In this study, a remote sensing model of bamboo carbon storage was established based on the data collected in Hongya County, a key demonstration county of the Convert Cultivated Land into Forests Project in Sichuan Province. The bamboo carbon storage was estimated before the project (1994), the fourth year after the project (2004) and the seventh year after the project (2007) with the remote sensing model of bamboo carbon storage. Quantitative analysis of the bamboo carbon storage changes in spatial and temporal pattern by 3S technology software showed that: Carbon storage and area of bamboo forest are increasing year by year from 1994-2007, while growth rate at earlier stages (1994-2004) was greater than that at the late stages (2004-2007) of Convert Cultivated Land to Forests Project. The spatial distribution of carbon storage and area of bamboo forest was similar, with a trend to spread over to low elevation, flat slope and different aspects. There were obvious variations in carbon storage and area of bamboo forest on the land with slopes greater than 25° during the early period of Convert Cultivated Land to Forests Project (1994-2004), and in 2004 the increment of carbon storage and area of bamboo forest was 79.53% and 78.18% of the total increment, respectively, which indicated that Convert Cultivated Land to Forests Project was the driving force for the increase of carbon storage and area of bamboo forest. The carbon density showed a decrease at first, followed by a increase, however its value decreased slightly relative to the initial value in 1994. The carbon density was 33.76 t C·hm^-2 in 1994, then it decreased to 33.25 t C·hm^-2 in 2004, but it increased to 33.67 t C·hm^-2 in 2007. The model, optimized by using kriging interpolation, can improve the prediction accuracy to some extent.

Periploca sepium, Syringa oblata and Forsythia suspense are three native and widespread shrubs in the Loess hilly regions. In this paper, growth, water consumption and other physiological characteristics of these seedlings under artificially simulated drought stresses were investigated. The two-year old seedlings were grown under well-watered and two different water stressed conditions. Results showed that the water consumption and growth rate of F. suspense were significantly higher than that of P. sepium and S. oblata. While F. suspense had high water consumption and growth rate, S. oblata showed low water consumption. The peak water-consumption and the fastest growth period for three shrubs under three different soil water conditions all occurred mainly from June through August, which are the rainy season in the Loess hilly regions. The root to shoot ratios in plants of P. sepium and F. suspense increased significantly under water deficit conditions. However for S. oblate plants, the ratio of root to shoot was largest under 75% maximum field capacity (FC), followed by that under 40%FC soil water condition, and it was smallest under moderate drought stress (55%FC). S. oblate seedlings showed significantly higher level of water use efficiency (WUE) than P. sepium and F. suspense. In the present study, eleven indexes, which were significantly different between treatments, were used to conduct a principal components analysis (PCA), and the result showed that among these three shrubs, P. sepium had the highest drought resistance capacity, followed by S. oblate, and then F. suspense. These three shrubs also had different drought-resistant mechanisms.

Models weere established with the stepwise regression and partial least-squares regression based on TM imagery and a survey of 143 plots in Changbai Mountain area of Heilongjiang to estimate the forest biomass. As much as 75 independent variables were selected out, including gray value of each band, the linear and nonlinear combinations between different bands of gray value (including 11 vegetation index), texture information and environmental factors. The stepwise regression equation was used to establish a model with five independent variables. The model had a standard fitting accuracy of 76.5%, the root-mean-square error of 19.12 t·hm^-2, and the correlation of the prediction values with the model and factually observed values was 0.860 3. Partial least squares method was used to establish a model with 10 independent variables. The model had a standard fitting accuracy of 85.8%, and the root-mean-square error of 9.92 t·hm^-2, and the correlation of the prediction values and observed values was 0.860 3. The results indicated that partial least squares method was better than the stepwise regression equation in this study.Total 2007 distribution maps of hierarchical of biomass in Changbai Mountain area were obtained by using the model established with the partial least squares. The mean prediction accuracy was 83.73% for 29 samples which had been evaluated by a test of inversion result of the samples.

