In order to understand the effect of land cover change from abandoned land to Caragana korshinskii forest land on soil water resources, the dynamics of soil water content with time in the soil layers from 0－400 cm in both of caragana forest land and wasteland was measured simutaneously with neutron probe in fixed positions, and effect of the land cover change on soil water resources was quantitatively analyzed. The results showed that there was a negative effect of the land cover change on soil water resources during the observed years (2002—2006), with the exception year in 2003 in which there was a positive effect of the land cover change on soil water resources because it was a wet year. The influenced degree of the land cover change on the annual averaged soil water content, soil water storage in the soil profile was exacerbated with plant age. The difference of soil water content and soil water storage between the two kinds of land cover type was increased with plant age. Because the precipitation is the only resource of soil water in the semiarid loess region, some proper measures should be taken at the fifth year of C. korshinskii forest to control its growth in order to reduce soil water consumption,prevent deep soil from desiccation and realize the sustainable use of soil water resources and vegetation resources.

The population dynamic and quantitative characteristics of Haloxylon ammodendron in Gurbantunggut desert was analyzed based on a theory of population dynamics and spectral analysis. The results showed that the survival curve of H. ammodendron populations tended to be the type of Deevey-Ⅲ. The mortality rate of H. ammodendron was high at early stage and low at late stage. There existed 2-4 death peaks in the population life process. Spectral analysis showed the natural regeneration process of H . ammodendron population was expressed in fluctuation of the number distribution of trees in different age grades. The quantitative fluctuation of H . ammodendron population exhibited in large cycles within each which there were at least two small cycles. The influences of these cycles dropped with the diminishment of cycle length, and the effect of fundamental wave was more distinct. The fundamental wave was mainly affected by environmental factors, to a less degree by its biological characteristics. Upscaling process of spectrograph in different habitat showed that the small scale changed prominently, while the large scale was relative steady. Therefore, the sampling area of H. ammodendron population fluctuation in Gurbantunggut desert was 4 400－5 600 m² in relative environmental condition, and 4 400－9 200 m² in otherwise condition.

In order to comprehend the sustainable developmental potential of Robinia pseudoacacia plantation in different habitats in Loess hilly region, diameter classes, species diversity, the soil moisture and nutrient were analyzed based on an investigation of R. pseudoacacia community in Zhifanggou and Liulinzhen of Yan’an Regions. The forests were planted 10, 25 and 40 years ago on the sunny and shady slope. The results showed that R. pseudoacacia plantations reached mature stage in 25 years, and the average diameter, height, understory species diversity, the soil moisture and nutrient reached stable state on both the sunny and shady slope. Height, diameter as well as other parameters, which reflect environment quality, increased quickly, but they did not show obvious increase after 25 years. On shady slope, the trees grew better and had adequate regenerated seedlings, there was rich species in the community, the soil moisture and nutrient were relatively abundant, and in general the R. pseudoacacia community had sustainable developmental potential. On the contrary,on sunny slope, the individuals were maldevelopment, there was no enough seedlings and lower species diversity in the community, the soil moisture and nutrient were relatively deficit, R. pseudoacacia community did not have sustainable developmental characters. In the future, it should be avoided to plant R. pseudoacacia on the sunny slope, and transformed the existing R. pseudoacacia plantations into R. pseudoacacia -sparse shrubs plantations in the loess region. In order to stimulate the regeneration of seedlings and promote the community evolving into an uneven-aged stand, some ungraded woods and diseased woods should be removed in the R. pseudoacacia plantations over 25 years old on shady slope. During the thinning process, the shrub layer should be protected by which the community complex structures are consummated to improve the ecological benefit.

