Height Growth Patterns Research Articles

1229 Growth Patterns in Dutch Children with Down Syndrome

Objective: The majority of children with Down syndrome (DS) have concomitant disorders, such as congenital heart defects (CHD), celiac disease, and hypothyroidism. We aim to establish growth patterns of height in Dutch children with DS, while taking into account the influence of the concomitant disorders. Methods: Out of the 30 regional outpatient clinics for children with DS in the Netherlands 25 participated. Children with Trisomy 21 karyotype of Dutch descent born after 1982 were included. Growth data were retrospectively collected from their medical records, as were data on concomitant medical conditions and treatments administered. The LMS method was applied to fit the growth references. Results: We enrolled 1,596 Dutch children with Trisomy 21 (56% boys). Children with DS without concomitant disorders and children with DS who suffer from only mild CHD showed similar growth patterns. Reference growth curves were therefore fitted from all measurements (n=3,728) of these subgroups. Mean final height was determined at 163 and 152 cm, respectively in boys and girls with DS. On the reference growth curves of the general Dutch population, the DS curves roughly follow the -2 SDS line with a deflection to the -2.8 SDS line after the age of 12 years. Conclusions: Children with DS without concomitant disorders and those with only a mild CHD show similar growth patterns of height. As compared to the general Dutch population, they are of short stature with an increasing height difference at older ages.

Dynamic height growth model for Spanish and Tunisian cork oak (Quercus suber L.) forests

Seven simple and advanced dynamic polymorphic functions were considered to develop a dominant height growth model for Spanish and Tunisian cork oak forests. Data from 115 stem analyses performed in two regions in each country were used to fit the equations. Parameter estimates were obtained using the Dummy variable method. Both numerical, graphical and biological consistency were used to compare alternative models. The dynamic equation finally selected was derived from the Hossfeld model by considering the shape parameter to be related to site productivity. An analysis of the dominant height growth patterns between the two countries indicated that the same dominant height growth model was valid for both countries. This dominant height growth model allows estimation of dominant height with a level of reliability of at least 83% from an age of 15 years for a prediction interval of less than 40 years.

Bone and body segment lengthening and widening: A 7-year follow-up study in pubertal girls

During growth bone increases in length and width as does the body size. The aim of this paper was to examine the growth pattern of body height and weight, and the width and length of various body segments, and to establish the timing of peak growth velocity (PV) in relation to time of menarche in a cohort of Finnish girls followed from age 10 until 18. The study was a 7-year longitudinal cohort study. Widths and lengths of body segments and bones were measured from DXA scan images using bone landmarks in 396 girls aged 10 to 13 years at baseline, and in 255 mothers and 159 grandmothers. The girls' growth velocities (rate of change with time) peaked at 13.5 months prior to menarche for height, 14.4 months for weight, and 15.4 months for BMI. Shoulder width peaked at 18.2 months, lesser pelvis width at 13.5 months and greater pelvis width at 11.6 months prior to menarche. The PV of various body segment lengths showed that the femur peaked earliest at 20.7 months prior to menarche, followed by the humerus (at 18.0 months), radius (at 17.4 months), tibia (at 17.5 months), and trunk (at 11.8 months), respectively. All the long bones were linearly correlated with height while the flat and irregular bones had a nonlinear growth relationship with height (r 2 = 0.73–0.88). By the age of 18 years the girls had reached their mothers' height (101%) and humerus, radius, femur and tibia lengths (100–101%), but not their mothers' shoulder, great pelvis and lesser pelvis widths (98%, 95% and 93%, respectively). Our data confirmed that, after bone elongation had ceased, segment width continued to increase, although at a slower speed, into early adulthood. The wide variations in growth velocity of these anthropomorphic measurements underscore the need to optimize nutrition and physical activity from early puberty onward in order to maximize bone development.

