In this study, the forest soil CH₄ oxidation rates were measured for consecutive 17 months(2009-04—2010-08) using static chamber and gas chromatography techniques. The results showed that soils of both natural forest and plantation were sinks for atmosphere CH₄. CH₄ oxidation rates varied from 10.83 μg·m^-2h^-1 to 75.02 μg·m^-2h^-1 for natural forest and from 7.66 to 46.40 μg·m^-2h^-1 for plantation during the observation period, and mean annual CH₄ oxidation rates in natural and plantation forest soils were 32.01 and 25.31 μg·m^-2h^-1, respectively. CH₄ oxidation rate was regulated not only by soil temperature, but also by soil volumetric water content and their interaction. While the soil volumetric water content significantly affected CH₄ oxidation rates, the effect of soil temperature was dependent on soil volumetric water content and soil depth.

The leaf litter decomposition of six representative tree species, Cunninghamia lanceolata, Pinus massoniana, Schima superba, Cinnamomum camphora, Cyclobalanopsis glauca and Castanopsis eyeri, in subtropical region was investigated with litterbag method under ambient and reduced ultraviolet-B (UV-B) radiation (22.1% below ambient) treatments. The results showed that there were differences in litter mass remaining rates of each species under two UV-B radiation treatments, except for a few decay stages during decomposition, and the difference became more obvious with decay time. The reduced UV-B significantly decreased the litter decomposition rates of six species by an extent from 33.3% for C. camphora to 69.6% for C. lanceolata (P<0.01). Both UV-B radiation treatment and litter type significantly affected litter decomposition rate (P<0.001), with a stronger effect of UV-B radiation than litter type. There were significantly negative correlations between decomposition rate and C:N ratio of leaf litter under both ambient and reduced UV-B radiation treatments (P<0.05).

In this paper, the response of the ecological dynamics and tree-growth to climate change was investigated at the treeline ecotones in Qilian Mountains. The results showed that the young plants (1-30 a age) occupied 80.5% of the total number of trees at the treeline ecotones. The population density increased by 23 times, however the tree limit position in the treeline ecotones was not significantly changed during the past 100 years. In addition, the radial growth of Picea crassifolia showed a steady increase trend in the past 30 years. According to the relationship between radial growth and climate, the radial growth of trees was positively and significantly correlated with mean temperature of the summer and fall, as well as the previous summer and fall, especially the previous fall and June.

Using a dimidiate pixel method, the annual maximum vegetation coverage in Three Gorges Reservoir Area (TGRA) from 2000 to 2009 was estimated based on the MODIS NDVI remote sensing data. Furthermore, the temporal-spatial variation and its driving force of annual maximum vegetation coverage were analyzed at pixel scale. The results showed that the annual maximum vegetation coverage was high in the most area of TGRA, and approximate 92% of the whole area had the annual maximum vegetation coverage greater than 60%. The annual maximum vegetation coverage increased with the increasing of elevation and slope. In recent 10 years, annual vegetation coverage of the whole area showed a weak increasing trend. The pixels with significant increase or decrease in the annual maximum vegetation coverage were only 7.16% of total pixels, and the vegetation coverage of Shizhu, Jiangjin and Fengdu had high degradation risk out of the total 20 counties. Precipitation was the dominant driving factor for annual fluctuation of vegetation coverage in TGRA. The annual maximum vegetation coverage was notably related to the accumulated precipitation from May to August. However, there was obvious spatial difference in the correlation. The significant positive correlation pixels mainly distributed in the western hilly farmland in TGRA, where the increase of precipitation can promote the vegetation growth. The precipitation was considerably negatively correlated with the vegetation coverage at the higher sea levels in the northeastern part of TGRA.

In this paper Ulmus pumila populations in two habitats of fixed sand dunes and low land between dunes in the Otindag sandy land were targeted and, the spatial distribution patterns and the associations of different developmental stages of the populations by using point pattern analysis. The results showed that the whole population in sandy lands between dunes had a clumped distribution at the scales <10 m. The young trees and middle-aged trees had random spatial distributions at a greater scale,however the mature trees had a clumped distribution. The spatial associations between different developmental stages exhibited at a smaller scale. With increasing scales,the spatial association between different developmental stages turned to be feeble. The whole population on fixed sand dunes had a clumped distribution at a smaller scale. With increasing scales,the population tended to have random spatial distributions. The spatial association of middle-aged trees and mature trees was positively correlated with each other. The spatial associations of different developmental stages were weak.

