Height Growth Patterns Research Articles

Cephalometric Evaluation of Facial Height Ratios and Growth Patterns: A Retrospective Cohort Study

(1) Background: This retrospective cohort study aimed to investigate the cephalometric evaluation of facial height ratio (FHR) and growth patterns. (2) Methods: We assessed facial height ratios, the y-axis to SN angle, and growth patterns in 94 participants from Timis County using digital cephalograms. Angle’s classification guided the categorization of participants. We digitally traced and analyzed cephalograms using the WebCeph imaging software. We conducted the statistical analysis using Python version 3.11.9. We performed the following statistical tests: Welch’s t-test or ANOVA (analysis of variance), Mann–Whitney U test or the Kruskal–Wallis test, χ2 test or Fisher’s, and logistic regression. (3) Results: Significant correlations were observed between FHR and craniofacial development, especially in hypodivergent growth patterns. Among the molar classes, the most predominant growth pattern in Class I was normodivergent (61.5%), followed by hypodivergent (33.3%). In Class II, hypodivergent growth was the most common (52%), with a smaller proportion of normodivergent cases (30.8%). Class III was characterized by a mix of growth patterns, with hypodivergent being predominant (14.7%). Across all groups, the y-axis to SN angle remained within normal limits, and a strong negative correlation with Jarabak’s ratio was found (r = −0.72, p < 0.001). This shows the importance of using holistic assessment methods in orthodontic practice. (4) Patients from Timis County mostly have a hypodivergent growth pattern across all types of malocclusions. Understanding these patterns is essential for comprehensive orthodontic treatment planning. We need to conduct further research to investigate the implications of these findings on treatment outcomes and patient care.

Visualization experiments and numerical simulation on the growth of fracture height in bedding-rich reservoirs

The development of shale bedding and differences in properties have significant effects on the growth of the fracture height. To investigate the impact mechanism of bedding on the fracture growth height, the visualization fracturing experiments based on polymethylmethacrylate (PMMA) samples were performed to investigate the impact of the injection rates, viscosity and temporary plugging parameters on the growth pattern of hydraulic fractures. Furthermore, the solid–fluid-damage fracturing coupled model considering the vertical distribution of bedding was constructed by the continuous-discontinuous element method, and the impact of key formation parameters and treatment parameters were investigated. The results show that the height growth pattern of PMMA samples was affected by the flow rate and fluid viscosity. The fracture can cross the bedding at high-viscosity fluid. But in low-viscosity fluid the fracture tends to be arrested by the bedding. And the fracture cannot cross the bedding again after In-fracture temporary plugging. The fractures vertical growth pattern mainly includes three types at various stratigraphic parameters and treatment parameters, “工” type fracture, “丰” type fracture, and “I” type fracture, respectively. For vertical stress differentials below 3 MPa or Young's modulus below 20 GPa or injection rates below 1.8 m3/min or the fluid viscosity below 5 mPa·s, the fracture will be limited within the bedding.

Long-term surveys of ungulates' effects on tree and shrub species in mountainous forests -outcomes and potential limits.

Ungulate herbivory might induce different effects on the diversity and growth of trees and shrubs. The density, distribution, and the species of ungulates as well as plant communities' composition and other factors determine whether ungulate herbivory promotes or limits plants' diversity and growth. The impacts of ungulates on woody plants are commonly surveyed with exclosure-control approaches. In practice, such surveys frequently only cover short periods of time, addressing immediate management needs. Long-term surveys, documenting lasting effects of ungulate herbivory, are highly needed, but still rare. However, the general transferability of outcomes of long-term surveys might be limited due to different disturbing factors. This study addresses two basic aspects of long-term monitoring in mountainous forests, based on a unique 30-year data set: (1) Possible long-term effects of herbivores on forest vegetation (e.g., species/structural diversity of woody plants) and (2) potential differences between short-term and long-term surveys in terms of height growth patterns. In our study, diversity of woody plant species showed great variability with no significant impact of ungulate herbivory. The presence of ungulates had a significantly negative effect on the vertical structural diversity and growth of trees. Due to the slower growth on control plots, it took trees longer to reach a 160 cm height-threshold with their terminal shoots than on exclosure plots. Our long-term control-exclosure data set indicated that long-term survey data indeed might differ from growth patterns represented by short-term surveys. This can be induced by several factors, like site-specific growth patterns of trees, occurrences of natural abiotic disturbances that influence the functional life of exclosures, and others.