Based on the investigated data of 54 plots of 18 sites in the west coastal area, north plain area, east coastal area and central mountainous area of Hainan Island, the biomass, carbon storage, carbon sequestration and spatial distribution of eucalyptus plantations in Hainan Island, southern China were analyzed. The results indicated that the mean total biomass was 49.72 t·hm^-2, and the biomass distribution of the forest system showed such a sequence as: arbor layer (85.10%)>litters (8.08%)>undergrowth layer (6.82%). The mean total organic carbon storage in the eucalyptus plantation ecosystem amounted to 88.84 t·hm^-2, of which there was 23.13% (20.55 t·hm^-2) stored in the arbor, 1.74% (1.55 t·hm^-2) in undergrowth vegetations, 2.17% (1.93 t·hm^-2) in litters, and 72.96% (64.81 t·hm^-2) in the soil (0-100 cm). The stem had the biggest organic carbon storage of the total carbon storage in various plant organs, accounted for 52.81% of carbon storage in arbor layer. The mean annual net productivity of eucalyptus plantations was 17.56 t·hm^-2a^-1, with a mean annual stored carbon up to 8.43 t·hm^-2, amounted to 30.91 t CO₂·hm^-2a^-1 . The total organic carbon storage and sequestration of the eucalyptus plantations of Hainan Island was 2 958.37×10⁴ t and 280.97×10⁴ t·a^-1, respectively. The carbon sequestration of eucalyptus plantations in the central mountain area (11.89 t·hm^-2a^-1) was largely higher than other three areas, such as the northern plain area (8.97 t·hm^-2a^-1), the western coastal area (7.18 t·hm^-2a^-1) and the eastern coastal area (8.26 t·hm^-2a^-1). The three areas had no significant difference in the carbon sequestration. Except for the western coastal area and the eastern coastal area, the carbon storage among all other areas was significantly different, mainly because of their different carbon storage of soil.

Betula microphylla var. paludosa is a salt tolerant plant and naturally grows in inland. In order to explore possibility in transplanting the species to marine salina, we investigated photosynthetic performance and leaf anatomic structure of B. microphylla , grown under control (nutrient soil) or salt-stress conditions (nutrient soil containing different salinity: 2‰, 4‰, 6‰, 8‰ of the solution for 60 days. The species had normal photosynthetic performance and leaf anatomic structure under lower salinity conditions. When soil salinity increased (≥0.4%), the net photosynthesis rate, stomatal conductance, transpiration rate, internal CO₂ concentration, and chlorophyll content in leaves all decreased, whereas the soluble sugar, proline and protein contents of leaf increased. Accordingly, cells of the palisade tissue in B. microphylla var. paludosa leaf elongated and piled closely, in comparison with that under lower salinity conditions, and the chloroplasts changed from elliptical shape to round shape and in which many 1ipid droplets and starch grains occurred in it. These results indicated that B. microphylla var. paludosa could tolerate salt-stress through modifying leaf physiological and morphological traits, reflecting an adapting potential to saline.

The features of changes in chlorophyll fluorescence in response to the water status of four woody species of Sophora japonica, Populus×canadensis, Gingkgo biloba and Pinus thunbergii were analysed in terms of their drought resistance. The analysis was carried out with the fast-induction kinetics associated with chlorophyll fluorescence and changes of relevant parameters in leaves of detached twigs during desiccation stress with a Handy PEA chlorophyll fluorometer. The results showed that with the progression of dehydration, the fast-induction kinetics of chlorophyll fluorescence in the four species changed significantly. The maximum primary yield of photochemistry of photosystem Ⅱ (F_v/F_o), maximum quantum yield for primary photochemistry (F_v/F_m), performance index (PI) all declined, with S. japonica having the fastest decrease, followed by P. ×canadensis, G. biloba and P. thunbergii, suggesting that their toleration to dehydration was in the same order accordingly. However, the threshold of relative water content (RWC) for the fast-induction kinetics associated with chlorophyll fluorescence was 60%~70%, 40%~50%, 30%~40% and 10%~20% for P. thunbergii, G. biloba, P. ×canadensis and S. japonica, respectively, indicating that the resistance of photosystem to dehydration of the plants was in a reversed order. It is concluded that S. japonica and P. ×canadensis have had a higher tolerance to dehydration, but higher rate of water use, suggesting they are not suitable for arid environments; whereas P. thunbergii has had a higher resistance to dehydration, but their inner tissues have had lower tolerance, suggesting it is suitable for semi-arid or dry sub-humid environment; However, G. biloba is intermediate between the above two types of plants in terms of the adaptability to water regimes.

