight. Currently, the use of the Helianthius tuberosus L. as a potential dietary strategy in patients affected by type 2 Diabetes is challenge. Moreover, deep understanding of the relationship between diet and composition of gut microbiota can bring the new insight in the treatment of inflammatory dependent diseases. The aim of this study was to examine an effect of plant growth retardant Chlorocholine Chloride (CCC) on the plants’ height of H. tuberosus and inulin content in the tubers. We examined in the field a procedure for its shoots reduction. Material for the experiment were bought in a Polish commercial company and 528 tubers were planted in field in the middle of April 2014. Then, half of them were sprayed with 0.75% retardant of CCC . Furthermore, every week for 12 following weeks, the plants’ heights were measured. After the vegetation was over, 6 tubers for each treatment were dug out and chemically analyzed for inulin content using High Pressure Size Exclusion Chromatography. After first week of CCC use, 16% decrease of the heights plants was observed. Height of plants sprayed with CCC were significantly different comparing to Control. Weekly growth was significantly slower in plants sprayed with CCC on first three weeks after applying retardant. Differences in plants height sustain to the end of measurements. Used retardant and its concentration did not affect the inulin content of the tubers.
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Godara, Rakesh K., Billy J. Williams y James P. Geaghan. "Effect of Shade on Texasweed (Caperonia palustris) Emergence, Growth, and Reproduction". Weed Science 60, n.º 4 (diciembre de 2012): 593–99. http://dx.doi.org/10.1614/ws-d-12-00006.1.
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Experiments were conducted on potted plants under field conditions in 2007 and 2008 at the Louisiana State University Agricultural Center's Northeast Research Station near St. Joseph, LA, to evaluate Texasweed response to shade. Shade levels of 30, 50, 70, and 90% were achieved using 1.8-m by 1.8-m by 1.8-m tents built using 2.54-cm-diam polyvinyl chloride (PVC) pipe and polypropylene fabric. Shade had no effect on Texasweed emergence but significantly reduced its growth. There were significant growth differences between plants transferred directly and gradually to a given shade level. At 100 d after emergence, plants gradually exposed to 30, 50, 70, and 90% shade had 13, 22, 37, and 58% less total dry matter per plants, respectively, than did those in 0% shade. Texasweed height in 70 and 90% shade was increased by 28 and 20%, respectively. Texasweed seemed to mitigate the adverse effect of shade by increasing specific leaf area (SLA) and percentage of leaf biomass. Increasing SLA and the percentage of leaf biomass appears to be a strategy for efficient allocation of biomass for light capture and carbohydrate synthesis, which can be used for height increase until the plant rises above the crop canopy. Although fruit production was significantly reduced, Texasweed was able to reproduce in 90% shade.
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Ramiro, Pedro, Mikel Ortiz, Amaia Alberdi y Aitzol Lamikiz. "Strategy Development for the Manufacturing of Multilayered Structures of Variable Thickness of Ni-Based Alloy 718 by Powder-Fed Directed Energy Deposition". Metals 10, n.º 10 (24 de septiembre de 2020): 1280. http://dx.doi.org/10.3390/met10101280.
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In this study, a manufacturing strategy, and guidelines for inclined and multilayered structures of variable thickness are presented, which are based on the results of an own-developed geometrical model that obtains both the coating thickness and dilution. This model is developed for the powder-fed directed energy deposition process (DED) and it only uses the DED single-track cladding characteristics (height, width, area, and dilution depth), the overlap percentage, and the laser head tilting-angle as inputs. As outputs, it calculates both the cladding geometry and the dilution area of the coating. This model for the Ni-based alloy 718 was improved, based on previous studies of the single clad working both vertically and at an inclined angle, adding the equations of the single clad characteristics with respect to the main process parameters. The strategy proposed in this paper for multilayered cladding consisted of both adding an extra clad at the edges of the layer and using a variable value of the overlap percentage between clads for geometric adaptations. With this strategy, the material deposition is more accurate than otherwise, and it shows stable growth. Manufacturing a multilayered wall of wider thicknesses at higher heights was utilized to validate the strategy.
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Butts, Thomas R., Jason K. Norsworthy, Greg R. Kruger, Lowell D. Sandell, Bryan G. Young, Lawrence E. Steckel, Mark M. Loux et al. "Management of Pigweed (Amaranthusspp.) in Glufosinate-Resistant Soybean in the Midwest and Mid-South". Weed Technology 30, n.º 2 (junio de 2016): 355–65. http://dx.doi.org/10.1614/wt-d-15-00076.1.
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Pigweeds are among the most abundant and troublesome weed species across Midwest and mid-South soybean production systems because of their prolific growth characteristics and ability to rapidly evolve resistance to several herbicide sites of action. This has renewed interest in diversifying weed management strategies by implementing integrated weed management (IWM) programs to efficiently manage weeds, increase soybean light interception, and increase grain yield. Field studies were conducted across 16 site-years to determine the effectiveness of soybean row width, seeding rate, and herbicide strategy as components of IWM in glufosinate-resistant soybean. Sites were grouped according to optimum adaptation zones for soybean maturity groups (MGs). Across all MG regions, pigweed density and height at the POST herbicide timing, and end-of-season pigweed density, height, and fecundity were reduced in IWM programs using a PRE followed by (fb) POST herbicide strategy. Furthermore, a PRE fb POST herbicide strategy treatment increased soybean cumulative intercepted photosynthetically active radiation (CIPAR) and subsequently, soybean grain yield across all MG regions. Soybean row width and seeding rate manipulation effects were highly variable. Narrow row width (≤ 38 cm) and a high seeding rate (470,000 seeds ha−1) reduced end-of-season height and fecundity variably across MG regions compared with wide row width (≥ 76 cm) and moderate to low (322,000 to 173,000 seeds ha−1) seeding rates. However, narrow row widths and high seeding rates did not reduce pigweed density at the POST herbicide application timing or at soybean harvest. Across all MG regions, soybean CIPAR increased as soybean row width decreased and seeding rate increased; however, row width and seeding rate had variable effects on soybean yield. Furthermore, soybean CIPAR was not associated with end-of-season pigweed growth and fecundity. A PRE fb POST herbicide strategy was a necessary component for an IWM program as it simultaneously managed pigweeds, increased soybean CIPAR, and increased grain yield.
