Stages Of Tree Growth Research Articles

Paired comparison of water, energy and carbon exchanges over two young maritime pine stands (Pinus pinaster Ait.): effects of thinning and weeding in the early stage of tree growth

The effects of management practices on energy, water and carbon exchanges were investigated in a young pine plantation in south-west France. In 2009-10, carbon dioxide (CO(2)), H(2)O and heat fluxes were monitored using the eddy covariance and sap flow techniques in a control plot (C) with a developed gorse layer, and an adjacent plot that was mechanically weeded and thinned (W). Despite large differences in the total leaf area index and canopy structure, the annual net radiation absorbed was only 4% lower in plot W. We showed that higher albedo in this plot was offset by lower emitted long-wave radiation. Annual evapotranspiration (ET) from plot W was 15% lower, due to lower rainfall interception and transpiration by the tree canopy, partly counterbalanced by the larger evaporation from both soil and regrowing weedy vegetation. The drainage belowground from plot W was larger by 113 mm annually. The seasonal variability of ET was driven by the dynamics of the soil and weed layers, which was more severely affected by drought in plot C. Conversely, the temporal changes in pine transpiration and stem diameter growth were synchronous between sites despite higher soil water content in the weeded plot. At the annual scale, both plots were carbon sinks, but thinning and weeding reduced the carbon uptake by 73%: annual carbon uptake was 243 and 65 g C m(-2) on plots C and W, respectively. Summer drought dramatically impacted the net ecosystem exchange: plot C became a carbon source as the gross primary production (GPP) severely decreased. However, plot W remained a carbon sink during drought, as a result of decreases in both GPP and ecosystem respiration (R(E)). In winter, both plots were carbon sources, plots C and W emitting 67.5 and 32.4 g C m(-2), respectively. Overall, this study highlighted the significant contribution of the gorse layer to mass and energy exchange in young pine plantations.

Tree Growth Stage and Environment After Pathogen Inoculation Alters Susceptibility of Pear Trees to Phytophthora Canker~!2009-11-17~!2010-01-01~!2010-04-29~!

We investigated whether pear (Pyrus communis L. OHF97) tree growth stage, nitrogen (N) status, wound age, and infection environment influences susceptibility to Phytophthora syringae Klebahn. Actively growing trees were sus- ceptible to the pathogen when inoculated before terminal budset and cooler temperatures increased disease severity. In the autumn, during early stages of dormancy development after budset there was no relationship between temperature after inoculation and susceptibility and as trees became more dormant a negative relationship developed between temperature and susceptibility. Altering tree N status in the autumn after budset by spraying leaves with urea had no influence on sus- ceptibility, regardless of environmental conditions after inoculation. Lesions developed when fresh wounds (0 d to 1 d old) were inoculated after budset, but as wounds aged they were less susceptible to infection. These results suggest a combination of tree growth stage when inoculated with the pathogen and environmental conditions afterward play impor- tant roles in disease development. Differences in susceptibility may be a direct result of temperature on pathogen activity or an indirect effect of temperature on tree metabolic activity. Differences in tree susceptibility related to dormancy devel- opment may be related to stem N status or the ability of trees to produce a barrier to infection after stems are wounded. Surface wounds inflicted during handling after budset may serve as infection locations for P syringae; however the length of time between wound formation and exposure to the pathogen dictates whether infection will occur when trees are in the early stages of dormancy development.

Kualitas Arang Aktif Kayu Gelam dan Aplikasinya untuk Meningkatkan Kualitas Air (Activated Charcoal Quality of Gelam Wood and Its Application to Improve Water Quality)

Gelam (Melaleuca cajuputi) is the dominant tree species grown in swamp forests, especially in tidal areas in Central Kalimantan. Gelam wood has been used for construction and biomass energy, which is due to high density of wood. Previously studies reported that the quality of charcoal from wood stems of Gelam was better than that from roots, fruits, flowers, branches and leaves. The study was to investigate the characteristics of activated charcoal from wood stem of gelam which taken from different site and growth stages of the tree, and its utilizations for water quality improvement. The parameters observed were yield, moisture content, volatile matter content, ash content, fixed carbon, absorption of benzene, iodine and methylene blue. The Gelam wood from different growth site and stage of trees (saplings, poles, trees) can be used as raw material for activated charcoal production. The quality of activated charcoal fulfilled the quality requirements of technical activated charcoal (SNI 06-3730-1995), activated charcoal for the purification of edible oil (SNI 06-4262-1996) and drinking water (SNI 06-4253-1996), except for absorption of benzene. Generally, the quality of water treated by activated charcoal increased and fulfilled the requirements of clean water standards (Departemen Kesehatan 1990).