In this paper, the effects of Robinia pseudoacacia plantation at different ages on soil enzyme activity was studied in loess hilly region using a method of time-space mutual substitution, slope cropland and Platycladus orientalis forest were selected as references. The results showed that urease, phosphatases, saccharase and catalase activities in the soil were increased significantly with increase of years, however cellulase fluctuated dramatically. In 50 years, activities of the enzymes increased by 160.2%,281.8%,162.2%,92.6%,73.8% respectively, compared to the slope cropland, but still lower than that in P. orientalis forest. Soil polyphenol oxidase was decreased by 39.11% and amylase was increased in the early years and then declined with time. The significant relationships were observed between soil urease, phosphatases, sucrase, cellulase, catalase, polyphenol oxidase activity and nutrient factors, therefore the enzymes could be used as biological indicators for assessing soil quality. SEI (soil enzyme index) increased at the early stage, followed by a relatively stable stage for 10 to 25 years, after then it continued to increase and reached to the maximum in the 50 years. But it was still lower than that of P. orientalis forest. It is concluded that low soil enzyme activity of slope cropland under erosive environment, owing to human cultivation activities, was improved greatly after planting the R. pseudoacacia forests, but it needs a longer time to reach to the level of P. orientalis forest, the climax community in this region.

In this paper, fine roots of Robinia pseudoacacia and the soil moisture were investigated using an auger in Ansai County and Jingchuan County of the Loess Plateau region from June 2007 to April 2008. A similar variation trend was found in both the fine root surface area density of Robinia pseudoacacia and the soil moisture, with the soil depth. A coupled model, S=pe^{sin π/6 t-m} ·W^ae^-bh, was established, describing the relationship between fine root surface area density and soil moisture, with soil depth and time. It is proved that the model could reflect the coupling relationship exactly. The fine root growth and soil moisture display annual cyclical changes in the model. The value of parameter a falls in between 0 and 1, which suggests the root growth of Robinia pseudoacacia just absorbs part of the soil moisture and could not cause soil desiccation in the investigated area.

An approach was proposed for calculating the rainfall-runoff responses in the fractal geometry, and it was established by using a recursive replacement algorithm of function (RRF) to two types of the strict self-similar river networks (SSN). In order to estimating the hydrologic responses, two sets of recursive equations were developed for two types of the SSNs, T₁ and T₂, respectively. To verify the RRF algorithm, two groups of data measured in the small catchments of Liaohe river in northeast China were used to examine influences of forests on the runoff of large watershed. According to the simulation of RRF, the favourable influences of forests in the small catchment on the runoff are not only maintained, but also further strengthened by the self-similar river networks.

In this study, association analyses between leaf autumn senescence and single nucleotide polymorphisms (SNPs) derived from amino acid change in the genes of photoperiod pathway of Populus tremula were conducted by linkage disequilibrium mapping (LD mapping) with naturally regenerated aspen populations. The results showed that nucleotide transition between A and G in the 291 nucleotide loci of Phytochrome A gene led to significant variation in autumn senescence index among the three genotypes of AA, AG and GG. The variance P-value between the three genotypes was 0.018 and the Bonferroni adjusted P-value became 0.04; No significant linear correlation was detected between all the selected SNPs in the candidate genes of photoperiod pathway and the senescence duration; Values of the same genotypes in the 291 nucleotide loci of Phytochrome A gene demonstrated significant variance in the starting day of senescence. But the Bonferroni adjusted P-value was more than 0.05, which indicated no significant variance existed between the senescence starting days of the three genotypes, which suggested the complication in regulating senescence starting day during autumn senescence in Europe aspen.

Two full-length cDNAs encoding aspartic proteinases(APs)were isolated respectively from the normal and mutant short catkin of the Castanea mollissima with RT-PCR and RACE amplification method. The sequence results showed that the full-length cDNA from normal was 1 822 bp, while that from mutant was 1 909 bp. They all contained a 1 539 bp open reading frame (ORF) which encoding a protein of 513 amino acids and had 83%, 80% and 75% amino acid sequence similarity with aspartic proteinases in Ricinus communis, Theobroma cacao and Vitis vinifera respectively. The two deduced proteins have six different amino acids, three of which are in the activity areas. Later they were confirmed to be existed both in normal and mutant short catkin,namely CmAPs1 and CmAPs2 (accession No.GQ984143 and GQ984144).The results of Realtime RT-PCR indicated that the expression of CmAPs1 and CmAPs2 gene in mutant catkins was both higher than that in the normal catkins in the primordia formation phase of catkin, floral cluster and flower. However, the expression of CmAPs1 and CmAPs2 gene in mutant catkins was so far lower than that in normal in the stage of perianth primordium formation (programmed cell death happened at the same time), it is speculated that CmAPs would be related to programmed cell death in the process of short catkin development.

