Based on data of Torreya fargesii distribution collected from literature and specimen records, as well as a field survey which covered 57 county-scale plots, the Genetic Algorithm for Ruleset Production (GARP) modeling approach was applied to predict its potential distribution range in China and analyze its distribution pattern and endangered causes. Our results indicated that:environmental factors, such as solar radiation, minimum temperature, maximum temperature and frost days, greatly influenced size of the potential range, while flow accumulation, mean annual temperature, wet days and water vapour pressure had little impact on the distribution. T. fargesii distributed disjunctively in subtropical mountains from 800 to 2 700 m and scattered in coniferous and broad-leaved forests, hillside thickets and ravine region. Potential distribution estimation indicated that the mountains in Central China would be the optimum habitats for T. fargesii to grow. Potential areas that we predicted suitable for growth of T. fargesii were much larger than its actual areas, suggesting that T. fargesii had been experiencing its extinct process. Most of the T. fargesii populations had a narrow distribution with very small population density, therefore, the habitat conservation would be crucial for T. fargesii protection.

The spatial distribution patterns and associations of different ages of P. tatarinowii were analysed in Langya Mountain, Anhui Province by O-Ring statistics in point patterns analysis. The results showed that the P.tatrinowii population was of an increasing one, the age class tended to be young ages and the age structure presented a reversedly J-shaped pattern. The age-classⅠexhibited a clumped spatial distribution at the scale of r<25 m. The age-classⅡexhibited a random spatial distribution the others displayed the pattern from random to the well-proportioned distribution with increasing the age-class; The associations of the all different ages showed non-associations except the first and the second age-classes that were positively related at the scale of r>8 m.

Based on eddy flux data collected in a poplar plantation of Yueyang in 2006, the flux source area was calculated using the FSAM model according to the continuous flux measurement with an open-path eddy covariance system. The results showed that:In the prevailing wind direction(0°~90°), the upwind range of flux source areas(P=0.9) was 110~3 500 m under stable air conditions, while it was 90~1 800 m under unstable air conditions. The range under stable air conditions in the direction of 180°~270°was 110~4 500 m, which was the largest of the three unprevailing wind directions, while under unstable air conditions, the ranges in the three directions were nearly the same (90~1 800 m). In the prevailing wind direction, the source area changed with atmospheric stability and source areas in the growing season are larger than those in the dormant season under the same atmospheric condition. Because of the big fetch, the measurements were able to represent the specific characteristics of the instrument location。

This paper reports the results of a statistical analysis on flora of the seed plants from the Lhasa River reaches, Tibet, China. There were 793 species (and varieties) in 285 genera of 72 families of wild seed plants found in the area, accounting for 43.90% in species, 24.89% in genera, and 14.97% in families of the seed plants from Tibet. Six species in three genera of three families belonged to gymnosperms, and the other 787 species in 282 genera of 69 families belonged to angiosperms. In the angiosperms,the dicots, with 642 species in 218 genera of 56 families, were predominant in the floristic composition and accounted for 77.78% in species, 76.49% in genera, and 80.96% in families of the seed plants from Tibet. The monocots had 145 species in 64 genera of 13 families, and accounted for 18.06%, 22.46%, and 18.28%, respectively. The seed plants in the Lhasa river reaches had four salient characteristics. 1) The species in the area were abundant in number, but the species within a genus were relatively scarce, and thus the number of species within a genus is relatively few, with the ratio of species to genus being 2.78. The genera with only one or a few species were abundant in the flora. 2) The flora was complicated in composition, with the families representing five areal-types and three subtypes, and the genera representing 15 areal-types and 10 subtypes. Among these elements, temperate ones were predominant, including 18 families, 194 genera, and 705 species, accounting for respectively 56.25%, 82.20%, and 90.38% of the total in the area. This result clearly showed a temperate nature of the flora in question. Tropical elements accounted for a relatively high proportion only at the familial level, but a very low proportion at both generic and specific levels, suggesting that this flora might have some historical relationships with tropical floras in the course of its origin and development. 3) The endemism was not high; there were no families endemic to China in the area, although seven genera and 324 species were China specific in the area. This reflected the relative youthfulness and strong differentiation and specialization of the flora in the area. 4) Floristically the seed plants from the Lhasa river reaches were closely related to the Sino-Himalayan elements, and were historically also somewhat related to the Mediterranean, western Asian and central Asian elements.

