[Objective] Evergreen-deciduous broadleaved mixed forest is one of the main vegetation types in northern parts or high elevations of subtropical regions of China. It is characterized as transitional features from evergreen to deciduous broad-leaved forests. Due to long term and repeated anthropogenic disturbances, these forests were subjected to different extents of degradation. Until now, very few studies have been carried out on mechanisms of restoration of the degraded forests. In this study, by comparing the roles of environmental and spatial factors in restoration and rehabilitation of communities, patterns of variation in community structure and species diversity during the natural restoration in subtropical regions can therefore be analyzed, laying a foundation for deepening our understanding of the mechanisms of natural restoration of this type of forest.[Method] 10 sample plots (20 m×20 m in size) were selected at random and configured as fixed plots for monitoring forest dynamics, respectively in old-growth forest, 35-year-old secondary forest (harvested in 1980) and 20-year-old secondary forest (harvested in 1995) in the Mulinzi National Nature Reserve in Enshi of Hubei Province. For forest communities at different stages of restoration, abundance of woody plants, basal area at breast height, species richness, and richness of rare species (100 individual trees as baseline) were compared. One-way ANOVA and Turkey-HSD were conducted to assess the differences in stem density, basal area, species richness, and rare species richness among the three succession stages. The redundancy analysis (RDA) and non-metric multidimensional scaling (NMS) ordinations were used to differentiate the plots. The environmental and spatial factors (PCNM variables) were treated as explanatory variables to partition the variations at each succession stage. The relative effects of environmental factors and restoration period after disturbance on the four community characteristics were analyzed by performing multivariable regression analysis.[Result] During the process of community restoration, the abundance of woody plants, species richness and rare species richness had a significant decrease, while basal area had a significant increase. Species composition were significantly different among different restoration forests (Adonis, P<0.05). However, all the soil factors did not show any significant differences. Environmental factors showed a greater influence than the spatial configurations. Environmental factors explained 31.4%, 36.8%, 54.1% of species composition variations of 20-year-old, 35-year-old secondary forest and old-growth forest, respectively. Spatial configuration explained 16.8% and 23.2% composition variations for the 35-year-old secondary and old growth forests respectively, while no significant influence on the 20-year-old secondary forest were found. The spatial auto-regression showed that soil pH, litter thickness, elevation, slope gradient, slope orientation and the restoration time played an important role in the restoration of community structure and species diversity.[Conclusion] The community structure, species diversity and environmental features of the subtropical evergreen-deciduous broadleaved mixed forest varied significantly during the secondary succession process after anthropogenic disturbances. Environment, space, and time were the key factors determining community composition and dynamics. The stochastic process (such as dispersal process or prior effect) exerted the greatest influence on community assembly at the early stages of forest restoration, meanwhile, the deterministic process represented by environmental filtering played a dominant role in community assembly of old-growth forest. The differences in species composition between secondary and old-growth forests declined gradually with the progress of secondary succession.

[Objective] The water and soil conservation measures should be water-saving and high-efficiency for controlling soil erosion but without threatening the security of water supply in the dry Loess Plateau of Northwestern China. The effects of different water and soil conservation measures on annual runoff and sediment yield should be separated and evaluated, for guiding the integrated management of watersheds.[Method] The typical small watershed of Zhifanggou, located at the Pingliang City of Gansu Province, was selected for this study. The long-term monitoring data of runoff and sediment yield within the period of 1955-2003 were used. The multiple linear relations among the annual runoff ratio, sediment yield module and the land use area ratios were fitted through regression analysis. These relations were used to separate and evaluate the effects of different conservation measures on annual runoff and sediment yield of the small watershed.[Result] The annual precipitation showed a non-significant decreasing trend within the period of 1955-2003, while the annual runoff and sediment yield module showed a significant decreasing trend. The runoff generation capacity of the small watershed was increased after vegetation destruction, but greatly decreased after vegetation restoration. The runoff interception capacity of the small watershed was increased after the implementation of engineering measures, such as the terrace and check dams, but this effect had been declined and even disappeared with the aging of these engineering measures, caused by the silt-up of check dams and the degradation of terrace fields. The ability of unit depth of annual runoff in soil erosion and sediment yield was reduced a lot with increase of forest and greassland, but not obviously decreased with the implementation of engineering measures. The multiple and linear relation between the annual runoff, annual precipitation and the area ratio of each land use category, and the relation among the sediment yield module and the annual runoff and the area ratio of each land use category were fitted. The coefficients in these relations indicated that the 2 land use categories of forestland, terrace and dam fields will decrease the annual runoff, and the decreasing intensity of forestland was 1.48 times of that of terrace and dam fields. The runoff was mainly generated from the 2 land use categories of grassland, slope farmland and others. The runoff ratio from grassland was 1.8 times of that from slope farmland and others. The forestland and grassland showed a function of reducing the sediment yield, in which the reducing intensity of forestland was 2.5 time of that of grassland; The sediment was mainly from the 2 land use categories of terrace and dam fields, slope farmland and others, in which the contribution to sediment yield from terrace and dam fields was doubled high as that from slope farmland and others. If the slope farmland and others is converted to forestland, grassland, terrace and dam field in an intensity of 10% of the total area of watershed, the annual runoff will be changed by -9.6,+4.2, -8.1 mm, and the sediment yield module will be changed by -6 367.0, -25 32.4,+300.5 t·km^-2a^-1, respectively.[Conclusion] The functional period of vegetation measures (afforestation, grassland restoration) for soil erosion control is expected to be longer than that of engineering measures (terrace and check dams). The forestland can well reduce the sediment yield module, but consumes much more water. The grassland has lower sediment yield reduction and water use efficiency compared with forestland, but it can maintain or even increase the water yielding ability of watershed. The terrace and dam fields have also an effect of reducing runoff, which is just slightly lower than that of forestland. However, their sediment interception ability will gradually lower or even disappear with the aging of engineering measures; moreover, their water use efficiency for reducing sediment is the lowest one. In summary, to meet the requirements of water-saving and high-efficiency in soil erosion control in the dryland regions, the dominant measures should be grassland restoration. In this way, we can get a long-lasting service of sediment reduction and erosion control, an unreduced or even enhanced water yield, and higher eco-water use efficiency in erosion control.