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Bian, Liming, Jisen Shi, Renhua Zheng, Jinhui Chen y Harry X. Wu. "Genetic parameters and genotype–environment interactions of Chinese fir (Cunninghamia lanceolata) in Fujian Province". Canadian Journal of Forest Research 44, n.º 6 (junio de 2014): 582–92. http://dx.doi.org/10.1139/cjfr-2013-0427.
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Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is the most commercially important conifer in China, and the Nanjing Forestry University – Fujian Province Chinese fir Cooperation (NJFU – Fujian Cooperation) breeding program has advanced it into the third cycle of selection and breeding. In this paper, we estimated genetic parameters from four sites for 80 half-sib families and summarized previous estimates of genetic parameters in Chinese fir with an objective to propose optimal breeding strategy. Heritability averaged 0.20 and 0.14 for height and diameter at breast height (DBH), respectively, for the four sites. A significant genotype–environment interaction (G × E) for growth was also observed among the four sites, with the greatest interactions between a marginal site and the three central sites in the Fujian Province Chinese fir plantation region. The average estimated type-B genetic correlation between the marginal site and the three central sites was 0.08 for height and –0.09 for DBH. However, the highly productive families were among the most stable across the four sites. The results from this study in combination with summarized genetic parameters from literature were used to discuss and propose an optimal breeding strategy for the third generation of the breeding program for Chinese firs in Fujian Province.
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Coelho, Antonio Eduardo, Luis Sangoi, Alvadi Antonio Balbinot Junior, Samuel Luiz Fioreze, Juliano Berghetti, Hugo François Kuneski, Lucieli Santini Leolato y Marcos Cardoso Martins Júnior. "Growth patterns and yield of maize (Zea mays) hybrids as affected by nitrogen rate and sowing date in southern Brazil". Crop and Pasture Science 71, n.º 12 (2020): 976. http://dx.doi.org/10.1071/cp20077.
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Sowing date and nitrogen (N) fertilisation modify the morpho-physiological characteristics of maize (Zea mays L.) plants, which can alter the yield. The aim of this study was to analyse the effects of sowing date and N rate on the growth-pattern characteristics of maize hybrids with contrasting cycles, and the subsequent relationship with grain yield. Two experiments were set up in Santa Catarina State, southern Brazil. Two maize hybrids (AG9025, super-early cycle; P30F53, early cycle), two sowing periods (early spring and late spring), and four rates of topdressed N (0, 150, 300 and 450 kg N ha−1) were tested. Plant height, leaf area index (LAI), and relative chlorophyll content (RCC) were evaluated. The increment in N rate increased plant height at the silking stage for early spring sowing, and had no effect for late spring sowing. Higher N rates increased plant height of P30F53 and did not affect plant height of AG9025. Increasing the N rate enhanced LAI and RCC at silking more sharply when maize was sown in early spring. Higher N rates resulted in increased RCC during grain-filling, as well as maintenance of LAI, factors that were strongly associated with grain yield, especially for early spring sowing with hybrid P30F53. This research shows that the use of increasing N rates is an adequate management strategy to increase maize grain yield when the crop is sown in early spring. When applied at this sowing time, N has greater effect on the elevation of LAI and RCC and their maintenance during grain filling.
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Sun, Ci, Michael B. Ashworth, Ken Flower, Martin M. Vila-Aiub, Roberto Lujan Rocha y Hugh J. Beckie. "The adaptive value of flowering time in wild radish (Raphanus raphanistrum)". Weed Science 69, n.º 2 (26 de enero de 2021): 203–9. http://dx.doi.org/10.1017/wsc.2021.5.
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AbstractHarvest weed seed control (HWSC) is a weed management technique that intercepts and destroys weed seeds before they replenish the soil weed seedbank and can be used to control herbicide-resistant weeds in global cropping systems. Wild radish (Raphanus raphanistrum L.) is a problematic, globally distributed weed species that is considered highly susceptible to HWSC, as it retains much of its seed on the plant during grain harvest. However, previous studies have demonstrated that R. raphanistrum is capable of adapting its life cycle, in particular its flowering time, to allow individuals more time to mature and potentially shed seeds before harvest, thereby evading HWSC interception. This study compared the vegetative growth plus physiological and ecological fitness of an early-flowering R. raphanistrum biotype with an unselected genetically related biotype to determine whether physiological costs of early flowering exist when in competition with wheat (Triticum aestivum L.). Early flowering time adaptation in R. raphanistrum did not change the relative growth rate or competitive ability of R. raphanistrum. However, the height of first flower was reduced in the early flowering time–selected population, indicating that this population would retain more pods below the typical harvest cutting height (15 cm) used in HWSC. The presence of wheat competition (160 to 200 plants m−2) increased flowering height in the early flowering time–selected population, which would likely increase the susceptibility of early-flowering R. raphanistrum plants to HWSC. Overall, early-flowering adaption in R. raphanistrum is a possible strategy to escape being captured by the HWSC; however, increasing crop competition is likely to be an effective strategy to maintain the effectiveness of HWSC.
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Dobrovolný, Lumír, T. Štěrba y J. Kodeš. "Effect of stand edge on the natural regeneration of spruce, beech and Douglas-fir". Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 60, n.º 6 (2012): 49–56. http://dx.doi.org/10.11118/actaun201260060049.
