Annual Height Increment Research Articles

HUBUNGAN SIFAT FISIK DAN KIMIA TANAH DENGAN PERTUMBUHAN MERANTI MERAH DI KHDTK HAURBENTES

Failure in degraded forest rehabilitation was caused by using chosen species without pay attantion on site characterictics. Species selection by looking at site limiting factor, will increase success in degraded forest rehabilitation. This research aims to study the influence of physical and chemical soil properties on growth of Shorea leprosula Miq , Shorea palembanica Miq , dan Shorea mecisopteryx. Data was analyzed using multiple linear regression analysis with mean annual increment (MAI) of height and diameter as dependent variable and soil properties as independent variable . The results showed that growth increment of S.palembanica was the most species that influnced by soil perperties with R 2 a djusted value for MAI- diam e ter and MAI- h e i gh t repectively, 0.946 and 0.674 whereas others two Shorea have R 2 a djusted value < 0.5. The research also showed that available P content was the limiting factor of the three species . T here wa s a difference of each species in respond to the available P content. MAI- height on S . mecisopteryx and MAI- diam e ter and MAI- h e i gh t on S . pelambanica will increase in line with decreasing available P content w hile S . leprosula require d P available increasing in order to increas e of MAI-diameter . This indicates that each species have specific response on certain soil properties content .

The growth trend of planted trees (Pinus sylvestris L.) in the early stage of plantation establishment

This study examined the growth of planted Scots Pine trees of different ages growing in the Tujyin Nars National park, located in Selenge aimag in the north of Mongolia. A total of seven, 50 x 20 m (0.1 ha) sized sample plots were established using a completely randomized sampling design. The tree growth monitoring was carried out between 2003 and 2017, by an annual repeated measurement at the end of each growing season. The total height, annual height increment and diameter at breast height were measured at sample plots and tree samples were taken for laboratory analysis. For statistical analysis, a One-way analysis of variance (One-way ANOVA) and F-test were applied. Our findings showed that the annual height (F=15.21, P&lt;0.0001) and radial increments (F=15.76, P&lt;0.0001) varied among plantations commensurate to their age. In our study, the highest height (46.5±6.1 cm) and radial (4.1±0.8 mm) increment were occurred in 12 and 10 years old plantations. Therefore, a strong positive correlation (r=0.99) between tree increment and plantation age was observed in plantations below 12 years of age. After this age, increment values were relatively stable, which tended to gradually decrease with plantation age. Our findings confirm that initial planting design leads to overcrowding with plantation age; therefore, implementation of a thinning practice is necessary after a plantation reaches 12 years of age. The ever-decreasing trend of both radial and height increments in plantations beyond 12-years of age supports the importance of thinning as a practice to reduce competition and to support the growth of remaining trees in older plantations.

Allometric models to estimate above-ground biomass and carbon stocks in Rhizophora apiculata tropical managed mangrove forests (Southern Viet Nam)

Mangrove forests can fix and store high quantities of carbon both in their soil and in their biomass, the latter peaking in the equatorial regions and decreasing with latitude. In Vietnam, more than 80% of the mangroves develop either in the Mekong Delta or in the Can Gio Estuary, which are characterized by tropical monsoon climates. Most of these mangroves were planted and are dominated by Rhizophora apiculata Blume. The main objectives of this study were to determine forest structure, above-ground biomass and carbon conversion factors for each tree component in order to obtain allometric equations and to derive carbon stocks for managed Rhizophora stands of different ages developing within this context. Thirty-six trees, having a diameter at breast height (DBH) ranging from 7.0 to 36.2 cm, from a planted mangrove forest were harvested in Ca Mau (Mekong Delta) to determine allometric equations. In addition, thirteen plots were established in both Ca Mau and Can Gio mangrove forests, to determine above-ground carbon densities. We proposed the following specific allometric equation to estimate total above-ground biomass (kg) for managed R. apiculata mangrove stands in Southern Vietnam: WTotal = 0.38363 * DBH2.2348 (R2 = 0.976, SE = 1.17, F = 1401, P < 0.001). The total above-ground biomass ranged from 135.4 to 523.6 Mg ha−1 depending on forest age and tree density. Consequently, and taking into account a carbon conversion factor of 44.09%, carbon stocks in the above-ground biomass of R. apiculata mangrove forests in Southern Vietnam ranged from 59.7 to 230.9 Mg C ha−1. The mean carbon partitioning in the tree biomass was: 77.11% for trunks, 11.87% for branches, 8.66% for prop roots, and 2.36% for leaves. However, this distribution, as well as annual height increments and biomass increase rates, also varied with forest age and tree densities. We suggested that tree density reduction through thinning activities allowed easier tree development, resulting in an increased biomass with enhanced allocation to branches and above-ground prop roots for the stability of the trees. Using the specific allometric equation and specific carbon conversion factor reduced the uncertainty in the estimation of above-ground biomass and carbon stocks.

