[Objective] The reasonableness of the stand state concerns the necessity and urgency of forest management, and the quality of evaluation of stand state directly affects the quality of management decision. Only by knowing the exact optimal stand state will it be possible to make an assessment of the reasonableness of the real forest stand, after which it is viable to manage forest with targeted operating adjustment. [Method] The forest is a complex ecosystem, the multi-index evaluation method is usually used to assess it. Following the principles of multi-indicators comprehensive evaluation, a new stand state reasonableness evaluation method based on unit circle has been presented in this paper. [Result] The research shows that the stand state depends on the size of closed chart area composed of real stand state indicators. This chart area as a proportion of the best stand state value(expected value)is the most appropriate measurement of real stand quality. Meanwhile, the best stand state value(expected value)always equals to the unit circle area π, namely the rule of π value of the best stand state. The method of unit circle has an essential difference from the usual multi-index system of radar chart in that the expectation of optimal stand state can be directly derived by the new method. The formula given by the research is able to calculate the real stand state which can be divided into five grades. The stand state can be described by stand spatial structure(stand vertical and horizontal structure), stand age structure, stand composition(tree species diversity and species composition), stand density, stand growth, climax tree species group or main tree species competition, stand regeneration, tree health and etc. This 8 aspects can characterize the major natural attributes of stand, and the corresponding value to each indicator can be assessed easily. To highlight the advancement and practicality of the indicators, most indicators mentioned in this paper use the latest research results and optional measure methods are given. Normalization processing of stand state indicators is crucial to the stand state evaluation. Applying this method to the stand state of natural Korean pine (Pinus koraiensis) broad-leaved forest and sharp tooth oak(Quercus aliena var. acuteserrata) mixed forest in China has shown visual and reliable evaluation results in accordance with real stand situation. [Conclusion] The stand state evaluation method based on the unit circle, especially the rule of π value of the optimal stand state, that has been put forward in this paper, lays a scientific foundation for forest management decision and provides an analysis method to evaluate the quality of different types of forest health in different areas.

[Objective] Determining the appropriate topographical conditions of seabuckthorn (Hippophae rhamnoides) plantations in semi-arid region of Loess Plateau in north Shaanxi could provide a basis for the stable construction and sustainable management of the plantation forest in this area. [Method] Seabuckthorn plantations with different topographical conditions were surveyed in Wuqi County, Yan'an City, Shaanxi Province using the method of sampling plots. The mortality of seabuckthorn plantations in different topographical conditions were analyzed by correlation analysis and single factor variance analysis from slope position, slope direction, and gradients. [Result] The mortality of seabuckthorn plantations increased firstly and then decreased from the top to the bottom of slopes. Non-significant differences of mortality were showed among the slope positions, although it is 38% at the top, 47% at the middle and 31% at the bottom of slopes. The mortality of seabuckthorn plantation at shady slope was the lowest among all the slope directions, with the maximum value of 21% and the average of 4%. The highest mortality occurred on sunny slope, with the minimum of 33% and the average of 63%. The mortalities of semi-shady and semi-sunny slopes were between those of shady and sunny slopes, and the average mortality of seabuckthorn plantations was lower on semi-shady slope than on semi-sunny slope. There were significant differences (P<0.05) between the shady slope and semi-shady slope, semi-sunny slope and sunny slope. The mortality of seabuckthorn plantations on different slopes rose with increasing gradients. On shady slope, the growth was not obvious. The variation of mortality with gradients was logarithmic on semi-shady slope, linear on semi-sunny slope and exponential on sunny slope. The morality of seabuckthorn plantations had non-significant correlation with the slope position, but significant (P<0.01) with the slope direction and the gradient. Moreover, the effect of gradient to the mortality was stronger than that of slope aspect. Seabuckthorn forests on shady slope presented a slight degradation (mortality 0%-30%). Seabuckthorn plantations on semi-shady slope and semi-sunny slope were the same, of which the flat slope (5°-15°) and the gentle slope (15°-25°) displayed slight degradations, the steep slope (25°-35°) and the extremely steep slope (35°-45°) showed moderate degradations (morality 30%-70%). Seabuckthorn plantations of the extremely steep slope on sunny slope showed a severe degradation, and other three gradient sections had moderate degradations (morality 70%-100%). [Conclusion] In the semi-arid region of Loess Plateau in north Shaanxi where the average annual precipitation is less than 500 mm, the main cause for death of seabuckthorn plantations was lack of water. Suitable topographical conditions were shady slopes, semi-shady and gentle slopes, semi-shady gentle slope, semi-sunny flat slopes, and semi-sunny gentle slopes.