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Our work aimed at studying the strategy of woody plants regeneration during the regeneration of a spruce stand with the admixture of beech and Douglas-fir by border cutting (NW-SE aspect) on acidic sites of higher elevations in the Bohemian-Moravian Upland. Spruce is better adapted to bear shade than Douglas-fir. Nevertheless, in optimal light conditions up to a distance of ca. 35 m (about 16% DIFFSF) from the stand edge, the Douglas-fir can put the spruce into danger as to height growth. By contrast to beech, the density of spruce is significantly higher within the distance of 45 m (about 15% DIFFSF) from the stand edge but further on the situation would change to the benefit of beech. The density of Douglas-fir significantly dominates over beech within a distance of 35 m from the stand edge; from 55 m (less than 15% DIFFSF), the situation changes in favour of beech. Beech can survive in full shade deep in the stand core waiting for its opportunity to come. As compared to spruce and Douglas-fir, the height growth of beech was at all times significantly greater at a distance of 25 m from the stand edge. Converted to practical conditions, spruce and Douglas-fir with individually admixed beech seedlings showed good prosperity approximately up to a distance of one stand height from the edge. A mixture of spruce and beech did well at a greater distance but good prosperity at a distance of 2–3 stand heights was shown only by beech. Thus, border regeneration eliminates disadvantages of the climatic extremes of clear-cutting and specifics of shelterwood felling during which one – usually shade-tolerant tree species dominates in the natural regeneration (e.g. beech).
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Thamrin, Syahruni, Budiman Budiman, Baso Darwisah y Junaedi Junaedi. "APPLICATION OF DRIP IRRIGATION ON COTTON PLANT GROWTH (Gossypium sp.)". Agric 29, n.º 2 (11 de diciembre de 2017): 113–20. http://dx.doi.org/10.24246/agric.2017.v29.i2.p113-120.
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The condition of cotton planting in South Sulawesi is always constrained in the fulfillment of water. All plant growth stages are not optimal to increase production, so it is necessary to introduce good water management technology, such as through water supply with drip irrigation system. This study aims to analyze the strategy of irrigation management in cotton plants using drip irrigation system. Model of application by designing drip irrigation system and cotton planting on land prepared as demonstration plot. Observations were made in the germination phase and the vegetative phase of the early plants. Based on the result of drip irrigation design, the emitter droplet rate (EDR) was 34.266 mm/hour with an operational time of 4.08 min/day. From the observation of cotton growth, it is known that germination time lasted from 6 to 13 days after planting, the average plant height reached 119.66 cm, with the number of leaves averaging 141.93 pieces and the number of bolls averaging 57.16 boll.
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Ganthaler, Andrea y S. Mayr. "Vaccinium gaultherioides: Another insight into water relations of alpine dwarf shrubs". Journal of Plant Hydraulics 2 (17 de noviembre de 2015): e004. http://dx.doi.org/10.20870/jph.2015.e004.
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Dwarf shrubs exhibit different requirements for a safe and efficient water supply compared to trees due their basitonic branching and low growth height. Though, only few studies dealt with the hydraulics of this growth form. Here we report key hydraulic parameters (vulnerability to drought-induced embolism, xylem hydraulic conductivity, cell osmotic potential, potential at turgor loss point) and related wood anatomical traits for Vaccinium gaultherioides, a wide-spread species in the European Alps. The results affirm the current knowledge, by indicating a relatively risky hydraulic strategy with low hydraulic safety compared to alpine trees and osmotic properties connected to the species’ soil humidity requirements.
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Gkourogianni, Alexandra, Melissa Andrew, Leah Tyzinski, Melissa Crocker, Jessica Douglas, Nancy Dunbar, Jan Fairchild et al. "Clinical Characterization of Patients With Autosomal Dominant Short Stature due to Aggrecan Mutations". Journal of Clinical Endocrinology & Metabolism 102, n.º 2 (21 de noviembre de 2016): 460–69. http://dx.doi.org/10.1210/jc.2016-3313.
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Abstract Context: Heterozygous mutations in the aggrecan gene (ACAN) cause autosomal dominant short stature with accelerated skeletal maturation. Objective: We sought to characterize the phenotypic spectrum and response to growth-promoting therapies. Patients and Methods: One hundred three individuals (57 females, 46 males) from 20 families with autosomal dominant short stature and heterozygous ACAN mutations were identified and confirmed using whole-exome sequencing, targeted next-generation sequencing, and/or Sanger sequencing. Clinical information was collected from the medical records. Results: Identified ACAN variants showed perfect cosegregation with phenotype. Adult individuals had mildly disproportionate short stature [median height, −2.8 standard deviation score (SDS); range, −5.9 to −0.9] and a history of early growth cessation. The condition was frequently associated with early-onset osteoarthritis (12 families) and intervertebral disc disease (9 families). No apparent genotype–phenotype correlation was found between the type of ACAN mutation and the presence of joint complaints. Childhood height was less affected (median height, −2.0 SDS; range, −4.2 to −0.6). Most children with ACAN mutations had advanced bone age (bone age − chronologic age; median, +1.3 years; range, +0.0 to +3.7 years). Nineteen individuals had received growth hormone therapy with some evidence of increased growth velocity. Conclusions: Heterozygous ACAN mutations result in a phenotypic spectrum ranging from mild and proportionate short stature to a mild skeletal dysplasia with disproportionate short stature and brachydactyly. Many affected individuals developed early-onset osteoarthritis and degenerative disc disease, suggesting dysfunction of the articular cartilage and intervertebral disc cartilage. Additional studies are needed to determine the optimal treatment strategy for these patients.
