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In this study, we examined the effects of cationic starch（CS） as a reinforcing agent and a binary reinforcement system with nanocellulose（NC） on the reinforcement of recycled paper produced from old corrugated cartons（OCC）. To determine an appropriate dosage of CS, we examined the effects of CS dosage on the performance of OCC recycled paper. Further, using the optimal dosage identified, the effects of its addition on the performance of OCC recycled paper were investigated by adding NC to form a binary reinforcement system. The strengthening mechanism of the CS-NC binary composite system was examined based on a combination of Fourier transform infrared spectroscopy（FTIR）, field emission scanning electron microscopy（SEM）, and thermogravimetric（TG） analyses. The results revealed that CS（1.5%） had the best enhancement effect on OCC recycled paper, with burst, tensile, and tear strengths of hand sheets being increased by 17.62%, 18.18%, and 22.93%, respectively, and air permeability being decreased by 28.55%, compared with the control group. Furthermore, we found that combined treatments with 1.5% CS and NC all enhanced the performance of OCC, with optimal effects being observed when NC was added at a 1% concentration. Compared with the improvements obtained with the sole addition of 1.5% CS, the combined treatment was found to increase the burst, tensile, and tear strengths of OCC recycled paper by a further 5.11%, 11.54%, and 13.46%, respectively, and reduced air permeability by 12.58%. The findings of FTIR analysis revealed that CS can bind to pulp fibers, and that the addition of NC increases the number of hydrogen bonds, thereby facilitating a tighter bonding between fibers. Moreover, SEM observations of the microscopic morphology of the surface of recycled paper indicated that the CS-NC binary system can contribute to a more compact and tighter inter-fiber bonding. In addition, the TG analysis results revealed that by enhancing fiber cross-linking, the CS-NC treatment could increase thermal degradation of the remaining residue of OCC recycled paper to up to 600°C. Our findings in this study indicate that treatment with a combination of CS and NC can significantly enhance the performance of OCC recycled paper. We believe that our results would provide a valuable reference for the repeated recycling of OCC. [ABSTRACT FROM AUTHOR]

In this study, tunicate cellulose nanocrystals(tCNC) were investigated as a filler added to bleached kraft pulp. First, tCNC were prepared through bleaching and acid hydrolysis. The structure, morphology, crystallinity, and particle size and zeta potential of the tCNC were characterized by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and a malvern particle sizer, respectively. Second, kraft pulp with a consistency of 10% was refined to 42 °SR through a PFI refiner. Then 60 g·m-2 handsheets were prepared from this pulp. Prior to preparing the handsheets, tunicate nanocellulose was thoroughly mixed into the pulp at four gradients:0.3%, 0.6%, 0.9%, 1.2%, and 1.5%. Cationic polyacrylamides(CPAM) were added to the pulp slurry as a retention agent. A control experiment was set up accordingly. The effects of tCNC addition on the tearing, tensile, burst, air permeability, and optical properties of the handsheets were evaluated. The results indicated that the maximum increase in the tear index was 12.00% when tCNC was added 0.6%. The tensile index reached its maximum value when tCNC was added at 0.6%, with an increase of 12.04% compared to pure pulp sheets. The tensile index increased by 16.55%. In this experiment, nanocellulose prepared from a mantle sea animal was used for the first time as reinforcing filler in papermaking, which has greatly extended the application of tCNC in the enhancement of paper strength. [ABSTRACT FROM AUTHOR]

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A standardized operation of the paper pot machine has not been achieved. Therefore, the effects of humidity on uniformity were investigated. The filling volume and sawing length of the machine-produced paper pots were measured under various humidity conditions(20%,31%,47%,63%,67%,89%,98%) and analyzed in SPSS. The results showed that humidity influenced the set filling volume versus the actual filling volume, as well as the sawing length, except under 63% and 67% humidity. Homogeneity of the data variance was calculated, and the paper pots prepared under 63% and 67% humidity were significantly different (P<0.05) from the other levels. In these cases, the actual filling volume was comparable to the set volume, and the sawing length was similar to the standard sawing length. The low standard deviation, coefficient of variation, and dispersion indicate that the optimum humidity range for machine paper pot formation is between 60% and 70%. Paper pots produced in this humidity range had a production pass rate of 99.17% and a total qualified seedling rate of 89.88%. Paper pots produced within the optimal humidity range enables a more uniform filling volume and sawing length. Additionally, the pass and qualified seedling rates can be improved. [ABSTRACT FROM AUTHOR]