[Objective] This study aims to analyze the relationship between surface soil physiochemical properties and the growth of dominant trees for mixed forest of conifer and broad-leaved species at different succession stages in order to explore the growth patterns of different stands and provide basis for sustainable forest management. [Method] The mixed forest conifers and broad-leaved trees at different succession stages (middle-aged forest, near-mature forest, mature forest, and old growth forest) in Jiaohe Management Bureau of Forestry Experimental Area, Jilin Province were studied. The methods of comparison and principal component analysis were used to analyze physical and chemical properties of the surface soil, the growth of dominant trees, and the relationship between them. [Result] with the succession of forest, the average diameter at breast height (DBH) of the dominant tree species increased, the average tree height varied slightly, the regeneration of Pinus koraiensis tended to be stable, and the number of Juglans mandshurica, Ulmus davidiana var.japonica, and U.macrocarpa gradually decreased in the upper overstory. With respect to the soil physical properties, the soil density was not significantly different among middle-aged forest, near-mature forest and mature forest and it reached the minimum at the stage of old-growth forest. With the succession of forest, the non-capillary porosity gradually decreased and capillary porosity gradually increased, as a result the variation of the total porosity was not significant. Among the four successional stages, the capillary water holding capacity and maximum water holding capacity at the stage of old-growth forest were the largest, which were 12.98% and 27.94% higher than middle-aged forest. With respect to the chemical properties of surface soil, the pH value of the soil layer at 0-20 cm of mature forest was the largest and that of near-mature forest was the smallest. The pH value of old-growth forest was between mature forest and middle-aged forest. The organic matter content of near-mature forest was the highest and that of mature forest was the lowest. In the old-growth forest, the total nitrogen, hydrolysable nitrogen, and available phosphorus were the highest among the four stage forests. The total phosphorus, total potassium, and available potassium in the near-mature forest were the highest. The mean tree height and mean DBH of the dominant tree species at different successional stages were all positively correlated with organic matter content, total phosphorus, total potassium, available phosphorus, and available potassium (mean tree height: r=0.980, 0.447, 0.921, 0.341, 0.546; mean DBH: r=0.003, 0.803, 0.083, 0.252, 0.448). The mean tree height of the dominant tree species was also negatively correlated with soil density, non-capillary porosity and pH value (r=-0.742, -0.358, -0.416), and significantly positively related to organic matter content, total nitrogen, and total potassium (r=0.980, 0.910, 0.921). The mean DBH of the dominant tree species was also positively correlated with soil density and total phosphorus (r=0.780, 0.803) and negatively correlated with maximum water holding capacity, and hydrolysable nitrogen (r=-0.562, -0.619). The maximum soil water holding capacity, soil density, hydrolysable nitrogen, and total phosphorus had great impacts on the diameter growth of the dominant tree species. [Conclusion] Capillary porosity, total phosphorus, and available potassium were the main factors affecting surface soil quality at different forest successional stages. The order of the comprehensive score of physical-chemical properties of surface soil at different forest succession stages was as follows: middle-aged forest

[Objective] Taxus cuspidata is a tertiary relic species and the national level endangered plants. The species composition and community structure of T. cuspidata forestand the spatial correlation between T. cuspidata and other major tree species were studied to explore the formation and maintenance mechanism of community biodiversity. [Method] According to the field protocol of the 50 hm² plot in Panama (Barro Colorado Island, BCI), a 25 hm² plot was established in 2014 in Muling National Nature Reserve of Heilongjiang Province. All woody plants with diameter at breast height (DBH) ≥ 1 cm were mapped, tagged, and identified to species. I (DBH < 10 cm), II (10≤DBH<30 cm), III (DBH≥ 30 cm). [Result] In the 2014 census, we documented 57 woody species with 63 877 individuals, belonging to 38 genera and 22 families. The mean DBH of all trees was 7.83 cm, all species were found when sampling area was set as 21 hm². The DBH distribution of all individuals showed a reversed "J" type. The DBH distributions of the T. cuspidata and Corylus mandshurica were approximate normal and "L" type, respectively, other major species showed reversed "J" type, including Tilia amurensis, Acer mono, Acer barbinerve, Acer tegmentosum, Betula costata, Abies nephrolepis and Pinus koraiensis. Within a scope of less than 50 m, Tilia amurensis, Acer mono, Corylus mandshurica, Acer tegmentosum, Betula costata displayed a gathered distribution, Abies nephrolepis, Acer barbinerve, T. cuspidata first displayed a gathered distribution, followed by random distribution and uniform distribution. The distribution pattern of Pinus koraiensis fluctuated between aggregate distribution and random distribution. T. cuspidata and Acer mono were negatively correlated at small spatial scales (1, 3, 5 m), and with the increase of spatial scale, became independent of each other, and went positively correlated when the spatial was larger than 30 m. T. cuspidata was negatively correlated with five species in different spatial scales, including Acer barbinerve, Acer tegmentosum, Betula costata, Corylus mandshurica and Pinus koraiensis. Generally. T. cuspidata was negatively correlated with Abies nephrolepis, but showing independent of each other at few scales. In contrast, T. cuspidata was independent with Tilia amurensis at most scales, and showing negative correlation at few scales. [Conclusion] T. cuspidata forest had a relatively high species richness. Sapling regeneration of most species was fairly good, but very poor for T. cuspidata.Spatial distribution of species was significantly correlated with habitat, and the species showed different habitat preferences. T. cuspidata may be a niche differentiation with some species, including Pinus koraiensis, Abies nephrolepis, Tilia amurensis, Acer tegmentosum, Corylus mandshurica, Betula costata and Acer barbinerve.

[Objective] This study aimed to investigate the impacts of biochar input on soil carbon (CO₂) emission and soil microbial community composition in Cunninghamia lanceolata plantation, which provided the valuable information for the biomass resources use and the carbon sequestration management for plantations in subtropical China. [Method] Soil was collected from the C. lanceolata plantation at Wanmulin Nature Reserve of Fujian province. Biochars, produced by charring C. lanceolata at three different temperatures (350℃, 550℃ and 750℃), were mixed with soils with or without addition of C. lanceolata litter, respectively, and then the mixture was incubated in the dark at 25℃ for 364 d. We used the alkali absorption method to observe soil CO₂ emission dynamic and utilized phospholipid fatty acid (PLFA) analysis to characterize the soil microbial community composition. [Result] Soil CO₂ emission rates declined with the incubation time and tended to be stable at the late stages of incubation with biochar addition. However soil CO₂ emission rates increased at the early stages and reached the maximum at 7 d and then decreased with biochar and litter addition. Regardless with or without litter addition, the pyrolysis temperature of biochar only significantly influenced soil CO₂ emission at the early stages of incubation (P<0.05), and the soil CO₂ emission rates with addition of BC350 (biochar produced at 350℃) were higher than with BC550 (biochar produced at 550℃) and BC750 (biochar produced at 750℃), and biochar produced at lower temperature (BC350) resulted in more cumulative soil CO₂ emission. The cumulative soil CO₂ emission with biochar was higher than that without biochar at the early stages of incubation, however, it was lower at the late stages. PLFA analysis showed that the biochar input influenced the soil microbial community composition. The abundance of Gram-negative bacteria significantly decreased in soils with biochar but without litter addition, while the abundance of actinomycetes significantly increased in soils with both biochar and litter. The biochars produced at different temperatures significantly influenced microbial community composition in soils only with litter addition (P<0.05). The high temperature biochar (BC750) resulted in more abundance of Gram-positive bacteria and less abundance of fungi than the lower temperature biochar (BC350). There was extremely significant positive correlation between cumulative soil CO₂ emission and the total PLFAs (P<0.01). [Conclusion] Biochars stimulated the soil CO₂ emission at the early stages of incubation but suppressed the soil CO₂ emission at the late stages, and biochars could alter microbial community composition in C. lanceolata plantation soil.