Growth pattern, growth deceleration, and relevant predictors in girls treated with GnRHa: a retrospective longitudinal study.

This study aimed to analyze the height growth pattern and the incidence of significant growth deceleration in girls with CPP and EFP on GnRHa treatment, and thereby identify relevant predictors of growth deceleration. The data of 99 girls diagnosed with CPP and 47 girls with EFP were included in this retrospective analysis. The incidence of growth deceleration was calculated in both the first and second years. Multivariate logistic regression analysis was used to identify predictors indicative of growth deceleration. Growth velocity (GV) trajectories showed gradual decreases to the nadir at 18months of treatment, and then they recovered till the 24th month of treatment, especially in girls with CPP. Nevertheless, the recovery was significantly greater in the CPP group than EFP. In the first year, no significant difference in the incidence of growth deceleration was found between the CPP group and the EFP group [17.35 vs. 25.53 %, p=0.249]; in the second year, the CPP group had alower incidence than the EFP group [42.86 vs. 76.92 %, p=0.027]. The multivariate logistic regression analysis suggested that bone age (BA) was an independent predictor of growth deceleration (OR=2.264, 95 % CI: 1.268-4.042, p=0.006). The result of ROC curves showed the cut-off value of BA was 11.05 years. GV varies at different periods during GnRHa treatment. GnRHa should be used with more caution for EFPtreatment than for CPP. BA can be used to predict the occurrence of growth deceleration during GnRHa treatment.

Association of height, foot length, and pubertal development in children aged 3-18: a cross-sectional survey in China.

This study aimed to analyze the growth patterns of height and foot length (FL) among Chinese children aged 3-18 and examine their associations with puberty development. A cross-sectional survey was conducted in September 2022 in Beijing. Data were collected through questionnaires and on-site physical examinations. The growth patterns and velocity of height and FL in different age groups were described, and their associations with puberty development were analyzed. From an age perspective, the peak FL growth occurred between 9 and 11 years (boys were 11 years and girls were 9 years), while the peak height growth occurred at 11 ~ 13 years for boys and 9 ~ 11 years for girls. Additionally, boys and girls reached 99.0% of their final FL at the ages of 14 and 13, respectively, while they reached 99.0% of their final height at the ages of 16 and 15, respectively. From the perspective of Tanner stage, the age of peak FL growth in boys coincided with the age of the G2 stage, while in girls it occurred slightly earlier than the mean age of the B2 stage. The peak height growth for both boys and girls occurred between Tanner stages 2 and 3. Boys and girls reach their peak FL growth at 11 and 9 years old, respectively, which were both 2 years earlier than their peak height growth. The peak FL growth occurred around the onset of puberty, while the peak height growth occurred between Tanner stages 2 and 3.