[Objective] In higher plants, sugars function as the main energy reserves, important signaling molecules, osmotic adjustment substances and the building blocks for other organic compounds, playing important roles during the entire life cycle. As sucrose transporters(SUTs) in plant, SUTs participate in sucrose loading from source tissues to phloem, transporting in phloem, and unloading from phloem to sink tissues. Therefore, SUTs are important in plant growth and development. There are big differences in sink tissues between woody plants and annual herbs and the carbon allocation mechanism in woody plants needs further investigation. In the present study, to further investigate the roles of PagSUT4 (GenBank No. KX545405) in sugar transportation, photosynthesis, and secondary growth, we generated PagSUT4 overexpression Populus lines and analyzed their phenotypes.[Method] The coding sequence of PagSUT4 was cloned using gene-specific primers from hybrid poplar clone 84K (Populus alba×P.glandulosa). The PagSUT4 expressions in roots, young leaves, mature leaves, primary stem, secondary stem, male flowers, female flowers, xylem and phloem were examined using qRT-PCR. To analyze the subcellular localization of PagSUT4, the gene was transiently expressed in tobacco leaf epidermal cells fused with YFP to its C-terminus. The coding sequence was cloned into PMDC32 to produce the 35S:PagSUT4 construct, and the latter was transformed into poplar 84K mediated by Agrobacterium tumefaciens and the transgenic lines with high expression of PagSUT4 were selected for further phenotypic analysis. The stem length, ground diameter, photosynthetic rate, intercellular CO₂ concentration, conductance to H₂O and transpiration rate of 2-month-old transgenic lines and non-transgenic controls in the greenhouse were measured. Moreover, the anatomy of stem sections of the 7^th internodes from them was performed.[Result] The results showed that PagSUT4 gene encoding a tonoplast-localized sucrose transporter. The PagSUT4 gene were ubiquitously expressed and showed high expression level in mature leaves, lignified stem, phloem and flowers. 13 transgenic lines with overexpression of PagSUT4 were obtained and the level of expression in leaves was significantly higher than that in the control. Stomatal conductance, transpiration rate and water use efficiency of the selected transgenic lines (S1 and S12) were higher than that of the non-transgenic controls, while the intercellular CO₂ concentration was lower in transgenic lines than that of the controls. The 2 transgenic lines exhibited 24% and 21% higher photosynthetic rate compared with the non-transgenic controls, respectively. The transgenic lines showed 22% and 17% increase in stem height, 9% and 7% increase in ground diameter, respectively. In addition, the two transgenic lines showed 32% and 21% increase in the xylem width of the seventh internodes, respectively.[Conclusion] Overall, PagSUT4 functions in mature leaves, secondary stem, phloem and flowers. Overexpression of PagSUT4 may promote the sucrose efflux from the leaves, the sucrose transport and unloading in the stem, have positive feedback effect on the photosynthesis through the enhancement of sucrose loading in source tissues and the unloading in sink tissues. The enhanced photosynthesis and increased sucrose unloading efficiency in the stem have promoted both height and diameter growth (development of secondary xylem) of the transgenic poplar trees.

[Objective] Real-time quantitative PCR (RT-qPCR) has become the preferred approach to the quantification of gene expression. Besides its simplicity and efficiency, this method requires suitable reference genes to guarantee the accuracy of the quantification. Betula luminifera is not only a high-quality timber species with excellent wood properties, but also an ideal species for genetic study. Stability of candidate reference genes in different tissues was investigated using RT-qPCR and expression analysis software to select suitable reference genes, the reliability of the reference genes was further verified through expression analysis of two functional genes in different tissues.[Method] 16 housekeeping genes were chosen as candidate reference genes, and specificity of the primers was investigated by agarose gel electrophoresis and melting curve of target amplified fragments. The software of geNorm, NormFinder and BestKeeper were used to analyze expression stability of reference genes in 16 different tissues. Furthermore, two functional genes were selected to verify the reliability of the suitable reference genes.[Result] Electrophoresis results showed distinct PCR products with the expected size, and the single-peak melting curves further indicated the specificity of the selected primers. Except 18S, the Ct values of the candidate genes were all between 25 to 30, indicating the expressions of these candidate genes were quite stable in different tissues. EF1α was characterized as the most stable gene based on NormFinder and BestKeeper analysis, while TATA was ranked in the first place according to geNorm. UBi-lp showed the most unstable expression. Furthermore, three top-stable genes (EF1α, TATA and UBi4) and the unstable gene UBi-lp were chosen to verify the reliability of the reference genes. As results, the two target genes showed consistent expression profiles when normalized by the three top-ranked reference genes, and UBi-lp failed to standardize the expression data.[Conclusion] EF1α, TATA and UBi4 were most stable reference genes in different tissues, the reliability of these reference genes were further confirmed by expression analysis of the target genes. Therefore, EF1α, TATA and UBi4 could serve as reference genes for gene expression among different tissues in B. luminifera.

[Objective] In order to develop genetically improved liaoning poplar (Populus×liaoningensis), the process of flowering and pollen germination were observed and analyzed.[Method] The process of flowering, pollen germination in vitro and the effect of different storage methods on pollen germination and growth of pollen tubes were investigated through water culture, pollen germination in vitro and pllen storing by means of drawing model pattern and graphic interpretation to systematically study the development of staminate catkin and pollen dispersal, and pollen germination in vitro, and to explore the impacts of different storage conditions on pollen germination and growth of pollen tubes.[Result] 1) Four stages such as bud time, extension period and so on belong to the course of the flowering. It will spent 12 days. After the anthers mature, it was easy to be dispersed for the pollen with slightly vibrate. 2) The optimal culture medium for germination was 210 g·L^-1 sucrose+30 mg·L^-1 H₃BO₃+10 mg·L^-1 CaCl₂, the rate of germination was up to 58.57%. Effects of temperature, sucrose, H₃BO₃ and CaCl₂ were remarkable in orthogonal design experiment(P≤0.05). The best culture medium for growth of pollen tubes was 150 g·L^-1 sucrose+40 mg·L^-1 H₃BO₃+10 mg·L^-1CaCl₂, the average length of tubes was 753.20 μm in seventh group. 3) The pollen tubes have no longer extended after 7 h culture in dark. 4) The germination rate was higher than any other temperatures(4℃ and room temperature) cultivating under the temperature of -20℃ and it's similar to the pollen tubes. When we laid aside the pollen in a constant temperature, as the time went on, the germination got lower and the length of the pollen tubes got shorter.[Conclusion] The pollen should be collected in the third stage to avoid the pollen loss. The relationship between pollen tubes and germination rates was no significant by statistic analysis. Pollen stored in a lower temperature had a higher viability, meanwhile, it took a shorter time for pollen tubes to reach to a same length. Compared with the fresh pollen, if the stored pollen was used to cross experiment, the times of the suitable pollination should be increased and the interval between the two fertilization should be extended.