[Objective] Nitrogen is the most important element for poplar plantation productivity. Studies on the dynamic changes of nitrogen cycle bacteria community in continuous cropping and rotation of poplar plantation and the structure features of nitrogen metabolism will help to reveal the obstacle mechanism of continuous cropping to nitrification bacteria in poplar plantation in terms of nutrient cycling. [Method] In this study, the Metagenome sequencing technology was used to study the soil nitrogen cycling bacteria community and the evolvement pattern of nitrogen metabolism along with the continuous cropping generation and different rotation patterns in generation Ⅰ of poplar plantation, continuous cropping generation Ⅱ of poplar plantation, rotated peanut field and the abandoned land after poplar clear cutting. [Result] There were 11 bacteria from 4 genera related to nitrogen cycle, among which Azotobacter had genera of Beijerinckia, Bradyrhizobium, Rhizobium, and Frankia; Nitrobacteria had Nitrobacter, and Nitrosospira; Denitrifying bacteria had Pseudomonas, Ralstonia, Burkholderia, Bacillus, and Streptomyces; Ammonifying bacteria had Bacillus, and Pseudomonas. After the first continuous cropping of poplar plantation, the total number of nitrogen cycling bacteria in the soil increased by 4.73%, and the type of nitrogen cycle bacteria in the soil remained unchanged. The relative abundance of nitrogen fixing bacteria increased by 53.44%, nitrification bacteria was no change, denitrification bacteria increased by 0.14%, and ammonifying bacteria increased by 1.33%. Compared with generation Ⅱ of poplars, there was no increase or decrease in the type of nitrogen cycle bacteria in the rotated peanut soil. The relative abundance of nitrogen fixing bacteria reduced by 71.14%, nitrifying bacteria, denitrifying bacteria and ammonifying bacteria increased by 120%, 15.63% and 20.76%, respectively. Compared with generation Ⅱ of poplars, species of nitrogen cycle bacteria in the abandoned land soil reduced and the abandoned land was lack of nitrification bacteria. The relative abundance of nitrogen fixing bacteria reduced by 79.10%, while denitrifying bacteria and ammonifying bacteria increased by 17.39%, 24.56%, respectively. After the first continuous cropping of poplar plantation, the metabolic activity of soil azotobacteria enhanced, Nitrobacter weakened, Nitrosospira enhanced, and ammonifying bacteria weakened. Compared with generation Ⅱ of poplars, only the metabolic activity of nitrification bacteria increased, while the other three kinds of nitrogen metabolism function bacteria decreased in rotated peanut field. The metabolic activities of all nitrogen cycling bacteria in the abandoned land were lower than that in generation Ⅱ of poplar plantation. [Conclusion] After the first continuous cropping of poplar plantation, the total number of nitrogen cycle bacteria increased in the soil, but the metabolic activity decreased. After the rotation of peanuts, the most of nitrogen cycle bacteria increased significantly, but only the metabolic activity of the nitrification bacteria increased significantly. Thus, rotation could improve the adverse effects of continuous cropping of poplar plantation on the growth and metabolic activity of nitrification bacteria.

[Objective] To elucidate the mechanism of photosynthetic characteristics and nitrogen allocation of Torreya grandis ‘Merrilli’ seedlings under different shading levels, the growth, gas exchanges parameters, chlorophyll content and leaf nitrogen content were measured. [Method] We measured the height, ground diameter, biomass, light response curve, CO₂ response curve, chlorophyll content, leaf nitrogen content of T. grandis ‘Merrilli’ seedlings under different shading levels(0%, 50%, 75% and 90%). [Result] The results showed that the leaf color of seedlings became much greener with the increasing level of shade levels. However, the diameter increment and biomass of seedlings showed an increase at first, followed by a decreased trend with increasing shade level. The seedlings at 50% and 75% shade levels had the greatest diameter increment, which was 215.2% and 233.6% of that at 0% shade level and 161.4% and 175.2% of that at 90% shade level, respectively. The biomass at 75% shade level was significanly higher than the other shade treatments, and was 141.0%, 111.5% and 114.0% compared with that at 0%, 50% and 90% shade level respectively. The root/shoot ratio of seedlings reduced gradually, while the chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoid (Car) content increased with increasing of shade levels. LCP (light compensation point), and LSP (light saturation point) decreased while the apparent quantum efficiency (AQY) increased with increasing of shade level. Maximum net photosynthetic rate (P_max), maximum RuBP carboxylation rate (V_cmax) and RuBP regeneration of photosynthetic electron transport rate (J_max) showed an increase at first, followed by a decreased trend with increasing of shade level and the highest parameters were observed at 50% and 75% shade levels. However, the leaf nitrogen content per unit area (N_a) showed a decrease trend with increasing of shade level. Moreover, the fraction of leaf nitrogen allocated to carboxylation (N_C), the fraction of leaf nitrogen allocated to bioenergetics (N_B), the fraction of leaf nitrogen allocated to light-absorbing pigment (N_L), and photosynthetic nitrogen utilization efficiency (PNUE) showed a decrease trend with increasing of shade levels, and the highest values of these parameters except N_L were observed at 75% shade level. [Conclusion] Shade treatment can effectively promote the growth of T. grandis ‘Merrilli’ seedlings. The seedlings grown under shade treatment can effectively use the lower light intensity at early morning or late afternoon in comparison to that grown at full sun light. Heavy shading (90% shading level) significantly decreased the P_max, which may be related to the capacity to capture more light, and thus more resources were used to the light protein, resulting in a decline in photosynthetic capacity. Compared with the 50% shade level, the 75% shade level had more nitrogen allocated to the photosynthetic mechanism, such as in N_c and N_B, and significant higher PNUE. Thus, our results indicate that T. grandis ‘Merrilli’ seedlings likely grow better at 75% shade level for seedling cultivation.