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Balcázar-Vargas, María Paula, Tinde R. van Andel, Paul Westers y Pieter A. Zuidema. "What drives the vital rates of secondary hemiepiphytes? A first assessment for three species of Heteropsis (Araceae) in the Colombian Amazon". Journal of Tropical Ecology 31, n.º 3 (17 de abril de 2015): 251–65. http://dx.doi.org/10.1017/s0266467415000115.
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Abstract:Secondary hemiepiphytes rely on other plants (hosts) to grow vertically. After germinating on the forest floor, their seedlings search a host to ascend. We recorded information on survival, growth, reproduction and vegetative propagation of three Heteropsis species, to evaluate what drives their vital rates. We measured 700 individuals of each study species between 2007 and 2009 in the southern Colombian Amazon. A gradual increase in stem length, leaf size, number of roots and plagiotropic branches was found with increasing height of Heteropsis individuals on their hosts. Survival of leafless non-climbing seedlings was very low (28% annually); increasing substantially (84–94%) once the seedling had ascended a host. The three Heteropsis species presented slow height growth rates (c. 2–8 cm y−1) with large variation, while a substantial percentage of the stems (31–62%) did not grow or dried out. Vegetative propagation in Heteropsis may act as a dispersion-propagation strategy to find a suitable host and reach the canopy again after falling. The slow growth rates suggest that Heteropsis individuals that have reached the canopy are rather old. Once plants have reached the tree crowns, their longevity is largely determined by the survival of the host tree.
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Karlsson, Bo, Hubert Wellendorf, Hans Roulund y Martin Werner. "Genotype × trial interaction and stability across sites in 11 combined provenance and clone experiments with Picea abies in Denmark and Sweden". Canadian Journal of Forest Research 31, n.º 10 (1 de octubre de 2001): 1826–36. http://dx.doi.org/10.1139/x01-113.
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In 1997, eleven combined Picea abies (L.) Karst. provenance and clone trials were assessed in two series, with identical genetic constitution and design, in locations ranging from western Denmark to central Sweden, after 14 and 11 years, respectively. The phenotypic variation was larger for mixtures of 24 clones than for seedlings in one series, although 10 times more genotypes were represented amongst the seedlings. This was explained by random C-effects due to propagation. Provenances of seedlings and clone mixtures were fairly stable across sites. Statistically significant clone × trial interaction of growth traits were of the same magnitude as the clonal effects. The median genotypic correlation across sites for total height growth was 0.54. Ecovalence values for growth indicated that most clones contributed about equally to the interaction, with a tendency for clones with early bud break to give a larger contribution. Damage caused by late spring frost was assumed to be a main cause of genotype × environment interaction. Since interactions relatively were more pronounced for growth increment than for the latest height, the interaction seems to increase with age. Cluster analysis based on genotypic correlations between pairs of trials gave a very scattered geographic pattern of the test sites. The results did not justify any suggestions for changes in the P. abies breeding strategy.
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Chukwudi, Uchechukwu Paschal, Funso Raphael Kutu y Sydney Mavengahama. "Influence of Heat Stress, Variations in Soil Type, and Soil Amendment on the Growth of Three Drought–Tolerant Maize Varieties". Agronomy 11, n.º 8 (27 de julio de 2021): 1485. http://dx.doi.org/10.3390/agronomy11081485.
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Food security in sub–Saharan Africa is threatened by the increasing incidence of heat stress. Therefore, ameliorating heat stress influence in plants is vital for sustainable crop production. A 2 × 3 × 3 × 2 factorial experiment fitted into a completely randomized design with four replications was performed. The factors were heat stress, maize variety, soil amendment, and soil type. The results showed that heat stress exerted a depressive effect on maize growth and yield attributes. It reduced the leaf chlorophyll content, leaf area, plant height, stem diameter, dry biomass yield, and harvest index by 35%, 36%, 41%, 59%, and 78%, respectively. Sandy clay loam soil provided a better maize growth condition than loamy sand soil. Organic manure soil amendment improved maize growth attributes over the mineral fertilizer in the non–heat–stress environment and ameliorated the negative impact of heat stress in the heat–stress environment. The ranking of the attributes identified leaf area, dry biomass yield, stem diameter, and plant height as the most discriminating and representative attributes. These attributes should be considered in maize development projects for heat–stress prone areas. Selection of appropriate maize variety and accompanying soil amendment should be integrated into food security strategy as they influenced maize growth and yield under (non–)heat–stress conditions.
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Kerslake, J. I., P. R. Kenyon, S. T. Morris, K. J. Stafford y P. C. H. Morel. "Effect of concentrate supplement and sward height on twin-bearing ewe body condition and the performance of their offspring". Australian Journal of Experimental Agriculture 48, n.º 7 (2008): 988. http://dx.doi.org/10.1071/ea08041.
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These studies investigated the effects of offering concentrate supplement, from day 102 of pregnancy, to twin-bearing ewes grazing a 2- or 6-cm sward, on the condition of the ewe and the performance of their offspring in 2005 and 2006. In both years, 80 twin-bearing ewes were randomly assigned to either the 2- or 6-cm sward height pasture treatment from day 70 of pregnancy until parturition. From pregnancy day 102, half of the ewes within each sward height were offered 400 g/ewe.day of concentrate supplement. From day 102 until day 140 of pregnancy, ewes offered the concentrate supplement gained more liveweight then ewes offered pasture only. While supplementation affected ewe liveweight, its effects on lamb birthweight and growth were variable. In 2006, concentrate supplementation within the 6-cm sward height treatment increased (P < 0.05) lamb birthweight from an average of 4.8 to 5.3 kg. In 2005, concentrate supplementation increased (P < 0.05) lamb growth by 20 g/day. These inconsistent and minor production gains are unlikely to be cost effective because of the satisfactory performance of lambs from all other nutritional treatments and the extensive feeding of concentrate supplement. Therefore, feeding 400 g/ewe.day of concentrate supplement from day 102 of pregnancy to twin-bearing ewes on a 2- or 6-cm sward height pasture appears not to be a viable management strategy for commercial sheep farmers.