Pinus koraiensis is one of the most important native tree species in northeastern region of China. It is important to select optimum seedling age for transplantation in a given site condition according to both seedling quality and field performance. Four kinds of seedlings, such as S2－0, S2－1, S2－2, and F2－0, were used to test differences in seedling quality in Jiangmifeng Forest Country of Jinlin. In comparison with S2－0, height, root diameter, FOLR, and dry mass of S2－1 were increased by 100%, 108.2%, 100%, 398.4%, respectively. The N, P, and K contents were improved by 368.6%, 646.2%, 349.3%, respectively. S2－0 had only 67.5% of survival rate when being outplanted in one year, while the survival rate of S2－1 was improved by 20.6%, and therefore, it is necessary to transplant S2－0 seedlings in a nursery for further culture. When 2－0 seedlings were transplanted in the nursery for another 2-year culture (S2－2), minor improvement of seedling quality was shown compared with the seedlings transplanted for another 1-year culture (S2－1). No differences in survival and increment of root diameter were found between S2－2 and S2－0. Height in F2－0 when lifted and survival when outplanted in 1 year were improved by 35.4% and 5.6% in comparison to S2-0, respectively, indicating that sowing in the fall was able to increase seedling quality. FOLR of S2－2, S2－1, S2－0 and F2－0 were 18, 14, 7 and 7, respectively. And initial FOLR was correlated significantly with the survival, total height and root diameter of the seedlings when being outplanted for 1 year. Thus, FOLR could be one of the reliable, feasible indicators to predict field performance for Pinus koraiensis.

Torreya grandis 'Merrillii’is an indigenous economic tree species in Zhejiang Province, but its potential economic value is not fully obtained because of the irrational regional distribution. The evaluation system of comprehensive regionalization was constructed according to its biological characteristics and the requirement to environmental factors which mainly included three climate factors, two topography factors and two soil factors. These regionalization indices were gridded by the mixed interpolation method. An evaluation model of comprehensive regionalization was established by using the index accumulation method (IAM). Taking account of the land use condition and eliminating the unsuitable planting regions, the results mainly included three grades of the suitable region, sub-suitable region and unsuitable region. The refined regionalization map was drew by using GIS technology, and the regionalization indices were calculated according to the grids of 100 m×100 m. The results of this study would provide a scientific basis for the production of Torreya grandis 'Merrillii’in Zhejiang Province.

To implement monitoring and assessment of national forest biomass, it is becoming the trend to develop generalized single-tree biomass models suitable for large scale forest biomass estimation. Considering that the theoretical biomass allometric model developed by West et al. (1997; 1999) was statistically different from the empirical one, the two parameters in the most commonly used biomass equation M=aD^b were analyzed in this paper. Firstly, based on the ideas of geometry, the theoretical value of parameter b was deduced, i.e., b=7/3(≈2.33), and the comparison with many empirical studies conducted throughout the globe indicated that the theoretical parameter could describe soundly the average allometric relationship between above-ground biomass M and D (diameter on breast height). Secondly, using 5 biomass datasets which consisted of 1 441 M-D pairs of sample trees, the new general biomass allometric model was validated. Finally, the relationship between parameter a and wood density ρ was analyzed, and the linear regression was developed. The new model, which is not only simple but also species-specific, offers a feasible approach on establishment of generalized biomass models for regional and national forest biomass estimation.