With a potting experiment, morphological parameters and five physiological indicators including malondialdehyde(MDA), catalase(CAT), chlorophyll(Chl), proline(Pro), and leaf water content(LWC) of the 4-year-old Pinus densiflora var. zhangwuensis and P. sylvestris var. mongolica were measured in different soil moisture gradient. The results showed that: P. densiflora var. zhangwuensis had significantly heavier total dry weight, dry weight of root, dry weight of stem and greater ratio of root and stem, had significantly smaller single needle area, and had slightly more thick needle than P. sylvestris var. mongolica. In different water gradient, P. densiflora var. zhangwuensis had lower MDA contents, and higher CAT and Pro contents than P. sylvestris var. mongolica. In mild drought area(40%FMC), MDA, CAT and Pro contents of P. sylvestris var. mongolica had a ascending trend in comparison with those in control area(100%FMC), and the three physiological indicators had a further increase in moderate drought area(30%FMC) and reached to the maximum in serious drought area(20%FMC). By contrast in mild drought area these three physiological indicators in leaves of P. densiflora var. zhangwuensis were lower than those in control area, and began to increase in moderate drought area, especially the CAT content was significantly higher than that in control area, and they also reached to the maximum in serious drought area. The above results determinated that P. densiflora var. zhangwuensis showed stress symptoms at a lower soil moisture, and it could endure and adapt to drought stress by improving protective enzyme activity(CAT) and increasing osmotic substance(Pro). At different moisture gradient, both Chl and LWC of P. densiflora var. zhangwuensis were more than those of P. sylvestris var. mongolica, and these two indicators in the same species had the same changing trend, which was : CK> mild drought area> moderate drought area> serious drought area.

Four-year-old potting seedlings of Prunus cerasifera var. atropurea were used to study the color parameters of leaves,variation of pigments,the content of soluble sugar and the activity of PAL under NaCl stress. The soil salt contents were 0.042(CK), 0.1%, 0.2%, 0.3% and 0.4% respectively. The results were as follows: with increasing prolonged of NaCl stress time,lightness L^* -value and hue angle h increased,chroma C ^* and chromatic component a^* -value decreased. Chromatic component b^* -value and the content of soluble sugar increased in the first 15 days and then decreased with time and soil NaCl concentration. The activity of PAL increased in the first 5 days of treatments and then decreased with 10th days after that it rose again. With extension of treatment time the L^* -value increased and pigment contents decreased,which indicated that: The lower the content of pigments,the higher the lightness. P. cerasifera var. atropurea changed the content of pigments and ratio of pigments by regulating,hence the soluble sugar and the activity of PAL, then the colors of leaves would turned to kelly. The NaCl treatments reduced the ornamental value of P. cerasifera var. atropurea .

Influences of NO on active oxygen metabolism and relevant quality of Chinese Bayberry (Myrica rubra) fruits were studied to provide scientific basis of NO application in fresh preservation. Fruits of Chinese Bayberry were immersed with 0,10,25,and 50 μmol ·L^-1 sodium nitroprusside(NO donor) respectively for 2 hours,and then stored for 16 d at (0±0.5)℃. Active oxygen production,relative electric conductivity,MDA content, enzymatic activity of SOD,CAT and POD and decay index were measured thereafter in every 4 days. The results showed that NO from 25 μmol ·L^-1 SNP significantly decreased the decay of Chinese Bayberry and inhibited the decline of vitamin C,titratable acid,and total sugar compared with the control fruits. NO treatment maintained significantly higher levels of SOD,CAT and POD activities of Chinese Bayberry,and inhibited the increase of H₂O₂,superoxide radical production,relative electric conductivity and MDA content. This study suggests that NO could maintain the balance of active oxygen metabolism in Chinese Bayberry,and thereby delaying fruit senescence and inhibiting fruit decay.