[Objective] Studies were conducted to use biotechnology for multiplication of selected superior Cryptomeria clones, in order to provide theoretical and technical basis for multiplication of superior Cryptomeria clones and preservation of the genetic materials of Cryptomeria clones.[Method] Young shoots of different Cryptomeria clones were taken as explants were sterilized and treated with different hormones with different concentrations in different growing media, and an orthogonal design L₉(3⁴) was used to analyze their interaction. Bud multiplication of six Cryptomeria clones and rooting ability of three clones were compared to analyze differences among clones.[Result] The results showed that all the six clones formed multiple shoots and there were great differences in bud multiplication among different clones. The multiplication coefficient of clone ‘Jing 1’ reached 5.00 on average. Besides, clones ‘011’, ‘3’, and ‘7’ also displayed superiority. On the other hand, the multiplication coefficients of clone ‘59’ and ‘68’ were 3.10 and 3.28 respectively, indicating poor bud multiplication and growth. The results showed that the interaction between 6-BA and NAA and 6-BA alone had a great influence on the multiplication coefficients of the clone ‘Jing 1’. However, the influence of NAA was not significant within a certain range of concentration. Significant influences on bud multiplication coefficient were found between 6-BA, NAA and their interaction in other 5 clones ‘011’, ‘3’, ‘59’, ‘70’ and ‘68’. There were differences among hormone types which play a leading role in bud multiplication of different clones. The main factor in the multiplication of clone ‘011’ ‘Jing 1’, ‘3’ and ‘70’ was 6-BA while the main factor in the multiplication of clone ‘59’ and ‘68’ was NAA. Three clones that produced adventitious roots displayed significant difference in rooting rate among clones, among the three clones, the clone ‘011’ showed the highest levels in rooting rate, number of average roots, the ability of forming adventitious roots, and the length of most roots of the clone extended from 2 to 3 cm. The rooting rate of clone ‘70’ took the second place with the length of roots extending from 2.5 to 3.5 cm. In contrast, clone ‘3’ had root length more than 4 cm but the lower rooting rate (75.6%).[Conclusion] By analyzing differences in bud multiplication and root induction among Cryptomeria clones, it indicated that the capacity of bud multiplication and rooting ability were genetically controlled. The regeneration capacity through tissue culture of different Cryptomeria clones requires specific types of culture media, and hormones and their respective proportions.

[Objective] This study was to investigate the effect of day length, temperature and water on the growth of terminal buds, and to ascertain the cause and mechanism of terminal bud death.[Method] The terminal bud growth and survival of the Paulownia spp. under artificial control by day length, day length and nutrition, day length and temperature and humidity was studied.[Result] Effects of photoperiod was able to seedling height was very significant. Appropriate photoperiod can promote seedlings high growth and extend growth period. The high growth stopping time was in turn 8 h (2011-08-27), 12 h (2011-09-03), 16 h (2011-09-03), 14 h (2011-09-10), 24 h(2011-09-24).24 h photoperiod had the longest growth period and terminal bud germination rateof cutting branches by 24 h treatment was supreme in hydroponic environment.The day length and nutrition had interaction effect on growth of terminal buds.Effect of nutrient on seedling height was very significant in 12 h and 24 h photoperiod. Effects of 12 h photoperiod and fertilization on the high growth was P >PK >K >N; The P or K fertilizer was able to promote seedlings diameter growth in 12 h; Single P or K fertilizer had small terminal bud germination rate of cutting branches in hydroponic environment after 12 h treatment. But terminal bud germination ratio of PK fertilizer was supreme in hydroponic culture of cutting branches. Under 12 h photoperiod with different fertilizer proportion,the seedling height growth mostly stopped on 3 September,2011, which was basically the same as 12 h photoperiod. The height growth with single application of P fertilizer and the treatment 6(N:P:K=2.5:2.5:2.5) stopped on September 10,and the height growth stopping delayed for a week.Under 24 h photoperiod with fertilization, K fertilizer could promote the high growth; CK and K fertilizer had relatively high terminal bud germination rate in hydroponic culture of cutting branches, K fertilizer in 24 h photoperiod played an important role on seedling growth in Paulownia. Under 24 h photoperiod with different fertilizer proportion,the seedling height growth 24 September,2011, which weas basically the same as 24 h.Before the height growth stopped in Autumn, the terminal bud of Paulownia spp. didn't die and continued growing in glasshouse (temperature above 18℃,24 h day length).[Conclusion] Different day length control and day length and nutrient control couldn't assure the terminal buds survival, but the artificial regulation of above 18℃and with a 24 h continuing light could achieve continuous growth of Paulownia spp.