The litter bag method was used to investigate the differences in dynamic weight loss rate, leaf litter decomposition rate and substrate quality of a Larix principis-rupprechtii plantation under different mountain site conditions in Beijing. The results showed that elevation and slope were two main factors in determining the site difference (Site class Ⅲ, Ⅳ). There were two peaks for leaf weight loss rate under two site conditions during the one-year observation. T_0.5 in Ⅲ and Ⅳ was 2.57 and 2.67 years, and t_0.95 was 11.09 and 11.24 years, respectively. The average annual weight loss rate, the decomposition rate and initial inorganic nutrient content in Ⅲ were higher than in Ⅳ. Compared with Ⅳ, the average C/N value and lignin content in Ⅲ were more benefit to the decomposition of coniferous litter. The initial inorganic nutrient content of litter was not significantly different between two site conditions, while the initial content of C and lignin existed significant (P<0.05) difference. Correlation analysis showed that there were significantly negative correlations between litter decomposition rate and total carbon, C/N ratio and litter layer thickness, and the correlation coefficients were -0.735, -0.569 and -0.758, respectively. Substrate quality indexes indicated that the forest density of 1 675 tree·hm^-2 was most favorable to litter decomposition in Ⅲsite condition, while the density in 1 300 tree·hm^-2 was the most beneficial to decomposition of coniferous litter in the Ⅳ site condition.

With the interpreted IKONOS4 satellite images collected in 2005, a 1∶10 000 forest map, the data collected in Class II forest survey in 2007, and surface runoff data obtained in the permanent runoff monitoring station, six site factors of slope gradient, slope position, soil thickness, soil thickness of A layer, soil type and soil water content were selected to establish a matter element model suitable to 297 forest sub-compartments. Further, the AHP was applied to modify the spatial structure and form the spatial para allocation of the protection forest system. The results showed that:1) the area allocation of different vegetation types was irrational, the area of a mixed coniferous and broad-leafed forest was 124.39 hm², accounting for 14.97% of the forested land,the mixed forest was consisted of two coniferous species accounted for 27.37% of the total forest land, and the pure forest was consisted of one coniferous species accounted for 42.48%. 2) After optimization, the area allocation of different vegetation types in the protection forest system ranked as:the mixed coniferous and broad-leafed forest (31.12%)＞shrub land (15.5%)＞the economic tree crops (12.28%)＞the mixed forest consisting of two coniferous species(11.46%)＞the pure broad-leafed forest(11.41%)＞the pure coniferous forest (9.51%)＞grass land (8.70%). Besides, the annual surface runoff could reduce 43 171 mm or 62.15%, annual soil erosion could decrease 465.97 t or 79.66%. 3) The following suggestions for spatial para allocation of the small watershed protection forest system were proposed:① reducing pure cypress or pine forest, and increasing alder-cypress, oak-cypress or pine-cypress mixed forest. As for the current cypress and pine pure forests, alder or oak could be introduced to develop a mixed forest. ② The canopy closure of pure cypress forest and alder-cypress forests should be maintained within 0.60-0.75,and the canopy closure of oak-cypress, pine-cypress or oak-pine forests should be controled within 0.6-0.8. ③ For improvement of current pure coniferous forests, an opening and beating-up method and the density regulation could be applied. For the opening and beating-up operation, strip cutting and replanting of broad-leafed species, such as oak, alder and camphor, could be applied. ④ For enrichment of species composition, the mixture ratio should be based on the specific site condition and tree features. In the neutral or minor acid purple soil, mixed cypress forest would be favorable; in the yellow and acid purple soil, cypress-broad-leafed or pine-broad-leafed forest would be suitable. In the grey sand soil, pine-broad-leafed forest could be dominated, and the broad-leafed species could reach to 20%-30%, even 40% in favorable sites.