Mangrove vegetation diversity after tsunami in east coastal area of Nangroe Aceh Darussalam

It has been conducted the research on mangrove vegetation diversity after tsunami in East Coastal area of Aceh. The method used square method. Amount of mangrove species at tree growth stage was consisted of 9 species. Rhizophora mucronata has the highest important value index (118.62%). The density of mangrove at tree growth stage was 118 tree./hectare, the diversity index was H =1.67. Amount of mangrove species at sapling growth which was found consisted of 10 species. R. mucronata has the highest important value index (138.28%). The density at sapling growth stage was 633 sapling/hectare, the diversity index was H =1.78. The growth of mangrove at seedling stage was consisted of 10 species. It shows that R. mucronata has the highest important value index (50.92%). The densitymangrove at seedling growth stage was 4925 seedling/hectare, the diversity index was H =2.13.© 2007 Jurusan Biologi FMIPA UNS SurakartaKey words: mangrove, diversity, coastal

Differences of Soil Microbial Biomass and Nitrogen Transformation under Two Forest Types in Central Germany

In order to observe the tree species effect on soil N status, soil microbial biomass C and N (Cmic, Nmic), potential N mineralization and potential nitrification (under laboratory incubation conditions, 22 °C) in different subhorizons (LOf1, Of2, Oh and mineral soil at 0–10 cm depth) were determined at three forest sites in central Germany. At each site, two contrasting stands (Beech, Norway spruce or Scots pine) were selected, where the initial soil conditions were similar. Three sampling dates that represented different stages of tree growth were selected: growing season - August, dormant season - November, after budbreak – April. In organic layers, Cmic-to-total C (Ct) ratios under beech and under conifer were 0.72–4.74% and 0.34–2.11%, respectively. Nmic-to-total N (Nt) ratios were 2.47–11.61% and 0.71–5.77%, respectively. Both concentrations of Cmic and Nmic were significantly affected by the stand type and sampling time. Potential N mineralization rates, ranging from 3.7 to 19.7 mg N kg−1 d−1, showed no clear pattern in relation to stand type. However, potential nitrification rates were mostly significantly higher under beech than under contrasting conifer. In mineral soils, concentrations of Cmic and Nmic showed a clear temporal pattern in the order: August>November>April. The average Nmic and Nmic-to-Nt were higher in soils from beech than conifer, while Cmic and Cmic-to-Ct ratios were similar between the two forest types. In organic layers, the highest values of Cmic-to-Nmic ratio and Cmic were found in November samples, especially under beech. By contrast, in mineral soils the highest value of Cmic-to-Nmic ratios were found in April samples, and at that time the Cmic concentrations were the lowest, especially under conifer. These results revealed the differences in microbial growth form and survival strategy associated with different tree species and soil layers.

Adapting a growth equation to model tree regeneration in mountain forests

Management and risk analysis of protection forests depend on a reliable estimation of regeneration processes and tree growth under different site conditions. While the growth of forest stands and thus the average growth of larger trees is well studied and published in yield tables as well as embodied in numerous simulation models, there is still a lack of information about the crucial initial stages of tree growth. Thus, we evaluated juvenile tree growth for different site conditions in the Swiss Alps and developed an approach to model both the early and later stages of growth based on the Bertalanffy equation. This equation is physiologically well founded and requires only two parameter estimates: a maximum tree height and a growth parameter. Data for the parameter estimation were available from studies of tree regeneration at a range of sites in Switzerland: growth patterns of larch (Larix decidua) were available from a high-elevation afforestation experiment. For spruce (Picea abies), data were obtained from a blowdown area in the Alps. The growth equation was fitted to the observed data and we found a good correlation of the fitted curves with the observed data. The parameter estimates were validated with independent data sets. The extrapolated growth curves, calculated with the estimated growth rates, correspond well to the validation data. Thus, it is possible to use the Bertalanffy equation to model both the early and later stages of growth. With this approach, we provide a basis for modelling the growth of juvenile and mature trees of different tree species in mountain forests of the European Alps.