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Guo, Fenghui, Xiliang Li, Saheed Olaide Jimoh, Yong Ding, Yong Zhang, Shangli Shi y Xiangyang Hou. "Overgrazing-induced legacy effects may permit Leymus chinensis to cope with herbivory". PeerJ 8 (8 de octubre de 2020): e10116. http://dx.doi.org/10.7717/peerj.10116.
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There is growing evidence that herbivory-induced legacy effects permit plants to cope with herbivory. However, herbivory-induced defense strategies in plants against grazing mammals have received little attention. To further understand the grazing-induced legacy effects on plants, we conducted a greenhouse experiment with Leymus chinensis experiencing different grazing histories. We focused on grazing-induced legacy effects on above-ground spatial avoidance and below-ground biomass allocation. Our results showed that L. chinensis collected from the continuous overgrazing plot (OG) exhibited higher performance under simulated grazing in terms of growth, cloning and colonizing ability than those collected from the 35-year no-grazing plot (NG). The enhanced adaptability of OG was attributed to increased above-ground spatial avoidance, which was mediated by larger leaf angle and shorter height (reduced vertical height and increased leaf angle contributed to the above-ground spatial avoidance at a lower herbivory stubble height, while reduced tiller natural height contributed to above-ground spatial avoidance at a higher herbivory stubble height). Contrary to our prediction, OG pre-allocated less biomass to the rhizome, which does not benefit the herbivory tolerance and avoidance of L. chinensis; however, this also may reflect a tolerance strategy where reduced allocation to rhizomes is associated with increased production of ramets.
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Fady, Bruno. "Variabilité génétique des composantes de la croissance en hauteur du Sapin de Céphalonie (Abiescephalonica)". Canadian Journal of Forest Research 20, n.º 9 (1 de septiembre de 1990): 1453–60. http://dx.doi.org/10.1139/x90-192.
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The annual height increment of the shoot can be divided into two morphogenetic components: the number of stem units initiated in the bud prior to bud break and their mean length. Observations were made on the lateral shoots of 43 Abiescephalonica open-pollinated families from three provenances located in an experimental site in southern France. Genetic parameters of the two components were evaluated with an analysis of variance. Correlations both between components and with annual height increment were examined at the phenotypic, genotypic, and individual levels. Differences between provenances were the result of number of stem units and annual height increment. Number of stem units presented a very high heritability and was strongly correlated to annual height increment at all variance levels. Mean stem unit length appeared to be more dependent on environmental variations and was less closely correlated to annual height increment, especially when genotypic data were considered. This particular growth strategy could be the consequence of A. cephalonica's adaptation to a Mediterranean-type climate. Of the two components studied, number of stem units was a better genetic predictor of annual height increment. A negative correlation between number of stem units and mean stem unit length was made apparent at the phenotypic and individual levels and should be considered when using number of stem units as a selection criterium.
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Chauhan, Bhagirath S. y David E. Johnson. "Responses of Rice Flatsedge (Cyperus iria) and Barnyardgrass (Echinochloa crus-galli) to Rice Interference". Weed Science 58, n.º 3 (septiembre de 2010): 204–8. http://dx.doi.org/10.1614/ws-d-09-00050.1.
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Rice flatsedge and barnyardgrass are widespread and competitive weeds in direct-seeded rice. Developing integrated weed management strategies that elevate suppression of weeds by rice through crop density, nutrition, and cultivar choice requires better understanding of the extent to which rice interferes with the growth of these weeds and how these species respond to resource limitation with crop interference. Rice interference reduced the height of barnyardgrass but did not affect height of rice flatsedge. These weed species were able to grow taller than rice and thus avoided being shaded. Increased specific stem length under crop interference may demonstrate a strategy of stem elongation to allow the top portion of the weeds to be kept out of shade. Rice interference reduced inflorescence and shoot biomass of both weed species. Barnyardgrass showed the ability to reduce the effects of rice interference by increasing leaf weight ratio. The present study shows that crop interference alone may reduce weed growth but may not give complete control of these weed species. This highlights the need for the integration of management practices to achieve control of these weed species.
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Back, Marina Martinello, Gabriela Fedrizzi y Paulo Vitor Dutra de Souza. "Growth and physiology of the citrange ‘Fepagro C37 Reck’ rootstock innoculated with arbuscular mycorrhizal fungi". Revista Ceres 65, n.º 4 (agosto de 2018): 356–63. http://dx.doi.org/10.1590/0034-737x201865040008.
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ABSTRACT The use of arbuscular mycorrhizal fungi (AMF) in the production of rootstocks is a strategy to promote faster plant growth. However, this response depends on the symbiont species. The objective of this study was to evaluate the influence of different species of arbuscular mycorrhizal fungus (AMF) on the development and physiology of citrange 'Fepagro C37 Reck' rootstock. Four species of AMF were used in the experiment: Scutellospora heterogama, Gigaspora margarita, Glomus etunicatum, and Acaulospora sp., and a control treatment. The experiment was arranged in a randomized blocks design, with 5 treatments, 3 replicates, and 10 plants per plot. Every 15 days, height (cm) and stem diameter (mm) of plants were measured in the nursery. At 330 days, the number of leaves, leaf area (cm²), fresh and dry mass of roots and shoot (g/plant), root and shoot reserve content, and AMF colonization were evaluated. The AMF inoculation promoted an accelerated vegetative growth, resulting in greater height and diameter. The fungi also promoted greater absorption of most of the nutrients and increase in all other parameters evaluated. However, no effect was found on the reserve content of the rootstock. Roots were colonized with moderate presence of arbuscules and low presence of vesicles. AMF, regardless of species, influence the development and physiology of the citrange 'Fepagro C37 Reck' rootstock.