Height growth patterns of genetically improved Scots pine and silver birch

Abstract The breeding of forest tree species in the Baltic region has notably contributed to wood production for the bioeconomy. Growth modelling is used for long-term estimates of forest development. However, usually based on data from unimproved stands, they may underestimate the growth of improved trees. Accordingly, it is important to identify and integrate the altered stand dynamics associated with improved planting stock into existing growth models to accurately capture the resulting gains or, alternatively, develop new functions specifically designed for improved trees. We used the generalized algebraic difference approach to model and analyze height growth patterns of Scots pine and silver birch with different genetic improvement levels (improved forest reproductive material categories ‘qualified’ and ‘tested’). Modelling was based on 14 260 and 55 926 height–age series from open-pollinated progeny trials in Latvia and Lithuania with an age range of 3–46 and 5–22 years for pine and birch, respectively. Dynamic generalized algebraic difference approach forms of commonly applied height growth functions with forest reproductive material-category-specific sets of coefficients were tested. The dynamic form of the Chapman–Richards and King–Prodan equations had the best fit for Scots pine and silver birch, respectively. The expected height growth of the category ‘tested’ was slightly better than the one for ‘qualified’, with more distinct differences in silver birch. The model with forest reproductive material-category-specific coefficients reflected the actual growth of improved trees; however, such application is limited to sites with medium and high site indices, where improved planting stock is typically used. We recommend the model for young stands up to the age of 20 and 40 years for pine and birch, respectively, considering the empirical data cover on which the functions are based. A unified dynamic height model with the same functional form but category-specific parameterization for different improvement levels allows a practical applicability and effective communication amongst diverse users, thereby promoting the utilization of the model amongst forest owners and managers who possess information regarding the origin of planting stock.

Reference Curves for Central Appalachian Red Spruce

Red spruce (Picea rubens Sarg.) was a prized timber species in West Virginia during the era of resource exploitation in the late 1800s and early 1900s. As a result, central Appalachian red spruce comprise a much smaller component of high-elevation stand composition and a greatly constricted presence across the region. Widespread restoration efforts are underway to re-establish red spruce across this landscape. However, without benchmarks to gauge growth rates and stand developmental patterns, it is unclear whether these efforts are successful. Our goal was to develop reference curves predicting centile height growth for understory red spruce (≤7.6 m) across the region. We reconstructed the height growth patterns of over 250 randomly selected red spruce seedlings and saplings from 22 high-elevation stands in West Virginia. We also harvested 24 mature red spruce from the same stands to develop juvenile growth curves up to 7.6 m to compare understory growth rates of historical to contemporary rates from the reference curves. Our constructed reference curves showed height growth tended to peak between 10 and 30 years of age. Total heights ranged from 0.95 m to 6.85 m after 50 years. We identified two demographic populations in the mature red spruce trees. All the mature red spruce trees that established after 1890 exceeded the 97% growth centile by age 80. By contrast, only two trees from the pre-1890 population reached the same level by age 80. This work highlights the varied ascension pathways to the overstory for red spruce.

THU194 Growth Pattern And Related Predictors Of Gonadotropin-releasing Hormone Analog Treatment In Girls With Precocious Puberty

Abstract Disclosure: L. Ouyang: None. F. Yang: None. Purpose: The purpose of this study was to analyze the height growth pattern during gonadotropin-releasing hormone analog (GnRHa) treatment in girls with central precocious puberty (CPP) and early and fast puberty (EFP), calculate the incidence of prominent height deceleration and explore the relevant predictors of prominent height deceleration, which may provide useful information for the application of GnRHa as treatement and other adjunctive treatments such as growth hormone (GH). Methods: Ninety-nine girls diagnosed with CPP and 47 girls with EFP were enrolled in this retrospective analysis, they were treated with GnRHa from 6 months to 2 years. Clinical indicators such as hormone levels, bone age (BA), and B-ultrasound indicators were included and shown every 6 months. The growth velocity (GV) of height and the change of height standard deviation score (SDS) were shown every 6 months and once a year. The incidence of height deceleration was calculated in both the first and second years of GnRHa treatment. Multivariate logistic regression analysis was used to explore the predictive indicators of height deceleration. Results: There was a statistically significant difference between girls with CPP and EFP in physical growth indicators, hormone levels, BA, BA advancement, and B-ultrasound indicators at the time of diagnosis (P < 0.05); however, these statistical differences gradually disappeared as treatment progressed. The treatment of GnRHa decreases the GV, BA, and levels of hormones in girls with CPP and EFP. The GV during GnRHa treatment in two groups reached a trough at 18 months, followed by a gradual rebound, but the rebound was significantly greater in CPP than in girls with EFP. The GV of girls with CPP was higher than that of girls with EFP, and the decrease in height-SDS of girls with EFP was more than girls with CPP during the entire of GnRHa treatment. The incidence of growth deceleration in CPP in the first and second year of treatment was 17.35% (17/98) and 42.86% (24/56), and EFP was 25.53% (12/47) and 76.92% (10/13), respectively. No significant indicators predicted the occurrence of growth deceleration (P<0.05). Conclusions: GnRHa is effective in slowing the GV of height, the maturation of BA, and hormone levels in patients with precocious puberty, and the treatment time of 2 years or more can lead to an adult height benefit. The girls with EFP seem to suffer more damage in GV, which might affect AH, so the use of GnRHa in treating EFP should be done with more caution than in CPP. An adequate period of observation in CPP is needed before adjunctive treatments such as GH are used due to the height ascent in the later stage of treatment (18 months to 24 months). None of the factors we studied predicted the incidence of height deceleration during the period of GnRHa treatment. Presentation: Thursday, June 15, 2023