The development of high-resolution remote sensing imaging technology provides a new way to the large-scale estimation of forest canopy density. The traditional inversion methods for canopy density only use spectral or topographical features of remote sensing images. However, due to the existence of the different thing with same spectrum and the same thing with different spectrum phenomena, it is difficult to improve the estimation accuracy of canopy density. Based on spectrum and other traditional features, this paper combines texture features of remote sensing images to estimate canopy density. Firstly, the gray level co-occurrence matrix (GLCM) texture features are computed using object-based method. Then, prinicipal component analysis (PCA) method is applied in correlation analysis and dimension reduction of texture features. Finally, spectrum and topographical features together with texture features are introduced into stepwise regression model to estimate canopy density. The experimental results showed that compared with the traditional method only based on spectrum or topographical features, the method combined with texture features greatly improved the estimation accuracy. The coefficient of determination (adjusted R²) increased from 0.737 to 0.805. The estimation accuracy increased from 81.03% to 84.32%.

Forest growth is mainly currently monitored using in-situ measurements in northeast of China. To effectively monitor forest growth disturbance at large scale, we attempted to use remote sensing technique, particularly, time series MODIS data from 2004 to 2006. The annual time series of 8-day enhanced vegetation index (EVI) dataset was generated and smoothed using a Savitzky-Golay filter. The EVI trajectory during growth season was simulated using a logistic model. From the simulated trajectory, the EVI area of growth season and annual EVI entropy were calculated. These two factors were combined to map the disturbance regions of forest growth. Finally, the disturbance regions were verified using a set of random samples. The result indicates that the disturbance points have distinctively higher entropy and lower peak. Some of these points also show abrupt EVI decline during the midseason of the peak phases or double peaks. This approach is demonstrated to be feasible for disturbance monitoring of forest growth.

A comparative study between autotetraploid and diploid Robinia pseudoacacia was carried out to investigate the mechanism of genetic variations of inflorescence in autotetraploid. The result showed there were no significantly differences in the length of inflorescence between autotetraploid and diploid R. pseudoacacia, but the number of florets was significantly more in autotetraploid than the diploid. The florets of the autotetraploid R. pseudoacacia in different positions showed the remarkable asynchrony. DNA sequences of homologous genes of LFY and TFL 1 were cloned from autotetraploid and diploid, and their homology reached to 98.44% and 98.00%, respectively. The treatment with the acazC could observably reduce the inflorescence variation and promote inflorescence bloom prematurely.

A total 61 clone parents and 320 open-pollination progenies from 8 clone individuals were identified by 12 polymorphic SSR loci. The result showed that the level of genetic diversity in progeny population was the same as in maternal population, progeny population had all alleles detected in maternal population, and there were not obvious surplus phenomenon of homozygotes in progeny population(F=0.046). The south crown had more strobili than the north crown, however the genetic diversity of the north crown strobili was not substantially reduced. The progeny of neutral trees had the same level of genetic diversity as in the progeny of partial female trees, with the fixation index tended to be zero, which was accorded with Hardy-Weinberg equilibrium. The multilocus outcrossing rate in the seed orchard was 1.097, and there was no significant inbreeding between parents (t_m-t_s=-0.031). The multilocus outcrossing rate and singlelocus outcrossing rate in the south crown were higher than that in the north crown. The multilocus outcrossing rate of partial female trees was the same as in neutral trees, and the neutral tree had no obvious declining outcrossing rate with reduced proportion of female and male strobilus compared with partial female tree, with the fixation index tended to be zero. The progeny of the second generation clonal seed orchard still had rich genetic diversity, gene exchange among clones was relatively sufficient, and biparental inbreeding was not significant.