Time shifts in height and diameter growth allocation in understory European beech (Fagus sylvatica L.) following canopy release

In understory trees, height–diameter allocation is subject several constraints: maximal height growth is limited, height growth is never null and, in terms of time dependency, diameter growth always precedes height growth. Understory trees experience a succession of canopy opening and closure events during their lifetime. Preferential allocation of their biomass to height or diameter growth is part of the acclimation process to their immediate environment. In this study, we investigated annual height and diameter increments in Fagus sylvatica understory trees submitted to canopy release. Annual height and diameter increments were obtained from retrospective stem analysis from the top of the tree to the stump on 39 understory trees. The relationship between height and diameter increments was investigated and temporal correlations among successive annual height and diameter increments were analyzed. An asymptotic relationship between annual height and diameter increment indicates that stem height growth was limited in understory trees. The intercept significantly differed from zero suggesting that height growth never stopped even when diameter growth was null. Following canopy release events, immediate diameter growth increase was observed while the height growth response was delayed, resulting in a time shift in the growth allocation strategy. Strong and asymmetric temporal correlations between annual height and diameter increments were observed: past annual diameter growth was positively correlated to present height growth. In understory trees, tree height is the main factor determining their potential growth since it determines their access to above-canopy light. However, the precedence of diameter growth over height growth suggests that tree growth is driven by diameter instead of height. This apparent discrepancy may be explained by the fact that, under closed canopy conditions, stem allometry reaches a functional threshold that forces tree to grow in diameter before growing in height.

Early Survival and Growth Plasticity of 33 Species Planted in 38 Arboreta across the European Atlantic Area

To anticipate European climate scenarios for the end of the century, we explored the climate gradient within the REINFFORCE (RÉseau INFrastructure de recherche pour le suivi et l’adaptation des FORêts au Changement climatiquE) arboreta network, established in 38 sites between latitudes 37° and 57°, where 33 tree species are represented. We aim to determine which climatic variables best explain their survival and growth, and identify those species that are more tolerant of climate variation and those of which the growth and survival future climate might constrain. We used empirical models to determine the best climatic predictor variables that explain tree survival and growth. Precipitation-transfer distance was most important for the survival of broadleaved species, whereas growing-season-degree days best explained conifer-tree survival. Growth (annual height increment) was mainly explained by a derived annual dryness index (ADI) for both conifers and broadleaved trees. Species that showed the greatest variation in survival and growth in response to climatic variation included Betula pendula Roth, Pinus elliottii Engelm., and Thuja plicata Donn ex D.Don, and those that were least affected included Quercus shumardii Buckland and Pinus nigra J.F.Arnold. We also demonstrated that provenance differences were significant for Pinus pinea L., Quercus robur L., and Ceratonia siliqua L. Here, we demonstrate the usefulness of infrastructures along a climatic gradient like REINFFORCE to determine major tendencies of tree species responding to climate changes.