Eight-year field performance of backcross American chestnut (Castanea dentata) seedlings planted in the southern Appalachians, USA

The American chestnut (Castanea dentata) is imperiled due primarily to two diseases caused by nonnative pathogens, notably chestnut blight and Phytophthora root rot (PRR) caused by Cryphonectria parasitica and Phytophthora cinnamomi, respectively. Field reintroduction trials are important to test trees bred for blight resistance under forest conditions to quantify survival and field performance in managed stands that represent future restoration sites. We planted 513 pedigreed bare-root (1–0) nursery seedlings into an even-aged regeneration harvest in the Blue Ridge Mountains of eastern Tennessee, USA to test effects of breeding, genetics, and seedling size class on field performance, including survival, total growth, incremental growth (a measure of growth efficiency), and height growth patterns. Mortality was highest in the first two years after planting, and PRR symptoms coupled with soil and root assays that tested positive for P. cinnamomi suggested this disease was a significant contributor to mortality. Chinese chestnut (C. mollissima), known to be resistant to P. cinnamomi and C. parasitica, had the highest survival (96 percent) compared to American chestnut (34 percent) and hybrid generations, including the BC3F3 generation (41 percent). Less advanced hybrid generations, such as the BC1F3 and BC2F3, had the greatest total height and ground-line diameter (GLD) and height growth efficiencies. BC3F3 generation seedlings were associated with higher-than-expected rates of nominal height growth patterns (i.e., flat growth rates over time or early mortality) compared to Chinese chestnut seedlings. Results, however, indicated the breeding program was successfully integrating desired American chestnut growth traits into the hybrid genome while transferring an intermediate level of resistance from the Chinese chestnut. We identified superior and inferior BC3F3 families that can help inform breeding and restoration efforts. Visually grading seedlings before planting affected survival and growth of generations and genetic families differently, indicating that refinement of nursery production and restoration plantings should consider genetic effects. Across generations, seedling size grading improved total height and GLD growth that would save resources necessary for competition control and animal browsing protection, but large-size seedlings also exhibited lower C. parasitica resistance rankings over time, probably owing to earlier bark fissuring. PRR probably affected outcomes, particularly for hybrid and American chestnut seedlings that have very low levels of P. cinnamomi resistance. Managers could expect advanced breeding generations to perform similarly to American chestnut in growth through the critical stage of early stand development. More durable resistance to C. parasitica and mitigation of PRR through better site selection and/or resistance screening will improve future restoration efforts.