MicroRNAs (miRNAs) are one kind of small RNAs that do not encode any proteins, however play critical role in developmental processes, metabolism and stress responses in plant. Here we present a study of bioinformatics prediction of miRNAs in Prunus using bioinformatics-based gene search based on blasting ESTs and GSSs in NCBI. Eleven precursors coding 11 mature miRNAs were found from 107 982 ESTs and 48 273 GSSs of Prunus, and 19 target genes, which encode proteins involved in developmental processes, metabolism and transcriptional regulation, were predicted. Further analysis of the miRbase database showed that 11 miRNAs belonged to 8 miRNA families from Prunus persica and Prunus mume, and were from 20 to 23 bp in length with 6 miRNAs being 21 bp in length. The miRNAs of ppe-miR162a and ppe-miR164f were the most conservative. In order to prove accuracy of the prediction, ppe-miR156h, pmu-miR482, ppe-miR399a, ppe-miR171 were identified by RT-PCR. The results showed that ppe-miR156h was expressed in flower buds of Prunus mume, and pmu-miR482, ppe-miR399a, and ppe-miR171a were expressed in leaves of Prunus persica.

Growth, oxalate efflux, and nitrogen, phosphorus and potassium uptake, by isolates of four ectomycorrhizal species:Lactarius deliciosus (Agaricales), Suillus luteus(Agaricales), Suillus grevillei (Agaricales) and Cenococcum geophilum (Eurotiales) were compared in pure culture in liquid media with variable concentrations of Al³⁺ (0, 0.20, 0.40 and 1.00 mmol·L^-1). The growth of the four ectomycorrhizal species were negatively but variably affected by Al³⁺. The two isolates originating from acidic soils in southwest China (L. deliciosus and Suillus luteus) showed less reduction in biomass compared to S. grevillei and C. geophilum originating from calcareous soils in northwest China. L. deliciosus and S. luteus also produced high oxalate accumulation in the culture solution with and without addition of Al³⁺. This could be beneficial to the fungi in reducing the concentrations of active Al³⁺ in culture solutions through the formation of chelate. In most cases of Al stress, higher accumulations of nitrogen, phosphorus, and potassium were observed in the mycelium of S. luteus and L. deliciosus than in S. grevillei and C. geophilum . Taking into account of higher biomass and larger nutrient absorption under Al exposure, S. luteus and L. deliciosus , indicating higher Al resistance of the fungal isolates from acidic soils than those from the calcareous, could be due to evolution and natural selection in acidic conditions. Furthermore, appropriate Al³⁺ in culture medium also increased in phosphorus concentrations in all of four fungal isolates, which could be one of beneficial patterns to precipitate intracellular Al³⁺ and diminish Al toxicity.

According to the concentration scale of oxalic acid, citric acid and malic acid in forest litter leachates of northeast China, Larix olgensis seedlings were foliar-sprayed with organic acids of different concentrations, and then subjected to low temperature (4 ℃). Effects of organic acids on physiological and biochemical characteristics of the seedlings were studied to investigate the regulation mechanism of exogenous organic acids on cold resistance of L. olgensis. The results showed that the organic acids of appropriate concentrations decreased electrolytes leakage and MDA content of the seedlings under low temperature stress. Activities of SOD, POD, APX and CAT, and concentrations of praline and soluble protein were enhanced to some extent with treatment of the acids. The chlorophyl contents were also increased. It is concluded that, exogenous organic acids could enhance the protective enzyme activity, reduce membrane lipid peroxidation, and increase osmoregulation and scavenging active oxygen abilities of L. olgensis seedlings under low temperature stress, resulting in an increase in the cold resistance of L. olgensis seedlings. The order of effects of the three organic acids on physiological and biochemical characteristics was:citric acid>malic acid>oxalic acid, and the optimum concentration of the organic acid was 5.0 mmol·L^-1.