This article studied the response characteristics of protective enzymes and malondialdehyde (MDA) at the early stage of the development of arbuscular mycorrhizal between AM fungi and Amorpha fruticosa with a potting experiment in a greenhouse. The result showed that at the early stage of A. fruticosa infected with AM fungi, protective enzymes (PPO and POD) of the root system were transiently activated, along with an accumulation of flavonoid (a kind of phytoalexin). The activities of protective enzymes and the flavonoid contents had greater increases in roots inoculated with GI (Glomus intraradices) than GM (Glomus mosseae). Additionally, the contents of MDA decreased respectively 26.6% and 25.8% in GM- and GI- colonized plants in 25 d after the seed germination. With inactivation of the protective enzymes, contents of soluble protein and GlcN(Glucosamine) increased and some new proteins occurred, which indicated that the degradation of chitin and emergence of new proteins were potential mechanisms regulating the defense responses of host plants to develop mutually beneficial symbiosis.

Many pine trees of Sect. Pinus are distributed throughout China, and are important species for afforestation in China. Seeds and seedlings of these closely related species are similar in morphological characters. It is difficult to identify them according to their morphology. Seeds and seedlings from 11 pine species were identified by integrating their different morphological characters of seeds (1 000-seeds weight, seeds shape and color) and seedlings (number of cotyledon, color of hypocotyls and seedling height), with their ISSR and SSR markers. At the same time, genetic relationship between those closely related species was assessed based on information from SSR markers. The results showed that P. tabulaeformis and P. caribaea were easily distinguished from 11 pine species according to morphological differences of seeds and seedlings, and 10 of 11 species were identified accurately based on ISSR and SSR markers. However, no species-specific primer (loci) was found to recognize P. densata because of its complicated genetic background. Genetic relationship between 10 pine species based on 41 polymorphic loci amplified by 5 pairs SSR primers was similar with relationship of traditional taxonomic groups. UPGMA dendrogram demonstrated that 3 taxonomical groups were clustered at the similarity coefficient of 0.6. The first group consisted of P. massoniana and P. densiflora . The second group had 6 species which further were divided into two sub-groups, with one sub-group including P. yunnanensis , P. kesiya , P. densata and P. tabulaeformis ; the other sub-group including P. thunbergii and P. sylvestris . The last group contained P. taeda and P. caribaea , and they had relatively distant relationship from other two groups, with the similarity coefficient of 0.42.

Hexie’ is the first distant hybrid between Section Moutan and Section Paeonia bred in China. In this paper we study the hybrid reproductive biology, including morphology of reproductive organs, pollen viability, pollination and seed-set conditions. The results showed that ‘Hexie’ flower had approximately 50 to 100 stamens, and the filaments were in various lengths from about 0.1 to 2.5 cm. There were four or five pistils, and the flower disc was succulent, and covered about two thirds of the carpel. Most of the pollens were abortive; and the vital pollen accounted for 4.1% tested by TTC. The mixed pollen grains from tree peony and herbaceous peony had a high germination rate on the stigma of ‘Hexie’. Most of the pollen tubes stopped growing and crimping on the stigma, while only the minority could enter the stigma. Moreover, the entered pollen tube swelled at the front end and twisted in the style, and the pollen tube growth was blocked by accumulated callose. The results demonstrated that pre-fertilization barriers resulted in the infertility of ‘Hexie’. When ‘Hexie’ was used as male parent, crossing with herbaceous peony cultivar 'Yanzi’ and 'Fen Hudie’ showed some compatibility, from which a few seeds and seedlings were obtained, indicating that ‘Hexie’ could be used as parent material for breeding various distant hybrids between tree peony and herbaceous peony.