[Objective] This study was to ascertain the impact of spatial structure on damaging degree of a natural secondary Japanese Red Pine forest in Kunyushan caused by pine needle blight, and provide academic direction for ecological control of forest pest.[Method] A six-hectares plot was set out in Kunyushan natural secondary Japanese Red Pine forest, three indexes, including mingling degree, neighborhood comparison and uniform angle, were selected and measured. The relationship between spatial structure and damaging degree of pine needle blight was analyzed. The disease incidence of host plants was used as damaging degree caused by pine needle blight based on a preliminary survey. To investigate the disease incidence, twelve twigs were pruned off randomly from four different directions (east, west, south and north) in the upper, middle and lower crown of each sample tree. Scab on needles of twigs caused by pine needle blight was observed. Disease incidence was calculated as the following formula, disease incidence (%)=length of scab/total length of needles×100%.[Result] 1) For pine needle blight on P. densiflora, all spatial structure indexes were negatively correlated with damaging degree, among which the two neighborhood comparison indexes of diameter at breast height (R²=0.962,P=0.003) and tree height (R²=0.794,P=0.043) were significantly correlate with damaging degree, and no significant relationship was found between damaging degree and Uniform angle index or mingling degree index. 2) For pine needle blight on P. thunbergii Parl, there was a negative linear relationship between damaging degree and mingling degree index (or diameter at breast height of neighbourhood comparison index), and the other spatial structure indexes were positively related with damaging degree, but all the relationship were not significant. 3) For pine needle blight on P. resinosa Ait, all spatial structure indexes were negative related with damaging degree, among which only the mingling degree index was significantly related. 4) In terms of host species, correlation between spatial structure with P. densiflora or P. resinosa was stronger than that with P. thunbergii. In terms of spatial structure, mingling degree and neighbourhood comparison were found stronger than uniform angle.[Conclusion] Among the spatial structure indexes, mingling degree and neighbourhood comparison were proved superior to uniform angle for regulating Kunyushan Web-spinning Sawfly ecologically. The relationship between spatial structure and damaging degree can be utilized, and to adapt ecological methods of rational planting and selective cutting for controlling pine needle blight damage during the course of forest management. For P. densiflora, mingling degree should be controlled beyond 0.5 to decrease damage; for P. thunbergii it should be controlled on a tolerable level; and for P. resinosa, mingling degree of middle level should be avoided. On the other hand, to take account of the difference of disease resistance among the above host plants, in order to strengthen resistance ability to pine needle blight of the ecosystem, a higher proportion of P. thunbergii and less P. resinosa should be planted for stand improvement.

[Objective] This study aimed at detecting the protein expression differences and the protein base of defense reaction in Chinese pine (Pinus tabulaeformis) induced by leaf-cutting and different number pine caterpillar(Dendrolimus tabulaeformis) feeding stimulation in the natural environment.[Method] 15-year-old Chinese pines with the similar growth potential were selected as the research object. The sample trees were treated with feeding stimulation by 10 or 30 pine caterpillars laid on the branch or with leaf-cutting, and the untreated trees served as the control in a Pinus tabulaeformis-Ameniaca sibirica mixed forest in Pingquan County, Hebei Province. The protein expression differences of the Chinese pine were studied by dimensional electrophoresis method.[Result] Through the calculation of protein point expression, compared with control, after feeding with 10 pine caterpillars the up-regulated protein spots were 9, down-regulated protein spots were 4, new increased protein spots were 20, and disappeared protein spots were 18. After feeding with 30 pine caterpillars the up-regulated protein spots were 5, down-regulated protein spots were 31, new increased protein spots were 23, and disappeared protein spots were 13. After leaf-cutting stimulation the up-regulated protein spots were 8, down-regulated protein spots were 9, new increased protein spots were 25, and disappeared protein spots were 17. Differential expression proteins were further identified by mass spectrometry. The database retrieval results showed that new increased proteins in the insect feeding trees were chloroplast ATP synthase CF0 β subunit, ascorbate peroxidase (APX), thiazole biosynthetic enzyme, Lhcb5 protein, ATP synthase β subunit and glutathione S-transferase, and down-regulated proteins were proteasome subunit and hypothesis protein CL304Contig1_01. In the trees simulated by leaf-cutting, new increased proteins were glutathione S-transferase and rubisco activase, down-regulated proteins were phosphoglycerate kinase Ⅰ and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) large subunit. Further analysis showed that the proteins involved in photosynthesis were the most, but the stress and defense related proteins were not expressed in the control tree. The stress and defense related proteins were highly expressed in the trees by insect feeding, and after feeding with 30 pine caterpillars, the proteins associated with synthesis were also expressed. After leaf-cutting stimulation, the stress and defense related proteins were also expressed, and the down-regulated proteins were related to energy-metabolism.[Conclusion] The results indicated tha t feeding and leaf-cutting stimulation could induce the stress and defense related proteins expressed, enhance photosynthesis, synthetic protein, reduce energy-metabolism protein in the Chinese pine. These changes are the protein base of defense reaction induced by pine caterpillar.

[Objective] In this study, we conducted a systematic investigation and analysis on Graphium spp. (Microascales:Graphiaceae) associated with Ips subelongatus Motschulsky (Coleoptera:Scolytidae) in three allopatric larches in northeast China. The study aimed at providing theoretical basis for controling the composite damages by I. subelongatus from the viewpoint of associated fungus pathogens.[Method] In this study, the associated fungi were separated and purified from the body of I. subelongatus and the gallery tissue from allopatric larches:Larix olgensis and L. principis-rupprechtii. Colonies and morphology characteristics were observed, and DNA sequence comparisons for rRNA-ITS and TEF-1α gene regions were conducted.[Result] Result indicated that two species Graphium laricis K. Jacobs, T. Kirisits & M.J. Wingf. and G. carbonarium Paciura, Z.W. de Beer, X.D.Zhou & M.J. Wingf., were stably associated with I. subelongatus. Moreover, G. laricis is a new record species in China. G. laricis and G. carbonarium were first isolated from I. subelongatus, and formed a new association with I. subelongatus. This finding not only enriched the number of strains, but also expanded the distribution range of G. laricis. Meanwhile, this study increased the number of species of Graphium which were isolated in China. G. carbonarium, which was only found from Pissodes sp. (Coleoptera:Curculionidae) in China, now was also isolated from I. subelongatus in this study. The result in this paper added the host species and extended the distribution of host as well. Moreover, the multi-gene sequences characteristic indicates that G. carbonarium, isolated from different hosts of Pissodes sp. and I. subelongatus, could have subspecies differentiation.[Conclusion] Multiple gene sequence characteristics showed that the associated fungi from host plants and bark beetles were two different ecological niches, suggesting that there would be exist differentiation phenomenon in G. carbonarium. The associations between Ips beetles and Graphium fungi exhibited an ideal insight into completely understanding the symbiotic relationship between I. subelongatus and Graphium fungi, and synergistic effect about harming hosts as well.