A total 25 Chinese chestnut (Castanea mollissima) varieties collected from different areas of China were used to study the composition and ratios of fatty acids in starch-surface-lipid (SSL). The results showed the SSL contained unsaturated fatty acid (UFA), accounting for 30%-50% and 60%-70%, and Saturated Fatty Acid (SFA), 30%-40% and 50%-70%. The SFA/UFA ratio of chestnuts from south variety population was lower than that of other two variety groups. The composition of two kinds of fatty acids was significant difference between different varieties, while no significant difference in the composition was found between different variety groups. C₁₆ and C₁₈ were two main fatty acids, and the former accounted for 15%-30%, among which saturated acid of C_16:0 was the main form, while the later accounted for 30%-70%, among which un-saturated acids of C_18:1 and C_18:2 were the main forms. The fatty acids of C_16:0, C_18:0 and C_18:1 were higher and C_16:1, C_18:2 and C_18:3 were lower in south variety group than other two variety groups, but no significant difference was found between different variety groups. Fatty acids of C₁₆ and C₁₈ between different variety groups were no obviously difference as well. In summary, the composition of fatty acids in starch-surface-lipid was closely related to the variety of chestnut and rarely related to variety group.

The effects of salicylic acid (SA) on a pathogen (Pestalotiopsis guepinii) of Camellia were investigated by glass germination method. The result showed that the SA of 0~5 mmol·L^-1 did not inhibit growth of the pathogen. The induced resistance of camellia could last 10~15 days, and the optimum induced time was interval 3 days. The MDA, lignin, soluble protein had different responses to the disease resistance of camellia induced by spraying SA. MDA content in leaves decreased in certain period of time, suggesting that the membrane lipids peroxidation was decreased, but the effects of SA gradually were weakened with time. The responses were different with different SA concentrations. The experiment of induction and challenge inoculation showed that the MDA concentrations were lower than that in the control at initial stage, and then increased slowly at later stage. The treatment of induction and challenge inoculation brought about the same change trend of lignin content as the induction treatment. High SA concentrations were more effective than the low concentration. The contents of soluble proteins in the treatment of induction and challenge inoculation exhibited the same change trend as that in induction treatment, but were higher than that in the latter and the control. The correlation analysis of biochemical reaction and disease index showed there were significant (P<0.05) correlations between the contents of MDA, lignin and disease index.

Both morphological characters and a portion of of 28S rDNA sequences were used to identifying Tomicus species. The specimens were classed into groups with the following characters:1) granules or punctures on interstria 2 on the declivity of the elytra. 2) length of the elytral interstrial hairs and hairs arising from punctures. 3)arrangement of pronotal punctures and hairs. These characters could be clearly examined under a binocular microscope at 30×magnification and they were applicable and valuable for the forest entomologists to identify Tomicus species. The phylogenetic tree established with difference in 28S rDNA sequence of D2 region revealed that the specimens of each group identified by morphological characters were also grouped together. The genetic distances of intra-species, inter-species and inter-genus were not overlapped. Genetic divergence of 28S rDNA was also useful for identifying Tomicus species.

A potting experiment was conducted to evaluate effects of three phosphate-solubilizing bacteria (PSB) (Pseudomonas chlororaphis, P. fluorescens, Bacillus cereus) and their mixture on rhizosphere soil microorganism and enzyme activities at three growth stages of pecan (Carya illinoensis) seedlings subjected to three application levels of calcium-superphosphate. Results showed that:Inoculation of the three PSB and their mixture increased the amounts of rhizosphere bacteria and actinomyces, reduced the amounts of rhizosphere fungi, and enhanced activities of phosphatase and urease. However, the effects on rhizosphere microorganism and enzyme activities decreased progressively with increase of calcium-superphosphate content. The bacteria mixture was stronger effects than that of any single bacterium, and brought about the most rhizosphere bacteria and actinomyces, the lest rhizosphere fungi, and the highest activities of phosphatase and urease in all three application levels of calcium-superphosphate compared to inoculation with any single bacteria.