Somatic embryos (SE) were induced from young zygotic embryos (ZE) of Sorbus pohuashanensis obtained after artificial pollination. The developmental process of ZE and SE was observed with paraffin section, scanning electron microscopy and transmission electron microscopy. The results showed that: 1) Somatic and zygotic embryogenesis underwent a similar course, by passing through globular, heart-shaped, torpedo-shaped stages and then reached mature stage; 2) SE derived from ZE cotyledons originated directly from single epidermis cell or indirectly occurred from single surface cell or inner cell of the embryogenic callus, but some of the indirectly occurred SE was possibly developed from multi-cell aggregates inside the embryogenic callus; 3) SE regenerated from single cells of ZE cotyledon epidermal and embryogenic callus surface had obvious suspensors during the early developmental stage, but they disappeared during torpedo-shaped stage; 4) There were no suspensors observed in SE regenerated inside embryogenic callus. 5) The first division of SE embryogenic cells was equally split, which was different from that of ZE; 6) Degradative cells around multicellular somatic preembryos displayed similar morphological patterns of programmed cell death.

Wood is an attractive renewable source of lignocellulosic biomass for biofuels production and pulping industry. One of the principal components of wood is cellulose, determining the morphology of plants and wood quality. In this study, we isolate seven cellulose synthase genes: PtoCesA4, PtoCesA5, PtoCesA7, PtoCesA8, PtoCesA13, PtoCesA17 and PtoCesA18 from Populus tomentosa by using RT-PCR and bioinformatics methods. A phylogenetic tree of Arabidopsis thaliana, Oryza sativa, Populus trichocarpa and P. tomentosa cellulose synthase gene superfamilies was constructed using the MEGA4.0 program. GenomeLab^TM GeXP genetic analysis showed that the transcription levels of PtoCesA17 and PtoCesA7 along with PtoCesA4, PtoCesA8 and PtoCesA18 were much higher in xylem than that in leaves in P. tomentosa, implying that these genes may function on secondary wall formation.

With one scope of QuickBird panchromatic band remote sensing image (total rows and columns are 26 574 and 28 606, corresponding to the real region of 15.994 km×17.164 km) in Shenzhen urban area as research object, using the GPS virtual reference network positioning system of Shenzhen urban area to survey the three-dimensional coordinates of 65 GCPs which are easily recognized on the image, the precision of surveying GCPs is centimeter-level. Calculate the point of center of gravity of 65 GCPs. On the basis of statistic of the deviation between the real distance of each GCP to the point of center of gravity and the corresponding distance on deformed image, analyzing the main factors that possibly influence the pixel displacement of QuickBird panchromatic band remote sensing image. The principal components are extracted by using principal components analysis. The quantitative estimation model used to describe the deformation mechanism of QuickBird panchromatic band remote sensing image is established according to the principal components, which can improve the estimation precision of image deformation to a certainty. The result will have some reference value to research calibration algorithm of high spatial resolution remote sensing image.

Site plays an important role in fitting height-diameter model in such a large scale as nation, whereas it is not known in most cases. Using the classified height method with double iteration algorithm, height-diameter model of six major tree species in china, including Quercus, Cunninghamia lanceolata, Pinus massoniana, Populus, Larix gmelinii and Pinus tabulaeformis,were constructed. The data came from height-measurement file in 7^th national consecutive forest inventory,total observations were 118 441,of which 79 095 observations used for model development and 39 346 observations used for model validation. Contrasting to ordinary method, the coefficients of determination reached 0.942 8-0.966 5 from 0.520 3-0.753 2. Parameter sensitivity analysis and model validation showed that models were robust in general and fitted parameters were statistically reliable. The classified height method is useful to construct height-diameter model for all tree species in china. Considering stand factors,the method is helpful to evaluate national forest site.