Prediction of species distribution and its changes play more and more important roles in the fields of ecological protection and application as well as global climate changes. It is impracticable to survey species distribution in large area, especially rare species. Considering that very few species distribution data have been accumulated, employ species distribution model fitting technique is highly necessary in the process of predicting species distribution. Sampling size has an important influence on expense of actual survey and accuracy of model prediction. In terms of accuracy of species distribution model and expense of forest survey, it is necessary to investigate the least sampling size when species distribution models reach the most accuracy. Thirty-four different sampling sizes(5, 6, 8, 10, 15, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 120, 150, 180, 200, 220, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 800, 900, 1 000 and 1 200) of four species were used to simulate the influence of different sample sizes on the precision and stability of MaxEnt species distribution model. The results showed that sampling sizes had no obvious influence on MaxEnt. The accuracy of MaxEnt was unstable when sampling size was small, but as sampling size was increasing(sampling size of training data was about 50, test data was about 120), the accuracy was more stable.

Immature embryos of Black Locust(Robinia pseudoacacia) were used as explants to study effects of immature zygotic embryo age, as well as the kind and concentration of plant growth regulators in culture media on callus and somatic embryo induction with an orthogonal experiment. The results showed that seeds collected 8 weeks(about 55 days) post-anthesis had the highest ability to initiate embryogenic cultures. The best callus initiation medium was MS+2,4-D 5.0 mg·L^-1+ BA 0.5 mg·L^-1, with which the highest callus induction rate, 95.42%±0.02%, was obtained. The best somatic embryogenesis medium was MS+NAA 0.5 mg·L^-1+BA 0.5mg·L^-1+Glutamine 250 mg·L^-1+Casein acid hydrolysate 500 mg·L^-1, and produced the highest direct and indirect somatic embryogenic frequency of 92.20%±0.12% and 90.73%±0.49%, respectively. Once globular-stage embryo formed, somatic embryos then matured and germinated to develop plantlets by transferring to the same medium without plant growth regulators.

Sequence Related Amplified Polymorphism (SRAP) analysis was applied to study the genetic diversity of Paeonia ludlowii, a species only distributed in Tibet of China. Sixteen pairs of SRAP primers were used to evaluate the genetic diversity of 79 samples from five natural populations. A total of 396 valid loci were obtained, of which 357 were exhibited polymorphism. The percentage of polymorphic loci (P_pl) and the mean diversity estimated with Shannon's index of phenotypic diversity(Η_sp) at species level were 90.15% and 0.252 1, respectively.At population level, P_pl was 31.82% and Shannon's index (H_o) ranged from 0.069 4 to 0.342 8, with an average value(Η_pop) of 0.130 7. Among the five populations, population C was especially more diverse(P_pl=82.32%,H_o=0.342 8). Those results indicated that there was a relatively high level of intraspecific genetic diversity. Analysis of molecular variance(AMOVA) demonstrated that a high degree of genetic differentiation occurred among the populations (Φ_{ST =0.415 8,P<0.001). The proportion of genetic variation among populations was 41.58%, while the proportion within population was 58.42%. A similar analysis result was exhibited by the genetic differential index(GST) of 0.430 9 and the proportion of diversity among populations with Shannon's index of 0.481 6. Mantel test showed that there was no significant correlation between geographical distance and genetic distance (r=0.597 5,P=0.905 5) among populations. A dendrogram conducted by UPGMA method using NTSYSPC(2.1) demonstrated that the range of genetic similarity coefficient was 0.47-0.99. The most of the individuals came from the same population had close genetic relationship, such as population of B, D, E,but individuals from population C could not be clustered together completely. A strategy for the conservation and utilization of P. ludlowii based on genetic diversity was proposed.}