Time-temperature superposition principle(TTSP) was used to examine dynamic viscoelastic properties of Chinese Fir(Cunninghamia lanceolata) wood at an extremely low moisture content(0.6%). Storage modulus and loss factor data were obtained at different constant temperatures ranging from 25 ℃ to 150 ℃ in frequency multiplexing experiments(0.1-20 Hz). All viscoelastic curves at other temperatures were shifted along the log-frequency axis to superimpose them on a reference temperature(i.e. 135 ℃ in this study) curve. The extended storage modulus and loss factor isothermal master curves were over a wide range of frequency. The shift factors were determined to be a function of temperature and fitted into the Arrhenius equation with the least squares method. The results showed that the storage modulus data were excellently fitted into the Arrhenius model, indicating the validity of the model to characterize the dynamic stiffness behavior of dry wood in the range of 25-150 ℃ using the TTSP. However, the time-temperature equivalence was not able to predict the damping properties.

The anatomy characteristics of cell wall and lignin distribution in different anatomical regions for 12-month old bamboo species Pseudosasa amabilis was investigated. The lignin distribution was studied by means of optical microscope and confocal laser scanning microscope and the color reaction. In addition, the distribution of lignin in different tissues(fiber, parenchyma and vessel) was investigated by visible-light microspectrophotometry coupled with the Wiesner and Mäule reaction. The cell walls of different tissues were all lignified and the lignin was widely distributed in different tissues, in which there was a difference between tissues and anatomical regions in lignin content. Guaiacyl lignin and syringyl lignin unit could be found in cell wall of fiber, parenchyma and vessel through Wiesner and Mäule reaction and the absorbance peak of spectrum. There was no regular variation in lignin content with different radial location of culms and different location in fiber strands. The lamellation of the fiber cell wall was generally had as alternating broad and narrow layers with alternating low and high concentration of lignin.

The objective of this paper is superior grade sports flooring for competition. Through testing the main performance indexes, this reseach is to investigate the property of sports flooring with different keel structural parameters.Orthogonal regression experiments were carried out in order to establish the regression equations between influence factors (keel siding, keel thickness, keel spacing) and experimental indexes (force reduction rate F_r, standard vertical deformationV_d, ball rebound rate B_r). Through SPSS analysis program it is found that all factors had significant effect on F_r,V_d and B_r respectively at significance level of 0.05 or above. After analyzing the best factor combinations for each index, this paper concludes the comprehensive best combination which is the span keel spacing 500 mm×500 mm, keel cross section 50 mm×50 mm. The research fills the blank of regression correlation between keel structure and main performance indexes of sports flooring. The results have important statistical effect on asisiting production procedure of the keel as important component of sports flooring. In theory the regression equations in this research can be applied in asisiting the design of keel structure and field installation technology of sports flooring.

To determine the states of water and its fraction in frozen tree in winter, the heating and cooling curves of Populus ussuriensis and Pinus koraiensis green timber specimens were tested and analyzed respectively using differential scanning calorimetry(DSC 204). The positions of exothermic and endothermic peaks, which were shown on the DSC curves, caused by freezing and melting of water in wood were located, and the areas of endothermic peaks were measured by using an integration method, then the states of water and its fraction in frozen wood were evaluated. The results showed that:1) It was feasible to determine the states of water and its fraction in frozen wood using DSC. The DSC curves illustrate that there were three types water in green wood:frozen free water, frozen bound water and nonfrozen water. 2) The positions of exothermic peak induced by freezing of free water in Pinus koraiensis and Populus ussuriensis specimens were about -13 ℃ and -18 ℃ as temperature decreased; the positions of endothermic peak induced by melting of bound water and free water were about -0.4 ℃, 6 ℃ and 0.8 ℃, 9 ℃ respectively as temperature increased. 3) Considering latewood and earlywood of sapwood and heartwood, the ratios of frozen water contents to moisture content were 80.3%, 75.8%, 75.2% and 77.3% in Pinus koraiensis, 69.4%, 68.5%, 63.3% and 89.0% in Populus ussuriensis when temperature was -60 ℃.

YP1.0-A is the third generation of full-automatic remote control carriage. It has the superiority that can substitute the stopper of semi-automatic carriage in the line of cableway by using hydraulic braking and can stop at any point of the cableway, and the hook of the carriage can move up and down automatically. Based on the analysis of the structure, main parameters, performance and the working principle of the YP1.0-A carriage, we design the remote control system,including the power supply, the remote control circuit and transmitting and receiving controlling etc, it enhances the sensitivity, accuracy and simplicity of remote control system, this will be to the advantage of ensuring production safety and achieving combined operation of remote control carriage in the engineering applications and finally improving the remote control cableway production efficiency.