Phenophase of plants is crucial to forecast a variety of seasonal weather events (such as dust storms, strong winds), and determine seasonal grazing and the building of sand-fixing vegetation in the desert region. Five Phenophases were divided based on observed phenology data of 36 plant species since 1974 in Minqin desert region with frequency statistical method of phenology. Sustained characteristics and combination characteristics of the phenophases were analyzed. The results showed that: Phenophase of plant active period was 212 days. The continuous green period was even longer, and the continuous flower color period was shortest. Flower color period, fruit bearing period and green period overlapped between the different plants. Salix matsudana had the longest active period, while Rhus typhina and Phragmites communis had the shortest active period. Populus euphratica and Rhus typhina had the shortest green period, and Phragmites communis had the shortest autumn color period. The plants in the desert exhibited huge differences in glorescence and fruit period. The plants started flowering early, and also stopped flowering early in terms of the phenophase on flower color period.

Identification of nematode feeding and pathogenicity-related genes of Bursaphelenchus xylophilus was critical to reveal the molecular mechanism of the Pine Wood Disease (PWD). In this study, a suppression subtractive hybridization (SSH) cDNA library was constructed from the mixed stage nematode cDNA of B. xylophilus isolate AN19#F1, which was driven by the egg cDNA of AN19#F1. A total of 34 contigs generated from 354 ESTs after cDNA sequencing were obtained. Among them 15 contigs were functionally annotated. Contigs, MixC12, MixC25 and MixC33 had high homology with Peroxidase, Beta-1, 4-endoglucanase, zinc finger family protein in the database, respectively. The genes were considered closely related to the feeding and pathogenicity processes. RT-PCR analysis confirmed the respective of the SSH cDNAs.

The gypsy moth, Lymantria dispar Linnaeus, is one of the most serious insect pests of palaearctic and nearctic forests. According to their geographical distribution and biology characteristics, they were divided into the Asian and European types of populations. We used amplified fragment length polymorphism (AFLP) to detect genetic diversities within and among the gypsy moth populations. Three fluorescent-labeled AFLP primer combinations were used on 26 L. dispar samples collected from different locations of Russia, Mongolia, Japan, United States of America and China, detecting a total of 507 polymorphic fragments. Genetic similarities based on these data were calculated and cluster analysis was performed to graphically display groupings between populations. L. dispar samples from these areas were grouped together corresponding to their origin. The result supported an observation that American population has greater genetic variation than other populations and has a longest genetic distance with the population of China. There was the smallest genetic differentiation between Mongolian population and the Chinese. The results demonstrate that AFLP analysis is a sensitive technique for distinguishing genotypes from different geographic origins and provides sufficient advice for the study of the origins of the gypsy moth, invasion and proliferation, heredity and variation, as well as developing quarantine measures.

Antioxidases are important defensive substance in plants, and can maintain balance of oxidative metabolisms in vivo to ensure healthy growth of plants. In this study, the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in needles of hybrids between Larix kaempferi, L. gmelinii and L. olgensis were assayed with UV-spectrometry to investigate variation in the enzymes among the hybrids. The results showed that there were significant difference (P<0.01) in SOD, CAT and POD activities among 7 families hybrids of two generations. Though POD activity of F1 generation was lower than F2 generation, activities of the CAT or SOD were higher than F2 generation, suggesting that heterosis of F1 generation was greater than F2 generation. Additionally, some hybrids, such as F1 generation of L. kaempferi 3 ×L. gmelinii 2, and F2 generation of L. kaempferi 12 ×L. gmelinii 9, expressed strong resistance to pests and could be used as resistance resources against larch pests.

Dastarcus helophoroides (Fairmaire) ( Coleoptera: Bothrideridae) is an important insect natural enemy for controlling Apriona swainsoni (Hope) ( Coleoptera: Cerambycidae). Adults and eggs of D. helophoroides were released in laboratory and semi-field condition to control A. swainsoni in Tai’an and Liaocheng of Shandong Province, and the optimum efficiency was up to 80% and 86.67%, respectively. Before releasing the natural enemy and after releasing it, the populations of A. swainsoni larvae per tree were investigated. Based on the investigation, the optimal controlling effect was as follows: After released just adults, or eggs, or a mixture of them outdoor, the reducing rate of the population of A. swainsoni larvae per tree was at 72.2%, 71.6%, 82.64%, respectively. However, the reducing rate have had no significant difference among the three treatments. Results showed that releasing adults and eggs of D. helophoroides in field could be an efficient measure for controlling A. swainsoni.