Base on data of one-year continuous measurements of stem sap flow density for Larix gmelinii by a TDP method and environmental factors of solar radiation, air temperature, soil temperature, air humidity and soil humidity, variations in the relations between the sap flow and environmental factors were investigated at different temporal scales(month, day and hour) paper. Stepwise regression analysis showed the major environmental factors influencing the stem sap flow were different under the different temporal scales. At the temporal scale of a month, soil temperature and soil moisture markedly affected stem sap flow density and one unit increase in soil temperature could induce an increase of 0.084-0.123 L·cm^-2 month^-1. At the temporal scale of a day, soil temperature, solar radiation and air temperature markedly affected stem sap flow, and a unit increase of of soil temperature the most significant factor among the three, could induce an increase of 1.9-2.7 mL·cm^-2 d^-1 in sap flow. As temporal scale become smaller to an hour, general high impacts were from solar radiation and air humidity although much complex patterns were found according to different season. On average, one unit increase in the two parameters could induce an increase of 1.239 mL·cm^-2 min^-1 and a decline of 0.056 6 mL·cm^-2 min^-1 in stem sap flow, respectively. With time scale from large to small, in general, factors most affecting stem sap flow changed from below-ground root-water-absorption related parameters of soil temperature and moisture to above-ground leaf transpiration related parameters of light and air humidity. Moreover, much less parameters (2) with higher R² (>89%) were found in the regression analysis at the large scale of month, while more parameters(≥4) with low R²(<0.76) were found at the small scale of hour. In the calculations of total tree or forests water consumption, accordingly, long-term monitoring of small amount of environmental parameters can be used to scaling-up with high precision, while such type of method may give large bias for short-term studies comparing with direct TDP method. Our findings would benefit the understanding stem sap flow features and its scale-up.

Chilling requirement for bud dormancy and caloric requirement for blooming of 12 Peach varieties grown in southwestern Zhejiang were studied. With the use of Utah model, results showed that: among the 12 peach varieties, those with low chilling requirement (550-650 cu) were Amygdalus persica 'Chunmi’, Prunus persica 'Chaohong’, P. persica var. nectarine 'Zhongyoutao11, P. persica var. nectarine 'Zhongyoutao7’and Prunus persica var. nectarine 'Zhongyoutao4’, those with middle chilling requirement (650-800 cu) were P. persica var. nectarine. 'Liyou5’, P. persica 'Cangfangzaosheng’, P. persica 'Yanhong’, P. persica var. nectarine. 'Liyou3’and P. persica 'Zaofengwang’, and those with high chilling requirement (900~950 cu) were P. persica 'Xinchuanzhongdao’and P. persica 'Chiyue’. Large differences of caloric requirements for blooming were found among different varieties grown in the same area, but small differences were found within the same variety in different years. A two-year consecutive experiment showed: the low caloric-requirement (400-500 d·℃) varieties were P. persica 'Chiyue’and P. persica var. nectarine 'Liyou3’, the middle caloric-requirement (500-600 d·℃) varieties were P. persica 'Xinchuanzhongdao’, A. persica 'Chunmi’, P. persica var. nectarine 'Liyou 5’, P. persica var. nectarine 'Zhongyoutao4’and P. persica var. nectarine 'Zhongyoutao7’, and the higher caloric-requirement varieties (600-700 d·℃) were P. persica 'Zaofengwang’, P. persica 'Cangfangzaosheng’, P. persica 'Yanhong’and P. persica var. nectarine 'Zhongyoutao11’, and the highest caloric-requirement varieties which need 700-800 d·℃ were P. persica 'Chaohong’. There was a significantly negative correlation in power function between chilling requirement and caloric requirement of the 12 peach varieties.

Pollen morphologies of 33 different wintersweet (Chimonanthus praecox) cultivars in Henan were observed under SEM. Results showed: the wintersweet pollen grains was iso-polar, bilateral symmetry, and existed in the form of single grain, and most of grains were prolate; the pollen had 2-colporate. The exine sculptures were verrucous, vermicule, perforated and cave-shaped; the pollen morphology. The exine sculpture features, pollen shape and pollen size) could be used as the reference bases in the wintersweet cultivars classifications. The pollen morphology was not directly correlated with the external morphology. This study dose not support hypothesis classifying and identifying wintersweet cultivars by pollen morphology alone.

The volatiles of the male Dendroctonus valens infected, artificially damaged and control Chinese pine (Pinus tabulaeformis), were extracted with Porapak Q absorbent in headspace absorption method for eleven consecutive stages. The chemical constituents of the volatiles were analyzed by GC and GC-MS and their relative contents of monoterpenes were determined by the normalized peak areas. The infected pines contained significantly higher ratios of (+)-α-pinene (more than 90%) and myrcene, but lower levels of (+)-3-carene, (-)-β-pinene, camphene and limonene, when compared to the control and damaged trees. The abundance of (+)-3-carene (less than 4%) in the infected pines was lower than that in control and damaged pines. However, the abundance of (+)-3-carene in damaged pines reached to the level of control pines gradually from a lower level. The abundance of (-)-β-pinene and limonene was similar in different treatment pines, but there were significant differences among them after infected by male accompanied with femal D. valens. Although it is unknown whether D. valens releases pheromone after attacking Chinese pine in China, our results suggest that D. valens might use specific variations of composition of the monoterpenes as chemical cues for host tree selection and population aggregation. Meanwhile, this study has an important significance for explaining resistance mechanism of Chinese pine and improving the monitor and control system for D.valens.