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Johnson, Fred A., David R. Breininger, Brean W. Duncan, James D. Nichols, Michael C. Runge y B. Ken Williams. "A Markov Decision Process for Managing Habitat for Florida Scrub-Jays". Journal of Fish and Wildlife Management 2, n.º 2 (1 de diciembre de 2011): 234–46. http://dx.doi.org/10.3996/012011-jfwm-003.
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Abstract Florida scrub-jays Aphelocoma coerulescens are listed as threatened under the Endangered Species Act due to loss and degradation of scrub habitat. This study concerned the development of an optimal strategy for the restoration and management of scrub habitat at Merritt Island National Wildlife Refuge, which contains one of the few remaining large populations of scrub-jays in Florida. There are documented differences in the reproductive and survival rates of scrub-jays among discrete classes of scrub height (<120 cm or “short”; 120–170 cm or “optimal”; >170 cm or “tall”; and a combination of tall and optimal or “mixed”), and our objective was to calculate a state-dependent management strategy that would maximize the long-term growth rate of the resident scrub-jay population. We used aerial imagery with multistate Markov models to estimate annual transition probabilities among the four scrub-height classes under three possible management actions: scrub restoration (mechanical cutting followed by burning), a prescribed burn, or no intervention. A strategy prescribing the optimal management action for management units exhibiting different proportions of scrub-height classes was derived using dynamic programming. Scrub restoration was the optimal management action only in units dominated by mixed and tall scrub, and burning tended to be the optimal action for intermediate levels of short scrub. The optimal action was to do nothing when the amount of short scrub was greater than 30%, because short scrub mostly transitions to optimal height scrub (i.e., that state with the highest demographic success of scrub-jays) in the absence of intervention. Monte Carlo simulation of the optimal policy suggested that some form of management would be required every year. We note, however, that estimates of scrub-height transition probabilities were subject to several sources of uncertainty, and so we explored the management implications of alternative sets of transition probabilities. Generally, our analysis demonstrated the difficulty of managing for a species that requires midsuccessional habitat, and suggests that innovative management tools may be needed to help ensure the persistence of scrub-jays at Merritt Island National Wildlife Refuge. The development of a tailored monitoring program as a component of adaptive management could help reduce uncertainty about controlled and uncontrolled variation in transition probabilities of scrub-height and thus lead to improved decision making.
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KASCHULA, S. A., W. C. TWINE y M. C. SCHOLES. "The effect of catena position and stump characteristics on the coppice response of three savannah fuelwood species". Environmental Conservation 32, n.º 1 (marzo de 2005): 76–84. http://dx.doi.org/10.1017/s0376892905001980.
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Fuelwood is still the primary energy source for rural households across the savannah biome of Africa. Coppice growth is an important species-specific trait that strongly influences fuelwood production and regeneration, and yet coppice growth patterns are poorly understood in African savannahs. It is therefore vital that factors affecting coppice growth of species, such as environment conditions and harvesting technique, be better understood in order to develop models for sustainable fuelwood use. This study investigated coppice growth and resource allocation strategies in relation to (1) position along the landscape catena and (2) harvesting technique, for three savannah fuelwood tree species: Dichrostachys cinerea, Albizia harveyi and Combretum collinum. The study was conducted in a dystrophic semi-arid savannah in the far north-east of South Africa. A total of 1146 harvested stumps were sampled in topland and bottomland sites in three locations around a rural village. Stump characteristics (diameter and height) and coppice shoot variables (number of shoots, length and diameter of each shoot, length of longest shoot, and diameter of fattest shoot) were measured for each stump. Three soil samples were taken in each site for physical and chemical analysis. No statistically significant differences were found in soil variables between topland and bottomland sites, probably due to low sample size. Coppice resource allocation strategies varied between species. D. cinerea exhibited a ‘quantity-driven’ strategy, with the production of large numbers of relatively small coppice shoots with high length:diameter ratio (shoot taper function). C. collinum exhibited a ‘quality-driven’ strategy, characterized by the production of a relatively low number of larger coppice shoots. Coppice growth variables for A. harveyi were intermediate between those of the other two species, suggesting a strategy where allocation of resources to the number and growth of shoots is more balanced. However, allocation of resources relative to the size of the cut stem, indexed by total shoot basal area:stump basal area ratio, did not differ significantly between species. Coppice growth was strongly favoured in bottomland sites for D. cinerea, and to a lesser degree, C. collinum. Catenal position had a negligible influence on coppice growth of A. harveyi. Number of shoots produced increased with cutting height for all three species. For all three species the number of shoots increased with stump diameter, and mean shoot size also increased with stump size for D. cinerea. There was a significant negative relationship between stump diameter and total shoot basal area:stump basal area ratio for A. harveyi and C. collinum. A framework for optimizing different coppice growth variables according to species, catenal position and harvesting technique is given.
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Hiura, Tsutom, Junji Sano y Yasuo Konno. "Age structure and response to fine-scale disturbances of Abiessachalinensis, Piceajezoensis, Piceaglehnii, and Betulaermanii growing under the influence of a dwarf bamboo understory in northern Japan". Canadian Journal of Forest Research 26, n.º 2 (1 de febrero de 1996): 289–97. http://dx.doi.org/10.1139/x26-032.