Stand Structure and Maintenance of Picea jezoensis in a Northern Temperate Forest, South Korea

Stand structure and spatial distribution of Picea jezoensis (Siebold et Zucc.) Carriere on Mt. Gyebang, Korea was investigated to provide information on the structural characteristics and the maintenance of P. jezoensis population in northern temperate mixed coniferous forests. Height and diameter at breast height (DBH) distribution, age, growth, and spatial distribution patterns of P. jezoensis were examined in thirty nine 100-400 m2 quadrats or circular plots. The overall stand structure attributes in the study sites are stem density of 709 trees ha−1, a mean DBH of 12.8 cm, and a mean height of 5.6 m, with reverse J shapes of DBH and height distributions. The stem density of P. jezoensis population was 81 trees ha−1, a mean DBH of 20.7 cm, and a mean height of 9.1 m, showing bimodal-like shapes in age and DBH distributions. Several growth release periods implied that P. jezoensis stands experienced small disturbances. The radius of patches of similar-sized P. jezoensis in the variogram was equivalent with the height of the tallest trees, indicating that patches were established following the fall of trees in the upper canopy layer. Small windthrows in this region contributed to the maintenance of the P. jezoensis stand by releasing sapling growth and providing nursing logs and space for seedlings.

Response of a boreal forest to canopy gap openings - assessing vertical and horizontal tree growth with multi-temporal lidar data

Fine-scale height-growth response of boreal trees to canopy openings is difficult to measure from the ground, and there are important limitations in using stereo-photogrammetry in defining gaps and determining individual crowns and height. However, precise knowledge on height growth response to different openings is critical for refining partial harvesting techniques. In this study, we question whether conifers and hardwoods respond equally in terms of sapling growth or lateral growth to openings. We also ask to what distance gaps affect tree growth into the forest. We use multi-temporal lidar to characterize tree/sapling height and lateral growth responses over five years to canopy openings and high resolution images to identify conifers and hardwoods. Species-class-wise height-growth patterns of trees/saplings in various neighborhood contexts were determined across a 6-km2 matrix of Canadian boreal mixed deciduous coniferous forests. We then use statistical techniques to probe how these growth responses vary by spatial location with respect to the gap edge. Results confirm that both mechanisms of gap closure contribute to the closing of canopies at a rate of 1.2% per annum. Evidence also shows that both hardwood and conifer gap edge trees have a similar lateral growth (average of 22 cm/yr) and similar rates of height growth irrespective of their location and initial height. Height growth of all saplings, however, was strongly dependent on their position within the gap and the size of the gap. Results suggest that hardwood and softwood saplings in gaps have greatest growth rates at distances of 0.5–2 m and 1.5–4 m from the gap edge and in openings smaller than 800 m2 and 250 m2, respectively. Gap effects on the height growth of trees in the intact forest were evident up to 30 m and 20 m from gap edges for hardwood and softwood overstory trees, respectively. Our results thus suggest that foresters should consider silvicultural techniques that create many small openings in mixed coniferous deciduous boreal forests to maximize the growth response of both residual and regenerating trees.

Estimation of height growth patterns and site index curves for Pinus radiata plantations in New South Wales, Australia

The objective of this study was to estimate the mean top height growth patterns and site index curves (base index age 20 years) for Pinus radiata stands grown in New South Wales, Australia. Garcia's stochastic differential equation version of the Bertalanffy-Richards equation was selected for stand height prediction using data from permanent growth and long-term experimental plots. This technique uses simultaneous maximum likelihood methods to estimate the global and local model parameters. Three regional base age invariant site index curves were created based on this height estimation methodology. These models may be used for modelling stand height growth as a component of a stand growth model and can also provide an indication of the productivity of the site quality of Pinus radiata stands planted in New South Wales, Australia.

Correlation of Body Growth and Bone Mineral Density Measured by Ultrasound Densitometry of the Calcaneus in Children and Adolescents