[Objective] Moso bamboo (Phyllostachys edulis) is an important ecological and economic bamboo species and it is critical to figure out how to increase its nitrogen (N) fertilizer use efficiency in the intensive management process. This study was conducted in an intensively-managed moso bamboo forest in Lin'an city, Zhejiang province, and aimed to explore the utilization and distribution of N fertilizer accurately, in order to provide a scientific support for precise fertilization and sustainable forest management. [Method] In this study, we set 6 sample plots with 20 m×20 m in size. These plots were fertilized or unfertilized, and each of them contained a quadrat with 5 m×5 m in size. By using ¹⁵N-urea and ¹⁵N tracer technique in the quadrat, we investigated the distribution in the bamboo and the N fertilizer use efficiency (NUE) derived from N fertilizer. [Result] The ¹⁵N distribution ratio (¹⁵NDR) and NUE were different between different ages of bamboos, with 1 a > 3 a > 5 a. One-year-old bamboo had significantly greater distribution ratio and NUE than the other two ages, whereas there was no significant difference in the distribution ratio and NUE between the latter ages. As for different organs, the culm, underground culm and leaf had higher ¹⁵NDR and NUE in one-year-old bamboo, while the underground culm and rhizome had higher ¹⁵NDR and NUE in 3- and 5-year-old bamboos. Meanwhile, the root, underground culm and leaf in one-year-old bamboo had higher ratio of ¹⁵N to total N, while the rhizome, root and underground culm in 3- and 5-year-old bamboos had higher ratio of ¹⁵N to total N. The NUE of the bamboo forest was lower, with only 13.96%±0.88%. [Conclusion] Young bamboo was able to absorb N from fertilizer more efficiently, while the underground organs had an increasing trend toward using fertilizer with increased age, suggesting that strengthening fertilization to young bamboo and underground organs could greatly promote fertilizer use efficiency. Moreover, moso bamboo forest had lower N fertilizer use efficiency, which deserves further researches in the future.

[Objective] This study aimed to evaluate phytoremediation potential of different Salix integra varieties in the remediation of lead contaminated soils and to provide information for clarifying the Pb toxicity to willow trees. [Method] To investigate the variation of Pb tolerance and accumulation in S. integra, ahydroponic experiment with three cultivated varieties of S. integra including Weishanhu, Yizhibi and Dahongtou was conducted and the seedlings were treated with three Pb concentrations (CK: 0 μmol·L^-1, T1: 100 μmol·L^-1, T2: 200 μmol·L^-1). [Result] Compared to the control, the height growth and biomass accumulation of seedlingsof all three varieties subjected to Pb treatments were inhibited significantly (P<0.05). The seedling height growth showed a significant decrease with the increase of Pb concentration, whereas no significant changes were observed in the dry weight of the aboveground parts and the root with 100 μmol·L^-1 and 200 μmol·L^-1 of Pb treatments. The Pb tolerance of the three varieties differed depending on the Pb concentration and the Pb accumulation varied in different organs. All three varieties showed high tolerance index (TI) under both Pb treatments, of which Weishanhu exhibited the highest TI, followed by Yizhibi, and Dahongtou had the lowest TI. The accumulation of Pb in different tissues was from high to low: root > stem > twig > leaf. Based on the calculation of translocation factor (TF) for the aboveground tissues, an extremely low TF was found in wood, new shoots and leaves, indicating that Pb sequestration was mainly restricted in roots. The aboveground Pb was mainly reserved in stem. In this study, Pb and other mineral elements distribution in leaf tissues were also investigated by synchrotron radiation X-ray fluorescence analysis. The results indicated that Pb concentrations were detected in the middle vein of leaves, which was similar to the distribution of other ions, such as Zn and K. According to Pearson correlation analysis, the accumulation of Pb in leaves was positively related with K, Zn, Ca and Fe, indicating the translocation of Pb in leaves may be related to the uptake of these ions. [Conclusion] S. integra can tolerate and accumulate high levels of Pb in the root when exposed to different Pb concentrations, and there is no significant difference in the tolerance to Pb among the three varieties. However, as a good candidates for phytoremediation, Weishanhu exhibits better growth and biomass accumulation than the other two varieties, thus could be recommended for phytostablization of Pb in contaminated areas.