Nueva ecuación dinámica de altura dominante e índice de sitio para Pinus chiapensis (Martínez) Andresen en Puebla y Veracruz, México

Introduction: Pinus chiapensis (Martínez) Andresen lacks in many areas of site index (SI) models to classify timber productivity. Objective: To develop a dynamic SI equation, using the generalized algebraic difference approach (GADA) to describe the dominant height growth pattern and classify the productivity of natural stands of P. chiapensis in Puebla and Veracruz, Mexico. Materials and methods: Four theoretical growth models were used to derive six equations in GADA, fitted to dominant height-age observations from stem analyses of 31 trees. Fitting was performed using the Dummy variable method, which is invariant to the base age; autocorrelation and heteroscedasticity were corrected. Results and discussion: Quantitative evaluation, graphical analysis of residuals and growth trends of equations allowed the selection of an equation derived from the Levakovic II model with higher predictive capacity. With this equation and a base age of 50 years, polymorphic SI curves with variable asymptotes were constructed to classify productivity into low, medium and high, corresponding to SI of 25, 32 and 39 m, respectively. The maximum mean annual increase for the SI of 32 m was 1.07 m∙yr-1 and occurred at 11.08 years. The equation exhibited better performance relative to a previously reported polymorphic equation. Conclusions: It is recommended to use the developed equation to predict dominant height growth and SI of P. chiapensis stands in Puebla and Veracruz, Mexico.

Assessment of height growth in Indian children using growth centiles and growth curves

Background Growth centiles and growth curves are two ways to present child anthropometry; however, they differ in the type of data used, the method of analysis, the biological parameters fitted and the form of interpretation. Aim To fit and compare height growth centiles and curves in Indian children. Subjects and methods 1468 children (796 boys) from Pune India aged 6–18 years with longitudinal data on age and height (n = 7781) were analysed using GAMLSS (Generalised Additive Models for Location Scale and Shape) for growth centiles, and SITAR (SuperImposition by Rotation and Translation) for growth curves. Results SITAR explained 98.7% and 98.8% of the height variance in boys and girls, with mean age at peak height velocity 13.1 and 11.0 years, and mean peak velocity 9.0 and 8.0 cm/year, respectively. GAMLSS (Box-Cox Cole Green model) also captured the pubertal growth spurt but the centiles were shallower than the SITAR mean curve. Boys showed a mid-growth spurt at age 8 years. Conclusion GAMLSS displays the distribution of height in the population by age and sex, while SITAR effectively and parsimoniously summarises the pattern of height growth in individual children. The two approaches provide distinct, useful information about child growth.

Association between height growth patterns in puberty and stature in late adolescence: A longitudinal analysis in chinese children and adolescents from 2006 to 2016.

IntroductionThe relationship between the characteristics of puberty growth and the stature (height and overweight and obesity) in late adolescence was not clear. We aimed to explore the effects of puberty growth patterns on the stature in late adolescence.MethodsA total of 13,143 children from a longitudinal cohort from 2006 to 2016 in Zhongshan city of China were included. The Preece–Baines growth curve was fitted for each individual child, and the age at peak height velocity (APHV), peak height velocity (PHV), and age at take-off (TOA) were obtained from the Preece–Baines model. To compare the difference in height in late adolescence (at 18 years old) at different pubertal height growth patterns (height spurt timing, intensity, and duration), the height at baseline was matched by using the propensity score matching. The log-binomial model was applied to assess the association between the three pubertal height growth patterns (timing, intensity, and duration) and overweight and obesity status in late adolescence, controlling the urbanity and body mass index (BMI) at baseline.ResultsAfter matching the baseline height, boys and girls in three pubertal patterns with early timing (P < 0.01), small intensity (P < 0.01), and short duration (P < 0.01) of height spurt had the lowest final height in the late adolescence. A 16% increase and 45% increase of risk for overweight and obesity were significantly associated with the early APHV in boys and girls, respectively, relative risk (RR) in boys, 1.16(95% confidence interval, CI: 1.03–1.30), P = 0.011; RR in girls, 1.45(1.21–1.75), P < 0.001. A 21% increase and 59% increase of risk for overweight and obesity were significantly associated with small PHV in boys and girls, respectively, RR in boys, 1.21(1.07–1.36), P < 0.001; RR in girls, 1.59(1.30–1.95), P < 0.001; and an 80% increase of risk for overweight and obesity with small spurt duration in girls (RR = 1.80; 95% CI: 1.49, 2.18; P < 0.001).ConclusionPubertal growth patterns, including earlier puberty onset timing, smaller puberty intensity, and shorter puberty spurt duration, had a positive association with lower height risks and higher overweight and obesity risks in late adolescence.