The assessment of growth, including the developmental change in bone mass, is crucial for child health care. We herein report normative values of bone mineral density (BMD) for calcaneus obtained from a large cross-section sample in Japanese school children. To investigate yearly physical growth from pre-school age to adulthood, we measured height, weight, body mass index (BMI), and BMD in 3,835 school children aged 3 to 18 (1,886 boys and 1,949 girls). Participating institutions included kindergarten, junior high schools, high schools, and a college of technology. The growth pattern (or velocity) of BMD (the ratio of trabecular bone area of the calcaneum) shows 3 phases according to the age rage: 3-10, 11-15, and 16-18 years for boys, and 3-7, 8-15, and 16-18 years for girls, both peaking at age 16 years. Likewise, that of weight shows 3 phases: 3-4, 5-15 and 16-18 years for boys, and 3-4, 5-14 and 15-18 years for girls, while the growth pattern of height shows 2 phases: 3-15 and 16-18 years for boys, and 3-13 and 14-18 years for girls, both sexes peaking at approximately 16 years. Therefore, the physical growth pattern of the school children shows progressive growth until 16 years, at which time growth is generally completed. In children under 16 years old, BMD of the calcaneus is higher in girls than in boys. Boys and girls show a similar growth pattern in body height and weight before peak development; however, the physical growth of boys eventually exceeds that of girls.

Base–age Invariant Polymorphic Height Growth and Site Index Equations for Peatland Black Spruce Stands

Abstract The goal of this study was to develop base–age invariant polymorphic height growth and site index equations for peatland black spruce (Picea mariana [Mill.]; BSP) stands situated within the western portion of the Northern Clay section of the Canadian Boreal Forest region. Procedurally, equation parameters were estimated via ordinary least squares analysis using 291 mean dominant height − mean stand age (Hd − As) data pairs derived from 42 permanent sample plots (PSPs). The predictive ability of the resultant height growth equation was evaluated by examining mean absolute and relative errors and associated 95% prediction intervals over 5-, 15-, 25-, 35-, and 45-year projection periods. Furthermore, using an independent data set consisting of 129 Hd − As data pairs derived from 24 PSP, the new height growth equation was compared with two preexisting equations. Overall, the results indicated that the predictions derived from the new equation were unbiased irrespective of error type or projection period length and that the new equation exhibited greater predictive accuracy and was more consistent with expected dominant height development patterns than the preexisting equations. Consequently, the new equations are recommended for use when describing height growth patterns or quantifying site quality within peatland black spruce stands.

Is the spatial distribution of European beech (Fagus sylvatica L.) limited by its potential height growth?

AbstractAim To improve our understanding of species range limits by studying how height growth, a trait related to plant survival, varies throughout the geographic range of Fagus sylvatica L. in France.Location The geographic range of beech in France, representing the western area of its European distribution, within which this species exhibits range distribution limits in both plains and mountainous areas.Methods A generalized linear regression model was used to link beech growth performance to environmental variables using data from 819 plots of the French National Forest Inventory (IFN) database. This model was applied to predict potential growth on 97,281 IFN plots covering the geographic range of beech in France. A kriging technique was used to interpolate estimated growth potential. Finally, the performance of plot‐based predictions of potential growth from the map (i.e. map quality) was evaluated against an independent data set.Results The beech growth performance model highlighted the major impact of climate on potential tree growth at a broad spatial scale. The relevant climatic factors were related mainly to spring cold, summer heat, and winter temperatures and rainfall. The study also revealed the predictive power of soil parameters, which explained a large proportion of the variation in potential beech growth (c. 30%). Analyses of height growth patterns near the boundary of the species range in France showed that the limit only partly coincides with the growth decline caused by climatic and soil factors. Along parts of the range limit, the predicted potential for growth was high, suggesting that in these areas the limit of the range could be explained by other factors, such as competition or constraints on reproduction.Main conclusions The spatial variation in the potential height growth of Fagus sylvatica can be explained by environmental factors and is partly correlated with its regional range limits. By identifying areas where growth potential constrains the geographic range of species, environmental growth models can help to improve our knowledge of the spatial drivers of species geographic range limits and shed light on their response to future environmental changes.

A Stand-Development Approach to Oak Afforestation in the Lower Mississippi Alluvial Valley

Abstract Oak (Quercus spp.) afforestation in the Lower Mississippi Alluvial Valley has involved planting 1-year-old bareroot seedlings on a relatively wide spacing in single-species stands or planting light-seeded species with oaks to form mixed-species stands. In the former case, the developing single-species stands have limited future management options because they do not provide structures that favor quality wildlife habitat or quality sawtimber production. In the latter case, species mixtures are being planted with little knowledge of subsequent stand development, leading to an inability to predict future stand composition for management purposes. In this article, we present a system to determine bottomland tree planting mixtures that will create single-cohort, mixed-species stands with a component of high-quality bottomland oak. Using individual species ecological life-history characteristics, such as early height growth pattern, relative twig diameter and durability, and developmental patterns in natural stands, bottomland species are rated for their ability to provide beneficial training effects that will lead to the development of quality oak boles. Incorporating such a system to determine species value in mixtures should provide an increased number of future options to meet explicit management objectives and promote improved restoration of bottomland hardwood ecosystems.