The effects of biological conservation practice on diversity of rove beetles (Coleoptera: Staphylinidae) were studied in Pangquangou Nature Reserve (111°22'-111°33'E, 37°45'-37°55'N, elevation 1 600-2 831 m), Shanxi Province, China. Pitfall catches were set in four sites, i. e. , Lüsechanglang of the core zone (CZ), Badaogou of the buffer zone(BZ), Shenweigou of the test zone, which is far from farmlands(TZFF) and Bashuigou of the test zone,which is near to farmlands(TZNF) to catch the beetles from May to September in 2006 and 2007. A total of 1 862 rove beetles belonging to 9 subfamilies were caught. Of these rove beetles caught, Aleocharinae accounted for 80.15% in number, as the dominant group; Staphylininae, Oxytelinae, Omaliinae and Tachyporinae accounted for from 1%~10%, as the common groups; and the Proteininae, Pseudopsinae, Steninae and Xantholininae accounted for less than 1%, as the rare groups. The Proteininae, Pseudopsinae and Xantholininae are the newly recorded subfamilies in Shanxi. There were difference in the beetle composition and numbers among the sites. CZ had the greatest number of individuals and relatively lower evenness index. BZ had a very high richness, diversity and dominance index. TZNF had a very high β-diversity index. A branching pattern was established for groups linkage, based on sub-family assemblages of the rove beetle in the four sites with Euclidean distance. BZ and TZFF were similar; CZ had a very low similarity with other zones. It is inferred that the high diversity of rove beetles species in BZ may be due to the edge-associated species and the presence of species from the adjacent habitats. Nevertheless, the biological conservation practice, which could relieve the pressure of human disturbance, significantly contributed to the re-establishment and maintenance of the diversity of rove beetles assemblages in the studied area.

In this study, based on data of the forest fire occurrence and meteorological variables in spring fireproofing period in Qiannan area, Poisson regression model, negative binomial model, zero-inflated negative binomial model and Hurdle model were respectively employed to predict the forest fires under fire-danger climate, and those models were compared with each other based on the prediction. The results showed that: Poisson regression model did not fit well into the over-dispersion data. Negative binomial distribution fitted better into the data than Poisson distribution. But both of them were not suitable for simulating zero drived dispersion data. Zero-inflated negative binomial regression model and Hurdle model were useful methods for such data. Zero inflated negative binomial regression model and Hurdle model performed better than other two models in predicting forest fires. Moreover, Hurdle model was even superior to zero-inflated negative binomial model.

Based on the conventional anatomical analysis, the pore structures of poplar tension wood, such as specific surface area, pore volume and pore size distributions were characterized by nitrogen adsorption-desorption method. The shapes of the pores were estimated by nitrogen adsorption isotherms. The results show that poplar tension wood with BET specific surface area of 21.9 m²·g^-1, which is 13 times higher than that in opposite wood. Poplar tension wood has intact mesoporosity (pore size between 2-50 nm) with inkbottle and slit shape pore, as well as a certain amount of micropores and macropores. The maximum value of pore size distribution appears at 5 nm. The pore volume with diameter ranging from 4-7 nm makes up 74.4% of the total, and larger than 15 nm, 10.8%. The high amount of mesopores can be attributed to the thick gelatinous layer in poplar tension wood.

A novel method of softwood species computer automatic recognition through cross-sectional microscopic images is proposed in this paper. The method extracts PCA(principle component analysis)feature of wood images, generate "EigenTrees", and then use SVM(support vector machine)to classify samples in feature space. Eight kinds of softwoods species, twelve samples in each species are used in our experiment. Using leave-one-out cross-validation(LOOCV), wood recognition experiments are carried out under different conditions on image split methods, classification algorithms of nearest neighbor and SVM, and various norm distances. The results of these experiments show that wood recognition by parts of wood micro-texture is possible under certain conditions.