Effects of Soil Compaction and Relative Light Intensity on Survival and Growth Performance of Planted Shorea macrophylla (de Vriese) in Riparian Forest along Kayan Ulu River, Sarawak, Malaysia

A study was conducted in riparian forest along Kayan Ulu River, Sarawak, Malaysia, to investigate the effects of soil compaction and relative light intensity (RLI) on survival and growth performance of planted Shorea macrophylla. The study sites were stands reforested in different years (1996: SPD96; 1997: SPD97; 1998: SPD98; 1999: SPD99). The survival, growth performance, soil compaction, and RLI were measured. SPD96 trees had the highest survival (84%) and showed the most favourable growth. Average height, mean annual increment in height, and RLI were highest in SPD97 while mean annual increment in volume was highest in SPD98. Soil compaction in SPD98 and SPD99 was higher as compared to SPD96 and SPD97. This was due to the compacted soils caused by anthropogenic activities and natural causes (wet soils) in riparian forest along Kayan Ulu River at shallow depth. High survival and favourable growth performance of S. macrophylla were influenced by the edaphic factor with special reference to less compacted soils and high RLI. Stepwise multiple regression demonstrated significant effects of soil penetration resistance at the depth of 0-30 cm and RLI on mean annual increment in diameter. Further ecological studies on other environmental factors should be implemented to draw up a Dipterocarp planting scheme for the future restoration of riparian ecosystem.

ДИНАМІКА І ПРОДУКТИВНІСТЬ СОСНОВИХ ДЕРЕВОСТАНІВ СУХОГО ЛИШАЙНИКОВОГО БОРУ В УМОВАХ ЗАХІДНОГО ПОЛІССЯ

За результатами аналізу структури лісового фонду Західного Полісся встановлено, що сухі бори у регіоні досліджень займають 13259,7 га, що становить 3,4 % від площі вкритих лісовою рослинністю земель. Досліджено хід росту соснових деревостанів в умовах сухого бору, за висотою, діаметром, сумами площ перерізів, запасами та кількістю стовбурів, а також використано аналіз ходу росту модельних дерев різних вікових груп. Встановлено, що усі деревостани на пробних площах є низькопродуктивними та належать до IV класу бонітету. Аналіз росту модельних дерев вказує на їх повільний ріст за висотою і діаметром. Встановлено, що кульмінація середнього і поточного приростів за висотою настає у віці 20-25 років, при цьому середній приріст за висотою не перевищує 0,25 м. Середні прирости за діаметром із зростанням віку збільшуються від 0,25 (20 років) до 0,27 см (60 років). Доведено, що середні прирости за висотою і діаметром сосни збільшуються у напрямку із заходу на схід регіону досліджень. Проаналізовано процеси зріджень деревостанів з віком та підтверджено його нерівномірний характер. У дослідних деревостанах 60-річного віку залишається не більше 13 % дерев від початкової їх кількості. Використавши регресійні рівняння для математичного моделювання динаміки таксаційних показників з віком, розраховано фрагмент таблиці ходу росту соснових деревостанів IV класу бонітету в умовах Західного Полісся.

Особенности строения смыкающихся лесных культур сосны обыкновенной

The article is devoted to the identification and study of the peculiarities of the structure, condition and growth of Scots pine plantations, created in the spring of 2007 on logging place. On test plots in cultures which are 6 and 9 years old, variability in the diameter of plant trunks at the soil surface (D0,0 m) and at the height of 1,3 m (D1,.3 m) has been studied. The character of their distribution along 1-centimeter steps of thickness was established. The variation of current plant growths in height according to the calendar years (2008-2016) was studied during their free growth a Artificial reforestation is one of the methods of sustainable reproduction of forests widely used in the forest districts of the European part of the Russian Federation. In order to assess growth and quality of close canopy pine forest cultures, to identify the features of their structure along the diameter, and to study the variation in annual increments in height in 6- and 9-year-old forest stands, trial plots were laid by the standard method. Statistical processing of data on the continuous counting of pine plants is made. It is established that the distribution curves of trees in 1-centimeter steps of thickness have a single-vertex character, similar to the "normal" distribution. For objective silvicultural and inventory characteristics of close canopy forest stands and their transfer to lands occupied by forest plantations, and also in order to reduce labor costs during their inspection and forest inventory operations, it is quite sufficient to measure diameters at the altitude of 1.3 m and a height of 5-7 medium-sized pine plants and calculate their respective arithmetic mean values. The revealed dependence between the diameter of plants at an altitude of 1.3 m and their diameter at the soil surface in close canopy forest stands can be used in calculating damage according to stumps, illegally felled young pine trees for New Year Holidays.