Variation structurelle à grande échelle et dynamique de croissance à long terme de Juniperus thurifera dans des forêts aménagées à Soria dans le centre de l’Espagne

• Juniper woodlands have a great conservational and productive importance in Spain. However, basic traits of their structural variation and growth dynamics are unknown. • To characterize the structural variation and assess both height and radial growth patterns, we sampled and measured stem cross-sections every 0.5 m in height from 107 Spanish juniper (Juniperus thurifera L.) trees, which were selected based on a 350 m regular grid over a whole woodland of 3 300 ha in area. We used dendroecological techniques and spatial analysis to study tree structure and growth. • Structural traits such as bole diameter and height were mainly determined by tree life-related parameters such as tree age and growth rate variation, while abiotic factors such as altitude played a minor role in determining structural variation. Over the last 300 years, juniper establishment has been continuous in time but discontinuous in space. Large-scale spatial heterogeneity of tree establishment, and the presence of an early growth suppression and abrupt growth changes in junipers > 100 years old are consequences of an intense management that almost ceased in the late 19th century. • Abrupt growth releases and suppressions were synchronic among different age classes, and coincided with documentary records on livestock decrease and key historical changes in land use. Growth patterns suggest that juniper is a brow sing-tolerant species that is able to survive large periods of intense browsing pressure.

INCREASED WILLOW HEIGHTS ALONG NORTHERN YELLOWSTONE's BLACKTAIL DEER CREEK FOLLOWING WOLF REINTRODUCTION

Gray wolves (Canis lupus) were reintroduced into Yellowstone National Park in 1995–1996. In August 2004 we measured plant architecture of Geyer willow (Salix geyeriana) stems along three 100-m reaches of Blacktail Deer Creek in Yellowstone's northern elk (Cervus elaphus) winter range to evaluate changes in patterns of browsing and height growth following wolf reintroduction. Average browsing intensities (n = 3 stream reaches) of 100% in 1997 decreased to 0%–55% by 2003, whereas average stem heights of 25–74 cm in 1997 increased to 149–268 cm by 2003, indicating that willow height growth was inversely related to browsing intensity. In addition, average willow canopy cover over the streams increased from <5% in 1997 to 14%–73% in 2004. These findings were consistent with a hypothesis that increased willow heights following the 1995–1996 wolf reintroduction represent a trophic cascade involving wolves, elk, and deciduous woody vegetation.

The effects of intensive management on the leaf characteristics and growth phenology of young yellow-poplar stems

Yellow-poplar ( Liriodendron tulipifera L.) is one of the more commonly regenerated species in upland Piedmont stands following clearcut reproduction methods. Recent studies show that a variety of silvicultural activities affect the growth of yellow-poplar seedlings. However, the factors responsible for these changes in growth have not been documented in detail. Weed control, fertilization and thinning treatments were imposed on rising 1- and 3-year-old naturally regenerated stands. Stem growth and monthly height growth patterns, and leaf physical and chemical parameters were compared by treatment during the third growing season after treatments were initiated. The response of yellow-poplar to fertilization suggests that inherent site resources are not suitable for optimal growth, especially when stem densities are high. Vector analysis of N, P and K responses to fertilization, weeding and thinning treatments demonstrated that yellow-poplar responded to ameliorations of N and P deficiencies. Thinned + weeded yellow-poplar, with or without fertilization, had a greater percentage of height growth later in the summer compared to other treatments. Foliar characteristics like leaf number, leaf size and nitrogen concentration were positively correlated with stem growth. The largest increases in leaf area were coincident with increases in foliar N and P.

