Objective: The survival and growth of reintroduced Thuja sutchuenensis seedlings in relation to environmental factors were studied to reveal the main environmental factors that affect the survival and growth of T. sutchuenensis at the initial stage of reintroduction and to provide a scientific basis for habitat management. Method: Using typical sampling method, 142 plots of 20 m×20 m were set up in the T. sutchuenensis reintroduction areas in Kaizhou district and chengkou County of Chongqing city to investigate the preservation ratio, tree height, basal diameter, crown width, and 26 environmental factors including climate, topography, soil, vegetation, and human disturbance. Grey relational analysis was performed to reveal the main factors. The regression analysis was used to reveal the variations of survival and growth of the reintroduced T. sutchuenensis seedlings with the environmental factors. Result: The main environmental factors affecting the survival and growth of T. sutchuenensis seedlings were different in different places. In Kaizhou, the main environmental factors were type of land use and management, minimum temperature of the coldest month, mean annual temperature, slope aspect, content of available soil potassium, content of available soil nitrogen, and total soil porosity. In Chengkou, the main environmental factors were minimum temperature of the coldest month, mean annual temperature, mean diurnal range of temperature (mean of monthly), slope, content of soil total potassium, non-capillary soil porosity, and weeds coverage. In Kaizhou, the seedling height and basal diameter of T. sutchuenensis were significantly (P < 0.05) or extremely significantly (P < 0.01) positively correlated with the minimum temperature of the coldest month and with the annual average temperature. The crown width was significantly (P < 0.05) or extremely significantly (P < 0.01) positively correlated with the content of available soil potassium content, content of available soil nitrogen, and total soil porosity. The preservation ratio of seedlings was significantly (P < 0.05) negatively correlated with the content of available soil potassium. In Chengkou, the seedling height, ground diameter, crown width of T. sutchuenensis were extremely significantly (P < 0.01) positively correlated with the minimum temperature of the coldest month. The crown width was extremely significantly (P < 0.01) positively correlated with content of total soil potassium. The crown width was significantly (P < 0.05) positively correlated with the annual average temperature. The seedling height was significantly (P < 0.05) positively correlated with the mean of diurnal range of temperature. The basal diameter and crown width of seedlings were the largest on shaded slopes, and the preservation ratio of seedlings was the highest on semi-sun slopes. In land use and management, the basal diameter of intercropping with crops was the largest, and the basal diameter of the understory interplanting was the smallest. The crown width of intercropping with the medicinal plants was the largest, and crown width of the abandoned land was the smallest; the preservation ratio and height of intercropping crops were higher, but they were not significantly different from type of land use and management. Conclusion: Environmental factors, such as climate, topography, soil, vegetation, and human disturbance, had a certain impacts on the survival and growth of T. sutchuenensis seedlings at the initial stage of reintroduction. Among these factors, the effects of climate and human disturbance were dominant. The minimum temperature of the coldest month was the main environmental factor in Chengkou, and the land use and management was the main environmental factor in Kaizhou. The impact of the other environmental factors was relatively small.

Objective: The effects of restoration of farmland to forests with different vegetation was analyzed in the Loess Hilly Region by assessing the soil carbon and nitrogen, dissolved organic matter contentand organic composition, fluorescence characteristics of the surface soil. This study was aimed to reveal the effect and mechanism of accumulation of water dissolved carbon and nitrogen in the soil of the farmland-converted forest, it will provide a scientific basis for the selection of types of returning farmland to forest and ecological function evaluation. Method: Armeniaca sibirica, Hippophae rhamnoides, Pinus tabulaeformis, Populus simonii, Robinia pseudoacacia, and R. pseudoacacia×Amygdalus davidiana mixed forest converted from cropland for 19 years and abandoned land as control were investigated by comparing the differences in the contents of soil organic carbon (SOC), total nitrogen (TN), water dissolved organic carbon (WDOC), and water dissolved organic nitrogen (WDON) in the surface soil (0-20 cm). Three-dimensional fluorescence spectroscopy technology and the parallel factor method was used to estimate the organic components, fluorescence index (FI), autotrophic productivity index (API), freshness index (β:α) and humification index (HI) of different soil water dissolved organic matters (WDOM). Result: Except for A. sibirica, the differences in SOC and TN contents of other forest types increased on average by 131.1% and 106.0%, respectively, over those of the abandoned land. Among the WDOC, the A. sibirica forest alone failed to increase the WDOC content, and the R. pseudoacacia×A. davidiana mixed mixed increased the most, reaching 108.9%. The WDON increased by 173.5% and 105.8% for R. pseudoacacia and the mixed forest land, respectively. The WDOC/SOC ratio of all forest soils was maintained at 0.30%-0.37%, and the WDON/TN percentage was 0.29%-0.64%. Both ratios were less than those of the abandoned land. The soil SOC: TN ratio of each forest type was 14.1-20.2, which was significantly higher than that of WDOC: WDON (9.0-16.5). The SOC: TN and WDOC: WDON of P. tabulaeformis forest are the highest, 44.1% and 98.9% higher than those of abandoned land. Three-dimensional fluorescence analysis showed that the WDOC of forest land reclaimed from farmland was mainly composed of stable macromolecular aromatic humus(C2), fulvic acid with a smaller molecular weight, humus acid(C2), and tryptophan-like(C3) compounds. Except for the H. rhamnoides forest macromolecular humus accounted for the largest proportion of all forest lands with an average increase of 45.1% when compared with abandoned land. There were no significant differences in FI, API and β:α indexes of the soil dissolved organic matters of different forest types, which ranged between 1.60-1.69, 0.57-0.62, and 0.56-0.61, respectively. The HI index of P. simonii and A. sibirica was significantly higher than that of the other forest types. Further correlation analysis showed that WDOC and WDON are extremely significantly positively correlated and significantly positively correlated with SOC and TN, respectively. C2 component is significantly negatively correlated with WDOC and WDON. WDOC: WDON is significantly positively correlated with SOC: TN, but is significantly negatively correlated with WDON/TN (P < 0.05). Conclusion: When compared with naturally restored abandoned land, farmland conversion to forests show the cumulative effect of total organic carbon and total nitrogen and it can significantly increase the WDOC content, especially for R. pseudoacacia mixed and single species that can simultaneously increase the dissolved carbon and nitrogen contents. At the same time, the soil WDOM of P. simonii and A. sibirica forests showed a relatively high degree of humification. This is because the farmland conversion to forests resulted in more stable and complex composition at the same time, the soil WDOM of P. simonii and A. sibirica forests showed a relatively high degree of humification, organic matters which increases the resistance to decomposition and is conducive to accumulation of soil carbon and nitrogen.