The nonlinear relationship between the chlorophyll content of Hopea hainanensis, an endangered tree species, and image features was discussed, and the feasibility of estimating the chlorophyll content of H. hainanensis by image color and texture features was studied in this paper, providing a reference for image-based non-destructive monitoring. The canopy chlorophyll content (SPAD value) and RGB images were obtained using a 2-year-old H. hainanensis as the research object. The generalized additive model (GAM) was used to explore the nonlinear correlation between the image color and texture characteristics and the SPAD values. The SPAD values were then estimated using the multiple linear regression, GAM, random forest, and XGBoost models based on the features without multicollinearity filtered by the Lasso algorithm. Among the 22-image color and texture features, the feature with the strongest linear correlation was a correlation standard deviation, which was positively correlated, while the feature with the strongest nonlinear correlation was entropy mean, which was inverse J-shaped and negatively correlated. The Lasso algorithm effectively removed the severe collinearity among multiple image features, and the VIF values of the 15 image features retained after screening were all lower than 10. Based on the results of estimating SPAD values using multi-image color texture features, the test accuracy of the XGBoost model was highest, and the average testing R~2, MAE, and RMSE were 0.757, 2.682, and 3.242, respectively. Therefore, there are certain nonlinear correlations between SPAD values of H. hainanensis and image color and texture features. The image estimation method based on the GAM model with nonlinear interpretation ability can be used as the optimal method for estimating the chlorophyll content of H. hainanensis. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the relationship between air anion concentration( AAC) and temperature and between AAC and humidity in five forest types at the same altitude from 6: 00 to 18: 00. The paper also shows the above mentioned relationships for evergreen broad-leaved forests at four different altitudes in Wuchaoshan National Forest Park. The results showed that AAC is higher in evergreen broad-leaved and deciduous broad-leaved forests than in other forest types. Additionally, daily AAC variations in the five forest types are unimodal in the autumn. As the altitude increases, the AAC generally decreases in the autumn, except in November. The AAC is positively associated with humidity and inversely correlated with temperature for three months in evergreen broad-leaved forests. However, these relationships are not uniform in other forest types and present monthly differences. In conclusion, the study shows that forest types, altitude gradients, and seasonal changes significantly impact forest AAC levels by changing the temperature and humidity conditions within the forest. [ABSTRACT FROM AUTHOR]

The aim of this paper was to study the characteristics of litter decomposition-soil and nutrients-soil enzymes and their correlations among different forest types in the south subtropical coastal land to reveal the mechanism of nutrient migration in coastal forest ecosystems and provide a scientific basis for their protection and restorations. Two typical secondary forests, Ficus altissima and Syzygium hancei, and Acacia mangium artificial forest were chosen as research objects to analyze the litter decomposition. The dynamic variation rules of soil nutrients and soil enzyme activities of the three stand types and their correlations were analyzed. The results showed that the litter decomposition rate was F. altissima forest＞Syzygium hancei forest＞A.mangium forest. The soil nutrient content was the highest in F.altissima forest or Syzygium hancei forest, and the lowest in A.mangium forest. The dynamic variation of the same soil enzyme activity was basically the same in the three stand types, and the enzyme activity peaked in August or November. Some differences in the correlation between the litter loss, soil nutrients, and soil enzymes were observed among the three stand types. Soil sucrase (SUC) activity in F. altissima and in Syzygium hancei forest was extremely significantly (P＜0.01) and significantly (P＜0.05) positively correlated with total nitrogen (TN) content, respectively. The catalase (CAT) activity of A. mangium forest was extremely significantly (P＜0.01) with available nitrogen (AN) content, and significantly (P＜0.05) positively correlated with total phosphorus (TP) content.The litter decomposition rate and soil nutrient content of the secondary forests of F.altissima and Syzygium hancei were better than those of the A.mangium forest. Therefore, in the process of restoring and maintaining coastal soil fertility, priority should be given to protecting natural vegetation and creating near-natural stratified forests according to the characteristics of native tree species to improve the ability of sandy soil to “self-fertilize”and accelerate the process of vegetation restoration and succession. [ABSTRACT FROM AUTHOR]