The variation of anthocyanin and the relevant biosynthesis enzymes in Prunus persica f. atropurpurea leaves was investigated after spraying the leaves with microelement (Fe, Mn, Zn, B). The results indicated that the content of anthocyanins in leaves was not significantly different in each treatment in the beginning of treatments. The content of anthocyanin increased after 20 days with spraying Mn and Zn, and the anthocyanins content had extremely significantly positive correlation with Mn content. Fe inhibited synthesis of anthocyanin in P. persica f. atropurpurea leaves. Among phenylalanine ammonialyase(PAL), chalcone isomerase(CHI), dihydroflavonol 4-reductase (DFR) and UDP glucose flavonoid glucosyltransferase(UFGT), the change of DFR activity was more significant than PAL, CHI and UFGT, and the DFR activity after spraying Mn and Zn and the activity was significantly higher than CK. Moreover, the DFR activity increased before the anthocyanin content did, which suggested DFR initiated the synthesis of anthocyanins.

This experiment,the influences of temperatures,pH values and inoculum concentrations on the number of adsorption and ingression of Ralstonia solanacearum to Eucalyptus urophylla × E. grandis root. The optimum temperature for R. solanacearum to adsorb to and ingress in the Eucalyptus root was 30 ℃.The more suitable pH value for the adsorption and ingression was 6.0 or 7.0. Number of the adsorption and ingression was very high under both 3.0×10⁸units ·mL^-1 and 3.0×10⁹ units ·mL^-1 inoculum concentrations. Higher concentration of R. solanacearum was favorable for its adsorption and ingression,but the number of adsorption and ingression did not increase accordingly when the concentration of bacteria was too high. The best conditions for R. solanacearum adsorption and ingression were 30 ℃,pH value 6.0 or 7.0 and 3.0×10⁸ units ·mL^-1 bacterial concentration or higher.

Twenty-three strains of Bursaphelenchus mucronatus were used for inoculating two-year-old seedlings the following of Pinus taiwanensis and Pinus thunbergii to investigate their pathogenicity in this study. The main results were: 1)Four of Twenty-three B. mucronatus isolates had pathogenicity on the two-year-ole seedlings of P. taiwanensis, and they were SFS4, ZJ1, KOR1 and SLD3 respectively. 2) Nine of Twenty-three isolates of B. mucronatus had pathogenicity on the two-year-old seedlings of P. thunbergii, and they were CFL1, SFS1, SFS4, SLD9, SDZ1, ANL5, ANL7, AHS9 and HYC1 respectively. 3)According to disease index, morbidity rate and disease rate of B. mucronatus to two-year-old seedlings of P. thunbergii, twenty-three isolates of B. mucronatus were divided into three levels: Class Ⅰ (strong pathogenicity), Class Ⅱ ( weak pathogenicity) and Class Ⅲ (no pathogenicity). 4)Three of four populations from Anhui province had pathogenicity to two-year-old seedlings of P. thunbergii, wmong which two populations (ANL5 and ANL7) had strong pathogenicity; Four (SFS1,SFS4,SLD9,SDZ1) of five populations from Sichuan province had pathogenicity to two-year-old seedlings of P. thunbergii, and another population (SLD3) had pathogenicity to two-year-old seedlings of P. taiwanensis; All four populations from Jiangsu province had no pathogenicity to two-year-old seedlings of P. thunbergii and P. taiwanensis