Objective: The effect of mixed management mode of different broad-leaved species on water conservation capacity of the litter and soil in Pinus massoniana plantation was evaluated and in order to provide a scientific basis for the construction and transformation of coniferous and broad-leaved mixed forests and the improvement of hydrological function. Method: Five mixed forests of coniferous and broad-leaved trees (P. massoniana×Bretschneidera sinensis, P. massoniana×Manglietia chingi, P. massoniana×Cercidiphyllum japonicum, P. massoniana×Camellia oleifera, P. massoniana×Michelia maudiae) with almost same site conditions and forest management models selected in Longli State-Owned Forest Farm of Guizhou Province were studied, and pure P. massoniana plantation was used as the control. Field investigation and indoor test were used in combination with volume of litter stocks, contents of soil aggregates and soil organic carbon to compare the characteristics of the litter-soil layer and the changes of water holding capacity of the different plantations after 15 years of transformation Result: The rank of the effective water conservation capacity of the litters in different plantations is P. massoniana×M. maudiae (23.11 t·hm^-2) > P. massoniana×C. japonicum (18.77 t·hm^-2) > P. massoniana×B. sinensis (18.28 t·hm^-2) > P. massoniana×M. chingi (16.01 t·hm^-2) > pure P. massoniana forest (13.39 t·hm^-2) > P. massoniana×C. oleifera (8.85 t·hm^-2). In 0-20 cm soil layer, the addition of B. sinensis, M. chingi, C. oleifera, and M. maudiae increased the soil saturated water storage of P. massoniana plantation by 6.94%, 9.00%, 15.10%, and 23.90%, respectively, while the addition of C. japonicum decreased the soil saturated water storage of P. massoniana plantation by 6.62%. In 0-100 cm soil layer, C. oleifera and M. maudiae increased the soil saturated water storage of P. massoniana plantation by 8.08% and 19.47% respectively. Soil capillary water storage, soil non-capillary water holding capacity and soil saturated water storage were positively correlated with soil organic carbon, soil capillary porosity, soil non-capillary porosity and total porosity (P < 0.01), and negatively correlated with soil density and fractal dimension (P < 0.05). The comprehensive coordinate method showed that M. maudiae is more suitable to be used as a mixed tree species for the transformation of P. massoniana plantation. The addition of C. oleifera will reduce the water conservation capacity of litter-soil layer of P. massoniana plantation, and it is not suitable to be used as a mixed tree species. Conclusion: 15 years after transformation of P. massoniana plantation by planting with different broad-leaved trees, water conservation capacity of the litter and soil was changed to various extents due to the changes of litter composition, quantity, and physical and chemical properties of soil. In our study, the order of water conservation capacity of litter and soil from strong to weak was P. massoniana×M. maudiae > P. massoniana×B. sinensis > P. massoniana×C. japonicum > P. massoniana×M. chingi > pure P.massoniana plantation > P. massoniana×C. oleifera. We suggest that forest resource managers take into account the impact of differences among tree species on the ecological hydrology of plantation and add appropriate species into the masson pine plantation when making management decisions.

Objective: The crown of autumn-color trees was investigated to construct and identify the key indices affecting scenic beauty estimation (SBE) based on HSV color space, and to reveal the quantitative relationships between color indices and SBE, in order to provide a basis for deepening studies on forest color and improving indicators system for assessing ornamental effect. Method: 190 photos of individual trees of 38 autumn-color species common in northern China during five coloration periods were investigated by color classification (dominant color, complementary color and intersperse color) of the photos using Photoshop and ColorImpact software, the values and area proportions of HSV (hue, saturation and value of color) color were extracted by category, synthesize dominant, assistant and whole indexes, and the three elements synthesized index, chromatic aberration indexes (interior of chromatic aberration, and external of chromatic aberration), the deviation indexes, and basic quantity indexes were calculated. Then psychophysical method were employed to acquire the SBE value of the pictures. Software SPSS and DPS were taken to analyze the correlation between the color indexes and SBE statistically. A multiple regression model was established based on the result, and the key indexes affecting SBE were identified. Result: The Pearson correlation analysis showed that the 5 special indexes affecting SBE(|r|>0.500, P < 0.01), saturation of assistant color (r=0.539, P < 0.01), saturation of whole colur (r=0.533, P < 0.01), biased exponent of dominant color and assistant color (r=-0.515, P < 0.01), relative area of dominant color (r=-0.521, P < 0.01), and relative area of whole color (r=-0.519, P < 0.01). 6 color indexes such as value, the chromatic aberration of hue, the interior chromatic aberration euclidean, the external chromatic aberration euclidean, the deviation, and the counting index, of which 12 indexes had an extremely significant correlation (|r|>0.300) with SBE). The correlaton between indexes mainly regards the between different indexes in the same index group. Among the three elements of color, both saturation and value have had a good positive linear relationship with SBE, while hue had no linear relationship with SBE. Among the chromatic aberration indexes, the chromatic aberratin of hue had a significantly negative linear relationship with SBE. The external chromatic aberration euclidean, biased exponent, and other external of chromatic aberration of single primary color possess a negative linear relationship with SBE. In contrast, the Interior chromatic aberration had a positive linear relationship or quadratic curve (level first and then rise) relationship with SBE. Among the deviation indexes and basic number indexes, the deviation of hue, the deviation of value, the relative area of color, and the maximum number of colors were optimally in a quadratic curve relation with SBE. The SBE model is a quadratic polynomial(R²=0.807). As illustrated in the model, a high SBE value is given to the colorscape of trees with a high ratio of hanging leaves, with hues closer to yellow-green, with a pure bright whole color, with distinct gradations of values. Among the two factors of saturation of whole color, the color landscape with strong value of dominant color and assistant color and value of contrast and harmonious saturation of dominant color and assistant color has good viewing effect. Conclusion: The sample color was allocated into different categories and then re-synthesized by categories, thereby realizing quantitative calculation of color indexes. Chromatic aberration and the deviation have explicit physical meanings and are effective indexes for quantifying the dimensionality reduction of the color index and improving evaluation efficiency. Containing 6 key indexes such as the chromatic aberration of dominant color hue and assistant color hue, saturation of whole saturation, biased exponent of dominant and assistant, the external chromatic aberration euclidean of dominant color and assistant color saturation, the deviation of whole color value, and relative area of whole color, the SBE model, can be used as an index system for comprehensive evaluation of SBE.