Adaptation of larch (Larix decidua) of Polish provenances under mountainous conditions of Beskid Sądecki (southern Poland)

A long-term study carried out within the 1967 All-Poland Larch Provenance Experiment investigated genetic variation in 20 Polish provenances of larch growing under the site conditions of the Beskid Sądecki Mts. (at a test site in Krynica). The study was based on the measurements of tree height made in individual larch populations during 1969–1999, i.e. when trees were 5, 8, 11, 15, 20, 25, 30 and 35 years old. The results showed a considerable adaptation stability of the provenances tested at the Krynica site. This stability, however, tended to decrease with increasing mean height of trees. An estimation of the effect of the “genotype (provenance) × years of observation (age)” interaction revealed a high stability of height growth in larch populations having extreme values of this trait. As follows from the study, it is possible, especially in the case of the latter group of provenances, to carry out effective selection in the early stage of tree growth, thus ensuring a permanent genetic gain.

졸참나무지엽과 소나무지엽의 사료가치에 관한 연구

본 연구는 산림부산물인 지엽류를 보다 효율적으로 활용할 수 있는 방안을 모색하고자 졸참나무지엽과 소나무지엽에 대한 사료가치를 구명하였으며 그 결과를 요약하면 다음과 같다. 일반조성분인 조단백질 함량은 참나무지엽과 소나무지엽이 각각 6.00∼7.89%, 5.15∼6.06%로 참나무지엽이 다소 높았으며 생육이 진행됨에 따라 참나무지엽은 감소하였으나 소나무지엽은 생육시기에 크게 영향을 받지 않았다. 조지방 함량은 각각 1.90∼2.68%, 6.30∼6.33%로 소나무지엽이 현저하게 높은 수준이었고, 조섬유 7 함량은 각각 33.3∼35.2%, 33.7∼34.8%로 비슷하였으며 생육이 진행됨에 따라 증가하는 경향이었다. 그리고 조회분 함량은 각각 3.13∼2.78%, 2.11∼l.93%로 참나무지엽이 약간 높았다. 무기물 함량은 Ca, Mg, Mn, Cu가 소나무 지엽보다 참나무지엽이 높은 수준이었고 P, K, Na, Fe, Zn은 비슷한 수준이었으며 생육이 진행됨에 따라 대부분 감소하는 경향이었다. 소나무지엽과 참나무지엽의 ABF 함량은 각각 47.7∼52.0%, 46.1∼48.1%로 비슷하였으며 생육이 진행됨에 따라 증가하였고(P<.05), NDF 함량은 각각 64.1∼67.9%, 65.0∼66.5%로 비슷하였으며 생육이 진행됨에 따라 소나무지엽은 증가하였으나(P<.05) 참나무지엽은 비슷하였다. 건물소화율은 소나무지엽이 51.7∼48.4%로 생육이 진행됨에 따란 감소하였고, 참나무지엽은 53.0%∼51.4%로 비슷하였다. 가소화양분층량은 참나무지엽이 50.9∼52.4% 이었고, 소나무지엽은 47.7∼51.1%로 생육이 진행됨에 따라 감소하였으며(P<.05), 상대적 사료가치는 참나무지엽과 소나무지엽이 비슷하였고 생육이 진행됨에 따라 낮아지는 경향이었다. 탄닌 함량은 참나무지엽과 소나무지엽이 각각 2.96%, 6.27%로 소나무지엽이 높았으며 지엽을 건조하였을 때 각각 2.46%, 4.79%로 탄닌 함량이 낮아지는 경향이었다. Chemical composition, mineral compounds, cellular constituents, digestibility for dry matter, total digestible nutrients, and tannin constituents were investigated to evaluate feed value for oak and pine browses to use effectively browses as forest by products. The results of this study were as follows : Crude protein was 6.00∼7.89% for oak browse and 5.15∼6.06% for pine browse sampled through July to October, It gradually decreased in oak browse but not in pine browse as the growth of tree was progressed stages. Crude fat content of oak and pine browse were 1.90∼2.68% and 6.30∼6.33%. Crude fiber content was 33.3∼35.2% for oak browse and 33.7∼34.8% for pine browse and they tended to increase according to the growth stage of trees. Crude ash was 3.13∼2.78% for oak browse and 2.11 ∼1.93% for pine browse, respectively. Ca, Mg, Mn and Cu content were higher in oak browse than those in pine browse, but P, K, Na, Fe, and Zn content were similar each other. Mineral contents were decreased as the growth of tree was progressed(P<.05). Acid detergent fiber content of pine and oak browse were 47.7∼52.0% and 46.1∼48.1%, and they increased as the tree grew. Neutral detergent fiber content of pine and oak browse were 64.1∼67.9% and 65.0∼66.5%. NDF content was increased according to the tree growth in pine browse but it was the same in oak browse(P<.05). in vitro digestibility of dry matter was 51.7∼48.4% for pine browse that decreased according to the tree growth(p<.05) and 53.0∼5l.4% for oak browse. Total digestible nutrients of oak browse was 50.9∼52.4% and that of pine browse was 47.7∼51.1% which decreased as the tree grew. Oak browse showed the same relative feeding value(RFV) as pine browse, and it decreased as the growth of tree was progressed(P<.05). Tannin contents was 2.96% for oak browse, 6.27% for pine browse. Tannin contents decreased when browses were dried.