Prediction of spatial distribution and occurrence area of alien forest pests and diseases is a prerequisite for making managing measures of biological invasions. In this paper data from 75 pine wilt disease occurrence points with geographic coordinates and 68 environmental variables were gathered in 2007. Four habitat modeling methods of Classification and Regression Trees(CART),Genetic Algorithm for Rule-set prediction(GARP),maximum entropy method (Maxent),and Logistic Regression(LR) were introduced to generate potential geographic distribution maps for invasions of pine wood nematode in Jiangsu province. Then the occurrence area was predicted in each county of Jiangsu province. Results showed that CART outperformed other three models. Slope, precipitation seasonality (bio15), compound topographic index (CTI), mean temperature of driest quarter (bio9), slope aspect, maximum temperature of warmest month (bio5) were the six forcing environmental factors. CART model predicted that future occurrence area of pine wilt disease would account for 39.04% of total pine forest, 2.73 times of present infected area of the pest. Yixing, Liyang and Jurong would be the most susceptible counties to the pest, while Yixing,Liyang and Nanjing urban would have the largest infected forest area.

A new canker disease had taken place on walnut (Juglans nigra) in Xinjiang. In resent years, it has caused severe damage to the walnut product. In this paper samples were collected from diseased walnut in walnut gardens and 2 isolates were obtained. The isolates were inoculated with both wound and healthy inoculation methods. Re-isolation from lesions formed by the inoculation was the same as the inoculatied isolate, demonstrating that the isolate was a pathogenic strain of Pythium oligandrum based on its morphology. The sequences of the isolates Pythium oligandrum were amplified by PCR technique with universal primers of fungi, and the sequences were further compared with that in GenBank. The molecular identification confirmed the results from morphology identification. This is the first report that Pythium oligandrum is the pathogen of walnut black water disease in China.

Antennal sensilla of a bamboo-shoot noctuid, Apamea apameoides, were observed with a scanning electronic microscope (SEM). It was found that the female moth had eight types of sensilla, and the male moth had nine types. Altogether 16 types of sensilla including common types and dimorphic types were identified with two trichoids, two chaetics, two basiconics, three coeloconics, two auriculates, two styloconics, one cavitata-peg, one squamiformic and Bhm. AuriculateaⅠb and A.Ⅱb separately occurred on female and male's flagella, the morphology of A.Ⅰb type was similar to slender leaves, and the top of A.Ⅱb was bifurcated. CoeloconicaⅡand C.Ⅲ occurred only on male's antennae, C.Ⅱ was composed of one nakedly cone-shaped sensillum and without microtrichia around, C.Ⅲ had the same centric structure as C.Ⅱ but enclosed by double peripheral microtrichia. StyloconicaⅡ was morphologically much smaller than S.Ⅱ, and only occurred on female’s antennae. The antennae exhibited obvious sexual dimorphisme;one typical character was that the flagella of female moth were half-fused in some antennal segments, however not happened to the male moth.

Insect wax is an important raw industrial chemical excreted by 2^nd instar male nymphae of the white wax scale Ericerus pela (Insecta). In the traditional technique for insect wax production, egg laying females(known as seed insects) are reared in high mountain areas in Yunnan Province and then the nymphae are transported over long distances to low mountain areas in Sichuan, Hunan Province where they produce wax. The breeding of white wax scale egg laying female and insect wax production presently do not take place in the same region. A new production model in which egg laying female rearing and wax production takes place in the same region has been developed based on biological and ecological characteristics of the white wax scale. When white wax scale eggs are incubated, the female nymphae are hatched before male nymphae. Eggs being incubated at RH 80%±10% nymphae started to hatch at 10 ℃. At 15－20 ℃ all eggs hatched in 16－20 days, with a hatching peak for female nymphae between 9－11 days, and a hatching peak for male nymphae between 14－15 days. At 25 ℃ all eggs hatched in 11－12 days, with a peak for the female nymphae between 4－5 days, and a peak for male nymphae between 10－11 days. At 30 ℃ all eggs hatched in 9－10 days, with a peak for female nymphae between 3－5 days, and a peak for male nymphae between 6-8 days. The hatching conditions for wax production were determined by the formula D =12.5-0.35 T based on the relationship between temperature and hatching rate. In the field, the formula H _{a(♀)=(31.91-0.224 K )% was established based on the relationship between effective accumulated temperature and hatch rate. In this new production model eggs were hatched in two different sites, but in the same region, and this model was able to reduce transportation costs. Based on the hatching character of white wax scale, eggs were incubated first at the egg laying female production site for 10, 15 and 18 days, and then transferred to the wax production. When egg laying females were transferred after 10 days incubation, about 65% female nymphae and 15% male nymphae were produced in the egg laying female sites. Later hatching at the wax production site resulted in 35% female nymphae and 85% male nymphae. If being transferred after 15－18 days incubation, there were about 70%－80% female nymphae and 25%－35% male nymphae produced in the egg laying female production site, while later hatching at the wax production site produced 65%－75% male nymphae and 20%－30% female nymphae. As compared to traditional wax production techniques, this new wax production model resulted in the same amount of egg laying insects, but wax production was about 30% less. Wax output using the new technique, however, can be improved by selecting the shade site and increasing the density of host plants at the wax production site. In this paper we analyze why only egg laying females are presently produced in high mountain areas and wax is produced in low mountain areas.}