Effect of intraspecific competition on biomass partitioning of Larix principis-rupprechtii

ABSTRACTIt is acknowledged that trees biomass allocation in response to environmental conditions. However, it remains poorly understood what strategies of plant biomass allocation with inter- and intraspecific interactions of tree species in forest stands. Such information is important for revealing strategies of plant biomass allocation with plant competition. To address this problem, a study was conducted in Larix principis-rupprechtii plantations to evaluate the impact of plant competition on plant biomass allocation in Shanxi Province, China. We measured a competition index (CI), stem, branch, foliage, and root biomass as well as element content (Carbon (C), Nitrogen (N), Phosphorus (P), Potassium (K)). Stem-foliage ratio (S/F), aboveground–belowground biomass ratio (T/R), average annual increment of biomass (AAB), height (AAH), and DBH (AAD) were calculated. The study found that the competition intensity of neighboring trees was closely related to the partitioning of biomass. Our results demonstrated that competition pressure of neighboring trees was a crucial factor to drive and regulate the distribution of biomass. Predicting biomass allocation–competition relationships could represent a supportive method for improving management of Larix principis-rupprechtii plantations in Mountain Taiyue areas.

Effect of weed control methods on growth of five temperate agroforestry tree species in Saskatchewan

Most tree species in agroforestry plantings are intolerant to vegetative competition and sites must be intensively cultivated to eliminate weeds. Many studies have been conducted to investigate what factors limit seedling growth because of the presence of vegetative competition in forest environments; however on agricultural sites there are few studies on weed management options for tree planting. This research quantified and compared growth of Manitoba maple (Acer negundo), green ash (Fraxinus pennsylvanica), Colorado spruce (Picea pungens), Scots pine (Pinus sylvestris) and Walker poplar (Populus x Walker) in response to combinations of in-row and between-row weed control methods. The study was established on an agroforestry planting on agricultural soils in Saskatchewan. Treatments included in-row weed control using herbicides or plastic mulch and between-row weed control using tillage compared with a non-weeded control. Weed control positively affected annual height increment, basal diameter and height of the agroforestry species. The impacts of weed control versus no weed control were significant in almost all instances. However, tree species responded differently to the method of weed control. Weed control by herbicide and plastic mulch were not significantly different for four of the five species under investigation. This research will help with prescribing weed control methods for agroforestry and afforestation plantings on agricultural soils.

The effect of oil shale ash and mixtures of wood ash and oil shale ash on the above- and belowground biomass formation of Silver birch and Scots pine seedlings on a cutaway peatland