The paper used the unmanned aerial vehicle (UAV) which can quickly obtain a wide range of vegetation images to capture the low-altitude aerial photograph)' and associated with the multivariate HoG features to recognize vegetation types. Firstly, the texture infonnation of the image were extracted by Gabor filter and using HSV and Lab color space transform to extract the color infonnation. Next, the image were divided into N cells, then computing the gradient of histogram of each cell based on the texture and color infonnation to fonn the multivariate HoG features. Finally, taking the cell as the classification unit, combining the random forest machine learning algorithm, vegetation types recognition model were established. Taking the Anxi County in Fujian Province as the test area, the results showed that it was feasible to identify the vegetation types by using the optical image of low-altitude aerial photography; the highest recognition accuracy in recognizing vegetation and non-vegetation was 96.04%; the recognition accuracy rate was 82.44% in recognizing vegetation types at 20 m and decreased with the height increase. Moreover, the vegetation images of aerial photography were further collected, which was captured at the Changting County of Fujian Province, as another data to prove the robustness of the model of vegetation type recognition in different areas, the highest recognition accuracy was 73.31%, the accuracy was similar compared with the result of Anxi County. In this paper, the vegetation images by using the unmanned aerial vehicle with optical camera were conveniently, econmically obtained; the proposed vegetation type recognition model can be easily applied to the field vegetation type monitoring and management as the high precision and its robustness in various regions. In addition, according to the recognition result at various aerial height, the proposed aerial height should not be too high, 20 m as the reference height of aerial photography was suitable. [ABSTRACT FROM AUTHOR]

Wood is an inexhaustible resource with many advantages, such as high abundance, renewability, biodegradability, and carbon balance. Anisotropic wood can serve as a substrate to facilitate the deposition and growth of micro/nano functional units for the development of anisotropic energy storage and conversion materials. Moreover, wood can serve as a raw material for preparing novel products with large surface areas and high reaction activities, such as 1 D nanofibrils, 2 D nanofilms, and 3 D gels, through disassembly and reassembly. These reassembled materials can also act as substrates that can be combined with micro/nano functional units for the development of green novel energy storage and conversion materials. In this paper, the recent research on wood-based energy storage and conversion materials, including supercapacitors, lithium-ion batteries, water splitting, and solar cells, is summarized, and the direction of future development is proposed by providing new ideas for the applications of this high-value resource. [ABSTRACT FROM AUTHOR]

This paper analyzes the change of H+ flow in the roots of two different clones of the Chinese fir ( Cunninghamia lanceolata) under different levels of phosphorus，discusses the relationship between root H+ flow and adaptation of C. lanceolata to low-phosphorus stress，and provides a scientific basis for the internal mechanism of high-efficiency phosphorus utilization in C. lanceolata under low-phosphorus stress conditions. Two C. lanceolata clones，M28 and M32，which display different phosphorus utilization efficiencies， were tested under three phosphorus supply levels reflecting normal supply， moderate deficiency， and severe deficiency over three time periods ( 3， 8， and 15 d) . The results showed significantly greater H+ inflow throughout the root system of M28 clone， but no significant difference in H+ excretion between the two clones over the different treatment time periods. The M28 clone was more sensitive to phosphorus stress than M32， as demonstrated by reduced H+ efflux under moderate phosphorus deficiency stress conditions， whereas M32 maintained H+ low efflux even under severe phosphorus deficiency stress conditions over the shortest time interval. For both the longer time periods， H+ efflux ceased， indicating that H+ efflux from the roots is a stress response to low-phosphorus conditions. The results show that different genotypes of C. lanceolata are capable of different levels of adaptability to conditions of low phosphorus. The H+ flow in the roots of the clone with high phosphorus utilization efficiency M28 was more sensitive to the change in phosphorus inputs， demonstrating that H+ flow in the roots of C. lanceolata is a stress response to changes in external levels of phosphorus. [ABSTRACT FROM AUTHOR]