The ASE, crystallinity and characteristic of FTIR of super heat-treated Larix spp.( heat-treated temperature ranging from 180 to 240 ℃,heat-treated time was 4 h) were determined and characterized by the research. Results showed: the value of ASE increased along with the heat temperature increasing ranging from 180 to 220 ℃ and was beyond 60%, but when the heat-treated medium was nitrogen, the value of ASE was lower than that of air. The spectrum of FTIR demonstrated that the stretching vibration of —OH groups at 3 380 cm^-1 was diminished accompanying the enhancing heat temperature and obviously changed. The relative intensity of carbonyl group at 1 730 cm^-1 decreased with the increasing temperature. At the same treated situation, the hydroxide and carbonyl groups in the nitrogen were lower than those of oxygen. The tendency of crystallinity of super heat-treated Larix spp. was firstly increased, then decreased and finally increased. The value of crystallinity in the nitrogen was higher than that of air and over 65% under identical circumstances.

Structural characterizations of four cellulose fractions isolated by alkaline hydrogen peroxide from defatting Mucuna sempervirens fiber were studied. With the increasing of fractional grade, weight-average molecular weight gradually decreased owing to the increase in splitting degree of cellulose molecular chain. Four cellulose fractions belong to cellulose Ⅰ. Except that there contained a little lignin and hemicellulose in the first fractional cellulose because there obviously appeared the absorbance spectra relative to lignin and hemicellulose in the FTIR pictures. However, there didn’t nearly contained lignin and hemicellulose in the second, third and fourth fractional cellulose because their purities were high above 97.0%. After fractionating, there happened some great changes for the structure of four cellulose fractions. That is, cellulose bundles became much shorter and much thinner from the first fractional cellulose to the fourth fractional cellulose. The crystalline degree of the first, second, third and fourth fractional cellulose increased in proper order, while the crystalline degree of first fractional cellulose was much lower.

The preparation of carbon/pottery composite from wood charcoal and clay was made with physical method and the effect of temperature and holding time on the adsorption capability of carbon/pottery composite was discussed in this paper. In addition, microstructure and pore distribution of carbon/pottery composite were characterized by SEM and BET and the idea of in situ activation was proposed.The results show the pore between wood charcoal and pottery developed during heating treatment while the clay did not block the pore structure of wood charcoal. On the other hand, the adsorption capability of lumpish shape was higher than pulverous shape. Furthermore, the activated reaction of carbon/pottery composite could be defined as in situ activation.Therefore, under optimized experimental condition,the adsorption values of methylene blue and iodine of carbon/pottery composite were 127.5 and 543.6 mg ·g^-1 respectively.

This article applies analytic hierarchy process(AHP)to evaluation and decision of furniture design scheme. AHP is used to establish the furniture design program theory evaluation hierarchy,and calculate and analyze furniture program evaluation index weights of all levels. It consists of two major contents: appearance attributes (MG), 42.86%; utility property (SY), 44.81%; economic attributes (JS), 12.34%. The second evaluation index weights of the furniture design scheme,such as furniture style (K_X), 0.150 8; furniture color (K_S), 0.127 0; furniture decoration (K_Z), 0.150 8; furniture features (K_G), 0.150 8; furniture materials (K_C), 0.146 5; furniture process structures (K_Y), 0.150 8; furniture prices location (K_J), 0.123 4. At the same time it builds the model of furniture design program evaluation to guide the furniture design.