Use of biofuel ashes for the afforestation of cutaway peatlands helps to balance the content of nutrients in peat substrate, which improves the survival of planted seedlings and increases significantly bio-production. The purpose of this study was to investigate the effect of fertilization with alkaline ashes on the above- and belowground biomass formation of four-year-old Silver birch (Betula pendula Roth) and five-year-old Scots pine (Pinus sylvestris L.) stands on a cutaway peatland. Five treatments were established: three mixtures with different proportions of wood ash (10–15tha−1) and oil shale ash (10–15tha−1), pure oil shale ash (10tha−1) and control (unfertilized plot). Three years after fertilization with ashes the content of phosphorus was up to 150 times and that of potassium 23 times higher in the peat substrate treated with ashes than on the control plot. The growth and biomass formation varied among treatments and depends strongly on the content of P and K in the growth substrate. The best results were observed on plots of Silver birch treated with mixed ashes; there the seedlings annual height increment was 2–3 times (first year), 5–7 times (second year) and 8–9 times (third year) greater than on the control plot. The effect of mixed ashes on the annual height increment of Scots pine was weaker: the annual height increment was 1.4 times (first year), 3 times (second year) and 5 times (third year) greater than on the control plot. The effect of pure oil shale ash on the growth and biomass formation of trees was the smallest. The greatest root collar diameter increment of birch and pine was observed on the third vegetation period. Roots formed the largest part of the total Silver birch biomass, followed by stem, branches and leaves. At the end of the third year after treatment the largest part of the biomass of Scots pine was allocated to the needles, followed by roots, stem and branches. The biomass and biomass production were the greatest on the plots treated with mixed ashes, especially on the WA15+OSA10 and WA15+OSA10 treatments. The total bio-productivity of birch was until 4 times intense than in the case of pine. The average current annual biomass production of Silver birch and Scots pine stands were respectively 0.17–0.21t ha−1 and 0.3–0.56t ha−1 (mixed ashes), 0.04t ha−1 and 0.16t ha−1 (OSA10) and 0.02t ha−1 (control).

SELECTION OF PLUS TREES FOR GENETICALLY IMPROVED TEAK VARIETIES PRODUCED IN BENIN AND TOGO

Cette étude vise la sélection d’arbres« plus » sur la base des caractères den- drométriques et des propriétés du bois dans des plantations de teck au Bénin et au Togo. La croissance de 569 arbres dans 5 forêts au Togo et 90 arbres dans 3 forêts au Bénin a été évaluée en mesu- rant le diamètre à hauteur de poitrine, la hauteur totale et la hauteur du fût. Les propriétés suivantes du bois ont été éva- luées et prises en compte pour la sélec- tion finale d’arbres « plus » : densité, pourcentage de bois de cœur et couleur. La durabilité naturelle du bois de cœur, le point de saturation des fibres, le module d’élasticité et les retraits ont été évalués sur la base de modèles spectroscopiques dans le proche infrarouge, préalablement construits. Nos résultats montrent qu’au Togo la variabilité inter-arbres en forêt est assez forte pour l’accroissement annuel en hauteur (0,81 ± 0,27 m), en circonfé- rence (2,95 ± 1,02 cm) et en hauteur des fûts (10,64 ± 3,51m). Au Bénin, si les per- formances dendrométriques des arbres ne varient pas de façon significative entre les forêts, pour la hauteur des fûts (10,99 ± 3,80 m), les valeurs du coeffi- cient de variation sont plus élevées (40 %) pour la forêt de Koto. Prenant en compte les propriétés du bois, la sélection finale multicritères montre que les peuplements d’Avétonou et de Tchorogo au Togo consti- tuent un groupe homogène affichant les plus fortes valeurs pour la densité du bois et le pourcentage de bois de cœur. Les arbres des forêts de Haho-Baloe et Eto ont des valeurs plus faibles pour la dura- bilité naturelle, le module d’élasticité, le pourcentage de bois de cœur et la densité du bois. Au Bénin, les arbres de la forêt d’Agrimey ont une densité plus élevée mais les valeurs pour le point de satu- ration des fibres, la durabilité naturelle et le retrait du bois sont similaires pour les trois forêts. La variabilité des perfor- mances dendrométriques et de la qualité du bois des arbres-candidat nous ont per- mis de sélectionner 33 arbres « plus ».

Initial Fertilization Impact on Norway Spruce Nutrition and Growth in the Krušné Hory Mts.