Currently，forestr^^ production methods in China are changing from large-scale skids to discrete，small-scale skids. Many hills in the forest areas of southern China have large slopes，"where large mechanized skidding is very inconvenient. Previously，forest harvesting used traditional cable "winches，"which have high operational intensity and inconvenient maintenance. For these reasons， and to accommodate the characteristics and development needs of contemporary forestry，a light cable winch with a clutchless drum was designed to improve operability and transfer capacity. This paper introduces the overall layout and working principle of the light cable winch，where a new reel selection mechanism was designed to replace the reel clutch in a traditional cable winch. The proposed mechanism has the characteristics of convenient operation， reliable and stable transmission， and a simple manufacturing process. The strength of the spline shaft and transmission gear of the reel selection mechanism has been evaluated. The selection of ( and design calculations for) the main components of the winch drive system， such as the transmission mechanism， forward and reverse gearboxes，and chain coupling are also presented. This series of work guarantees that the proposed light cable winch has multiple gears that function in both forward and reverse directions. A lightweight design for the reel was obtained using Matlab. The design was optimized with the objective function of minimizing volume，considering the design variables of reel diameter and reel wall thickness. Based on the optimization data，a 3D model of the reel structure was established using SolidWorks. Finite element analysis was carried out through meshing， applying load， adding constraints， and calculating. The stress contour plot of the reel is presented， and the results show that the optimized reel meets the strength requirements. The proposed light cable winch uses a new reel selection mechanism， has a compact structure， and is reliably secure. The proposed winch is lightweight， convenient for transportation and operation， and has improved working efficiency. [ABSTRACT FROM AUTHOR]

In order to find out the spatial variation characteristics and sampling spacing of soil bulk density, 100 m×100 m area was selected for the mature forest of Cunninghamia lanceolata, and a total of 100 plots were set up by grid method (10 m×10 m). The spatial heterogeneity of soil bulk density in different soil depths (0-20, 20-40 cm) was analyzed by classical statistics and geostatistics, and the optimal sampling spacing and sampling number were explored by "resampling". The purpose of this paper is to reduce the consumption of manpower and material resources for soil bulk density sampling. In this study:the soil bulk density and the coefficient of variation of soil increase with the increase of the soil layer, the coefficient of variation is middle variation, 0-20 cm, and the optimal model of 20-40 cm is the exponential model and the spherical model, and the spatial distribution is plaque-like, and belongs to the medium-space self-correlation. The increase of sampling spacing will lead to the pattern of "decrease-stability-limit" of sampling number. Although the coefficient of variation does not change much, it can obtain a more real coefficient of variation of soil bulk density. The variation degree of spatial autocorrelation, fitting effect and nugget below 20 m×20 m sampling spacing are better. In the analysis of spatial variation in small scale (100 m×100 m), the sampling spacing is 20 m×20 m and the sampling number is arranged 25, which can not only meet the accuracy of Kriging interpolation, but also save manpower and material resources. [ABSTRACT FROM AUTHOR]

The effect of ammonium polyphosphate (APP) and zinc borate (ZB) on flame retardant and smoke suppression properties of MDF (the panels with 930.25 cm2 were prepared in laboratory) by thermo gravimetric/differential scanning calorimeter (TG/DSC), cone calorimeter (CONE, the experiments were repeated 3 times and taken an average), and scanning electron microscope (SEM) were researched in this paper. Results showed that, the residual mass of MDF with APP was increased by 5.93% compared to the control. Flame retardants of APP had positive effects on decreasing heat release which the heat release rate (HRR), total heat release (THR), and peak heat release rate (peak-HRR) were included when MDF subjected to combustion, and APP treated MDF had burned out after 38 s test with apparent flame retarding effect. But total smoke production (TSP) of APP treated MDF has been increasing when the test is over, the smoke suppression properties is poor. The residual mass of MDF with ZB was increased by 8.79% compared to the control, and ZB had positive effects on decreasing heat release which the HRR, THR, peak-HRR, TSP, somke production rate (SPR), peak carbon monoxide yield (peak-COY), and peak carbon dioxide yield (peak-CO2Y) were included when MDF subjected to combustion. The peak-COY were reduced by 98.65% with addition of ZB compared to the control which showed excellent smoke suppression performance, but the residual of ZB treated MDF was almost white ashes resulted in the bad effect of flame retardant. The residual mass of MDF with APP+ZB was obviously increased by 15.97% compared to the control, and the heat and smoke release were reduced in combustion. The peak-COY were reduced by 77.03% with addition of APP+ZB compared to the control. The elements of P, N, and B in APP+ZB have significant synergistic char forming which lead to a dense carbon layer and integrity fiber carbon after CONE test, which had significant effect to improve flame retardant and smoke suppression properties. The purpose of efficient flame retardant and the least release of fumes can be achieved when the flame retardants of APP and ZB were combined use, so that the casualties in the fire were reduced. [ABSTRACT FROM AUTHOR]