Objective: This study aimed to detect the jujube witches'-broom(JWB) phytoplasma status of jujubes cultivated in three jujube orchards after inoculating the trees by graft, and to analyze the transmission, epidemic, heritable variation, and phylogeny of different phytoplasma strains; and reveal the relationship between different phytoplasma strains and different resistance jujube cultivars. Method: In April 2017, different resistant jujube scions were collected and grafted on the phytoplasma-infected rootstocks cultivated in three jujube orchards including Yuquanshan and Changping orchards in Beijing and Juncheng orchard in Tang county, Hebei province. The total DNA of scion and rootstock tissue samples were extracted from August to October of that year, to be used as templates for PCR amplification. Specific PCR products of 16S rDNA, 16S-23S intergenic region(SR), secA, tuf, fusA-tuf intergenic region, himA and its downstream putative protein gene were sequenced. Genetic variation and phylogenetic evolution were analyzed with obtained sequence data. Result: The symptom severity of resistant scions was generally lower than that of susceptible rootstocks. No phytoplasma was detected in all of T30 scions without symptoms of witches'-broom by direct and nested PCR and LAMP. The homology of 16S rDNA, SR, tuf and secA gene sequences of JWB phytoplasma isolates from three orchards was 100%. According to the base variation of himA and its downstream putative protein gene at 117, 154 and 190 bp sites in 38 samples, JWB strains from Junchengzhen were clustered in the T-A type, JWB strains from Yuquanshan and Liangjiagou were clustered in the C-A type, while JWB strains from Changping were clustered in the C-C type. According to the insertion or deletion of base A at 39 bp in the sequence of the fusA-tuf intergenic region in 29 samples, JWB strains from Yuquanshan and Juncheng were clustered in the TJ2(A+) type, while others were clustered in the TJ1(A-) type. There were dominant strains in each orchard that cause the sequence types of both regions(himA and its downstream putative protein gene, intergenic region of fusA-tuf genes) were mutually corroborated. Conclusion: In this study 'Junyou No.2' (Z18) jujube is for the first time identified as the high resistant cultivar to JWB. The variations of different JWB strains from two orchards have no significant correlation with the disease resistance of cultivars, while with the regional difference. The gene sequences of JWB strains from the two regions provide the evidence that JWB strains of Yuquanshan are not originated from Sihong County, Jiangsu Province. The results are helpful to reveal the genetic variation characteristics of JWB phytoplasma population and provide a theory basis for rational utilization of resistant cultivars and JWB disease control.

Objective: The purpose of this study is to develop a technique for high quality chromosome preparation of root tips, in order to improve the fluorescence in situ hybridization(FISH) system for 45S rDNA and 5S rDNA of Hydrangea macrophylla 'Endless Summer' with dispersed and good morphology chromosomes in the cell division phase, which would provide a basis for improving the molecular cytogenetic study of Hydrangea. Method: Root tips taken from semi-lignified branches of H. macrophylla 'Endless Summer' through hydroponic culture were pre-treated with 1 MPa nitrous oxide, 0.7 mmol·L^-1 cycloheximide and 2 mmol·L^-1 8-hydroxyquinoline respectively. Chromosome was prepared after meristem enzymolysis of the pre-treated root tips with a mixture of 4% cellulase and 2% pectinase, and the metaphase chromosome was hybridized in situ with 45S rDNA and 5S rDNA probes. Result: 1) Materials pre-treated with 1 MPa nitrous oxide for 0.5 h, their chromosomes were still insufficiently condensed and too long for analysis; those pre-treated for 1 h, the chromosomes condensation were appropriate, and the centromeres of most chromosomes could be identified; pre-treatment for 2 h, the chromosomes were over-condensed and punctate. Materials pre-treated with 0.7 mmol·L^-1 cycloheximide for 1 h and 3 h, their chromosomes were insufficiently condensed; pre-treatment for 5 h, the chromosomes were properly condensed, but the centromere positions of most chromosomes were not discernible. All materials pre-treated with 2 mmol·L^-1 8-hydroxyquinoline for 2 h, 4 h or 6 h, their chromosomes condensation were all appropriate, but the chromosome centromeres could not be identified. So 1 h treatment with 1 MPa nitrous oxide is the most suitable pre-treatment condition for H. macrophylla 'Endless Summer' root tips. 2) Three enzymatic treatment time gradients were used. Chromosomes digested for 0.5 h, their cytoplasm could be observed obviously around the metaphase and the nucleus; chromosomes digested for 1 h, their background were clean and the chromosomes well dispersed; when digestion time expanded to 2 h, the chromosomes were easily lost and many incomplete mitotic phases were observed. Therefore, the most suitable treatment for H. macrophylla 'Endless Summer' root tip was digested in the mixture of 4% cellulase and 2% pectinase at 37℃ for 1 h. 3) H. macrophylla 'Endless Summer' is diploid with 36 chromosomes (2n=2x=36). The FISH of 45S rDNA long and short probes showed similar effects, both produced strong hybridization signals which located at the end of the short arm of a pair of acrocentric chromosomes. Both the long and the short 5S rDNA probes only revealed weak FISH signals, but the detection rate of the long probes was higher than that of the short probes. The 5S rDNA located at the long arm ends of one pair of telocentric chromosomes. Conclusion: This study successfully established a high quality metaphase chromosome preparation and rDNA physical localization technical system for H. macrophylla. This system can efficiently analyze and determine the chromosome number and rDNA distribution in Hydrangea plants. This can be used in Hydrangea resources identification and provide a basis and guidance for Hydrangea hybrid breeding.