[Objective] Fuel flammability evaluation is one of the most important topics in forest fire research. Different evaluation methods arise due to varied definitions of flammability. One-dimensional methods are commonly used at present. Importance of multidimensional evaluation based on multi-aspects of flammability has already been recognized by researchers but concrete work is not reported. It is not clear whether the two methods are similarity. This study is to identify the differences between one dimensional and three-dimensional method for a better understanding of fuel flammability.[Method] Leaves or needles of seven typical tree species in southern China were used for cone calorimeter analysis. Parameters such as heat release rate and total heat release were obtained. Flammability of the fuels was evaluated for one-dimensional flammability using a principal component ranking method which is commonly used in literatures, and for three-dimensional flammability using heat release parameter recommended by a literature. Spatial distances between the flammability manners were computed for each evaluation methods. The seven species were ranked according to the distances between the two methods. Ranking analysis was conducted on the rankings between the two methods to determine similarity of one-dimensional method and three-dimensional method.[Result] Among the 21 ranking pairs in comparison of two methods for each of the seven species, only two pairs were same in ranking and three with difference of one in ranking, and the rest pairs has large differences in ranking. The ranking correlation coefficients was 0.078, suggesting that the one dimensional method and three-dimensional method would be different and not explicitly connected. Among the ranking analysis of one dimensional ranking and rankings in each of the three dimensions, one dimensional ranking is only remarkably correlated with sustainability but not with ignitibility and combustibility. This indicates that one dimensional method reflects more on sustainability for the seven species.[Conclusion] For the seven species concerned, one dimensional flammability evaluation is significantly different from the three dimensional one, in term of either individual species or all the seven species. Three-dimensional flammability evaluation can reflect more aspects of complicated flammability and providing more information, aiding better understanding fuel flammability and explaining fire behavior while one-dimensional evaluation methods are easy to use. Further work should be conducted to determine better use of the two evaluation of methods.

[Objective] This study was designed to investigate the changes of viscoelastic properties of Chinese fir during moisture adsorption process, to clarify the effects of moisture on frequency-dependency viscoelastic properties, and to supplement the coupling effects of moisture and mechanical force on wood viscoelasticity.[Method] Dynamic mechanical analysis (DMA Q800) was used to determine the changes of storage modulus and loss factor of Chinese fir samples with a moisture content of 0.6%. The temperature was 30℃, and the relative humidity (RH) was selected as 30%, 60% and 90%. The differences of viscoelastic properties among frequencies (1-50 Hz) were compared. The adsorption process in this study was divided into RH_ramp period and RH_isohume period. During the RH_ramp period, the RH increased from 0% to 30%, 60% or 90%, respectively with a ramping rate of 2%·min^-1. During the RH_isohume period, RH kept constant at 30%, 60% or 90% for 240 min.[Result] Regardless of frequency, storage modulus decreased and loss factor increased with the increasing moisture adsorption time, respectively. Changes of storage modulus were significantly less than those of loss factor. Both the changes of storage modulus and loss factor per unit change of moisture content decreased with the increasing moisture adsorption time. Furthermore, in any time point during the moisture adsorption process, higher value of storage modulus was found at higher frequency. As frequency increased, loss factor decreased at the beginning and then increased. The character frequency according to the minimum value of loss factor occurred from 10 to 30 Hz, and shifted to higher frequency with the prolonged adsorption time. The ratio of storage modulus tested at 1 and 20 Hz was about 0.98, and no remarkable changes were found during the adsorption process. The differences of loss factor at 1 and 20 Hz increased at the beginning and then decreased, achieving its maximum value at the end of RH_ramp period.[Conclusion] During the adsorption process, the plasticize effect of water molecular was the major reason for decreasing storage modulus and increasing loss factor. The plasticization effect of the monomolecular water layer was greater than that of each additional polymolecular water layers. The mechanosorptive effect led more significant changes of dynamic viscoelastic properties during RH_ramp period than RH_isohume period. The character frequency according to the minimum value of loss factor was shifted to higher frequency with the increase of moisture content, which meant the faster movements of polymer molecular and less relaxation time with more moisture content. The transition of the α-relaxation process (attributed to the glass transition of hemicellulose) and the β-relaxation process (assigned to the reorientation of the methylol groups in amorphous wood cell walls and the reorientation of adsorbed water molecules) moved to a higher frequency with the increasing moisture content. The changes of moisture content caused the unstable state of wood cell wall, and aggravated by the change of RH.