Model for partial discharges associated with treeing breakdown: II.tree growth affected by PDs

The model for partial discharges (PDs) in tree channels indicatesthat PDs in an electrical tree are inclined to be induced and concentratednear the needle tip, and the total field distribution is dynamicallyinfluenced by the PDs. In view of the effects of PDs on tree growth, a newmodel for tree growth is put forward. Tree growth is related to both thedamage caused by PDs and by the local field. In the early stage of treegrowth, the damage by PDs is concentrated near the needle tip, but thedamage by the local field is inclined to be higher at tree tips. By usingthis model, various experimental phenomena can be explained.

Soil Water Components Based on Capacitance Probes in a Sandy Soil

Understanding soil water movement is needed to manage irrigation to minimize water drainage, nutrient leaching below the root zone, and contamination of groundwater. We hypothesized that soil water content determined by capacitance probes can be used for irrigation scheduling and estimating soil water components. Objectives of this study were (i) to evaluate the performance of capacitance probes for optimizing irrigation management for ‘Hamlin’ orange trees [Citrus sinensis (L.) Osb.] on Swingle citrumelo [Citrus paradisi Macf. × Poncirus trifoliata (L.) Raf.] rootstock on a Candler fine sand soil (hyperthermic, uncoated, Typic Quartzipsamment) in Central Florida and (ii) to determine soil water balance components. Irrigation levels were determined based on available soil water (ASW) and tree growth stage. The soil water data measured at finite time interval by capacitance probes were used with irrigation and rainfall data to calculate daily evapotranspiration (ET) and drainage rates. Daily ET rates showed strong seasonal patterns and varied from &lt;0.4 mm d−1 in January to 5 mm d−1 in July and August. The annual ET in 1997 was 920 mm or 53% of the total water input (irrigation and rainfall). The cumulative annual drainage in 1997 was 890 mm, or 47% of the total water input. Furthermore, 82% of the cumulative annual drainage was contributed by rainfall. Irrigation based on monitoring soil water content using capacitance probes minimized water drainage below the root zone in a system where rainfall contributed substantially to drainage.

Short-Term Effects of Defoliation by Sawflies (Hymenoptera: Diprionidae) on Above- and Below-ground Growth of Three Ponderosa Pine Genotypes

Diprionid sawflies (Hymenoptera: Diprionidae) feeding on ponderosa pine, Pinus ponderosa Dougl. ex Lawson, divide food resources by feeding at different times during the season and on different aged trees. Whereas some species prefer adult trees, others have specialized on pole-size trees, and yet others on seedlings. Some attempts have been made to determine whether conifer growth compensates in response to herbivore damage as do certain nonwoody plants; however, the impact of defoliation in conifers may depend on the growth stage of trees, The presence or absence of compensatory growth in seedlings is critical because for most pine species, early growth allocation can impact growth in the long term. We induced attacks by Neodiprion gillettei Rohwer on 1-yr-old ponderosa pine seedlings to determine the effect of defoliation on above- and below-ground growth. Three pine half-sib families whose parent trees were either susceptible or resistant to pine sawflies were used in the experiment, Growth was evaluated through destructive sampling. We found no evidence of seedling compensatory growth in response to herbivores. Defoliation reduced both above- and below-ground biomass. Stable root:shoot ratios indicated that foliage removal resulted in an approximately equivalent reduction in below-ground biomass. Differences in growth patterns among genotypes were found as well.