Objective: The oleoresin in the stem of Sindora glabra contains rich sesquiterpenoids, while terpene synthase is one of the key enzymes in the terpene biosynthesis pathway. Cloning and expression analysis of S. glabra sesquiterpene synthase gene SgSTPS3 is helpful to explore the formation mechanism of S. glabra oleoresin, which will provide a new theoretical basis for analyzing the mechanisms of terpenoid biosynthesis and metabolism in forest trees. Method: Based on the previous transcriptome data, the sesquiterpene synthase gene SgSTPS3 was cloned from the stem of mature S. glabra, and analyzed by bioinformatics tools. Prokaryotic expression in Escherichia coli cells, and identification by-products by GC-MS. The expression levels of this gene at different ages (0.5, 1.5, 15, 30 years old) and in differet organs (root, phloem, xylem, tender leaves, old leaves) of S. glabra were also analyzed by quantitative real-time PCR. To analyze the response pattern of this gene to hormones, salicylic acid (SA), methyl jasmonate (MeJA), and the combination of SA+MeJA were applied. Result: The full-length cDNA sequence of SgSTPS3 gene including 1 701 bp was cloned and encoded 566 amino acids(GenBank accession number: MW345633). The multiple sequence alignments indicated that SgSTPS3 had the highest homology with Copaifera officenalis CoTPS3 and Copaifera langsdorffii ClTPS3, reaching 87.68%. Biochemical analysis showed that its protein was a multifunctional enzyme. When farnesyl pyrophosphate(FPP) was used as a substrate, it was mainly catalyzed and produced sesquiterpene cyclosativene, copaene and cis-β-copaene; when geranyl pyrophosphate(GPP) was used as the substrate, it was mainly produced monoterpene linalool. The expression level of SgSTPS3 gene was significantly different in different organs and at different ages: in different organs of same plant age, the highest expression level appeared in the root of 0.5 and 1.5 years old plants, and the hightest in the phloem of 15 and 30 years old plants; for the same organ at different ages, the expression of roots decreased with age, while the expression in the xylem increased with age; the expression in phloem of 30 years old plants was significantly higher than that of the other three ages, but there was no significant rule between young and old leaves. Hormone treatment was performed on the leaves of 2 years old S. glabra, the highest expression level of this gene appeared in 12 h after salicylic acid(SA, 50 μmol·L^-1) spraying, 35.07 folds compared to the control, and the lowest was in 72 h. In addition, its expression was highest at 6 h and lowest at 24 h after methyl jasmonate (MeJA, 100 μmol·L^-1) treatment. Moreover, the expression of SgSTPS3 gene was similar to that of the control group, under the treatment of SA(50 μmol·L^-1)+MeJA(100 μmol·L^-1), with a poor induction effect. Conclusion: SgSTPS3 was a sesquiterpene synthetase gene with multi-substrate enzyme catalytic function, and its expression level was higher in the root of seedlings and the phloem of adult plants. The regulation of different hormones on SgSTPS3 gene was significantly different, among which SA(50 μmol·L^-1) had the best induction effect, and MeJA (100 μmol·L^-1) came the second.

Objective: The identification of interspecific poplar hybrids at seedling stage is challenging because of the morphological similarity. Here, we developed species-specific InDel markers to identify the interspecific hybrids between Populus deltoides and P. simonii, in order to lay a foundation for the identification of hybrids and molecular marker-assisted breeding in poplar. Method: Ten individuals of each P. deltoides and P. simonii were resequenced to screen species-specific InDels, which were further applied for primer designing. The resulted primers were tested for their versatility and specificity using 8% non-denature polyacrylamide gel electrophoresis. The selected species-specific polymorphic primers were used to identify interspecific hybrid progeny between P. deltoides and P. simonii. Result: Resequencing reads from each ten individuals of P. deltoides and P. simonii were mapped onto the genome of P. deltoides for comparisons, and a total of 359 733 InDel sites with a length difference larger than 5 bp were obtained, of which 18 418 sites are conserved within species but different between species. Based on the genome sequence of P. deltoides, 17 956 primer pairs were successfully designed using Primer3. Ten primer pairs from different chromosomes were selected and tested for their versatile in P. simonii by SeqHunter2 software. A total of six primer pairs were versatile between P. deltoides and P. simonii. The electrophoresis with 8% non-denature polyacrylamide gel showed that primers Psi2-1 and Psi13-14 were polymorphic between P. deltoides and P. simonii. Both primer pairs were then screened in natural population of P. deltoides and P. simonii each with fifty clones separately. The primers Psi2-1 amplified specific bands of 128 bp and 139 bp respectively in P. deltoides and P. simonii. And both of these bands were amplified in interspecific hybrids. Primers Psi13-14 amplified specific bands of 132 bp and 144 bp respectively in P. deltoides and P. simonii. And both of these two bands were successfully amplified in the interspecific hybrids. The two pairs of primers can be used to identify the hybrids between P. deltoides and P. simonii with an accuracy of 100%. Conclusion: This study confirmed that species-specific InDel markers can be used for the identification of interspecific hybrids of P. deltoides and P. simonii, which is of great significance for the identification of interspecific hybrid and breeding of new varieties of poplar.

Objective: The purpose of this study was to explore the stability and expression of exogenous gene in transgenic poplar 107(Populus×euramericana 'Neva') and to screen transgenic lines with double resistance to Lepidoptera and Coleoptera pests, providing valuable reference for breeding new varieties of transgenic poplar with multiple genes resistant to pests. Method: PCR, toxin protein content detection and insect resistance detection were performed in 2-year-old field seedlings of three lines (ECAA1-3) transformed with Cry1Ac-Cry3A-BADH genes and three lines (ECAB1-3) transformed with Cry1Ac-Cry3A-NTHK1 genes. Result: PCR gel electrophoresis test proved that the target gene was still in the genome of transgenic poplar 107. The detection of Bt toxin of transgenic poplar 107 showed that the 2-year-old transgenic lines in August all contained Cry1Ac and Cry3A toxin, but the content of Cry3A toxin was relatively high. The toxic protein content of Cry1Ac was 3.60-20.76 ng·g^-1, and the toxic protein content of Cry3A was 3 479.66-7 230.29 ng·g^-1. Indoor insect feeding test showed that the transgenic poplar 107 had resistance to both Hyphantria cunea and Plagiodera versicolora larvae, among which ECAB1 had the highest lethal rate to H. cunea (100%), and ECAA1, ECAA2 and ECAA3 significantly inhibited the growth and development of H. cunea larvae of the first instar. With the exception of transgenic line ECAA2, all the other lines showed high insect resistance to P. versicolora, with the lethal rate of 100% for the first instar larvae, 85%-100% for the first and second instar mixed larvae, and over 66% for adults. Conclusion: The exogenous genes of transgenic poplar 107 were still present and stably expressed, and their insect resistance was significantly improved compared with that of non-transgenic controls. However, there were significant differences among different transgenic lines, the strains ECAA3 and ECAB1 showed high insect resistance to the larvae of H. cunea and P. versicolora.