Pseudoregma bambusicola is a pest of Bambusa multiplex. In this study, population dynamics of P. bambusicola were investigated in one-year-old B. multiplex coupled with ecological factors such as natural enemies and weather. The aphids were observed to firstly infest the bottom of bamboo shoots in late May in 2008, and then disperse into the whole bamboo clusters quickly. Population density of the aphids was highest during the period from August to September in 2008, then declined, and it did not rise until the early March in 2009. The 1^st-4^th instar nymphae could be found contemporarily in the whole year yound, however the age ratio of the nymphae (the 3^rd-4^th instar population:the 1^st-2^nd instar population) was classified as two distinguishable stages, one from early October in 2008 to the mid-March in 2009 with the ratio of 0.932, the other in the rest time with around 0.5. In the meanwhile, the occurence of three dominant natural enemies was regular pattern dependent on time. The population density of Asilidae sp. was highest from March to May in 2008, and the peak of population density of Lemnia saucia occurred between August and September in 2008, and the population density of Taraka hamada showed two peak periods during separately from July to August in 2008, and from November of 2008 to February of 2009. Among the three natural enemies, only Taraka hamada could prey on bamboo aphids all-year-round, and other two predators overwintered in the weeds beside the bamboo clusters from December in 2008 to February in 2009. Precipitation had some effect on population density of the bamboo aphids to some extent, and around 8.33%-20% of the aphids in the infested bamboo clusters was removed by continuously heavy rainfall.

To investigate the role of nitric oxide (NO) and nuclease in pine wilt disease, we examined NO content and nuclease activity in pine needles of Pinus taeda,P. massoniana,P. thunbergii inoculated with nematodes (Bursaphelenchus xylophilus) for 4, 12, 24, 48, 72, 96 and 120 h. The results showed that NO content in pine needles after the inoculation was P. taeda < P. massoniana < P. thunbergii, and this phenomenon was particularly evident at 12-48 h after the inoculation; the increase range of NO content in pines compared to their treatment which inoculated with distilled water was ranked as P. taeda > P. massoniana > P. thunbergii at 48 h after the inoculation. Meanwhile, the nuclease activity was significantly different in pine species after inoculation of the nematodes. The activity of single-stranded nucleic acid enzyme was in a rank of P. taeda > P. massoniana > P. thunbergii at 4-48 h after inoculation, however the activity of double-stranded nucleic acid enzyme in P. taeda was lower than P. thunbergii and P. massoniana during 4-96 h after inoculation. These results suggested that changes in activity of double-stranded nucleic acid or single-stranded nucleic acid enzyme in different pines were related to their resistance. The observation of symptoms showed that P. thunbergii first appeared wilt symptoms, followed by P. massoniana, and then P. taeda. The changes of NO content and nucleic acid enzyme activity were closely related to the development of pine wilt disease symptoms.

A non-invasive geophysical exploring method,ground penetrating radar (GPR) technique was used to detect subterranean termite nests. With a simulation experiment in which the GPR was used to detect the target's profiles of artificially buried metal pipes and termite carton nest, linear regression models between target and image sizes were established. Two and three dimensional nest images were created. After field survey,excavation was conducted to verify targets based on representative GPR profile data,features of GPR profiles of metal objects,voids,tree roots and termite nests were describe. The average error rate in determining nest size was 1.93% using the linear correlating model. Our study showed that GPR system was a useful assistant tool for monitoring and prevention subterranean termite.