Compared to modern crops, forest trees have some inborn characteristics, such as long life span, gigantic size, and high genetic load, which make trees difficult to manipulate in genetics studies,and lead to the progress of their basic genetic studies lagging behind that of many other important organisms. The poor research basis is the major factor that hampers the proceeding of forest improvement programs. Molecular breeding is the key technology to overcome the long breeding cycle of forest trees. Identification and functional analysis of gene/genes underlying important traits are the preconditions for molecular breeding practice in tree species. With the fast development of life technologies, new hot topics are popping up in the basic studies of forest genetics and breeding. In this paper, we briefly introduce the progress of some hot topics in the basic studies for woody plants, including tree genome and functional genomics, linkage and association analyses, wood formation mechanisms, and molecular breeding. Although achievements from the relevant studies are not in practical applications yet, they will provide important technical storage for future tree breeding programs. We wish this review could help to accelerate the progress of the relevant studies.

In this paper, we reviewed the current status of studies on the forest fuel treatment and reduction, and discussed the topic in three aspects which include forest fuel treatment techniques, landscape scale fuel treatment and the ecological effects of fuel treatment. In addition, the suitable approaches of forest fuel treatment were discussed. The results showed that the forest management measures and biological fuel break construction should be taken as the main approach of fuel reduction and should be given the priority. It is suggested that the forest fuel management in the landscape scale should be enhanced; the ecological effects of fuel treatment measures should be comprehensively considered; and the ecological adjust and control of forest fuel should be realized.

In order to understand effects of host plant, geographical distance and pesticide stress on the genetic structure of the spruce spider mite (Oligonychus ununguis), different populations of the mite were used for analyzing the sequence variation of the mitochondrial cytochrome oxidase I gene (COI) segment. Genetic differentiation was very small in the mites collected from different species of Castanea mollissima, Quercus acutissima, Q. variabilis, Q. dentate, which distributed in a narrow range(3-500 m), and in the mites from the same species of host plants that distributed in a larger area(25 km). These populations were clustered in the same branch of the NJ phylogenetic tree and the genetic distance between them was 0-0.001. There was significant genetic differentiation of the mites collected on Q. variabilis from two different districts, Taian district of Shandong Province and Jiaozuo district of Henan Province. The mites from these two provinces were distributed in two different branches of the NJ phylogenetic tree. The population suffered long period pesticide stress had significant genetic differentiation from the population that had not experienced the pesticide stress, although they were collected from the same host species of Q. acutissima away from about 500 m. Genetic distance between the two populations was 0.015, and they were clustered in the different branch. of the NJ phylogenetic tree. Results showed that geographical isolation and pesticide stress were possibly the important factors affecting population differentiation of O. ununguis.

In this work the supercritical fluid extraction with carbon dioxide was applied to extract roots of Stellera chamaejasme. The extracts were evaluated through the antifungal activity against Monilinia fructicola. Furthermore, the active compounds from the extracts were separated by macroporous resin and analyzed using gas chromatography-mass spectrometry (GC-MS). The results showed that the extracts had strong antifungal activity against M. fructicola with inhibition ratio of 88.71% at 2 000 μg·mL^-1, minimum inhibitory concentration (MIC) of 250 μg·mL^-1, and minimum fungicidal concentration (MFC) of 2 000 μg·mL^-1. After separated with macroporous resin chromatography, fourteen fractions were collected from the extracts. Fraction 4, 7, and 12 in a concentration of 2 000 μg·mL^-1 presented highly antifungal activity against M. fructicola, with inhibition ratio of 83.97%, 80.23%, and 75.69%, respectively. The GC-MS analysis revealed that the main active compounds from fraction 4, 7, and 12 included hexanedioic acid;bis(2-ethylhexyl) ester;β-sitosterol;7-methyl-Z-tetradecen-1-ol acetate9;9-hexadecenoic acid,hexadecyl ester,(Z);1,2-benzenedicarboxylic acid,diisooctyl ester;(3β,24Z) ,stigmasta-5,24(28)-dien-3-ol;stigmastan-3,5-diene, and squalene.