Objective: In view of the shortcomings of the bivariate joint distribution function commonly used in the investigation of forest structure characteristic factors, a bivariate distribution(density)function with a low applicable condition, wide adaptation range and great application value was selected to provide a reference for accurately measuring the joint distribution of forest structure characteristic factors. Method: Five commonly used bivariate Copula density functions, bivariate S_bb functions and bivariate Weibull distribution functions, were selected to describe the bivariate joint density of DBH and age of moso bamboo(Phyllostachys edulis) based on 177 continuous inventory plots in Zhejiang Province in 2009, and the measurement accuracy of each function was compared and analyzed. The optimal Copula function of DBH and age was selected based on the metrics of bivariate frequency histogram and AIC. The bivariate Copula joint density model of DBH and age for moso bamboo in Zhejiang Province was established. The goodness of fit of the model was tested using Kolmogorov test. Result: The coefficient of determination(R²) of bivariate Weibull distribution function and the bivariate S_bb function was 0.990 1 and 0.736 2, respectively, and the R² of bivariate Gumbel Copula density function was 0.984 1 with the lowest AIC value of -19.519 6. The maximum deviations of the cumulative value of the bivariate Gumbel Copula function, the bivariate Weibull distribution function and the bivariate S_bb function were 0.007 0, 0.015 8 and 0.078 1. The critical significance value was 0.179 8. Conclusion: Bivariate Gumbel Copula probability density function is the best Copula function for representing the joint distribution of moso bamboo DBH and age. The measurement accuracy of bivariate Weibull distribution function is the highest, but the number of the parameters used is more than that of those used in the bivariate Copula function. Therefore, iterative parameter of bivariate Copula function is easier to be converged. The accuracy of bivariate S_bb function is the lowest. The joint distribution of DBH and age of moso bamboo all obey these three distribution functions. Bivariate Copula function is suitable for arbitrary edge distribution of DBH and age, that is, it does not need to determine the class of marginal distribution function. When there are only marginal distribution values of DBH and age, the joint density value of DBH and age could be obtained using the bivariate Copula function. Thus, the bivariate Copula function has a wider applicability and a higher application value than the commonly used binary distribution function.

Objective: This study was implemented to explore the potential of multi-temporal, multi-spectral, and high-spatial-resolution images in larch plantations identification, and to find a method for rapid identification of larch plantations integrated with multiple classifiers by multi-feature combination scheme, so as to provide a reference for remote sensing monitoring and management of larch plantations and forest resource investigation. Method: In this paper, first of all, the key period and parameters of larch identification were determined from multi-temporal Landsat8 OLI images of Mengjiagang forest farm in Heilongjiang Province by analyzing the seasonal and spectral features of larch. Secondly, the feature information extracted from images was screened through the variable importance metric (VIM) to establish multi-feature data sets of different phenological stages. Finally, a classification method with the multi-classifier ensemble was established by using the advantages of random forest (RF), support vector machine (SVM), maximum likelihood classification (MLC), and back-propagation (BP) neural network, to extract larch plantations. Result: Using the classification of multi-classifier integration, the overall accuracy was 93.8%, and the accuracy of extracted larch plantation area was 96.3%. Compared with RF, MLC, SVM and BP, the overall accuracy was improved by 10% on average. Conclusion: This paper found that compared with single-phase images, multi-temporal data contains more phenological phases of larch, reflecting the unique seasonal characteristics of larch, which is more conducive to the extraction of larch. At the same time, the multi-classifier integration strategy combines the advantages of each classifier, which would effectively improve the overall accuracy and achieve high-precision extraction of larch plantation.

Objective: We conducted a 4-year (2011-2015) litterbag experiment with Cinnamomum camphora and Pinus massoniana litter to explore the dynamics of soil arthropod diversity during the litter decomposition in low mountains and hilly areas of Sichuan, and the changes of the composition and diversity of the soil arthropods community were determined. The objectives of the study are to understand the differences between the short-term and long-term changes of the composition distribution in the soil arthropod community during the long-term litter decomposition, and the changes of soil arthropod diversity during the decomposition of different types of litters. Method: In November 2010, 15 litter collectors were installed in the study site of C. camphora and P. massoniana forests. The fallen leaves of two tree species were collected monthly, and then brought back to the lab for air drying. In October 2011, the air-dried leaves (10±0.05 g) were put into prepared littebags (20 cm×20 cm, the upper and lower apertures were 3 mm and 0.04 mm, respectively). In November 2011, all the litterbags were buried in five (5 m×5 m) plots on the forest floor and the buried litter decomposition bags were retrieved 11 times from December 2011 to October 2015. The soil arthropods were separated and collected by Tullgren funnel, and then counted and classified under anatomical microscope and biological microscope. Result: During the 4-year study period, a total of 4 648 soil arthropods were captured in the litterbags of C. camphora and P. massoniana, belonging to 17 orders and 58 families. The dominant groups of C. camphora were Isotomidae, Onychiuriclae, Liacaridae and Nothridae. The individual density and group number of soil arthropods in the two litter leaves had similar dynamics. The individual density of soil arthropod community in C. camphora reached the highest at 746 d and fell rapidly afterwards, while the that in P. massoniana reached the highest at 398 d. The two communities reached maximum at 746 d, with similar dynamics of group number in the litter decomposing processes. Fungivore arthropods had the highest proportion in the both litters, accounting for 39.48% and 38.78% of the total catch, respectively. The saprophagous arthropods presented the lowest, accounting for 8.02% and 8.05%, respectively. With the decomposition process of litter, phytophagy and predatory arthropods reduced, while the fungivore arthropods increased. Non-metric multidimensional scale (NMDS) results showed a high similarity in the composition of the two soil arthropod communities. Cluster analysis showed that the similarity of soil arthropod community structure diminished with the decomposition process. Conclusion: The soil arthropod community structure is significantly affected by litter types and decomposition phase during litter decomposition in low mountains and hills area. Compared with broadleaf litter, coniferous litter is more dependent on specific groups of soil arthropods. The differences in soil arthropod community composition and diversity in disparate litter types are most obvious in the mid-decomposition phase (2-3 years), indicating the importance of long-term monitoring of soil fauna response to litter decomposition.