Wood and other plant raw materials could be converted to thermoplastic material by benzylation. Pulp cellulose was benzylated by using benzyl chloride as etherifying agent. Effects of reaction time and reaction temperature on degree of substitution (DS) of the products were studied. DS of the product increase under longer reaction time or higer reaction temperature. Products were characterized by FTIR, DSC, X-ray diffraction, etc. It showed some of hydroxyl of the products was substituted by benzyl, crystal was destroyed and thermal stability of the products descended slightly. Vicat softening point and melting temperature of the products were tested and the results revealed that thermoplasticization of the products improve with its DS. Rate constant of reaction of pulp cellulose benzylation under different reaction temperature was ascertained. Activation energy of cellulose benzylation was calculated, it was 46.1 kJ·mol^-1.

In the goal of increasing the efficiency extraction of lignin from bamboo by atmospheric acetic acid process and of understanding the chemical structure changing during the process, series of single factor experiments had been done in present investigation. This result shows the optimum extraction conditions is: 90% aqueous AcOH, 3%H₂SO₄, ratio of liquor to bamboo fillings 12 ∶1, pulping temperature 106 ℃, and pulping time 2.5 h. The UV, FTIR, and NMR spectra results shows that the functional groups and chemical bond in MWL and acetic acid lignin are quite similar, excepting acetic acid lignin has more phenolic hydroxyl groups, so its chemical activity is more stonger, which is an advantage for further utilization.

Natural tourism resources, as one of public resources, hardly avoid the dilemma called "tragedy of the commons", which is the basic cause why natural tourism resources are frequently destroyed and misused. Therefore, debates are extensively aroused in academic field whether or not the values of natural tourism resources actually exist. In this paper, we applied different value theories to analyze the values of natural tourism resources from connotation and characteristics of tourism resources. Additionally, we discussed major factors that influenced the values of natural tourism resources. Lastly, the calculation and realization approaches of values of natural tourism resources were explored from four aspects.

Malus hupehensis seedling were cultured in a 1/2 strength Hoagland solution with pH3, pH4 and pH6 to study effects of acidity in rhizosphere on their photosythesis, the net photosynthesis (P_n), stomatal conductance (G_s), intercellular CO₂ concentration (C_i) and chlorophyll fluorescence parameters in the leaves in 8 days after tredtment. The results showed that the P_n and G_s reduced, the C_i raised; the efficiency of light energy capture by open photosystemⅡ (PSⅡ) reaction centers (F' _v/F' _m), maximum photochemistry efficiency of PSⅡ(F_v/F_m), actual quantum yield of PSⅡ(Φ_PSⅡ), photochemical quenching of PSⅡ(q_P) reduced; the fluorescence intensity F_k at 300 μs increased, and the quantum yield for electron transport (φ_Eo), the performance index on absorption basis (PI_ABS) and the density of active reaction center (RC/CS) all decreased significantly. Furthermore, the range of variation of these parameters increased with reducing pH the solution of rhizosphere. These results displayed that rhizosphere acidification damaged the oxidation and reduction sides of the reaction centers of PSⅡ of the leaves in M. hupehensis, and further decreased the activity of PSⅡand P_n.

An experiment with factorial design was conducted to investigate the effects of substrate composition, container size, slow-release fertilizers and air-cutting root on growth of one-year old seedling of Ormosia hosiei, Taxus wallichiana var. mairei and Phoebe chekiangensis. T. wallichiana var. mairei and P. chekiangensis were sensitive to substrate composition, while O. hosiei was scarcely affected by substrate composition. T. wallichiana var. mairei was favorite and tolerant to slow-release fertilizers fertilizers, and the height and ground diameter were promoted by the increased amount of the fertilizers. Slow release fertilizers also were beneficial to O. hosiei and P. chekiangensis which showed the largest height and ground diameter when 2.0 kg·m^-3 and 2.5 kg·m^-3 slow-release fertilizers were applied, respectively. Height and ground diameter of T. wallichiana var. mairei, and ground diameter of O. hosiei were promoted with increasing container size. A 4.5 cm×10 cm container was found to be the optimal size for P. chekiangensis. Root air-pruning promoted growth of O. hosiei and T. wallichiana var. mairei, but not for P. chekiangensis. There were significant interactions between different factors, and the change in single factor might affect the relative performance of seedling growth. Based on the main effects and interaction effects, three optimal seedling cultivation schemes were selected for each of the three elite timber species.