[Objective] This research was carried out to investigate the effects of simulated rain addition on branch growth rate, aboveground biomass, and leaf/shoot ratio and to explore the allocation characteristics of photosynthetic products and adaptation of desert species Nitraria tangutorum to different rain addition treatments. [Method] A field experiment was set in Dengkou of Inner Mongolia to investigate a typical desert plant N. tangutorum growing at the eastern edge of the Ulanbuh Desert. The species grown under natural environment were subjected to five rain addition treatments (increased by 0%, 25%, 50%, 75% and 100% of local mean annual precipitation, respectively) from 2008 to 2014 successively. The aboveground biomass, ratio of leaf to shoot, branch growth rate, and seasonal distribution of dry mass of reproductive and vegetative branches under five rain addition treatments were analyzed. [Result] 1) 75% and 100% treatments showed significant effects on branch dry mass in 2013 and 100% treatments showed significant effects on branch dry mass in 2014. The relative growth yield and relative growth rate of N. tangutorum branches increased after rain addition in the early growing season. These results indicated an incremental growth rate of reproductive and vegetative branches which means N. tangutorum shrubs would capture more optical energy and absorb more carbon dioxide from the surrounding environment. 2) In the growing season of 2013, the rate of biomass gain in vegetative branches and the rate of biomass loss in reproductive branches increased with the increase of rain addition, suggesting an advanced allocation of reproductive growth in the early growing season and vegetative growth in the late growing season. In growing season of 2014, the rate of biomass gain in vegetative branches and the rate of biomass loss in reproductive branches declined with the increase of rain addition. These biomass changes were mainly due to the very little natural rainfall in the early growing season and simulated rain addition slowed down the biomass decrease in reproductive branches. With different rainfall additions, N. tangutorum showed different biomass allocation strategies, indicating that N. tangutorum possess absolute regulatory ability and adaptability to precipitation variation. 3) In 2013, the aboveground biomass increased by 63.70%-151.60% and the ratio of leaf to shoot increased by 18.61%-48.83% after rain addition. In 2014, the aboveground biomass increased by 72.32%-134.28% and the ratio of leaf to shoot increased by 40.87%-140.56% after rain addition. Aboveground biomass and the ratio of leaf to shoot increased with the increase of rain addition, gradually. The facts that rain addition led to the increase of aboveground biomass and the ratio of leaf and shoot suggested N. tangutorum shrubs would allocate more photosynthetic products to the above-ground portion and accelerate the growth of leaves. [Conclusion] In conclusion, N. tangutorum would enhance the growth rate of branches and leaves, regulate the photosynthetic product allocation between reproductive and vegetative branches, and increase photosynthetic product allocation on leaves to adapt to increased precipitation in the context of global climate change.

[Objective] Comparisons of direct, indirect and composition effects of acid rain treatments on biomass allocation and physiological characteristics in Elaeocarpus glabripetalus seedlings were carried out in order to provide a scientific basis to study the mechanism of E. glabripetalus seedlings responding to simulated acid rain. [Method] Potted plants were used to establish the experiment, treatments included 2 different pH values of acid rain (pH2.5 and pH5.6) and 4 different models of exposure to acid rain, including 1) aboveground exposure: only the aboveground of seedlings were exposed to acid rain; 2) soil exposure: only the soil around seedlings was exposed to acid rain; 3)whole exposure: the seedlings and soil were both exposed to acid rain; 4) Control: exposed to distilled water with pH7.0. Biomass accumulation and allocation, chlorophyll content and chlorophyll fluorescence characteristics, malondialdehyde(MDA) content and membrane permeability, the activity of antioxidant enzymes were measured. [Result] 1)The growth of seedlings were inhabited to different extents when exposed to acid rain at pH2.5 level, and significant differences were found among the 3 models of exposure to acid rain. Compared with the control, total biomass, height increment, diameter increment of seedlings for the model of aboveground exposure decreased by 16.7%, 28.1% and 25.7% respectively; those of soil exposure decreased by 10.9%, 4.7% and 17.5% respectively; those of whole exposure decreased by 18.5%, 5.2% and 27.5% respectively. For the underground exposure, the ratio of leaf biomass to total biomass increased, and those of stem and root biomass decreased. The chlorophyll a (Chl a) content, total chlorophyll (total Chl) content, chlorophyll a/b(Chl a/b) were significantly lower than those of the control. For the aboveground exposure, primary photochemical efficiency of PSⅡ(F_v/F_m) and potential activity of PSⅡ(F_v/F_o) were significantly lower than those for the control; for the whole exposure the F_v/F_o and actual photochemical efficiency of PSⅡ (Φ_PSⅡ) were significantly lower than those for the control; No significant differences were found between the soil exposure and the control in F_v/F_m, F_v/F_o and Φ_PSⅡ. For all the 3 exposure models, membrane permeability, MDA content and antioxidant enzymes activity were significantly higher than those for the control, and those for the soil exposure were the highest. 2)At the pH5.6 level, there were no significant difference in biomass of seedlings between the 3 exposure models and the control, but Chl a content, total Chl content and Chl a/b decreased significantly, and membrane permeability, MDA content, peroxidase (POD), catalase (CAT) activity increased significantly compared with the control. For the aboveground exposure and the whole exposure, F_v/F_o and Φ_PSⅡ were significantly lower than those for the control. [Conclusion] The soil exposure had both negative and positive effect on the seedlings, while the aboveground and whole exposures inhabited the seedlings, and the effect of whole exposure was greater than that of aboveground exposure, but the whole exposure did not change the biomass allocation of seedlings. The effect of acid rain at pH5.6 on seedlings was significantly lower than that of acid rain at pH2.5.