Objective: Casuarina equisetifolia is an important shelter forest species in the coastal area of South China. It is necessary to select improved varieties resistant to bacterial wilt. This study aimed study the variation of disease resistance characteristics of different germplasm resources, so as to provide scientific basis for the selection of disease resistant materials. Method: In this study, eight physiological and biochemical traits of saplings from 20 provenances in the five-year-old provenance family experimental forest in Xuwen, Guangdong Province were detected and analyzed. Result: After Casuarina equisetifolia was inoculated with Ralstonia solanacearum, there were significant differences in disease index and relative disease intensity among provenances. The activities of SOD, CAT, POD and PAL, and the contents of soluble sugar, chlorophyll, total phenols and flavonoids showed significant or extremely significant differences among provenances. The variation coefficient of these traits was 17.75%, 27.72%, 64.31%, 38.65%, 25.31%, 16.63%, 44.00% and 29.50%, respectively. The traits means of the largest provenance were 1.61, 2.74, 13.75, 2.46, 2.43, 1.98, 2.93 and 2.59 times of those of the smallest provenance, respectively. The results indicated that the above traits of the tested provenances varied greatly and had strong selection potential. The results of correlation analysis showed that SOD and CAT were significantly positively correlated with total phenols and flavonoids, the correlation coefficients varied from 0.233 to 0.466, whereas they were significantly negatively correlated with POD and chlorophyll. The total phenols were found the highest significantly positively correlated with flavonoids, their correlation coefficient was 0.722. There was a significant or extremely significant positive or negative correlation between physiological and biochemical traits and disease characteristics, indicating that physiological and biochemical traits and disease characteristics might be controlled by the same or similar regulatory mechanisms. Through the comprehensive evaluation of 8 physiological and biochemical traits, six provenances of 18144, 18142, 18135, 18355, 18128 and 18122 were selected from 20 provenances. The average values of SOD, CAT, PAL, soluble sugar, total phenols and flavonoids were 1.35%, 25.32%, 13.19%, 19.69%, 32.52% and 32.24% higher than the overall average value, respectively. Conclusion: The six resistant provenances selected by physiological and biochemical traits can be used as materials for further genetic improvement.

Objective: In this paper, the volume specific heat, radial and tangential thermal conductivity and thermal diffusion coefficient of wood obtained from experimental measurement were used to establish the wood volume specific heat model and wood anisotropic thermal conductivity model based on fuzzy least absolute nonlinear regression method, analyze the law of wood thermophysical parameters, and provide a basis for the study of wood thermal conductivity law. It was expected to provide a theoretical basis and data support for the formulation of wood thermophysical property evaluation standards. Method: The experimental samples were obtained by cutting 130 kinds of common woods. Among them, the experimental samples used to measure the volume specific heat of wood were 18 mm in diameter and 2 mm in thickness; the experimental samples for measuring the thermal conductivity and thermal diffusion coefficient of wood were two rectangular samples of 50 mm×50 mm×20 mm. Firstly, the Hot Disk thermal constants analyser was used to test the thermal physical parameters of the experimental samples, and the volume specific heat, radial heat conduction rate, radial thermal diffusion coefficient, axial thermal diffusivity and axial thermal diffusion coefficient of wood samples were obtained. The experimental data were divided into two parts: training set and validation set. Furthermore, a fuzzy least absolute nonlinear regression method suitable for regression analysis of small sample data sets was proposed, and the wood volume specific heat model and anisotropic heat conduction model of wood were established. Firstly, Gaussian membership function was constructed to blur the data. Then a singleton fuzzier was constructed to generate the fuzzy rule base. The product inference engine was used to carry out fuzzy reasoning on the input space elements, and the reasoning results were obtained. Finally, the least absolute regression criterion was used to optimize the obtained results, and a class of nonlinear wood radial and axial thermal diffusivity and thermal conductivity models were established. The model was used to analyze and predict the thermal diffusion and thermal conductivity processes of anisotropic wood in real time. Result: The results showed that the fitting degree of the fuzzy least absolute nonlinear regression (FLANR) was 0.997 6, and the mean velative error(MRE), maximum relative error(MARE) and mean square error(MSE) were 0.026 0%, 0.049 1% and 0.035 2%, respectively. In comparison, the fitting degree of ANFIS prediction was 0.963 1, and the MRE, MARE and MSE were 0.189 3%, 2.176 2% and 0.799 3%, respectively. For the wood anisotropic heat conduction model, a single comparison one of the output variables (the wood axial heat conduction rate) in the wood anisotropic thermal conductivity model showed that the fitting degree of the predicted results of FLANR was 0.958 1, and the MRE, MARE and MSE were 0.190 2%, 0.348 1% and 0.085 3%, respectively. In comparison, the fitting degree of FLS prediction was 0.604 5, and the MRE, MARE and MSE were 2.169 4%, 5.260 9% and 2.910 6%, respectively. The fitting error of FLANR prediction was obviously less than those of ANFIS and FLS, and the model had a good fitting effect and generalization. Conclusion: It might be feasible to use the fuzzy least absolute nonlinear regression to model the specific heat of wood volume and anisotropic thermal conductivity of wood. The calculation time of this method was short and the generalization was good. The established wood thermal physical property parameter model would provide guidance for the follow-up research on wood thermal conductivity.