Effects of changes in traditional management on height and radial growth patterns in a Juniperus thurifera L. woodland

In order to understand the effects of changes in traditional forest management on Spanish juniper ( Juniperus thurifera L.) forest dynamics, height and radial growth patterns were studied in 107 juniper trees in Cabrejas del Pinar (Soria, Central Spain). Suppressions in height and radial growth were common until the second half of XIXth century. These suppressions occurred at relatively low tree heights, and affected 30% of the sampled trees. The individual suppressions ended abruptly with a sharp increase in height and radial growth. These results fit well into the browsing cessation model, suggesting that an intense browsing pressure shaped this forest. The timing in the reduction of the browsing pressure matches the regional decrease in transhumant livestock that occurred in Spain during the second half of XIXth century. No difference in height-growth rate between suppressed and non-suppressed trees was observed for post-suppression period, indicating a high recovery capacity for J. thurifera. We observed a high variability in height-growth rate during post-suppression periods. This variability was poorly related to site factors (competition, landform), being related to tree life (age and presence of past suppression events). Traditional logging based solely on trees morphological traits may be partially responsible of this pattern.

Characteristic Height Growth Pattern in Patients with Pseudohypoparathyroidism: Comparison between Type 1a and Type 1b.

Pseudohypoparathyroidism (PHP) is a metabolic disorder characterized by organ resistance to the action of parathyroid hormone. PHP type 1 is subclassified into two apparent disorders, type 1a (PHP1a) and type 1b (PHP1b). Patients with PHP1a show Albright hereditary osteodystrophy including short stature. Patients with PHP1b have no such skeletal defects, however, literature regarding the growth of PHP1b is not currently available. We evaluated growth charts of PHP patients, including four PHP1a patients and six PHP1b patients. Growth patterns were different between PHP type 1a and 1b. Adult height was abnormally low in all PHP1a patients. The growth pattern of PHP1a was characterized by mild growth impairment in the prepubertal period, a blunted growth spurt and premature cessation of the growth spurt. The adult height of male PHP1b was slightly lower than average. An early growth spurt was observed only in male patients with PHP1b and it may reduce the adult height of male patients with PHP1b. This warrants further investigation into the growth and pubertal development of PHP1b patients.

Comparative Height Growth and Forest Structure of Fraxinus Spaethiana and Pterocarya Rhoifolia in Natural Reforestation Stands in Steep Valleys of Central Japan

Height-growth analysis was used to examine forest structure and compare Pterocarya rhoifolia and Fraxinus spaethiana growth characteristics within and between each species in two P. rhoifolia-dominant and two F. spaethiana established contemporaneously in the sere, species vertical stratification 25 years after stand initiation was such that P. rhoifolia dominated the overstory but F. spaethiana the understory, including that P. rhoifolia grew about 4 times more rapidly Similarly, F. spaethiana dominated the overstory but not the understory, in a stand where it established mainly by itself, 25 years after Initiation. However, comparing the two different stands, P. rhoifolia overstory heights were about two times greater than F. spaethiana. This suggests that in a disturbance regime, forest regeneration is affected by height-growth patterns such that P. rhoifolia's ability to achieverapid height growth allows it to dominate where lights growth allows it to dominate where light resources are continuously abundant.

Modelling dominant height growth and site index curves for rebollo oak (Quercus pyrenaicaWilld.)

A dominant height growth model and a site index model were developed for rebollo oak (Quercus pyrenaica Willd.) in northwest Spain. Data from 147 stem analysis in 90 permanent plots, where rebollo oak was the main species, were used for modelling. The plots were selected from the National Forest Inventory at random in proportion to four biogeoclimatic stratums. Different traditional and generalized algebraic difference equations were tested. The evaluation criteria included qualitative and quantitative examinations and a testing with independent data from another region. The generalized algebraic difference equation of Cieszewski based on Bailey equation showed the best results for the four stratums. An analysis of the height growth patterns among ecological stratums was made in order to study the necessity of different site index curves. Results indicated the validity of a common height growth model for the four stratums. In spite of the irregular height growth pattern observed in rebollo oak, probably due to past management, the model obtained allows us to classify and compare correctly rebollo oak stands growing at different sites.