Cell Wall and Lumen Percentages in Relation to Wood Density of Nothofagus Nervosa

Cell wall and lumen percentages were determined for vessels, fibres and rays from 10 trees of Nothofagus nervosa (rauli), and analysed in relation to ring number from the pith, ring width, and density. Increase in density across the juvenile wood was mainly associated with an increase in fibre wall %, which outbalanced a simultaneous increase in vessel lumen %. Decrease in density across the mature wood was associated with changes in both fibre wall and total lumen percentages. Though density varied only slightly with ring width, this was accompanied by appreciable changes in percentages of different cell types. These trends in the wall and lumen percentages of the various cell types suggest that some physical properties may vary more within the tree (or with growth rate) than is suggested by the limited variation in density that is found in rauli. There were significant between-tree variations in both density and cell types, indicating the possibility of selection for either at an early stage of tree growth.

Electrical tree tests. Probabilistic inference and insulating material evaluation

In this paper the application of neural network (NN) to the probabilistic inference of partial discharge (PD) phenomena generated from electrical tree growth is presented. On the basis of experimental results of measurements of trees occurring in a needle-plane arrangement, stochastic quantities are derived, which are relevant to PD pulse amplitude and phase. The NN trained by these quantities shows the feasibility of evaluations that connect tree-growth stage, i.e. the amount of damage produced by the tree, with a reduced set of these quantities. This set is, in turn, obtained applying a NN operating for data compression. In this framework, the NN can also recognize a material, among those used for training, associating to it the specific tree-growth feature.

Study on dynamics of stem form of Korean pine trees in natural forest stand

A new method was proposed to study the dynamics of stem form of natural Korean pine (Pinus koraiensis) tree. In natural Korean Pine forest, the occurring time of maximum height and diameter is very difference. This paper connected stem form to stage of tree growth to analysis the form dynamic of Korean pine. The monpmolecular equation was chosen as the stem model. The result shows that the maximum growth year of natural Korean pine is earlier than diameter.

Recycling of the naturally-occurring 15N In an established stand of Leucaena leucocephala

The natural 15N abundance method was used to trace the sources of N in a stand of Leucaena leucocephala and its understorey species. Changes in the δ 15 N of various above-ground parts of the L. leucocephala trees and understorey vegetation were monitored for 6 yr. The resulting data provide the first direct evidence of internal N cycling between a N 2-fixing tree and non-N 2-fixing understorey species within an agro-ecosystem. The δ 15N of all tree parts and understorey vegetation decreased with time. One year after the plantation was established, the non-N 2-fixing understorey species exhibited a significant enrichment in 15N relative to the L. leucocephala. At 4 and 6 yr after planting, however, the δ 15N value of the understorey vegetation had decreased significantly and was nearly identical to that of the L. leucocephala. The decline in δ 15N values of the understorey species was attributed to net N-mineralization of plant parts shed by L. leucocephala, and to root exudation and decay. That is, a portion of the N 2 fixed during the early stages of tree growth was made available to the understorey species through the decomposition and subsequent incorporation into the available soil-N pool of the abscissed L. leucocephala parts. This indicates that there was a tight coupling between N 2 fixation and the availability of net mineralized N. The natural 15N abundance method appears to provide a suitable means by which the fate of fixed-N in a forest ecosystem can be monitored, provided the difference between the initial (δ 15N value of the N 2-fixing and non-N 2-fixing (reference) species is of sufficient magnitude. The rate of change in the δ 15N value of the understorey species can provide valuable insights into the intensity of net N-mineralization and N-cycling.