Objective: In order to deepen our understanding of the cell wall biosynthesis and mechanical failure of rattan cane (Calamus simplicifolius, an important commercial rattan species in China), cell wall ultrastructure and polysaccharides composition of the middle lamella (cell corner middle lamella, ccml, and compound middle lamella, cml) were investigated, which will provide theoretical instruction for the toughening of rattan cane and manufacture of rattan based composites. Method: The rattan cane sections delignified by acid sodium chlorite was visualized by TEM(transmission electron microscope) and confocal Raman microscopy in order to reveal the ultrastructure and polysaccharides composition in middle lamella areas. Result: TEM images revealed that the fiber and parenchyma wall was divided into middle lamella (ccml and cml), primary wall and alternating broad and narrow layered secondary wall. After partial delignification, fibrillar structures at the ccml of fiber were observed, while the cml was detached from the adjacent secondary wall. The cml area of parenchyma was swelling and distorted. High spatial resolution confocal Raman microscopy was used to visualize the lignin, cellulose, xylan and pectin distribution. The secondary wall and middle lamella of fiber and parenchyma was easily differentiated by integrating over the band regions from 2 789-3 000 cm^-1 (C-H stretching). By integrating over the lignin band at 1 598 cm^-1, it was found that the lignin located at middle lamella areas between fiber and parenchyma was more difficult to be removed relative to that between fibers, while there existed large number of lignin within the secondary wall, probably due to the linkage between lignin and polysaccharides by ether and ester bonds. By integrating over the cellulose, xylan and pectin band at 380 cm^-1, 1 318 cm^-1 and 854 cm^-1, it was found that cellulose and xylan were uniformly distributed within the fiber and parenchyma secondary wall, while pectin mainly accumulated within the middle lamella areas, especially the cml between parenchyma. Conclusion: The ultrastructure and polysaccharides composition of the middle lamella in rattan cane was investigated by combining in TEM and confocal Raman microscopy. Entangled fibrillar structure was visualized in the delignified ccml of fiber, while parenchyma displayed swelling cml and enlarged gap between adjacent cells. Furthermore, Raman images revealed that there was abundant pectin and small amounts of xylan in the middle lamella, while cellulose homogeneously deposited within in the secondary wall.

Objective: In order to explore the feasibility of domestic construction oriented strand board (COSB) used in cross-laminated timber (CLT) production, expand the raw materials source of domestic CLT products, promote the application of COSB in timber structure buildings, and evaluate the influences of configuration and layer number on flexural behavior of CLT, the flexural behavior of hybrid CLT (HCLT) fabricated from COSB and lumber were investigated in this paper. Method: The HCLT panels with different layer number (three and five layers) and five configurations were fabricated from COSB and SPF(spruce-pine-fir) dimension lumber. The bending strength, bending modulus and failure modes of CLT and HCLT specimens in major and minor strength direction were evaluated by four-point bending test. The theoretical values of bending properties were calculated by shear analogy method, and the finite element models were built to analyze the bending performances of HCLT. Result: The main failure modes of test specimens in major strength direction were rolling shear failure of transverse layer of lumber and tensile failure of bottom layer. The tensile failure of specimens in minor strength direction was mainly occurred at the gaps between bottom layers due to no edge-gluing. HCLT had higher bending properties than generic CLT. All the bending strength of HCLT in major strength direction were higher than those of generic CLT (group A1). The bending stiffness of the three- and five-layer HCLT specimen (A3 group) were 10% and 31% higher than those of generic CLT (group A1), which were 76% and 48% for bending strength, respectively. The improvement of bending properties was more significant for specimens in minor strength direction. The bending stiffness of three- and five-layer HCLT specimen (group B4) were 447% and 83% higher than those of generic CLT (group B1), which were 118% and 40% for bending strength, respectively. With the increase of the COSB layer number used in HCLT, the bending properties in minor and two-way strength direction of HCLT were improved, and the difference of bending properties between two directions was reduced. Considering the material economy and mechanical properties comprehensively, the A3 and B3 group, which only using COSB as transverse layer, had better two-way bending properties. With the increase of the layer number, the bending stiffness and strength in minor strength direction of CLT and HCLT increased, however, the bending strength in major strength direction decreased. The shear analogy method could predict well the bending properties of CLT and HCLT in major strength direction. For minor strength direction, due to no edge-gluing between the same lamination and other influencing factors, there were certain relative errors between the theoretical and experimental values. The outer layers could not be neglected for theoretical calculation in minor strength direction for the tested specimens having COSB layers as outer layers. The established finite element models could analyze well the bending behavior of HCLT. Conclusion: Compared with sawn timber, COSB has better mechanical properties in minor strength direction. The application of COSB in CLT, especially used as transverse layer, could improve the rolling shear and bending performances of CLT. There is a good feasibility for the application of COSB in CLT.

Objective: This research aimed to study the effect of late season irrigation on seedling's morphology, physiology and afforestation performance of Populus tomentosa, in order to provide a scientific basis for precision irrigation in hardening period of seedlings. Method: Tissue culture seedlings of P. tomentosa were transplanted in nursery field. Four different soil water potentials (-20 kPa, -40 kPa, -60 kPa, and -80 kPa) were set as the initial irrigation threshold, and the conventional irrigation(the initial irrigation threshold was at less than -80 kPa) served as the control. The seedlings were subjected to the different irrigation treatments at lignification stage to investigate the changes of seedling water consumption, morphology, physiology and afforestation performance. Result: 1) Late season irrigation had a significant effect on the growth of seedling height and root collar diameter(RCD) at hardening phase (p < 0.05). When the initial irrigation threshold were -20 or -40 kPa, the seedling growth was the largest at the lignification stage, and the seedling height increment, RCD increment and biomass were 15.51%, 6.41% and 57.5% higher than those of control, respectively, but the two treatments had no significant difference. 2) The differences in nutrient status had no obvious pattern among different treatments. However, The nutrient mass per plant with -20 and -40 kPa treatments was the largest, followed by that with -60 and -80 kPa treatments, which were significantly increased by 59.4%, 48.6%, 36.1% and 25.3% respectively compared with the control. 3) Treatments of -20 kPa could delay the defoliation time of seedlings for about 5-7 d and increase the accumulation of photosynthetic products by about 12.5% compared with the control. Although late season irrigation could cause partial dry shoots in winter, it had little effect on the overall overwintering of seedlings. 4)After outplanting, seedlings treated with the initial irrigation threshold of -40 kPa had the highest survival rate of 93%, two years later, its tree height and diameter at the breast height (DBH) were significantly higher than the control by 83.2% and 115.1%, respectively. Conclusion: Proper late season irrigation in hardening phase can promote seedling growth, nutrient reserve and significantly improve the seedling growth after outplanting. Although it reduces the cold tolerance slightly, it has little effect on the overall overwintering. By intergrating the seedling growth in the lignification stage and outplanting effect, the initial irrigation threshold of -40 kPa has the best effects when seedling are cultivated in areas with similar conditions to the experimental site.