[Objective] To explore the principle and methods for dynamic measurement of lumbers Poisson's ratio,the theoretical basis for the dynamic test of Poisson's ratio was given, and a simple and practical method to test the Poisson's ratio of wood was provided.[Method] In this paper, the principle and method of the dynamic measuring Poisson's ratio of wood were described by two aspects:the stress-strain physical relationship (Hooke's law) and the stress and strain analysis of the first-order cantilever bending mode. Five kinds of sawn timber including balsa (Ochroma lagopus), spruce (Picea asperata), scots pine (Pinus sylvestris), ash (Fraxinus chinensis) and beech (Fagus sylvatica). were selected. Cantilever boards were cut with aspect ratio of 6, 5, 4, 3 in tangential section, radial section and cross section. Then the ANSYS shell63 unit was applied to calculate the strain and stress under the first-order bending mode. Strain rosette paste position for dynamic measuring the Poisson's ratio of wood was determined by analysis of the stress-strain relationships. Finally, static tests were conducted to verify the correction of dynamic Poisson's ratio tests.[Result] When the cantilever board suffered first-order bending vibration, the ratio of the transverse strain ε_y and longitudinal strain ε_x was increased with the increasing distance between the loading point and the cantilever end. The ratio of the transverse stress σ_y and longitudinal stress σ_w was small in the whole board, and decreased from a positive value to negative value with the increase of the distance to the cantilever end. In the position of σ_y equal to zero, the absolute value of the ratio of transverse strain and longitudinal strain was not only equal to Poisson's ratio μ_LT, μ_LR and μ_RT was also equal to the ANSYS input Poisson's ratio. Therefore, the strain rosette paste position for dynamic testing the Poisson's ratio of wood could be determined.[Conclusion] The strain rosette paste position for dynamic testing the Poisson's ratio, and of wood was depended on the position where the transverse stress was equal to the zero. As for the cantilever board with tangential section, the strain rosette paste position was related to the density and the width-and-length ratio of board. With regard to the cantilever board with radial section and cross section, the strain rosette paste position was only depended on the length-and-width ratio of board. The lateral and longitudinal strain spectrum was measured by transient excitation, and the dynamic Poisson's ratio was determined by the ratio of transverse and longitudinal strain's linear spectral amplitude of the first-order bending frequency. The ratio of the transverse stress and longitudinal stress in the cantilever board were very small, the maximum ratio for beech was 0.043, and the maximum ratio for balsa wood, spruce, Scots pine and ash wood were all about 0.02. Therefore, the stress distribution in cantilever boards was different from the isotropic material such as low carbon steel and aluminum. However, due to the greatly different in wood orthotropic elastic modulus, the ratio of transverse stress σ_y and longitudinal stress σ_x should not be ignored when dynamic testing the Poisson's ratio of wood. The correction of the dynamic method was verified by the static axial tension test and four point bending test. Furthermore, the dispersion of the wood Poisson's ratio was improved by dynamic measurement compared with the static test.

[Objective] Strain Irpex lacteus CB1(Il-CB1)was identified firstly and its decoloring conditions to congo red was systematically studied so as to prove its application potentials in dye decolorization.[Method] On the basis of morphological identification, the ITS sequence of Il-CB1 was cloned and its phylogenetic analysis was made. The effects of pH value, congo red concentration, and adding time of dye on decoloring congo red by Il-CB1 were tested through single factor experiments, and the effects of other five factors including carbon concentration, nitrogen concentration, Cu²⁺ and Mn²⁺ concentration and inoculum volume on decolorization of Il-CB1 were studied through orthogonal experiment.[Result] The ITS sequence of Il-CB1 and other 24 ITS sequences from different I. lacteus strains clustered together, indicating that Il-CB1 was I. lacteus. The effect of pH value on congo red decolorization showed that decolorization percent increased first and then decreased with the increase of pH value. The decolorization percent both was very low under pH 3 and 8, the optimum pH value was 6.0. Decolorization percents under different congo red concentrations increased first and then decreased with the increase of congo red concentration. Decolorization percent under 100 mg·L^-1 congo red was the highest, and it decreased significantly under 250 mg·L^-1 congo red, indicating that lower congo red concentrations promoted decolorization, while higher congo red concentration inhibited decolorization. Orthogonal experiment showed that the most optimal culture parameters to decolorization were:glucose 10 g·L^-1, peptone 3 g·L^-1, Cu²⁺ and Mn²⁺ both 0.2 mmol·L^-1, 7 mL inoculum volume of mycelium liquor in 100 mL culture solution bottled in 250 mL flask. Decolorization percent was 99.60% on 5 d under above-mentioned conditions. Decolorization at different adding time of congo red was tested based on all above optimal culture conditions.The initial decolorization percent remained at a high level and it was up to 99.99% on 5 d when congo red was added 3 d after Il-CB1 was cultured.[Conclusion] Il-CB1 was identified as Irpex lacteus, it could degrade congo red effectively and might have extensively application potentials in degradation of dye wastewater.

[Objective] The sympodial bamboos is an important potential energy source,, and studies of gross caloric values (GCV) of them is of great significance. This study aims to determine the GCV of different organs of bamboo and estimate the standing crop of energy (SCE) of 8 sympodial bamboo species in China. By comparing the differences of SCE of 8 sympodial bamboo species, advantageous specie can be identified for developing biomass energy from sympodial bamboos. This study was intended to provide basic data for the development and utilization of biomass energy from sympodial bamboos.[Method] Leaves, branches and culms of the 8 sympodial bamboo species (Bambusa textilis, Bambusa chungii, Dendrocalamus latiflorus, Dendrocalamopsis oldhami, Dendrocalamus membranceu, Dendrocalamus giganteus, Bambusa burmanica and Neosinocalamus affinis) were selected as experimental materials. Biomass of the samples were investigated, the GCV of the samples was measured with the calorimeter, and the SCE was estimated.[Result] 1) The biomass of 8 sympodial bamboo species were ranged from 16.68 to 77.72 t·hm^-2, the biomass of Dendrocalamus giganteus was the highest, the biomass of Dendrocalamus latiflorus was the lowest. Besides, the biomass of different bamboo organs was in the following order:culms > branches > leaves. There were variations in the distribution of biomass among different organs. 2) The GCVs of different organs among the 8 sympodial bamboo species ranged from 16.407 to 19.948 kJ·g^-1. The GCVs were decreased with the increase of age of the bamboos. The GCV of each organ was higher in Bambusa burmanica than in the other species. The GCV of leaf (16.652 kJ·g^-1) and branch (17.522 kJ·g^-1) was lower in Dendrocalamopsis oldhami than in the others. The GCV of culm was significantly lower in Neosinocalamus affinis (17.710 kJ·g^-1) than in the others. Except for Neosinocalamus affinis, the GCVs of different organs among other sympodial bamboo species were in the following order:culms >branches > leaves. The GCVs of different organs of Neosinocalamus affinis were in the following order:branches > culms > leaves. 3) The SCEs of 8 sympodial bamboo species were in the following order:Dendrocalamus giganteus (142.17 MJ·m^-2) > Bambusa chungii (115.41 MJ·m^-2) > Neosinocalamus affinis (112.97 MJ·m^-2) > Bambusa burmanica (95.26 MJ·m^-2) > Bambusa textilis (87.50 MJ·m^-2) > Dendrocalamopsis oldhami(85.31 MJ·m^-2) > Dendrocalamus membramaceus (85.14 MJ·m^-2) > Dendrocalamus latiflorus (31.34 MJ·m^-2).[Conclusion] 1) Sympodial bamboos are potential energy sources, influenced by biological characteristics of the bamboos, characteristics of the bamboo forest and climate conditions, there were significant differences in GCV, biomass and its allocation among the 8 sympodial bamboo species. 2) Because of the different habitats of 8 sympodial bamboo species, the comparison between different bamboo species based on SCE is more reliable. There were significant differences in the SCE and the distribution of SCE among 8 sympodial bamboo species. Different SCEs of different species mainly depended on the difference of biomass. 3) By comparing the SCEs of the 8 sympodial bamboo species, Dendrocalamus giganteus was more advantageous over the other species, in favoring utilization and development of biomass energy from sympodial bamboos and follow-up studies in future.