The aim of this study consisted in verifying the hypothesis whether the application of tableted fertilizers Silvamix® Forte, Silvamix® R, Stromfolixyl® and calcareous dolomite affected significantly the nutrition and growth of Norway spruce. In order to carry out research investigation, the experimental Suchdol locality has been selected as it represents large‑scale reclaimed sites in the Krušné hory Mts. Ameliorating agents were applied using the initial spot fertilization of Norway spruce plantations. In the course of two years, activities as follows were carried out annually: (1) top shoots measurement, (2) sampling the latest needle year‑class. The applied fertilizers impact on the concentrations of nutrients in needle dry matter was not significant with minor exception. Fertilizers Silvamix® Forte and Silvamix® R can be recommended to support seedlings growth in the area of interest since there had been positive effect on annual height increment found out. Calcareous dolomite showed the most favourable effect on the shoot biomass growth. Stromfolixyl® fertilizer had no effect on the annual increment; its impact on the nutrition can be characterized as insignificant since fertilized individuals showed lower phosphorus concentration in needle dry matter.

Species characteristics and intraspecific variation in growth and photosynthesis of Cryptomeria japonica under elevated O3 and CO2.

In order to predict the effects of future atmospheric conditions on forest productivity, it is necessary to clarify the physiological responses of major forest tree species to high concentrations of ozone (O3) and carbon dioxide (CO2). Furthermore, intraspecific variation of these responses should also be examined in order to predict productivity gains through tree improvements in the future. We investigated intraspecific variation in growth and photosynthesis of Cryptomeria japonica D. Don, a major silviculture species in Japan, in response to elevated concentrations of O3 (eO3) and CO2 (eCO2), separately and in combination. Cuttings of C. japonica were grown and exposed to two levels of O3 (ambient and twice-ambient levels) in combination with two levels of CO2 (ambient and 550 µmol mol-1 in the daytime) for two growing seasons in a free-air CO2 enrichment experiment. There was no obvious negative effect of eO3 on growth or photosynthetic traits of the C. japonica clones, but a positive effect was observed for annual height increments in the first growing season. Dry mass production and the photosynthetic rate increased under eCO2 conditions, while the maximum carboxylation rate decreased. Significant interaction effects of eO3 and eCO2 on growth and photosynthetic traits were not observed. Clonal effects on growth and photosynthetic traits were significant, but the interactions between clones and O3 and/or CO2 treatments were not. Spearman's rank correlation coefficients between growth traits under ambient conditions and for each treatment were significantly positive, implying that clonal ranking in growth abilities might not be affected by either eO3 or eCO2. The knowledge obtained from this study will be helpful for species selection in afforestation programs, to continue and to improve current programs involving this species, and to accurately predict the CO2 fixation capacity of Japanese forests.

Introduction of suitable species for planting in gaps of different size (case study: Loveh forest, Golestan, Iran)

This study was carried out in Loveh forest, north of Iran. We measured the quantitative characteristics of seedlings including collar diameter (measured at 1 cm above the soil surface), height, and current annual height increment and calculated the mean annual increments of height and diameter. Ten gaps with the same climatic, edaphic and topographic conditions were selected. In each gap, two transects, 2 m wide, were laid along the longest (North-South) and the shortest (West-East) axis. Nine sampling microplots, 4 m&lt;sup&gt;2&lt;/sup&gt; area, were established: one at the centre, four at the edges and four under the canopy within the transects. Results showed that the highest frequency of seedlings was seen in medium-size gaps (200–500 m&lt;sup&gt;2&lt;/sup&gt;). Quantitative characteristics of oak seedlings were better in small and medium-size gaps. There was a significant difference in the length of spring shoots, mean annual increment of height and mean annual increment of diameter between the species. Hornbeam, wild service and wild cherry seedlings are recommended for faster gap recovery, as the results showed that these species had the highest values of studied variables.