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We studied regeneration patterns of the four canopy dominants, Abiessachalinensis (Fr. Schm.) Masters, Piceajezoensis (Sieb. et Zucc.) Cam, Piceaglehnii (Fr. Schm.) Masters, and Betulaermanii Cham., of an old-growth (>400 years) boreal coniferous forest in northern Japan. Age and size structure, height growth, and diameter growth of tree populations in a 40 × 40 m plot were analyzed. Seedling establishment was restricted to nurse logs and mounds (98%), where the influence of dwarf bamboo (Sasasenanensis (Franch. et Sav.) Rehd.) was limited. Abiessachalinensis had a high density (10 263/ha) but a high mortality (8.4%/year for saplings, 1.7%/year for canopy trees) and a short canopy residence time. It also showed a more rapid tree-ring width increase after disturbances. Piceaglehnii had a low density (1450/ha) but a low mortality (6.9%/year for saplings, 0.1%/year for canopy trees) and a longer residence time in the canopy. Piceajezoensis had an intermediate density (8206/ha) and its mortality rate for canopy trees (0.9%/year) was lower than that of A. sachalinensis, although its sapling mortality rate (8.1%/year) was similar to that of A. sachalinensis. Betulaermanii had a higher mortality (14.1%/year for saplings, 2.4%/year for canopy trees) than the conifers. On the other hand, B. ermanii had the highest height growth and P. glehnii had the lowest. The mortality and average height growth of saplings showed a trade-off relationship. The trade-off relation in life history strategy may contribute to the coexistence of these species. The proportion of the gap area created in the forest was 1.2–2.4%/year, and a forest turnover time calculated from aboveground volumes was 87–99 years. These values were similar to a weighted mean of the estimated life times of the constituent species, 71 years for A. sachalinensis, 123 years for P. jezoensis, and 49 years for B. ermanii.
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Zou, Xiaodan, Anjie Liang, Bizhi Wu, Jun Su, Renhua Zheng y Jian Li. "UAV-Based High-Throughput Approach for Fast Growing Cunninghamia lanceolata (Lamb.) Cultivar Screening by Machine Learning". Forests 10, n.º 9 (19 de septiembre de 2019): 815. http://dx.doi.org/10.3390/f10090815.
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Obtaining accurate measurements of tree height and diameter at breast height (DBH) in forests to evaluate the growth rate of cultivars is still a significant challenge, even when using light detection and ranging (LiDAR) and three-dimensional (3-D) modeling. As an alternative, we provide a novel high-throughput strategy for predicting the biomass of forests in the field by vegetation indices. This study proposes an integrated pipeline methodology to measure the biomass of different tree cultivars in plantation forests with high crown density, which combines unmanned aerial vehicles (UAVs), hyperspectral image sensors, and data processing algorithms using machine learning. Using a planation of Cunninghamia lanceolate, which is commonly known as Chinese fir, in Fujian, China, images were collected while using a hyperspectral camera. Vegetation indices and modeling were processed in Python using decision trees, random forests, support vector machine, and eXtreme Gradient Boosting (XGBoost) third-party libraries. The tree height and DBH of 2880 samples were manually measured and clustered into three groups—“Fast”, “median”, and “normal” growth groups—and 19 vegetation indices from 12,000 pixels were abstracted as the input of features for the modeling. After modeling and cross-validation, the classifier that was generated by random forests had the best prediction accuracy when compared to other algorithms (75%). This framework can be applied to other tree species to make management and business decisions.
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Sugiharto, Arwan, Toga Pengihotan Napitupulu y Made Sudiana. "The influence of biocarrier of Aspergillus niger and Trichoderma harzianum toward vegetative growth of sorghum in the field experiment". Journal of Microbial Systematics and Biotechnology 2, n.º 2 (30 de diciembre de 2020): 28–34. http://dx.doi.org/10.37604/jmsb.v2i2.60.
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Compared to other cereal crops, sorghum has a higher drought tolerance trait. However, efforts are needed to increase the productivity of sorghum, particularly in drought marginal land. One strategy to be implemented is the utilization of soil microorganisms formulated with biocarrier. Therefore, the aim of this study was to evaluate the influence of the fungal strain Aspergillus niger and Trichoderma harzianum formulated with compost and zeolite as biocarrier towards vegetative growth of sorghum. The field experiment was designed as a randomized block designed, factorial pattern with 4 replications. The first factor was selecting biocarrier, namely zeolite, compost, and a mixture of zeolite: compost (1:1). The second factor was the fungal inoculants, A. niger, and T. harzianum. The observed parameter was the growth profile of sorghum during vegetative growth, including stalk diameter and height. The results showed that the type of biocarrier, as well as the fungal strains did influence the growth of sorghum. The highest stalk diameter and height of sorghum were obtained after application of A. niger formulated with a mixture of zeolite: compost (1:1), with 17% and 41.2% higher than control, respectively. This condition shows that a mixture of zeolite and compost is seemingly able to create better micro-ecological conditions for fungal microbes to function effectively. Therefore, our findings suggested the addition of zeolite to compost for the application of biocarrier in the field experiment.
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Oxy Handika, Denis. "Keluarga Peduli Stunting Sebagai Family Empowerment Strategy Dalam Penurunan Kasus Stunting di Kabupaten Blora". Dinamisia : Jurnal Pengabdian Kepada Masyarakat 4, n.º 4 (16 de septiembre de 2020): 685–92. http://dx.doi.org/10.31849/dinamisia.v4i4.3981.
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Stunting is a form of growth faltering due to chronic nutrient deficiency that lasts from the womb until the age of 24 months. This situation not only makes the children height short but also manifests an increase in children's morbidity and mortality, as well as children's cognitive, motor, and verbal development which is not optimal it ultimately results in low human resources. Family-based intervention can be an effective step in helping the government reduce the prevalence of stunting. By using the participatory action method in the implementation of empowering family activity for stunting, the people of Jomblang Village, Jepon District, Blora Regency are equipped with knowledge about strengthening 1000 HPK, screening stunting independently, optimizing exclusive breastfeeding, processing breast milk and making MP-ASI based on available resources. around the place of residence. The results of this devoted family empowerment service devotion are increasing community understanding of stunting, 1000 HPK, exclusive breastfeeding, skills in processing milk and community independence skills in making MP-ASI Sujaka.