Information on spatial and temporal patterns of forest fires contributes to effective fire management. Based on data of the forest fires occurred in Heilongjiang Province from 1980 to 2005, the spatial and temporal distribution of forest fires was studied by using of statistical analysis and spatial analysis method. The results indicated that forest fires fluctuated obviously year to year. The burned area was somewhat correlated with the total number of fires. The number of spring fires and the burned area contributed 72.52% and 84.39% to the total fires and area, respectively. The number of summer fires and the burned area were relatively less and smaller. Fall had a short fire season. Heihe city had the greatest number of forest fires and the Daxing’an Mountains region had the largest burned area in the 13 administrative regions studied. The Daxing’an Mountains had the highest fire frequency and the largest burned area over the 5 landscape areas, and its fire burned area accounted for 89.42% of the total. The fire frequency showed a reducing trend with altitude rise in the mountainous areas. The forest fire occurrence and the spatial and temporal variation are useful information for classing the forest fire danger rank and forecasting forest fires, and the information would have important theoretical and practical significance for efficient management in forest fire fighting and prevention.

The observation and analysis have been operated about the structural features of Betula schmidtii by those instruments biomicroscope and ESEM. Result showed that iron birch belonged to diffuse-porous wood, structure was even and smooth, the zone of demarcation of growth increments were visible, the color was greatly different during heartwood and sapwood, and pores were visible by naked eye. Pore arrangement involved solitary one and multiple one, pore cluster was slim, multiple pore were usually ribbon-like aggregations of 2, 3 or 4 cells extending in the radial direction, intervessel pit was the type of alternate, perforation plates was that of scalariform, rays amount was from 1 to 5, and longitudinal parenchyma was thin. The physical nature and mechanical properties of Betula schmidtii have been testde, analysed and studyed contrastively with other kinds of wood. The results showed that the basic density of iron birch was 0.747 g·cm^-3, air-dry density was 0.904 g·cm^-3, and oven dry density was 0.875 g·cm^-3. The shrinkage coefficient of radial direction in the state of air-dry was 0.12%, the tangential one was 0.20%, and the volume one was 0.38%. The coefficient of radial shrinkage in the state of oven dry was 0.23%, the tangential one was 0.28%, and the volume one was 0.53%. The bending strength of tangential direction was 233.32 MPa, the modulus of elasticity of bending strength was 17.87GPa, the shear stresses at right parallel to the grain in the radial surfaces was 16.32 MPa, the tangential one was 16.40 MPa. The crushing strength at right parallel to the grain was 89.88 MPa. the strength of toughness was 153.71 kJ·mm^-2. The strength of rigidity in the radial section was 8 042.22 N, the tangential was 7 794.17 N, and the cross one was 8 778.85 N.

Camellia oleifera ‘Huajin’ is an elite variety selected from a stand of Camellia oleifera raised from seeds. The fluids mature around Frost's Descent, average weight of individual fruit is 51.59 g, and maximum weight of individual fruit is 80.40 g, The fluids have a seed-producing rate of 36.38% and the seed has a average oil content of 46.00%. At least 900 kg oil per hectare can be produced in flourishing fruit period, therefore the new variety has elite characteristics such as high yield, large fruit, and anti-adversity.

The poplar variety ‘Quanhong’, was derived from a bud mutation of another poplar variety, ‘Zhonghong’. The variety is formed after years of research and cultivation. The whole leaves and new shoots were dark purple from bud flushing in spring to late June. The leaves became purple from July to September. After October, the leaves turned to bright red. One-year seedlings turned into dark purple at the end of July. Petioles and veins of leaves were bright red. The variety is suitable for growing in a wide range of regions.