Survivorship and Growth Performance of &lt;i&gt;Shorea macrophylla&lt;/i&gt; (de Vriese) after Enrichment Planting for Reforestation Purpose at Sarawak, Malaysia

Reforestation may offer one means of mitigating the processes of forest land degradation and is indispensable in an effort to conserve forest biological diversity in the tropics. Thus, a preliminary assessment was conducted in order to evaluate the survivorship and growth performance of Shorea macrophylla (de Vriese) after enrichment planting for reforestation purpose in Sarawak, Malaysia. This study was conducted at reforestation sites located at Sampadi Forest Reserve, Sarawak, Malaysia where indigenous Dipterocarp species, S. macrophylla (de Vriese) were planted by line planting system. Study sites were established at reforestation areas at different age stands; (planted in the year 1996; SM96, 1997; SM97, 1998; SM98 and 1999; SM99). The assessment on the growth performance of planted S. macrophylla was evaluated by measuring the trees total height, Diameter at Breast Height (DBH) and calculation of the percentage of survival. The findings indicated a positive tree growth in terms of growth performance and survival which clarified the efficacy of line planting technique adapted in the studied sites. Growth performance in terms of survivability; Mean Annual Increment of Height (MAIH) and Diameter (MAID) in SM96 revealed the highest growth rate as compared to SM97, SM98 and SM99. For the average tree height and diameter at breast height, the results showed that the tree height and diameter in SM96 were 11.8 m and 14.7 cm, respectively. Meanwhile, SM99 recorded the lowest average tree height and diameter reading with 8.8 m and 6.6 cm, respectively. Nonetheless, high survival percentage of S. macrophylla were depicted in this study with 89% of survival in SM96, followed by 80, 82 and 57% in SM97, SM98 and SM99, respectively. Substantial growth performance and high survival percentage of S. macrophylla implied that microclimate condition such as competition between planted and existing pioneer species of the study sites may have affected the tree growth performance of the planted S. macrophylla. Notwithstanding, further studies are essential in order to find out the plant-soil association of S. macrophylla where other environmental factors may affect the growth and survival of the planted species.

Is the secular trend in height delaying overweight rise among adolescents? The Brazilian case.

To explore if the secular trend in height is contributing to delay overweight rise among Brazilian adolescents. Changes in BMI mean over time were fitted using linear regression including as independent variables survey year, height, survey-specific income quintiles, age and an interaction term of height × survey year. Overweight was defined as BMI≥25·0 kg/m2. Changes in overweight prevalence over time were fitted using Poisson regression. Four national household surveys: 1974/5, 1989, 2002/3 and 2008/9. Brazilian adolescents. Mean values of height and BMI increased over the period, for both sexes and in all age ranges, except for girls aged 14-19 years from 1989 to 2002/3. The highest average increment and mean rate of height were between 1989 and 2002/3 and in 10-15-year-olds. The annual increment of height decreased from 2002/3 to 2008/9 in parallel with the increment in BMI rate. After fitting the regression model, the height × survey year interaction and per capita income were strong vectors to increase BMI mean. Changes in increment rate of height played a protective role against overweight in the last two periods for both sexes, mainly for girls. The period from 1989 to 2002/3 was the strongest vector associated with overweight in boys and the association decreased to the next period, from 2002/3 to 2008/9. BMI and height of adolescents have increased in a wavering and alternate way throughout four decades in Brazil. The rate of height increment has played a protective role against overweight in adolescents.

Growth of native tree species planted in montane reforestation projects in the Colombian and Ecuadorian Andes differs among site and species