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Siliprandi, N. C., E. M. Nogueira, J. J. Toledo, P. M. Fearnside y H. E. M. Nascimento. "Inter-site variation in allometry and wood density of Goupia glabra Aubl. in Amazonia". Brazilian Journal of Biology 76, n.º 1 (22 de enero de 2016): 268–76. http://dx.doi.org/10.1590/1519-6984.22514.
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Abstract The present study aims to compare the allometry and wood density of Goupia glabra Aubl. (Goupiaceae) in two different terra-firme sites in Amazonian forest. A total of 65 trees ≥ 10 cm DBH was sampled in both sites, with 39 trees in Nova Olinda do Norte (NOlinda, near the Amazon River) and 29 trees in Apuí (near the southern edge of the Amazon forest). Except for the relationship between DBH (diameter at breast height) and Ht (total height), allometric relationships for G.glabra differed significantly between sites. Apuí had lower intercept and greater slope for log10 (DBH) versus log10 (Hs – stem height), and, conversely, greater intercept and lower slope for log10 (DBH) versus log10 (Ch – crown height). The slope differed significantly between the sites for DBH versus Cd (crown diameter), with greater slope found for NOlinda. Mean basic wood density in Apuí was 8.8% lower than in NOlinda. Our findings highlight the variation in adaptive strategy of G. glabra due to environmental differences between sites. This is probably because of different canopy-understory light gradients, which result in differentiation of resource allocation between vertical and horizontal growth, which, in turn, affects mechanical support related to wood density. We also hypothesize that differences in soil fertility and disturbance regimes between sites may act concomitantly with light.
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Ott, Grace C., Sharon R. Freeman, Matthew H. Poore y Carrie L. Pickworth. "11 Impact of weaning strategy on calf performance, behavior, and activity". Journal of Animal Science 97, Supplement_1 (julio de 2019): 12–13. http://dx.doi.org/10.1093/jas/skz053.027.
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Abstract Weaning is known to be the most stressful time in a beef calf’s post-natal life. Weaning stress may have long-term impacts on cattle performance. This study was conducted to determine differences in calf stress under three weaning strategies. Two hundred twenty-nine Angus or Angus-Simmental cross pairs at two locations were assigned to one of three weaning treatments: abrupt removal of the calf on d 0 (Abrupt, n = 77), fenceline contact for 7 d prior to removal of the calf on d 7 (Fence, n = 79), and abrupt removal of the calf on d 84 (Late, n = 73). Behavioral observations were conducted pre- and post-weaning and total activity was measured prior to and after weaning using accelerometers placed on collars on five calves per treatment. Calf weights, hip heights, and body condition scores (BCS) were collected to evaluate calf performance post-weaning. Data were analyzed using PROC MIXED of SAS. Statistical significance was determined at P < 0.05 and a tendency at 0.05<p<0.10. Skeletal growth via hip height was not affected by weaning treatment. During the first 28 d after initial weaning, the Abrupt calves lost while the Late weaned calves gained weight (-0.09 and 0.49 kg/d, respectively; P < 0.05). Fence were intermediate weight and tended to be different from both treatments (0.02 kg/d; P = 0.09). Overall ADG was not affected (P > 0.10) by timing or strategy of weaning. Total activity was greater (P < 0.05) in Abrupt than Fence on d 1 and d 2 post-wean (Abrupt 26772 and 22346 and Fence 22235 and 16691 relative activity units/hour, respectively). Calf activity was elevated (P < 0.05) on day of weaning until d 2 post-wean then returned to pre-wean level by d 3 for all treatments. Short-term differences in calf performance warrant further exploration of the possible long-term effects on heifer development and steer feedlot performance.
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XIE, Miao-Miao, Yu WANG, Qiu-Shuang LI, Kamil KUČA y Qiang-Sheng WU. "A friendly-environmental strategy: application of arbuscular mycorrhizal fungi to ornamental plants for plant growth and garden landscape". Notulae Botanicae Horti Agrobotanici Cluj-Napoca 48, n.º 3 (24 de septiembre de 2020): 1100–1115. http://dx.doi.org/10.15835/nbha48312055.
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The demand for ornamental plants is increasing due to urban greening and rural construction, while the growing environment of plants, especially the soil environment, is deteriorating. Hence, sustainable methods of ornamental plant cultivation need to be developed quickly. The application of arbuscular mycorrhizal fungi (AMF) to ornamental plants can be one of the eco-friendly ways to achieve the objective. Soil AMF establish mycorrhizal symbiosis with roots of ornamental plants, which can develop a marvelous mycorrhizal mycelium network in the rhizosphere to stimulate nutrient and water acquisition of host plants. Numerous researches have proven that AMF improved the quality of ornamental plants, like fruit yield, height, biomass, seed quality, the size and number of flowers, leaf, and root. In addition, mycorrhizal fungi also improve nutrient uptake and endogenous hormone balance of host plants. Another important function of AMF is to regulate the physiological, biochemical, and molecular responses of host plants to adversity, including drought stress, temperature stress, heavy-metal stress, and insect and disease stress. From the perspective of the ecological garden landscape, AMF richness would maintain plant abundance, nutrient and energy balance, and higher productivity in normal and soil environment stress, thus, establishing a friendly-environmental ecosystem. This review also provides the basis to exploit and improve the commercial application of AMF in ornamental plants in the future.