Objective: This paper aimed to explore the effect of combined application of nitrogen, phosphorus and potassium on the growth and leaf color of Cotinus coggygria, and to solve the problems of poor growth and dim leaves of C. coggygria in autumn and winter. Method: In this study, 4-year-old potted seedlings of C. coggygria were used as experimental materials. Three factor and three-level orthogonal design experiments were carried out with urea (N 0, 7.5, 15 g·plant^-1), calsium superphosphate (P 0, 12.5, 25 g·plant^-1) and potassium sulfate (K 5, 10, 15 g·plant^-1). Plant height (H), ground diameter (D) and leaf area (LA), leaf color parameters, leaf pigments including chlorophyll (Chls), carotenoids (Car), and anthocyanins (Ant), soluble protein content (SP), soluble sugar content (SS), and phenylalanine ammonia-lyase(PAL)activity were measured under the different N, P and K combination conditions, and the relationships between N, P and K and plant growth or leaf color were determined. Result: 1) The reasonable combined application of N, P and K was able to promote the growth of C. coggygria. The increment of plant height in treatment T3(N₁P₃K₃) and T9(N₃P₃K₂) was significantly higher than that of the control (p < 0.05). Except for T5(N₂P₃K₃) and T7(N₃P₁K₃), the growth of ground diameter of other treatments was significantly higher than the control(p < 0.05). Except for T1(N₁P₁K₁), T4(N₂P₁K₂), and T8(N₃P₂K₁), the increment of leaf area in other treatments was significantly higher than that of the control (p < 0.05). 2) Reasonable combined application could also increase the pigment content of C. coggygria leaves. T6(N₂P₃K₁), T7, T8 and T9 treatments could significantly increase the total chlorophyll content in the vigorous growth stage and the mid-discoloration stage. T5, T7, T8 and T9 significantly increased carotenoids content in the vigorous growth stage. T3, T4, T5, and T6 significantly increased anthocyanins content at the terminal discoloration stage. 3) The results of the redundancy analysis showed that N and K were the main nutritional factors affecting height, leaf area, chlorophyll and carotenoids, while P was the main nutritional factor affecting ground diameter and anthocyanins. Anthocyanins was a key factor for red color of C. coggygria leaves, which was positively correlated with phenylalanine ammonia-lyase activity and negatively correlated with soluble protein and soluble sugar. Conclusion: The response of plant growth and leaf color to different ratio of N, P and K application is different. Within the scope of this experiment, T3 (N, P and K applying amounts of 0, 25, 15 g·plant^-1, respectively) and T9(N, P and K applying amounts of 15, 25, 10 g·plant^-1, respectively) promote both growth and leaf color. But in the long run, N deficiency would affect the growth of C. coggygria and affect the color quality of leaf, finally. Therefore, T9 treatment can maintain growth and color quality of leaf, and enhance the ornamental value.

Objective: This study aimed to explore the relationship between the degradation of tree potential of Rhododendron moulmainense and the physical and chemical properties as well as the microbial community structure in the rhizosphere soil in Wutong Mountain of Shenzhen by analyzing the physical and chemical properties and microbial community diversity of the rhizosphere soil. Method: The water content, pH value, organic carbon, total nitrogen, and mineral nitrogen of rhizosphere soil of R. moulmainense trees with different tree potential in Wutong Mountain were analyzed. Additionally, the DNA of rhizosphere soil was extracted, and was used to investigate microbial diversity and community structure using high-throughput sequencing technology. Result: The result showed that there was no significant difference in physicochemical properties of rhizosphere soil among the three tree potentials. A total of 681 807 effective bacterial sequences were detected in rhizosphere soil of three tree rhizosphere, with an average of 79 898 effective bacterial sequences per sample, of which 2 008 OTUs were obtained, belonging to 438 species and 27 phyla. The dominant bacteria were Acideobacteria (36.3%-47.2%), Proteobacteria (31.2%-32.0%), and Chloroflexi (3.0%-7.7%). A total of 710 302 effective fungal reads were detected, with an average of 79 862 effective reads per sample, which concluded 1 129 OUT clusters, belonging to 489 species and 10 phyla. The dominant fungi were Basidiomycota (49.3%-59.3%), Ascomycota (32.0%-40.8%), Mortierellomycota (1.7%-4.6%). The result of alpha diversity analysis showed that there was no significant pattern in the richness and diversity of rhizosphere soil fungal community among different tree potentials, but the richness and diversity of bacterial community gradually increase with the decline of tree potential, and the greater the difference of tree potential, the more significant the difference of community richness index (Ace, Chao1, PD_whole_tree) (P < 0.05). Beta diversity analysis showed that there was no correlation between bacteria and tree growth. However, fungi were correlated with tree growth. LEfSe analysis showed that there were significant differences in fungal taxa between dominant Rhododendron rhizosphere soil (AR) and inferior Rhododendron rhizosphere soil (DR). The differential microorganisms were mainly Archaeorhizormyces, Phaeosphaeriaceae, Helotiales, Arthrobotrys, Pseudaleuria, and Pyronemataceae. The Helotiales belongs to the root fungus of the azalea plant. Conclusion: There is no difference in soil physicochemical properties among R. moulmainense trees with different growth potentials, indicating that the variation of soil physicochemical properties may not be big enough to affect R. moulmainense, growth potential. The differences in the structure of soil microbial communities are correlated with R. moulmainense, growth potential.