Influence of Different Electrodes and Tissues on the Impedance Spectra of Scots Pine Shoots

Impedance spectra (20 Hz-1 MHz) of shoots of Scots pine (Pinus sylvestris L.) were measured using a circuit analyzer. Two types of electrodes were used: (1) polarizable silver needle electrodes, and (2) an electrolyte cell with reversible Ag/AgCl electrodes. The electrode impedance of the silver needle electrodes was high, especially at low frequencies, and was most prominent in impedance measurements of wood (xylem and pith). The impedance spectra of shoots changed over time with the growth stage of trees in the spring. In the case of quiescent trees, the impedance spectra of the shoot, bark (phloem and cortex), and wood differed from each other. All spectra were characterized by a strongly depressed center(s), which suggests a distribution of relaxation time(s).

Pear, Insect Growth Regulator Tests, 1987

Abstract Mature pear trees were sprayed with handguns operating at 600 psi to evaluate pesticides for control of pear pests. Plots consisted of 5 single-tree replicates in randomized block design. Treatments were applied 3 times, 29 Apr (petal fall), 29 May, and 20 Jul. Treatments were evaluated for PP and mite control by counts made at 2-wk intervals. Adult PP were counted from a 5 beating-tray sample/ replication. PP nymphs and mites were counted from a 50-leaf sample/replication. Leaf samples consisted of the proximal, distal, and 3 leaves from between on each of 10 terminal shoots. Leaves were brushed and resulting slides were examined using a binocular dissecting microscope. PP and PRM russet were rated according to U.S. grade standards for fresh market Bartlett' pears on 2 samples of 25 mature fruits per replication. Fruit and foliage were examined after each spray for phytotoxicity. The test orchard was sprayed with Pydrin 2.4 EC 1 pt/acre at cluster bud stage of tree growth to reduce density of overwintered adult PP.

Pear, Grape Mealybug Control, 1983

Abstract Twenty-five-year-old Bartlett pear trees were sprayed with handguns operating at 600 lb/in2 to evaluate pesticides for control of grape mealybug. Plots consisted of 4 single-tree replications assigned at random to trees preselected for heavy infestation of the pest. Pesticides were applied when crawlers were active, 1 Apr. and 3 May, corresponding to cluster bud and petal fall stages of tree growth. Mealybug density was estimated by counts of nymphs on five-spur samples per rep three times during the test period. All tissues on spurs were examined using a dissecting microscope. Russet on fruit caused by mealybug honeydew was checked by examining two 10-fruit samples per rep at harvest time. Fruit firmness, soluble solid content and size were also measured on the harvest samples.

THE LARCH CASEBEARER (LEPIDOPTERA: COLEOPHORIDAE) AND ITS PARASITES: II. THE INFLUENCE OF DIFFERENT GROWTH STAGES OF LARIX OCCIDENTALIS FOLIAGE ON CASEBEARER DEVELOPMENT AND SURVIVAL

AbstractLast-stage larvae of Coleophora laricella (Hbn.) were transferred to foliated Larix occidentalis Nutt. trees in four stages of growth for feeding. Based on insect survival, development rate, and size, trees with newly flushing foliage were best for rearing; trees which had completed shoot elongation were nearly as favorable. Both were distinctly superior to trees with elongating shoots and to trees with foliage so old that the current year’s buds were breaking. It is important to recognize the effects of tree growth stage when rearing C. laricella parasites in the laboratory, because parasite survival and sex ratio can be significantly influenced.

THE CONTROL OF WINTER EGGS OF PANONYCHUS ULMI (ACARINA: TETRANYCHIDAE) AND BRYOBIA RUBRIOCULUS (ACARINA: TETRANYCHIDAE) BY M2060 (2-FLUOROETHYL (4-BIPHENYLYL) ACETATE) AND OTHER PRODUCTS IN LEBANON

AbstractPanonychus ulmi (Koch) and Bryobia rubrioculus (Scheuten) are very serious pests on apple trees in Lebanon. The effectiveness of M2060 (2 fluoroethyl (4-biphenylyl) acetate), Ovamort, Diotol, Genite, and Citronol plus parathion was investigated on the winter eggs of these two mites in the laboratory and in the field. M2060-oil was highly effective and superior to all products at early and late dormant stages of tree growth. The nearer to egg hatch the other products were applied, the more effective they were.