[Objective] To find a suitable spacing configuration with which more dry biomass of poplars can be harvested in a short period of time, we conducted a study on photosynthetic characteristics and growth of a 2-years-old new variety of poplar (Populus×euramericana. ‘Bofeng 3) for pulpwood production under short rotation management in this article.[Method] The forest micro-environment, photosynthetic characteristics and growth of poplar in the plantation with 3 spacing configurations (row spacing×plant spacing, treatment 1:120 cm×30 cm, treatment 2:40 cm×90 cm, treatment 3:60 cm×60 cm) were investigated.[Result] 1) Results showed that seedling height and collateral number in treatment 1 were significantly higher and more than those in treatment 2, and the leaf area per plant and collateral branch length were significantly greater than those of treatment 3 and treatment 2. The dry biomass yield in unit area in the all 3 configurations was more than 3.00×10⁴ kg·hm^-2. The biomass yield in treatment 1 was about 4.23×10⁴ kg·hm^-2, and was significantly higher by 24.41% and 17.50% than that in treatment 2 and treatment 3, respectively. 2) The stand micro-environment was affected by different spacing configurations. An appropriate increase in row spacing and decrease in plant spacing were able to increase density of C_a, canopy temperature (treatment 1 > treatment 3 > treatment 2) and reduce canopy related humidity (treatment 1 < treatment 3 < treatment 2). 3) Variation of micro-environment in different configuration forests influenced differentially photosynthetic characteristics. The diurnal variation of net photosynthetic rate (P_n) of the variety in all three configurations showed a bimodal curve, the daily accumulation of P_n (165.66 μmol·m^-2d^-1) in treatment 1 was 7.03% higher than treatment 2 (P<0.05). 4) Correlation analysis showed that dry biomasses of aboveground part were both significantly or very significantly (P<0.01) correlated to seedling height, leaf area per plant, PTL and daily accumulation of photosynthesis per plant, and seedling height was significantly correlated to diameter at breast height.[Conclusion] The results suggest that proper adjustment of spacing configurations of the short-rotation forests with high density can improve micro-environment and increase photosynthetic potential of Populus×euramericana ‘Bofeng 3’, then affect plant growth, finally influence the accumulation of aboveground dry biomass. For a rotation of two years, the configuration (120 cm×30 cm) can obtain the maximum biomass of P.×euramericana. ‘Bofeng 3’ and the configuration shows a certain promotional value.

[Objective] The increased atmospheric N sedimentation in recent years has brought the increased N availability and N/P ratio in forest soil, which would impact growth and P efficiency of mycorrhizal symbiosis plants. This study investigated effects of continuous N sedimentation on the ectomycorrhizal symbiosis of Pinus massoniana seedlings under low P stress to provide a theoretical basis for exerting the mycorrhizal potential to improve efficiency of Masson Pine P and growth.[Method] An elite breeding population of P. massoniana was used as test materials, two P conditions (homogeneous low P and heterogeneous low P among soil layers) and two N sedimentation levels were simulated in a pot experiment.[Result] 1) Under different P environments,,there were different responses of 2-year-old mycorrhizal seedlings to sustainable increase of N sedimentation. Under the homogeneous low P condition, N sedimentation significantly reduced the mycorrhizal infection rate and degree of P. massoniana seedlings, and inhibited the growth and P absorption efficiency of P. massoniana mycorrhizal seedlings, resulting in a significant reduction of P. massoniana biomass. Under the heterogeneous low P condition, simulated continuous N sedimentation increased seedlings mycorrhizal infection rate and degree, promoted the plant absorption of N and P, and thereby increased the seedlings biomass accumulation. 2) Under the homogeneous low P condition, N sedimentation significantly increased the plant N/P ratio, by which the seedlings growth was limited by P element, but was not sensitive to the increase of N. Under the heterogeneous low P condition, continuous N sedimentation improved the effectiveness of mycorrhizal effect and promoted the seedlings P and N absorption, and thus improved the seedlings growth. 3) Under the homogeneous low P condition, N sedimentation improved the nutrient status of mycorrhizal soil. Soil N and P levels were increased, but pH values did not change significantly. This was due to increase in the mycorrhizal effectiveness. Under the heterogeneous low P condition, simulated continuous N sedimentation reduced the inhibition degree of inoculation mycorrhiza fungi on soil nutrients, but soil pH value decreased significantly.[Conclusion] The effectiveness of mycorrhizal effect had different responses to increased N sedimentation under two P environment. Under the homogeneous low P condition, the effectiveness of the mycorrhiza effect increased. The status of soil nutrient was improved, but with the steady accumulation of soil effective N, soil P element was relatively serious deficiency. With the significantly increased plant N/P ratio, the limited degree of seedlings growth by P element was increased. Under the heterogeneous low P condition, the continuous N sedimentation reduced the limited degree of soil nutrient by mycorrhizal, thus the mycorrhizal fungi infection of the seedlings was promoted. Ultimately the accumulation of seedling biomass was increased.