The Historical Complexity of Tree Height Growth Dynamic Associated with Climate Change in Western North America

The effect of climate on tree growth has received increased interest in the context of climate change. However, most studies have been limited geographically and with respect to species. Here, sixteen tree species of western North America were used to investigate the response of trees to climate change. Forest inventory data from 36,944 stands established between 1600 and 1968 throughout western North America were summarized. The height growth (top height at a breast-height age of 50 years) of healthy dominant and co-dominant trees was related to annual and summer temperatures, the annual and summer Palmer Drought Severity Indexes (PDSIs), and the tree establishment date (ED). Climate-induced height growth patterns were then tested to determine links to the spatial environment (geographic locations and soil properties), the species’ range (coastal, interior, or both), and traits (shade tolerance and leaf form). Analysis was performed using a linear mixed model (total species) and a general linear model (species scale). Climate change was globally beneficial, except for Alaska yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach), and growth patterns were magnified for coastal-ranged, high-shade-tolerant, and broadleaf species, and mostly at the northernmost extents of these species’ ranges. Nevertheless, growth patterns were more complex with respect to soil properties. A growth decline for some species was observed at higher latitudes and elevations and was possibly related to increased cloudiness, precipitation, or drought (in interior areas). These results highlight the spatio-temporal complexity of the growth response to recent global climate change.

Responses in growth and emissions of biogenic volatile organic compounds in Scots pine, Norway spruce and silver birch seedlings to different warming treatments in a controlled field experiment

We investigated the responses in growth and emissions of biogenic volatile organic compounds (BVOCs) in Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies [L.] Karst.) and silver birch (Betula pendula Roth) seedlings to a simulated climate warming of +2 °C (T2) and +4 °C (T4), compared to the ambient conditions, during two growing seasons (2019–2020) in a controlled field experiment in central Finland. In all seedlings, height was measured weekly. Diameter was measured continuously for one seedling from each tree species per plot. For shoot and root biomass measurements, half of the seedlings were harvested at end of the first growing season and the rest at the end of the second growing season. Foliage BVOC emission rates were measured at the end of the second growing season. Biomass, height, and diameter growth of silver birch did benefit the most from warming in both growing seasons. In the Scots pine and Norway spruce seedlings, height and diameter growth increased with increasing temperature in the second growing season, more so in Scots pine. Overall, the shoot and root biomass of conifer seedlings increased with increasing temperature. In the conifer seedlings, warming increased biomass and diameter growth more than height growth, due to their predetermined height growth pattern. The warming increased BVOC emissions more clearly in silver birch, whilst the BVOC emissions were in conifers less sensitive to temperature variation. Based on our findings, silver birch seedlings could be expected to benefit the most from warmer growing conditions and Norway spruce the least.

Verification of Changes in Body Proportions in Humans

So far, the growth curves proposed by Scammon (1930) have been often used to advantage when explaining the changes in human proportions. With regard to these explanations, the growth was understandable if seen as the relative growth of the general growth pattern for things such as height and weight and the neural growth pattern showing growth of the head. However, the point here is that the validity the logic for the growth curves proposed by Scammon almost 90 years ago should obviously be tested. Even assuming that the growth curves of Scammon (1930) were to be re-examined, the changes in human proportions can probably not be verified simply with the differences between the general and neural type growth patterns alone. Thus, it is necessary to verify the actual height and weight growth patterns and the head growth pattern. Therefore, the present study attempts to verify the changes in human proportion by applying the wavelet interpolation model to growth distance values obtained through measurements of growth in height and head circumference from early childhood to adults, and to analyze the behavior of the velocity curves of height and head circumference derived as differential curves. As result, this study was able to provide unequivocal findings on the changes in proportion by applying the wavelet interpolation model proposed by the author (1999) (2006). However, the study had the limitations that there was no longitudinal data on the organs, actual face length, or longitudinal data on head circumference.