The conditions of transforming between positive external effects and negative external effects of commercial forest were demonstrated on the basis of analyzing the phenomenon of the two effects in the producing process of forestry,and the works of externalities of commercial forests were treated as concealed influences.In the light of the theoretical foundation to solve the problem of externality,the suggestions concerning to the following measures about commercial forest internalization of externalities were presented combining with the real situation of production of commercial forest: make up for the silviculture work by margin; forest road construction,the design of optimization to cutting area and the work for prolonging the rotation period should be recouped appropriately; remit or reduce the tax of wood production; invest in afforestation on the barren mountain in full; purchase the current forest,etc.

Structural proteins are important compositions in plant cell wall, and the first structural protein detected in plant cell wall is one of extensins which account for 1%-15% of the dry weight of the primary cell wall.The term extensin generally refers to all hydroxyproline-rich glycoprotein members in an inclusive sense. However, the term is also used to specifically describe HRGPs possessing Ser-Hyp₄ repeat motif. Their major functions are to control cell wall extension, and to enhance the mechanical resistance of plant cell wall. In recent years, studies on rsh mutant of Arabidopsis demonstrated that extensins also played an essential role in initiating the cell wall formation, which was a nascent function of extensins. The post-translational modifications of extensins include proline hydroxylation and the subsequent glycosylation of Hyp and Ser residues, intra- and inter-molecular cross-links activated by peroxidase, self-assembly through linear and lateral molecule links. Since extensins are one of the main structural proteins in plant cell wall, studying the function and structure of extensins is important for our better understanding about cell wall structure and cell wall assembly.

Definitions and evaluation methods of forest degradation from different organizations were reviewed. The feasibility using criteria and indicators of the sustainable forest management to evaluate the forest degradation was discussed, and the relationship between forest degradation and carbon emission was elaborated. At last, the prospect in forest degradation research was proposed.

Young trees are at the most sensitive stage to environmental stress in the life history of forest species, and they play a key role in maintaining and regenerating the population. An experiment was conducted to study the quantitative characteristics, growth dynamics of young trees and the effect of stand condition (adult tree, shrub layer and herb layer) on regeneration in Pinus thunbergii coastal protection forest in northern Shandong Peninsula. The mean density of young P. thunbergii trees was 4 024 tree·hm^-2, in a range of 50－24 300 tree·hm^-2. There was a positive exponential correlation between height and basal diameter, indicating that the young P. thunbergii population was at the rapid growth stage. Age structure of young P. thunbergii population was fairly complete, and it could be expressed as a one-humped curve. The middle-aged young P. thunbergii trees made up a large proportion, which indicated that the young P. thunbergii population stayed in a stable state currently. The height structure of young P. thunbergii population was of pyramid types, and the number of young trees decreased with increase in height grade. Most of young P. thunbergii trees were distributed in 0.3－0.9 m from a standing tree, and the number of young P. thunbergii trees decreased nearer to or far from the standing tree. Correlation analysis showed that the growth status of adult P.thunbergii trees was a driving factor to the regeneration of young trees, while shrub and herb layer had no relation to the regeneration of young trees. The forest crown closure might be a main influencing factor to the regeneration of young trees.