Global Climate Change has a rapid and far-reaching impact on fire activities in forests. This paper made use of regional climate models’output and the calculated Canadian Forest Fire Weather Index (FWI) to analysis the changes on fire danger and fire season in future periods under SRES A2 and B2 scenarios on the scale of 50 km × 50 km. The results would provide a reference for future fire management planning in the study area. China’s regional climate for the period (1961—2100) under SRES A2 and B2 was modeled from a regional climate model system (PRECIS). The results were interpolated to 1 km×1 km scale by using ANUSPLIN software. The results showed that: PRECIS model had a good ability to simulate temperature and precipitation of the study area in baseline period. Spatial distribution of the temperature and precipitation was basically consistent with the observed values. Compared with baseline period, the FWI values in fire season (from November to the next May) for Southeast China will increase an average of 1.66 and 1.40 in 2040s under scenario A2 and B2 respectively. Meanwhile the average FWI ratios would increase by an average of 1.22 and 1.24 times under scenario A2 and B2 respectively,and range 1.1-1.5 times in most areas of the region. The change of FWI ratios suggested that the potential burned areas would increase by 22% and 24% than those in baseline period. Under the two scenarios the fire season would prolong significantly. In 2040s the total days with high,very high and extreme high fire danger rating would increase 17 and 13 days under scenarios A2 and B2,respectively. It is suggested to strengthen early warning,fire monitoring and fuel management in southwest China for preparing for the climate change.

Steam heat treatment can darken wood color remarkably. There is a highly relativity among the color change degree, heat treatment time and temperatures. The specimens of Chinese White Poplar (Populus tomentosa) was steam heat- treated in an airtight equipment with an atmosphere within comprising less than 2 percent oxygen content at temperatures from 170 to 230 ℃ for time from 1 to 5 hours, respectively. Saturated steam was used as a heating medium and a shielding gas. The results showed that the chroma difference (ΔC^* ) was decreased gradually while the color difference (ΔE^* ) and hue difference (ΔH^* ) were increased with the increase of temperature and the extension of treatment time. This indicated that the color of steam heat-treated wood became darker and darker compared with original color. Compared with treatment time, treatment temperature played a more important role to change the color of heat-treated wood during the process of heat treatment according to the results of ANOVA and multiple comparison analysis. Additionally, the regression models among the color difference, treatment temperatures and times were established. The results suggested that the better color of wood could be obtained after steam heat treatment compared with original color as well as the dimensional stability would be improved. Therefore, the value of the timber could be increased and the application fields could be extended after the steam heat treatment.

Three-year-old seedlings of loblolly pine (Pinus taeda) were selected as materials in this article. The seedlings were planted in spring and divided into five groups,then were artificially inclined at the angles of 0°,15°,30°,45°and 60° from the vertical. After four months,the anatomical properties and their variation patterns of compression wood changed with the different inclined angles were determined every three month (totally five times). The following conclusions were drawn: 1) With the increase of the inclined angle,the wall thickness of tracheid increased and the outline of the tracheid became round,the intercellular spaces and helical ribs were obvious and increased gradually in all sections derived from the inclined seedlings. 2) With the increase of the inclined angle,the tracheid length decreased firstly and then increased,the minmum value reached at 30°,the tracheid width decreased firstly and then increased,the minmum value reached at 45°,the double wall thickness increased firstly and then decreased,the maximum value reached at 45°.The ANOVA results revealed that there was highly significant effect of inclined angle on the tracheid length,the tracheid width and the double wall thickness. 3) With the increase of inclined angle,MFA increased firstly and then decreased,the maximum value reached at 30°. The ANOVA results revealed that there was significant effect of inclined angle on MFA. 4) With the increase of inclined angle,the proportion of tracheid and ray varied fluctuately,the proportion of resin canal increased firstly and then decreased,the maximum value reached at 30°. The ANOVA results revealed the effect of inclined angle was significant on proportion of the resin canal,but not significant on the proportion of tracheid and ray. 5) From the variation patterns of the different wood anatomical properties at different angles,the leaning angle of 30°-45° was an important turning point for the formation of compression wood and the further study was needed to understand this mechanism.