[Objective] An in vitro rapid propagation protocol was developed for Paeonia ostii to provide new method for the rapid propagation and cultivating elite varieties of oil tree peony. [Method] Buds were collected as explants in spring from selected individual plants of P. ostii and inoculated in the medium WPM+6-BA 0.5 mg·L^-1+GA₃ 0.2 mg·L^-1. Individuals or genotypes suitable for in vitro culture were selected by induction and multiplication ratios at initiation stage, among which the optimal one was studied further to set up rapid propagation protocol. During multiplication, the Ca(NO₃)₂ concentrations in the basal medium and combinations of plant growth regulators (PGRs: 6-BA, GA₃, NAA, KT and TDZ) were studied by single-factor and randomized block design. During root inducing phase, the effects of cold treatments and IBA concentrations were evaluated by single-factor design. And at acclimation stage, in vitro rooted plantlets were classified by the rooting quality and transplanted into a greenhouse to investigate their survival rates. [Result] 1) The initiation performance of P. ostii in vitro culture was genotype-dependent. In 17 selected individuals with high seed yield, 7 individuals were suitable for in vitro initiation with induction rate≥50% and multiplication rate≥2.50, and the best FD10 (induction rate=100%, multiplication rate=4.58) was selected to set up rapid propagation protocol. 2) The optimal multiplication medium was WPM (Ca(NO₃)₂ 1 544 mg·L^-1)+6-BA 0.5 mg·L^-1+GA₃ 0.2 mg·L^-1, on which the highest multiplication rate (3.87) was obtained after 40 days of culture. And 6 subcultures were carried out. 3) By the effects of cold treatments and IBA concentrations in rooting, a two-step rooting protocol was set up. The shoots were cultured in the medium 1/2 MS+IBA 2.0 mg·L^-1+putrescine 1.0 mg·L^-1 for 30 days (including a 4℃ cold treatment of 8 days at the beginning) for root induction, and finished within 30 days, followed by culture in the medium 1/2 MS (double strength of CaCl₂) +activated charcoal 4.0 g·L^-1 for 20 days for root formation. The highest rooting percentage (56.67%) was obtained. 4) The in vitro rooted plantlets were classified into 3 grades by their rooting quality, and the percentage of grade 1 was 84%, while the grade 2 and grade 3 were 12.5% and 3.5%. During acclimatization the rooted plantlets were transferred into pots containing a mix of peat:vermiculite:perlite(1:1:1 by volume)substrate. After 60 days, plantlets of the grade 1 that had less callus survived 66.67%, but those plantlets that had obvious callus development died away totally, indicating the rooting quality was really an essential factor for survival of in vitro rooted plantlets of tree peony. [Conclusion] The rapid cloning propagation of P. ostii was genotype-dependent, and a rapid propagation protocol of FD10 was developed. The optimal medium for multiplication was WPM (Ca(NO₃)₂ 1 544 mg·L^-1)+6-BA 0.5 mg·L^-1+GA₃ 0.2 mg·L^-1, and the protocol for optimal rooting was 1/2MS+IBA 2.0 mg·L^-1+ putrescine 1.0 mg·L^-1, with 8 days cold treatment at the beginning of the rooting stage. The survival rate of transplanted plantlets in grade 1 was 66.67% 60 days after transplanting.

[Objective] Daba mountains is one of the most abundant areas of biodiversity and walnut (Juglans regia) resources because of its unique geography and climate. In recent years, walnut resources lose dramatically in this area due to human intervention. In view of the serious situation, investigations were carried out on the nut phenotypic diversity and genetic diversity of walnut populations originated from seedlings in Daba mountains to know its nut phenotypic variation, germplasm characteristics and genetic structure. [Method] Variation of 12 nut phenotypic traits (30 representative nuts per sample) and 16 gene loci (1 seedling per sample and 16 SSR primers were used) of 386 samples from 12 seedling populations in Daba mountains were analyzed. [Result] 1) The variation coefficient of nut phenotypic traits of 12 seedling populations in Daba mountains was between 26.75%-34.36%, with an average of 30.60%. And the germplasm resource of small nut (less than 6 g) accounted for a certain proportion. The Shannon index of the populations was between 1.112-1.546, with an average of 1.324, and the expected heterozygosity ranged from 0.612 to 0.718, with an average of 0.688, suggesting abundant variations in nut phenotypic and genetic diversity in this area. 2) The phenotypic and genetic differentiation among populations in this area was small, with differentiation coefficients of 8.15% and 6.32% respectively. 3) Cluster analysis showed that the Manhattan distance of nut phenotypic traits and the genetic similarity coefficient were positively related to the geographic distance. [Conclusion] There were large nut phenotypic diversity and genetic diversity in walnut trees in Daba mountains because of long-term regenerations from seedlings and adaptation to diverse site conditions. The Daba mountains is an important area of genetic diversity of walnuts in China. This study would provide an important basis for the walnut breeding and conservation in the region.

[Objective] Shivaphis pteroceltis is a new pest on Pteroceltis tatarinowii, a member of the national grade Ⅲ rare and endangered tree species. The pests had the characteristics of rapid propagating, large quantity, strong outbreak, and long time damage, and cause serious damage to leaves, fruits and young branches of P. tatarinowii. Based on the study of the biological characteristics of S. pteroceltis, the ecological characteristics, such as the effective accumulated temperature, the influence of temperature on the size, population dynamics, and the phototaxis, were further studied in this paper, to lay a foundation for integrated control the pest. [Method] Five treatment temperatures were set to calculate the development threshold temperatures and effective accumulated temperatures by the linear regression method. Developmental duration of the insect under different temperatures was observed and recorded by rearing some wingless parthenogenetic aphids in culture dish in which the leaves of P. tatarinowii were placed, and the improved method of leaf discs was used to rear the aphids. The body length and body width of each aphid were observed, measured and recorded in different temperature gradients. SPSS was used to analyze the data of body length and body width to investigate whether there was a significant difference on aphid size between different temperature treatments. Population dynamics from the hatch of the winter egg of S. pteroceltis to the leaf blade was regularly observed, and then the population dynamics figure of S. pteroceltis and winged and wingless aphids quantity dynamic figure were drawn. According to the characteristics of aphid yellow taxis, the yellow boards were hanged at different heights in P. tatarinowii forest in study sites. The number of aphids was daily counted, and at last the data was collected and processed. [Result] The results showed: the developmental threshold temperature was (6.40±1.01)℃ and the effective cumulative temperature was 223.11 day degree±13.12 day degree, and the K'/K=15.89, indicating that there were 15-16 generations every year in Zaozhuang area. Within a certain range, with the increase of temperature, the development duration was shorter, and the size was smaller in the same age. There were three peaks of the aphid outburst, June 10th, July 30th and September 20th, in Zaozhuang City, Shandong Province. Population dynamics was sensitive to the environment factors such as wind and rain. The trapping effect of yellow sticky card was better in the lower canopy. [Conclusion] In the temperature range of 17-29℃, with the increasing of temperature, the developmental rate of aphid increased and the developmental duration decreased. The pest occurrence trend and the change law provide a theoretical basis for the prediction and comprehensive control. In order to reduce the manslaughter for natural enemy of the pests, such as ladybird, in actual production, the high-incidence season of the natural enemy should be avoided in trapping the pests.