In order to decrease the intensity of labor of attending personnel, raising degree of safety and machining accuracy, an experiment was conducted on wipe-off knot and split bamboo tubes. Based on the improved design of existing processing equipment, an all-in-one machine continuing to wipe off knot and split half-and-half or segment of bamboo cube was developed. The processing conditions of wiping off and splitting bamboo tubes was analyzed in the paper. The structure and working principle of the all-in-one machine for wiping off and splitting bamboo tubes were discussed. The main working parameters were also given. Compact structure and lower floor space were possessed to the all-in-one machine. The clamping time of the bamboo tube is 1-2 in general. The all-in-one machine fits processes of all kinds for the cross-section of bamboo tubes with rectilinear figure. [ABSTRACT FROM AUTHOR]

lirontispa longissima (Gestro) congregates in the unfolded heart leaves of palm plants; therefore, it is difficult to control the pest because the pesticide cannot enter and contact the pest. In this paper, antennal potential technology and behavioral bioassays were used to screen compounds that exert strong stress on Ii. longissima, thereby forcing B. longissima to leave the heart leaves and expose them to the stimulating volatile plant compound odors. The results showed that the adult antennae had the strongest response to cinnamaldehyde among the 9 volatile compounds tested, with the relative reaction values of the electroantennogram reaching 128.17±0.44 and I03.87±2.54. The lowest potential occurred for linalool, a-pinene, and menthol with relative reaction values of the electroantennogram reaching 33.28±1.18 and 15.95±0.91, 31.90±0.69 and 16.86±0.33, and 32.90±1.60 and 14.55±0.5I, respectively. Except for turpentine and 1-heptenal, the relative reaction values of the electroantennogram produced by the rest of the compounds with the antennae of females were significantly greater than those of males. There was a positive correlation between the relative reaction values of the electroantennogram and the concentration of cinnamaldehyde for adult Ii. longissima. The behavioral bioassay showed that cinnamaldehyde that was diluted less than 5x!04 times significantly repelled adult Ii. longissima, and the higher concentration corresponded with a higher rate of the targeted response. When diluted 1x10" times, the repellent rate reached 72.41%±3.16% and 70.22 + 3.22%. Thus, it can be seen that cinnamaldehyde had the strongest stimulatory and stress effects on adult Ii. longissima of the 9 compounds tested. [ABSTRACT FROM AUTHOR]

Abstract; Based on the field investigation data of 48 Cycas micholitzii target trees and 757 eompetitive trees in Guangxi, this paper analyzed the intraspeeific and interspecific competition intensity of Cycas micholitzii. The Hegyi individual competitive indices (/c) model was used to explore the effects of species competition on the natural regeneration of Cycas micholitzii. ITie results showed that the intraspeeific and interspecific competition intensity of Cycas micholitzii accounted for 3.79% and 96.21% of the total competition intensity, respectively, indicating a remarkable effect on the interspecific competition. The value of the main competition intensity was laid out in numerical order, i. e., Lysidice rhodostegia> Litsea glutinosa>Ficus erecta var. beecheyana>Oimocarpus longan> Cipadessa cinerascens>Alchornea trewioides > Cycas micholitzii. Notably, the competition intensity of Cycas micholitzii decreased between the height of objective trees and the competition intensity and between competitive and objective trees in the whole forest and the Cycas micholitzii population nearly conformed to a power function, while that between other competitive trees and objective Cycas micholitzii trees conformed to an S curve equation. In conclusion, this model could effectively predict the intraspecific and interspecific competition of Cycas micholitzii. Individuals of Cycas micholitzii<().6 m in height should be protected. Artificial tending measures can be taken to reduce the pressure of interspecific competition in order to increase the natural regeneration success rate of Cycas micholitzii. [ABSTRACT FROM AUTHOR]