Modeling tree regeneration height growth after an experimental hurricane

Annual height growth rates for six species of tree seedlings were modeled during the first 10 years of cohort initiation following an experimental hurricane in central Massachusetts. Selected canopy trees in a second-growth, transition oak – northern hardwoods forest were pulled over with a winch in a 50 m × 160 m area. Regeneration height growth did not follow the species-specific patterns anticipated if the disturbance had been stand replacing. Instead, the temporal increase in shade from crown expansion and sprouting of residual trees slowed cohort development and resulted in a variety of annual height growth patterns among species. Height development was followed separately for advance regeneration and new seedlings of red maple white ash, black cherry, black and yellow birch, paper birch, and red oak. All species had increasing height growth rates for 3 years followed by either decreasing or unchanged (flat) rates except red maple and ash advance regeneration, which had increasing rates throughout the measurement period. After 10 years, black and yellow birch, and red maple are the most numerous species and compose the majority of the tallest regeneration. Red oaks, which dominated the original stand, are few and unlikely to emerge to the canopy of the new cohort.

Pattern of growth and adiposity from infancy to adulthood in atopic dermatitis

Impaired linear growth has been reported in children with atopic dermatitis (AD) but the pattern of growth in height and weight through childhood and adolescence has not been described. To define the pattern of linear growth and adiposity in AD from early childhood through to adult life. Growth measurements of 70 male and 40 female patients with AD followed through childhood and adolescence were studied retrospectively and compared with the 1990 U.K. normal values. Height, weight and body mass index (BMI) were converted to standard deviation scores (SDS). Regression analysis examined whether the mean trend was different from zero. While dermatitis was the predominant atopic problem in all 110 patients, 92 had a history of asthma which was mild in 85 of 92. Regression analyses showed that the trends in height, weight and BMI SDS for AD patients were significantly different from zero and also different between males and females. Both sexes were short and relatively overweight from early childhood, a trend that was more pronounced in males than females. At 5 years (school entry), the 50th centile BMI of male (but not female) patients was 0.44 kg m(-2) higher than the reference population but height and weight were lower. The age at adiposity rebound in AD males and females was 0.8 year and 0.7 year later than the U.K. population (6.2 years vs. 5.4 years and 6.2 years vs. 5.3 years, respectively). AD patients attained peak height velocity later than the 1990 U.K. population (males 16.0 years vs. 13.5 years, P = 0.0002; females 13.4 years vs. 11.0 years, P = 0.008). In addition, males had greater mean gain in height during late adolescence (12.2 vs. 8.8 cm, P = 0.03) and were shorter as young adults (170.9 vs. 177.6 cm, P = 0.0005). Our patients with AD were relatively overweight very early but had a later adiposity rebound, were short in childhood and had a delayed adolescent growth spurt. Serial growth measurements should be done on all children with troublesome AD and can be helpful in counselling about the growth prognosis.

Polymorphic site index curves for black spruce and trembling aspen in northwest Ontario

Site index curves were developed using stem-analysis data from dominant and codominant trees in 230 black spruce and 194 trembling aspen plots located in mature, well-stocked, even-aged stands. Black spruce plots were in five separate and independent data sets located on mineral and organic soils; trembling aspen plots were in three separate and independent data sets located on mineral soils. Computations showed that the Newnham nonlinear regression model was slightly more precise than other models commonly used for developing site index curves. This model accurately expresses polymorphic height growth for a wide range of site index and age and constrains predicted height to agree with specified 50-year tree height (site index). Computations showed that height-growth curves were similar for each of the five black spruce data sets; likewise, curves for each of the three trembling aspen data sets were similar. Therefore, the five black spruce and the three trembling aspen data sets were combined for computing a single set of black spruce and a single set of trembling aspen site index curves for Northwest Ontario. Comparisons between our Northwest Ontario site index curves and other black spruce and trembling aspen curves showed large differences in height-growth patterns for older ages. Reasons for these differences are uncertain but in many instances these could be artifacts related to study methods involving various amounts and kind of data and variations in analytical techniques. In some cases differences in climate, soil and topography may also be related to variations in these site curves. Key words: site quality evaluation, polymorphic height growth, site index curve comparisons