[Objective] Burkholderia pyrrocinia JK-SH007 is a strain of biocontrol bacteria which was isolated from the stem of poplar. In order to evaluate the safety of B. pyrrocinia JK-SH007, this study aimed to evaluate the micro ecological effects and the biological safety of the natural environment after its entry into the natural environment. [Method] A solid plate method was used to investigate the potential effects of JK-SH007 on the activity change of the four main soil enzymes, and the Biolog ECO microplate method was applied to assay the microbial community and its function diversity in rhizosphere soil of aigeiros poplar (Populus deltoides). [Result] The results showed that from the over trend, the numbers of bacteria, actinomyces and fungi in poplar rhizosphere soil gradually increased and were significantly higher than control with the extension of time after being inoculated with strain JK-SH007. The number of these microorganisms reached the peak (3.36×10⁹ cfu·g^-1 dry soil; 7.50×10⁷ cfu·g^-1 dry soil; 1.14×10⁷ cfu·g^-1 dry soil) in 150 day post-inoculation, and then decreased significantly, but by then were still higher than these of control plants. The soil enzymes activities (acid phosphatase, alkaline phosphatase, dehydrogease and invertase) with inoculation of strain JK-SH007 were all higher than that of control, especially for alkaline phosphatase and invertase. The Biolog ECO plates analysis showed that AWCD values on day 10, day 20, day 60, day 150 and day 180 after inoculation were higher than control treatment. At the early stage of the inoculation, soil microbial diversity (Shannon index, Simpson index and McIntosh index) had no obvious regularity. At the 120th day, 150th day and 180th day post-inoculation, the three parameters of the functional diversity of the soil microbial communities were all slightly higher than those of control. But, the differences were not significant. [Conclusion] Strain JK-SH007 may play roles in improving total microbial activity of poplar rhizosphere soil, increasing soil fertility and enriching soil communities. All of these are conductive to maintaining and promoting the soil fertility and health. But these benefits would be decline over time. At the same time, all of results showed strain JK-SH007 had no or less menace to the indigenous microorganisms in the environment, suggesting that it is safe to put strain JK-SH007 into use as a potential bio-control factor in the future.

[Objective] The characteristics of bird communities in Beijing urban green areas in winter were investigated in order to provide basis for the conservation of urban birds. [Method] Forty urban greenlands were classified into rural park, urban park, linear greenland and campus greenland. They were surveyed systematically with transect method during the period between Nov. 2013 and Jan. 2014. [Result] A total of 8 853 birds representing 57 species in 30 families and 12 orders were recorded. Among them, 35 species of passerine birds were observed (61.40% of total), followed by anatidae birds (9 species, 15.79%). It was found through analysis by residential types that there were 36 species of resident birds (63.16%), 19 species of passing birds (33.33%), 8 species of summer birds (14.04%) and 13 species of winter birds (22.81%). The resident birds were the major components of the winter bird community. Analysis by feeding guild showed that the insectivorous birds contained the most species (28 species, 63.64%), and there were only 8 species of omnivorous birds, but 3 923 omnivorous individuals were recorded (63.64% of total individuals), and omnivorous species were the dominant group in the community. According to the encounter rates of birds, tree sparrow (Passer montanus, 56.14 individual·h^-1), azure-winged magpie (Cyanopica cyana, 31.39 individual·h^-1), mallard (Anas platyrhynchos, 23.76 individual·h^-1) and magpie (Pica pica, 20.69 individual·h^-1) were the dominant species in the bird communities in winter. Nine species were observed in all of the four greenland types, among which magpie (observed in all the 40 greenlands), tree sparrow (observed in 36 greenlands) and azure-winged magpie (observed in 35 greenlands) were the most widely distributed species. In the four types of greenlands, rural park held the highest richness (9.72±1.81, mean±SE), but the difference were not statistically significant. Diversity in the liner greenland (0.87±0.16) was significantly lower than that in rural park (1.29±0.49, P<0.05) and urban park (1.48±0.16, P<0.05). Intra-similarities of the bird communities in rural parks were significantly lower than those in campus greenlands (0.60±0.06, P<0.01), urban parks (0.56±0.03, P<0.05) and linear greenland (0.54±0.18, P<0.01). Inter-similarity between rural park and urban park was highest, but lowest between rural park and campus greenland. [Conclusion] The rural parks located at the edge of the city with a larger green area had higher bird species richness and diversity, and provided the birds with a shelter in winter. Omnivorous birds adapted to the urban environment better, with a wide distribution and a high density. In the future, vegetation that can provide bird with food in winter should be contained in the urban greenland planning and larger greenlands should be constructed.