The antibacterial effect of the clove extract as experimental materials on the species of Fusicoccum sp.,Penicillium sp.and Cladosporium sp. and its mechanism were investigated in this paper. The results showed that the ethanol extract of the clove showed better inhibition effect on three fungus, of which it had an especially significant inhibition effect on Cladosporium sp.. The clove ethanol extract of 3. 125 mg·m L-1 had a bactericidal effect on Cladosporium sp.. Compared with control group without treatment, the behaviors of Cladosporium sp. treated with the clove extract of 1 mg·m L-1 were as follows: the morphology of mycelium was abnormal. The electrical conductivity increased and the soluble protein content of mycelium was about three times of that of the control group. The total sugar content of mycelium decreased by 87.18%. Moreover, the spore stalk was thin and slender, and it was easy to fall. In addition, the sporulation inhibition rate reached 69.31%. Therefore, it is speculated that the antibacterial mechanism of clove extract is achieved by destroying the cell membrane structure of the Cladosporium sp. and inhibiting the growth, metabolism, and reproduction of the fungus. [ABSTRACT FROM AUTHOR]

To increase the oxidation degree of the 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)-oxidized cellulose, tEMPOoxidized cellulose with high oxidation degree and high carboxyl content was prepared using DMAc/Li Cl system by a two-step process in this paper. The first step was to destroy the cellulose crystal °C by using DMAc/Li Cl system to obtain amorphous cellulose powder.The second step was to oxidize the cellulose powder by TEMPO/Na Br/Na Cl O. The TEMPO-oxidized cellulose was analyzed by headspace gas chromatography, conductimetry,Fourier transform infrared spectroscopy(FTIR),nuclear magnetic(NMR),X-ray diffraction(XRD). Results of FTIR and NMR showed that the TEMPO-oxidized cellulose was prepared successfully. XRD analysis showed that the crystalline region of cellulose °C was completely destroyed by the solvent. The carboxyl content measured by headspace gas chromatography was up to 2.02 mmol·g-1, and the oxidation degree measured by conductimetry titration was 97%. [ABSTRACT FROM AUTHOR]

Single-tree biomass model is the basis of stand biomass and carbon storage. This paper used the joint nonlinear estimation to establish the compatible model with the measured datum of 90 trees of Cinnamomum camphora in Guangdong Province. The coefficient of determination (R²), total relative error (ETR), mean percent deviation (EMR) and mean percent estimate error (EMP) were used to evaluate the model accuracy. The compatible model was also compared with the individual model. The model for classified diameter class and the proportion for each component were also analyzed. The results showed: the estimate accuracy of compatible model reached over 90%. ETR and EMR were below 3.0% while R² were more than 90.0%; compared with individual model, ETR, EMP and ERMS were slightly large while EMR was much smaller, but additive model maintained good compatibility between the total and components. For the small diameter below 4 cm, two models both performed poorly, however, compatible model performed better for the 2 cm diameter whereas individual model performed better for the 38 cm large diameter; the proportion of stem wood biomass accounted for the most of the aboveground and followed by branch, stem bark and foliage. With the increase of the diameter, the ratio of components showed different change. The compatible model established by the joint nonlinear estimation performed accurately and predicted well for single-tree and contributed to the accurate biomass estimation and carbon storage for C. camphora in Guangdong Province. [ABSTRACT FROM AUTHOR]

The 3rd generation seed orchard of Chinese fir covering 87.6 hm² was established in Guangze Huaqiao National Forest Farm by using 90 elite clones of the 3rd generation production population. This paper describes the technique of the 3rd generation seed orchard of Chinese fir based on the planning and design, clone arrangement, grafting technique and management, etc. Nine years after grafting, the average tree height, DBH and crown width of the orchard were 5.10 m, 14.74 cm and 4.72 m, respectively, and the cone yield was 1 313.90 kg⋅hm-2 with a seed yield of 42.70 kg⋅hm-2 in a seed rate of 3.25%. The analysis on the characters of the tree growth, seed yield and seeds indicated that the seed yield could be increased by tree management especially treetop pruning, combining with the genetic selection of parental seed-yielding characteristics. The afforestation comparision experiments of the progeny from the 3rd generation seed orchard to the popular cultivar of Chinese fir in Fujian Province showed that the progeny from the 3rd generation seed orchard grew rapidly. At the age of fifth year, the average tree height, DBH and volume of them were 7.12 m, 10.94 cm and 0. 039 9 m³, and annual growth were 1.42 m, 2.19 cm and 0.007 98 m, respectively. [ABSTRACT FROM AUTHOR]