Forest management measures have a significant impact on carbon and nitrogen cycling in the forest ecosystems. In order to understand any effect of different fertilization treatments on water-soluble organic carbon, nitrogen (WSOC, WSON) contents, and emission of greenhouse gases, a fertilization experiment was conducted in the typical Phyllostachys edulis stands located in Lin'an, Zhejiang Province. Six treatments were applied in this study: 1) no fertilization; 2) ordinary fertilization amount; 3) 2 times of ordinary fertilization amount; 4) half of ordinary fertilization amount; 5) only nitrogen fertilizer; and 6) P fertilizer and potash. WSOC and WSON contents, and emission rates of greenhouse gases (CO₂ and N₂O) were determined. The results showed that CO₂ and N₂O emission rates significantly increased with increase in the amount of fertilization (P<0.05). In comparison with the control treatment, application of urea significantly increased emissions of CO₂ and N₂O (P<0.05). The emission of CO₂ was not significantly changed after 1 month of calcium superphosphate and potassium chloride application, while it significantly increased (P<0.05) after 6 months. Large amount of fertilizer (treatment 2 and treatment 3) significantly increased WSOC content (P<0.05); and relatively small amount of fertilizer (treatment 4) and fertilization of super-phosphate and potassium chloride (treatment 6) had no significant effect on soil WSOC content. Fertilization treatment (except for treatment 6) significantly increased WSON content (P<0.05). Correlation analysis showed that CO₂ and N₂O emission rates from the soil of P. edulis stands were significantly correlated to WSOC and WSON contents, respectively, indicating that increase in contents of WSOC and WSON caused by fertilization was probably the reason for the increase in emission of greenhouse gases.

Artemisia halodendron is a dominant species of desert vegetation and an important sand-fixed plant in northeastern China. In this study, inter-simple sequence repeat (ISSR) markers were applied to investigate the genetic diversity and differentiation of five natural populations of A. halodendron . A total of 230 bands were amplified by 12 ISSR primers, of which 226 were polymorphic. Percentage of polymorphic bands (PPB) and Shannon's phenotypic diversity index ( H_o ) were respectively 98.26% and 0.329 6 at the species level,and 61.22% and 0.285 3 at the population level, showing a high level of genetic diversity. Analysis of molecular variance (AMOVA) revealed that 90.1% of the total genetic diversity occurred within populations. Based on the clustering analysis(UPGMA), the five populations were divided into two groups: the Hulunbuir Sandy Land group and the Horqin Sandy Land group. The Mantel test showed that genetic distance was significantly positively correlated with geographical distance.

Effects of methyl methane sulphonate (MMS) on the morphological changes of the seedlings of Paulownia tomentosa × P.fortunei with witches’ broom and the phytoplasma existence were investigated. The treated seedlings were analyzed with SSR method. The results indicated that MMS treatment was able to morphologically eliminate the diseased symptom of the diseased seedlings, but growth of the seedlings decreased if MMS concentration was over 60 mg ·L^-1. Moreover, there still existed the phytoplasma in the infected seedlings after being treated with 20 mg ·L^-1 MMS, and the digestion sites of those DNA from the healthy, diseased and the diseased seedlings treated with 20 and 100 mg ·L^-1 MMS with SSR analysis were all the same.

Fifteen kinds of young plantation wood, commonly used for hardware tool handle from Yongkang in central Zhejiang Province, were used to compare and comprehensive evaluate physical and mechanical properties. The result showed each timber trait was significantly different among tree species. The difference of full-dry density was most than that of other physical properties. The oven-dry density of Sapindus mukorossi was 1.99 times higher than that of Alniphyllum fortunei . Species with better dimensional stability were Michelia chapensis, Schima superba, Pterocarya stenoptera and Cyclobalanopsis glauca. Toughness of all tested wood was above middle, with that of Camptotheca acuminata, Ligustrum lucidum and Ilex micrococca were higher than the average of domestic broad-leaved wood. And hardness of most tested wood was above middle, but compressive strength parallel to grain, bending strength, modulus of elasticity were low. Processing applicability of fifteen young tree species were comprehensive evaluated by coordinate synthesis method. The result showed that wood processing adaptability of Sapindus mukorossi, Schima superba and Cyclobalanopsis glauca were the best, that of Ligustrum lucidum, Koelreuteria bipinnata var . integrifoliola, Liquidambar formosana, Ilex micrococca and Platanus orientalis were the second, and that of Camptotheca acuminata, Liriodendron chinense and other five tree species dropped to the worst in turn.