[Objective] In this study, ICESat-GLAS waveforms was combined with HJ-1A/HSI hyperspectral imageries to realize regional estimation of forest canopy height. [Method] We extracted parameters(waveform length W and the terrain slope parameter TS)from ICESat-GLAS waveforms, and built the forest canopy height model with W and TS. The model was used to calculate forest canopy height within each GLAS footprint of the study area. For HSI imageries, the minimum noise fraction(MNF)method was applied to decrease noise and reduce the dimensionality of HSI imageries and the first three MNF components(MNF1, MNF2, MNF3)were selected for further research. Afterwards, the SVR method was applied to establish the relationship between GLAS estimated forest canopy height and the three MNF components, and accordingly the full covered regional forest canopy height map was produced. [Result] The results showed that there was a significant linear relationship between TS and terrain slope(R²=0.78). The R² and RMSE value of the forest canopy height model built by W and TS were 0.78 and 2.51 m, respectively, and the validation results were R²=0.85 and RMSE=1.67 m. The R² and RMSE of SVR model were 0.70 and 3.62 m, respectively, with the validation results of R²=0.67, RMSE=4.42 m. The estimation error of the forest canopy height map was calculated and analyzed by field sample data, and the maximum, minimum and mean value of estimation error were 7.10 m, 0.07 m and 1.78 m, respectively. The standard deviation was 1.49 m, as well as Q1 and Q3 were 0.75 m and 2.31 m, respectively. [Conclusion] TS can perfectly reflect terrain slope. In addition, the linear relationship model built in the study overcomes the difficultly explaining problem of logarithm model in flat area. The study demonstrated that it holds great potential to estimate regional forest canopy height by combining ICESat-GLAS waveforms and HJ-1A/HSI hyperspectral imageries, which overcome the disadvantage of ICESat-GLAS in the aspect of regional estimation caused by its discrete distribution and improve the estimation accuracy.

[Objective] In order to find gap of non-availability in most domestic literatures, which sawing velocity was dropped down due to the frequent change of saw line, this research investigated a heuristic rule for rectangular parts cutting layout of wood-based panel, built mathematical model and studied solving method. [Method] Based on the situation that in a suit of material list, coupled dimension existed among two or more kinds of parts, therefore, a grouping and dimension reducing heuristic rule was put forward. All rectangle parts were sorting by coupled dimension in descending order, each group consisting no more than four kinds parts. Taking the minimum remaining area as evaluation index, a part-oriented mathematical model was set up. In this model, the quantity demanded for base panel was estimated by setting redundancy factor, and four aspects including quantity, length, width and area of placed parts on base panel should be all wlthin the limitation value. Moreover, layout width ratio was set and single unit saw line width was added on length and width of both rectangular parts and base panel so as to offset fictitious saw line loss located at undermost and rightmost side of base panel. Genetic algorithm (GA) was adopted to find global optimal solution for layout and punishment function was used to deal with constrains. By integer coding of chromosome, establishing of initial population, punishment factors with certain adaptability and fitness function based on exterior point punishment function and genetic manipulation, vector on behalf of layout solution was calculated through the layout algorithm which was built in cooperation with GA toolbox of MATLAB. Instances were applied to test feasibility of the model and algorithm. [Result] Layout solution of all rectangular parts was described by four parameters, consisting of code, row and direction (vertical and transverse). Layout matrix has 4 rows, and the column was the total quantity of all parts. Each column represented layout solution of each part. The instances showed that multiple parts could be grouped based on coupled dimension-based heuristic rule, optimal controlled vector standing for layout solution for each group was divided into four sections with varied height, and these four sections meant the four parameters. It was also demonstrated that GA tended to convergence within limited iterations and gave relatively good capability of global optimization. In addition, visualization of layout solution displayed meet the demand of "guillotine cutting" and the regular saw line was good for increasing sawing efficiency. [Conclusion] The coupled dimension-based heuristic rule and part-oriented mathematical model were suitable for cutting layout of wood-based panel and therefore a new method was presented for cutting layout of panel-type furniture. However, in order to enhance cutting productivity, the elements such as feeding times of cutting saw, optimized selection of punishment factor should also be taken into account comprehensively.

[Objective] Woodland is an important part of forest resources, and is the basis of the forest. In this paper, I aimed to find out the forest region of Heilongjiang Province forestry with area change of main driving factors and to the forestry with area change in the degree of influence, so as to provide a reference and basis for the relevant decision-making departments. [Method] This study selected the forestland using data during 1986-2013 from forest industry region of Heilongjiang Province and corresponding indexes data of social and economic impact factors.On the basis of qualitative research, 12 indicators were selected from the three aspects consisting of economy, society and policy factors.The data of 1994-2002 were adjusted by the statistical caliber after 2002, SPSS18 was applied to establish multiple linear regression model and test the model. [Result] The forestry land area of influence factor model for forest region of Heilongjiang Province was obtained:Y=900.565-11.082D₁-53.463X₆, R²=0.867, F=81.421, model passed the test. The forestry industry output value, the average annual wages of staff and workers, the proportion of the first and third industry, diversified output value occupancy, forestry investment in fixed assets, population at the end of the year, and the casualties because of working in forestland were showed significant correclation with the change of forestry land area, respectively.The implementation of the Natural Forest Protection Project and diversified output value occupancy affects the changes of forestry land area extremely significantly. In 1998, the implementation of the Natural Forest Protection Project plays a negative role in reduced forest area land area.Once the diversified output value occupancy increased a percentage point, the forestry land area reduced 5 300 hm². [Conclusion] The results indicated that more attention should be paid to protect woodland resource in the process of diversification, and finally realize the sustainable use of woodland resources.