Based on former work, Xinjiang Tianshan forest ecology station and Xinjiang University, set up a large scale permanent plot in northern Picea schrenkiana var. tianschanica forest covering 8 hm² and then all-around investigation on the plot have been carried out favourably in order to make the long-term observation and research. On the base of its foundation and investigation, the three-dimension visualization analysis and management of the basic information of the plot have been realized based on GIS. This study work is essential and useful for the long time management and maintenance, the refreshment and analysis of basic information and investigation data, the detailed illustration of forest community movements of this large scale permanent plot. It also provides a beneficial case for same work about forest ecology.

Branch surface area(BSA), an essential crown structural characteristic, and branch surface area index (BAI), an important forest structural attribute, have significant implications for studying forest structural and protective effects of shelterbelt. The variation in BSA was investigated for 6-year-old and 9-year-old Populus × euramericana "Zhonglin 46" stand in Henan Eastern Plain. The results showed that specific shoot area decreased significantly with increasing tree age, and averaged 12.55 and 11.36 cm²·g^-1 in 6-year-old and 9-year-old trees, respectively, however, total branch surface area increased significantly with increasing tree age, and averaged 7.53, 14.55 m², respectively. In addition, surface area of the primary branch axis was significantly influenced by the position in the crown. It decreased significantly from the interior to the exterior of the crown, however, vertical distribution of surface area of the primary branch axis wasn't the same for 6-year-old and 9-year-old Populus × euramericana "Zhonglin 46" stand. There were different classes of lateral shoots in different stand age, three classes of lateral shoots in 6-year-old poplar and four classes of lateral shoots in 9-year-old poplar. Lateral shoot surface area decreased over successively higher order. Branch surface area on individual tree was a function of tree size and several variables representing the size and vigor of the crown. This equation was reliable to predict branch surface area at the tree-level and to estimate branch surface area and BAI at the stand-level.

Incidence of jujube black tip disease, a new disease which is very serious for the jujube, was investigated in 7 sites with the air polluted by fluorides and one site without air pollution in Jinzhong City of Shanxi Province from May to September 2009. The fluorides content of jujube fruits,jujube leaves and atmosphere in the jujube main production areas were examined,and the correlation of fluorides content among atmosphere, jujube leaves and jujube fruits were analyzed.The goal of the study was to test if there were the correlations between fluoride content and jujube black tip disease. The results showed as follows:The longer jujube leaves and fruits exposure in the air, the higher fluorides content jujube leaves and fruits had;The top of jujube tree had more fluoride content than the middle, the middle had more than the basal, fluoride content of fruit skin was more than that of the flesh;The absorption rate and accumulation of fluoride in jujube leaves and fruits were positively correlated with the fluoride concentration in atmosphere during the jujube growing period;The fluoride content of jujube leaves and fruits was negatively correlated with the distance to pollution source;The incidence of jujube black tip disease was positively correlated with the fluoride content of jujube leaves, fruits and atmosphere.

The ‘jindai’ is a new Ginkgo cultivar which bred by selection of ginkgo branches with spot leaves, and through grafting propagation and optimization culture. Main characteristics include fan blade with a shallow center crack, shallow wavy leaf margin, long petiole; longitude yellow stripes on green background leaves with vertical yellow stripes across the longitude stripes. The striped leaves account for 40%~80% of the whole leaves. Female, female cone has a long stalk, and the end has 1~2 disk-shaped beads, each student 1 ovule which develops into a seed. Seed is drupelike, subglobose, exocarp fleshy, with white powders. From October to November fruits ripe, with yellow or orange color, bad smell. Testa is bony, white; endotesta is membranaceous. The striped leaves maintain the characteristics from spring to autumn. The cultivar can be widely applied to the sidewalks, parks, gardens, squares and other tourist spots.