Bamboo-based SiC ceramics were prepared by carbothermal reduction reaction between charcoal and silica that was introduced into bamboo through a sol-gel and vacuum/pressure infiltration process. The microstructure, chemical compositions and mechanical performances of the prepared ceramics were characterized. Experimental results showed that the phase compositions of the ceramics were highly dependent on the sintering temperate and time. 1 450 ℃ and 5 h could ensure almost all the SiO₂ to be transformed into SiC while lower temperature and longer or shorter time will remain or produce certain quantity of SiO₂ in the ceramics. The produced biological ceramic was actually a composite of higher proportional C and SiC, which was mainly formed and distributed on the surface of bamboo carbon. Compression strength, bending MOE and MOR of the composite ceramics were all found to increase and then decrease with the increase of SiO₂ weight gain. Optimal mechanical performances were achieved when SiO₂ weight gain was 10% and much more superior to those of bamboo carbon.

Poplar (Populus spp.)veneers were dyed using wood thermochromic gent including thermochromic dye, chromogenic agent, 1-tetradecanol and sensitizing agent though ultrasonic impregnation and the impregnation process of reversible thermochromic poplar veneers was investigated in this research. The results showed that the effect of ultrasonic power on ΔE^* was greatest and its effect on ΔE^* was the most remarkable at 0.01 levels based on variance analysis. The second effecting factor was impregnation time and the last was impregnation temperature. According to variance analysis, their influence on ΔE^* was not remarkable at 0.01 levels. The optimum impregnation process was impregnation temperature 75.0 ℃, impregnation time 4.0 h, and ultrasonic power 120.0 W. The new product of reversible thermochromic poplar veneers was finally made in the laboratory. Its color gradually changed from blue to wood color with temperature increase from 26 ℃ to 32 ℃. Otherwise, its color gradually changed from wood color to blue with temperature decrease from 32 ℃ to 26 ℃.

Use larch dimension lumber from China and imported truss plates to manufacture truss plate connection, and test the tension properties of the connection. The testing result point out that larch dimension lumber from China can take the place of SYP to manufacture timer truss. Three new truss plates were designed, which used domestic zinc coated steel. Test the behavior of domestic truss plate. The testing result point out that domestic truss plate meet the requirement of volume production, and new designs can advance the performance of truss plate connection. But domestic truss plate need to adjust the processing technic, then can use in actual production.

Authors put over a kind of method which checks and adjusts the dynamic tensile force range of band saw blades. It results its natural frequency under static and dynamic states, and come to calculats static tensile force and dynamic tensile force of band saw blades by means of the string vibration formula, its calculating precision is to be identical with adjusting tensile force range of band saw blades. The result showed that regularity to utilize string vibration simplified theory model accorded the actural condition of relationship tensile force and natural frequency with woodworking band saw blades. Meanwhile, it's full reciivability that the paper bringed forward the measure method of dynamic natural frequency and static natural frequency,as this study question to adjust inspection and acceptance means of dynamic tensile force of band saw blades and its engineering application. It inspected and measured natural frequencies of band saw blade to determine its tensile state,so that realized dynamic adjustment of tensiled band saw blade by means of shock excitation, and had supervise signification to lucubrate of woodworking band saw blade theory and improvenment of its equipment technology.

The progress of genomics research on bamboo is summarized in this review. I focus on development of molecular markers (RAPD, RFLP, AFLP and ISSR) and their application on bamboo studies, including bamboo genes related to flowering, cell wall synthesis, photosynthesis and stress tolerance, the genome sequencing of bamboo and comparative genomics with other species. The basic research on bamboo genomics is still missing and the bamboo gene functions are hard identified. Therefore, bamboo genetic transformation system should be established, and the research on comparative and functional genomics and the molecular marker-assisted breeding should be emphasized in the future.