The tropical Andes in Ecuador and Colombia are a biodiversity hotspot that has endured centuries of forest clearance and degradation. Forest restoration has been identified as a regional conservation priority; in recent decades, native species reforestation projects have proliferated, but little information exists on growth performance of commonly planted tree species in relation to site and soil nutrient status. This study analyzed growth of seven common native species (Alnus acuminata, Baccharis bogotensis, Cedrela montana, Myrica pubesens, Quercus humboltii, Sambucus nigra, Smallanthus pyramidalis) on 12 montane forest sites across the northern region of the tropical Andes. Andean alder (A. acuminata) was the most commonly planted species, and grows at a mean annual diameter increment (MAI-d) of 1.81 cm y−1 and a mean annual height increment (MAI-h) of 0.95 m y−1. S. pyramidalis, a short lived pioneer of the Asteraceae family, also exhibited fast growth rates of 1.64 cm MAI-d and 1.21 m MAI-h. Andean oak (Q. humboltii) was the second-most commonly planted species, growing with an MAI-d of 0.99 cm and MAI-h of 0.56 m. Soil magnesium and potassium were significant predictors of MAI-d and MAI-h for A. acuminata, while soil nitrogen, phosphorous, sodium, and calcium were negatively associated with growth (p < .001). We speculate that A. acuminata did not grow as well on soils richer in calcium and phosphorus because they were less conducive to nitrogen symbiosis common to this species. Soil magnesium and calcium were significant predictors (p < .05) of diameter growth for Q. humboltii. For both species, we attribute growth responses to soil nutrients as a result of the variable nature of fertility in the complex and variable soils that make up the volcanic and surficial geological landscape of the northern Andes. Results indicate that native species can grow in a variety of soil conditions, and exhibit growth rates comparable to non-native species. However, our results suggest native species are site restricted for best growth and should be planted on particular soils. We make recommendations for reforestation for the species in this study.

The Fertility Status of Soils at Rehabilitated Degraded Land in Universiti Putra Malaysia Planted with &lt;i&gt;Pinus caribaea&lt;/i&gt; and &lt;i&gt;Swietenia macrophylla&lt;/i&gt;

Soil fertility (both physical and chemical) is one of the important factors limiting plant growth. So, the fertility of the soils should be determined before growing crops and after the establishment of forest rehabilitation. A study was conducted to determine the fertility status of soils at rehabilitated degraded land in Universiti Putra Malaysia. The main objective was to compare the fertility of soils planted forest and pasture. Three sites studied were pines plantation (Pinus caribaea), mahogany plantation (Swietenia macrophylla) and pasture area. At each site, three squares of 20×20 m were selected and two depths of soil sample were collected, topsoil (0-20 cm) and subsoil (20-40 cm), from six points within the squares. The physical properties of the soils analyzed were bulk density, soil texture and moisture content, while the chemical properties were pH, total C and N, cation exchangeable capacity and exchangeable cations (Al, Ca, Mg, K and Na). The mean annual increment of height, diameter and volume of planted forest were also taken. The increment of height, diameter at breast height and volume of P. caribaea and S. macrophylla did not show any comparative difference for the cause of the similarity in the increment of patterns catalysed at the same location and climatic condition. P. caribaea showed higher SFI value compared to the other study plots, especially for the topsoil. In contrast, pasture plot had higher SEF, followed by P. caribaea and S. macrophylla plantation plots. P. caribaea showed the highest SFI value, while pasture plot had highest SEF, followed by P. caribaea and S. macrophylla plantation plots. Further study on bigger forest plantation having different types of plant species and land topography needs to be conducted to allow individuals and bodies in the field of forest plantation to gain the opportunity and implement the right approaches to establish forest plantation with good planting establishment practices.

Dinamica şi caracteristicile creşterii a şase clone de plop hibrid pe parcursul unui ciclu de producţie într-o plantație comparativă din Depresiunea Rădăuţi

The poplar (Populus spp.) plays an important role in worldwide forest economy, responding to the necessities of obtaining high biomass production in a short time. Short rotation forests (SRF) are developing continuously in Romania. Several studies have been undertaken to identify the clones with high productivity and suitable technologies. The aim of this study was to register the annual increments in diameter, height and volume in an experimental poplar crops with a short-term rotation of 5 years. The poplar cultures are composed from 6 types of hybrid poplar clones (AF2, AF6, Monviso, A4A, Pannonia and Max4) with a density of 2667 trees ha-1. The research results show a clear differentiation among clones’ increments. The highest increments were obtained with AF2 and AF6 clones in five years, with almost 0.038 m3 an-1. The lowest increment was observed for Max4 clone with 0.028 m3.