Modeling post-logging height growth of black spruce-dominated boreal forests by combining airborne LiDAR and time since harvest maps

Increase in forest disturbance due to land use as well as climate change has led to an expansion of young forests worldwide, which drives global carbon dynamics and timber allocation. This study presents a method that combines a single airborne LiDAR acquisition and time since harvest maps to model height growth of post-logged black spruce-dominated forests in a 1700 km2 eastern Canadian boreal landscape. We developed a random forest model in which forest height at a 20 m × 20 m pixel resolution is a function of stand age, combined with environmental variables (e.g., slope, site moisture, surface deposit). Our results highlight the model's strong predictive power: least-square regression between predicted and observed height of our validation dataset was very close to the 1:1 relation and strongly supported by validation metrics (R2 = 0.74; relative RMSE = 19%). Environmental variables thus allowed to accurately predict forest productivity with a high spatial resolution (20 m × 20 m pixels) and predicted forest height growth in the first 50 years after logging ranged between 16 and 27 cm·year−1 across the whole study area, with a mean of 20.5 cm·year−1. The spatial patterns of potential height growth were strongly linked to the effect of topographical variables, with better growth rates on mesic slopes compared to poorly drained soils. Such models could have key implications in forest management, for example to maintain forest ecosystem services by adjusting the harvesting rates depending on forest productivity across the landscapes.

Regional height growth models for Scots pine in Poland

Site productivity remains a fundamental concern in forestry as a significant driver of resource availability for tree growth. The site index (SI) reflects the overall impact of all environmental factors that determine tree height growth and is the most commonly used indirect proxy for forest site productivity estimated using stand age and height. The SI concept challenges are local variations in climate, soil, and genotype-environmental interactions that lead to variable height growth patterns among ecoregions and cause inappropriate estimation of site productivity. Developing regional models allow us to determine forest growth and SI more appropriately. This study aimed to develop height growth models for the Scots pine in Poland, considering the natural forest region effect. For height growth modelling, we used the growth trajectory data of 855 sample trees, representing the Scots pine entire range of geographic locations and site conditions in Poland. We compared the development of regional height growth models using nonlinear-fixed-effects (NFE) and nonlinear-mixed-effects (NME) modelling approaches. Our results indicate a slightly better fit to the data of the model built using NFE approach. The results showed significant differences between Scots pine growth in natural forest regions I, II, and III located in northern Poland and natural forest regions IV, V, and VI in southern Poland. We compared the development of regional height growth models using NFE and NME modelling approaches. Our results indicate a slightly better fit to the data of the model built using the NFE approach. The developed models show differences in height growth patterns of Scots pines in Poland and revealed that acknowledgement of region as the independent variable could improve the growth prediction and quality of the SI estimation. Differences in climate and soil conditions that distinguish natural forest regions affect Scots pine height growth patterns. Therefore, extending this research to models that directly describe height growth interactions with site variables, such as climate, soil properties, and topography, can provide valuable forest management information.

Abiotic and biotic determinants of height growth of Picea abies regeneration in small forest gaps in the Swiss Alps