[Objective] The aim of this study was to explore variation characteristics of soil microbial community diversity in purple soils at different re-vegetation stages on sloping-land in Hengyang, Hunan Province, South-central China.[Method] By using the spatial series to replace time series, four typical vegetation types, bare land, herbaceous and shrubby communities, as well as arboreal community, were selected to study the soil microbial community diversity by using the Biolog-ECO micro-plate technique. The four communities in purple soils on sloping-land were similar, and typical, and denoted four different re-vegetation stages.[Result] The soil microbial metabolic activity increased after re-vegetation(P<0.05) significantly; The average well color development(AWCD), which is used to represent soil microbial activity and functional diversity, followed the order of arboreal community>shrubby community>herbaceous community>bare land at the different re-vegetation stages, and followed the order of 0~10 cm soil layer>10~25 cm soil layer>25~40 cm soil layer in the different soil layers at the same re-vegetation stage; The Shannon-Wiener species richness index(H), Shannon-Wiener evenness Index(E), Simpson dominance index(D) and McIntosh index(U) at four different re-vegetation stages were the highest in arboreal community(P<0.05), the second in herbaceous community and shrubby community(P>0.05),and the lowest in bare land (P<0.05); The carbon and nitrogen source utilization intensities followed the order of arboreal community >shrubby community >herbaceous community>bare land at different re-vegetation stages(P<0.05), and followed the order of 0-10 cm soil layer >10-25 cm soil layer >25-40 cm soil layer in different soil layers(P<0.05); Principal component analysis(PCA) showed that two factors in relation to carbon and nitrogen sources from 31 carbon and nitrogen types could explain 37.24% and 15.89% of the variation, and carbohydrates, amino acids, intermediate metabolites, and secondary metabolites were the main carbon and nitrogen sources separating the two principal component factors; The results of correlation analysis indicated that total organic carbon(TOC), total nitrogen(TN), total phosphorus(TP) and available phosphorus(AP) had important influence on soil microbial community diversity.[Conclusion] All the results indicated that re-vegetation could enhance the soil microbial metabolic function which was beneficial to the reproduction of soil micro-organisms, thereby promoting an increase in soil carbon and nitrogen source utilization intensities.

[Objective] As a main white-rot fungus, Irpex lacteus shows very strong wood degradation ability. Here, we analyzed and measured the activities of five extracellular lignocellulolytic enzymes and intracellular proteome of Irpex lacteus induced by birch and spruce wood sawdust to explore the mechanism of substrate utilization by this fungus and provide more information and scientific basis for screening high efficient strains in biological pulping, prevention of forest disease and degradation of industrial pollutants.[Method] We measured the activities of five main extracellular lignocellulolytic enzymes and the changes the of intracellular proteome of I. lacteus subjected to birch(Betula playtyphylla) or spruce(Picea korainsis) sawdust or no sawdust (served as control).[Result] The enzyme activities induced by sawdust were higher than that of the control. There were significant differences in the manganese-peroxidase and laccase activities between the sawdust-treatments and control. The laccase activity was the highest among ligninolytic enzymes, followed by lignin-peroxidase activity, and manganese-peroxidase activity was the lowest. The exoglucanase activity was much higher than that of endoglucanase in the cellulose degrading enzymes. Compared with the control, 32 proteins with significantly differential expression were detected after being induced by sawdust. Three differential expression proteins were found in different substrates. Among these differential expression proteins, the proteins induced by birch sawdust were involved with membrane protein, membrane transportation and energy, while the proteins induced by spruce sawdust were all related with protein synthesis.[Conclusion] The lignocellulolytic enzymes activities and intracellular proteome of I. lacteus induced by different substrates were significantly different. Thus, the membrane transportation of secretory proteins could be a key in determining birch wood-decaying ability of I. lacteus, while the protein synthesis would play an important role in degrading spruce.

The ‘Senmiao Yellowhorn’ is a new yellowhorn cultivar by selection. It has good characteristics such as late phenology; high ratio of bisexual flower/total flower, axillary bud capable of bearing fruits, and stable yield. Compared with ordinary Yellowhorn control the phenology of ‘Senmiao Yellowhorn’ is later seven to ten days. The ratio of bisexual flower/total flower is 48%. The capsule is spherical; Each cluster has three to seven capsule; The single capsule weight, transverse diameter, and vertical diameter are 21.85 g, 54.27 mm, 52.35 mm, respectively. The seed number in each capsule is 16.73; The weight of 1 000 seeds is 714.13 g. The recommendation cultivation density of ‘Senmiao Yellowhorn’ is 2 m×3 m.The suitable cultivation region is Ningxia, Inner Mongolia, Shaanxi, Gansu and other main planting area of Yellowhorn.

The new variety of Paulownia fortunei, ‘Tetraploid Paulownia fortunei 1’ was obtained through cluchicines induction combined with tissue culture and clonal selection with P. fortunei as the parent plant. The characteristics of this new variety are superior to its progenitor in growth, physical and chemical properties of wood, natural stem-join, and stress resistance. Its seedlings can be propagated by means of tissue culture and buried-root, and ‘Tetraploid Paulowina fortunei 1’ would be popularized in the natural distribution and cultivated areas of P. fortunei.

Dendrocalamopsis oldhami HuaLÜzhu was breed by natural variation from D. oldhami. The shape of bamboo shoot looks like a horseshoe or cone, the color of bamboo culm is mainly green, and yellow cord in green; branches are very low, bamboo culm branches from 2nd or 3rd joint. The height of mature bamboo is 5-12 m, DBH is 3-8 cm. Shooting period is from early June to mid October, and the maximum period of shoot is July-August. Bamboo shoot yield is 5 250~7 200 kg·hm² in 3-4 years old bamboo, and 7 500-9 000 kg·hm^-2 in mature bamboo. The bamboo shoot had excellent quality, and its sugar content is high, taste is sweet. This bamboo variety can be used for the production of bamboo shoots and also can be used as ornamental.

The new variety of Morus alba, ‘Yuesang51’ was obtained by the methods of artificial tetraploid induction and cross breeding, between the female Youxuan02 (Morus atropurpurea Roxb.) 2x and the male diploid germplasm A03-112(Morus atropurpurea Roxb.) 4x. The characteristics of this new variety is superior to ‘Tang10×lun109’ in leaf yield, leaf quality, stress and disease resistance. ‘Yuesang51’ is mainly propagated through seeding method and suitable for germinating and growing in the south of the Yangtze River.