CBF transcription factors play a central role in controlling freezing tolerance in plants. A novel CBF/DREB1 gene was isolated, from Corylus heterophylla, one of the cold-hardiest Corylus species, named as ChCBF. Sequence analysis revealed that ChCBF had 1 053 bp in full length and contained an open reading frame (ORF) of 684 bp encoding a 227 predicted amino acids residues which possessed conserved AP2/EREBP domain for the CBF function. Sequence alignment and phylogenetic analysis revealed that conserved domain of ChCBF shared high identity with CBF homologues from other plant species in all conserved regions. Expression profiling of ChCBF was performed by qRT-PCR method, ChCBF transcripts were highest at the stage of cold acclimation (CA), while the level of ChCBF was down-regulated during the coldest mid-winter (MW), and increased again as buds deacclimated (DA). ChCBF transcripts were rapidly and highly induced when plants were exposed to low temperatures of 4 ℃, and ChCBF was activated in 4 h reaching a peak, suggesting that the critical transcriptional changes of ChCBF occurred majorly during the initial 4 hours and it was possibly involved in early-stage responses to low temperature. Spatial expression analyses revealed that the transcription level of ChCBF was relatively higher in bud than that in male inflorescence and bark tissues. These results suggest that ChCBF may participate in the cold acclimation process and show temporal-spatial specific expression characteristics in hazelnut.

In this paper, the pattern of dynamic change of Jujube’s stem diameter and its influencing factors (the soil moisture and meteorology factors)were studied under two soil water potential gradients (T1: -15~ -25 kPa,equivalent to field capacity 65%-70%; T2: -45--55 kPa,equivalent to field capacity 50%-55%). The factors influencing the model prediction were analyzed through establishing regression model between maximum daily trunk shrinkage (MDS) and reference crop evapotranspiration (ET₀), daily mean vapor pressure deficit (VPD), daily temperature difference (DTD) and air water potential (Ψ_a). The results showed that: 1) The fluctuation of soil water potential of T2 was greater than that of T1. The values of maximum daily trunk shrinkage (MDS) and trunk daily growth (DG) of T2 were greater than that of T1, while the values of maximum trunk diameter (MXTD) and minimum trunk diameter (MNTD) were smaller than that of T1. 2) The linear correlation coefficients between MDS and air evaporation strength index and temperature index were much greater under both soil water potential gradients, while the linear correlation coefficient between MDS and meteorology factors in T1 was greater than that of T2. (3) Extreme weather conditions caused sharp change (extreme value) in stem diameter and influenced the prediction accuracy of MDS model during the experimental period.

Extracts of Stellera chamaejasme by supercritical fluid extraction (SFE) were shown to have acaricidal activities against Tetranychus cinnabarinus. In this experiment, the supercritical parameters of CO₂ in SFE were optimized for extracting the components of Stellera chamaejasme by uniform experimental design, and the extracts were further analyzed by GC/MS method. The results showed that the optimal condition of supercritical CO₂ extraction was extracting pressure 49 MPa, extracting temperature 15 ℃, resolution pressure 43 MPa, and resolution temperature 6.25 ℃. Under the optimal condition, the theoretical extract rate was 3.77%, and the measured extract rate was 3.75%. Extracts of Stellera chamaejasme with the optimal SFE condition had higher contact and systemic toxicity against Tetranychus cinnabarinus in comparison with that by cold-soaked extraction method, with LC₅₀ value of 2.407 mg·mL^-1 and 2.990 mg·mL^-1, respectively. There were 13 compounds detected in the extracts, which accounted for 99.99% of all components. The major compounds were squalene, 9,12-octadecadienoic acid (Z,Z)-,n-hexadecanoic acid,quinoline, and campesterol. Squalene was for the first time found from S. chamaejasme. Squalene was found to have contact and systemic toxicity against T. cinnabarinus, with LC₅₀ value of 9.918 mg·mL^-1 and 12.918 mg·mL^-1, respectively.

This paper investigates bamboo planks processed from 170 various bamboo stems and their carbon transfer ratio. Analysis of carbon transfer ratio of bamboo stems with 5 different specifications and different bamboo diameters. Relationship between bamboo plank carbon sequestration and diameter at breast height were established. Results indicate the following: 1) Carbon transfer ratio of different bamboo diameters differed significantly (P<0.01). Carbon transfer ratio of bamboo stems with 5 different specifications ranged from 35.0% to 39.7%,with an average of 37.0%. 2) Total carbon transfer ratio of different bamboo diameters rangeed from 10% to 35%. As the diameter increased,the utilization ratio of the whole moso bamboo also increased linearly. 3) Using the above established relationship and the probability distribution model of moso bamboo.