In managed mountain forests, height growth of Norway spruce (Picea abies (L.) Karst) regeneration is a decisive factor for the gap-filling process, especially when the silvicultural goal is to provide continuous protection against natural hazards such as snow avalanches or rockfall. For the planning of management interventions, robust predictions on height growth of regeneration at the scale of forest gaps are thus needed. However, there is a lack of such data for trees of intermediate sizes, and existing studies fail to cover large environmental gradients. The goal of our study is to identify the key factors that influence height growth of Norway spruce regeneration in small gaps of spruce-dominated forests in the Swiss Alps. Furthermore, we assess whether there are site-specific differences of height growth or whether it follows a similar pattern along a large gradient of temperature (i.e., along elevation) and of water and nutrient availability (i.e., among different phytosociological site types) within the upper montane and subalpine vegetation belts. On 124 plots, >2′000 observations of annual height increments of Norway spruce regeneration (10 cm tree height to 12 cm stem diameter) in gaps were collected. Using linear mixed effects models and cross-validation for model selection, we identified the best variable combinations to predict annual height growth. Consistently across the entire gradient, the most important factors were 1) the positive effect of tree size, 2) the negative effect of competition by the surrounding stand, and 3) local topography. We found site-specific differences in height growth patterns such as gap size and therefore direct radiation being the most important competition measure in subalpine sites, as opposed to diffuse radiation in high montane sites. However, the pooled model for the entire environmental gradient allowed for predictions of regeneration height growth with similar explanatory power as the more specific models while containing comparable effect sizes. Furthermore, competition can be equally well expressed by metrics based on basal area measurements as by metrics derived from hemispherical photography. Based on these relatively simple models, accurate and robust predictions of the development of Norway spruce regeneration in gaps of managed mountain forests are possible.

Knee height and knee height/height ratio of healthy schoolchildren

Background Knee height (KH) is rarely used to estimate stature in children, although its measurement might have benefit because not influenced by some musculoskeletal disorder in spinal region. Knee height and knee height/height ratio are typical in children due to different in pubertal timing of each child.&#x0D; Objective To derive a formula to estimate body height using knee height and to analyze the patterns of knee height and knee height/height ratio of healthy schoolchildren.&#x0D; Methods This cross-sectional study involved healthy children in one elementary school and one junior high school in Surakarta, Central Java. Demographic data were collected (sex, age, and ethnicity). All anthropometric measurements (height, weight, sitting height, and knee height) were taken three times, and their means were calculated. Linear regression analysis was used to compare height from knee height and sitting height. Non-parametric analysis through locally weighted scatterplot smoothing (LOWESS) was used to analyze the growth patterns of knee height, knee height/height ratio, and sitting height/height ratio.&#x0D; Results There were 633 children (328 boys and 305 girls) in this study. The formulas for the estimation of height were as follows: for boys, 2.40 × KH (cm) + 1.36 × age (years) + 20.31; and for girls, 2.48 × KH (cm) + 1.15 × age (years) + 19.58 (adjusted R2=0.97). Knee height increased earlier than sitting height in both boys and girls during childhood to adolescent period. Boys had a longer period of knee height increment than girls.&#x0D; Conclusion Knee height may be a useful alternative to estimate height in children. Knee height increases faster than height and sitting height in both boys and girls.

Effects of overstory competition on canopy recruitment patterns of naturally regenerated longleaf pine on two site types

Recent interest in continuous cover forest management of longleaf pine (Pinus palustris Mill.) ecosystems raises questions of long-term sustainability because of uncertainty in rates of canopy recruitment of longleaf pine trees. We destructively sampled 130 naturally regenerated, midstory longleaf pines across an 11 300 ha, second-growth longleaf pine landscape in southwestern Georgia, United States, to reconstruct individual tree height growth patterns. We tested effects of stand density (using a competition index) and site quality (based on two site classifications: mesic and xeric) on height growth and demographics of midstory trees. We also compared height growth of paired midstory and overstory trees to infer stand regeneration and recruitment dynamics. In low-density stands, midstory trees were younger and grew at greater rates than trees within high-density stands. Midstory trees in low-density stands were mostly from a younger regeneration cohort than their paired overstory trees, whereas midstory–overstory pairs in high-density stands were mostly of the same cohort. Our results highlight the importance of releasing midstory longleaf pine trees from local competition for sustained height growth in partial-harvesting management systems. They also demonstrate patterns of long-term persistence in high-density stands, indicating flexibility in the canopy recruitment process of this shade-intolerant tree species.