[Objective] Soil organic C,total N ,and total P were measured in Chinese fir plantations at 3 different ages (7-, 17-, and 25-year-old) and changes of these elements along soil profile were also investigated in these plantations, in order to provide a scientific basis for sustainable management of Chinese fir plantations. [Method] The study was conducted at the National Key Field Observation Station of Central South University of Forestry and Technology, located in Huitong, Hunan Province of China. Three plantations at different ages were selected within the station and three plots in size of 20 m×20 m were set up for each of the three plantations. Based on the principle of ‘random’, ‘equal’ and ‘pooled’, soil samples were collected from 0-20, 20-40, and 40-60 cm depths, respectively, at three sampling points with a triangle shape within each plot. Soil organic C, total N and total P were analyzed. C:N, C:P, N:P and C:N:P ratios were estimated. [Result] The contents of soil organic C,total N, and total P ranged 12.14-19.52, 1.43-1.89,and 0.32-0.40 g·kg^-1 in the studied plantations, respectively. The contents of soil organic C and total N decreased with the increase of soil depths in 7-, 17-and 25-year-old stands. Total P contents did not significantly differ among soil depths in the studied stands. Soil C:N of the 3 plantations was respectively 11.73, 8.70, and 8.52, displaying a declining trend with aging.. In addition, soil C:N ratio was significantly higher in 7-year-old plantations (P<0.05) and significantly lower in 17- and 25-year-old plantations (P<0.05) when compared to the control plots (9.52) (plots with slash burning but before afforestation). Soil C:P ratios were 57.42, 36.27, and 40.54 in the studied plantations and 55.70 in the control, which were all lower than the national mean (61). Soil C:P ratios were significantly higher in 7-year-old plantations and the control plots than in 17- and 25-year old plantations. Soil N:P ratios were 4.87, 4.18 and 4.76 in the studied plantations and no significant differences from each other. But soil N:P ratios were lower in the studied plantations compared to the national mean (5.2), and significantly lower when compared to the control (5.85) (P<0.05). Soil C:N:P ratios were 56:5:1,36:4:1,41:5:1 in the three plantations and 55:6:1 in the control, all were lower than the national mean (60:5:1). [Conclusion] Soil C, N ,and P contents were gradually restored with the aging of plantations. Our study suggested that N was relatively adequate, but P was relatively lack in the studied sites. It was likely that net mineralization of soil microbial biomass P occurred in order to maintain a relative equilibrium of P in soils under low soil C:P ratio condition. Soil C:N, N:P ,and C:P ratios were in a relative steady state along soil profile in the plantations. Soil C:N and C:P ratios were mainly affected by soil total C in the study area. As a consequence, to regulate soil organic C content is a critical target in sustainable management of Chinese fir plantations.

[Objective] Selection of plant species with strong ability to retain pollutants of particulate matters (PM) and its size fractions and suitable for local conditions should be chosen to ensure greening policy be designed to reduce PM pollution. In this study, the amounts of PM and its size fractions (PM_2.5, PM_>2.5) captured by leaves of twenty-three plant species on the basis of per unit leaf area, per leaf, per plant and per unit green area in the region of Beijing were investigated to find out the appropriate species. [Methods] The amounts of PM (PM_2.5, PM_>2.5) captured by leaves of twenty-three plant species were examined in this study. The collected leaf samples were washed using a brush with ultrapure water (ELGA, Buckinghamshire, UK) and then filtered through two types of membranes (w₁) with pore sizes of 2.5 and 0.1 μm, respectively. Then the membrane with PM (w₂) was weighed using balance with an accuracy of 0.1 mg (SI-114, Denver Instrument, USA) after dried at 40℃ for 24 h. The total hemi-surface leaf area (S) was measured using Image J software (Version 1.46; National Institutes of Health, Bethesda, MD, USA) after scanning (HP Scanjet 3570c, Japan). The PM (PM_2.5 and PM_>2.5) retention amounts were calculated as (w₂-w₁)/S. The PM (PM_2.5 and PM_>2.5) retention amounts per leaf, per tree and per unit green area were calculated based on the PM (PM_2.5 and PM_>2.5) retention amount per unit leaf area, single leaf area, and leaf area index (LAI). Data were subjected to ANOVA with multiple comparisons by using SPSS 19 (IBM, USA), with a level of significance at P<0.05. [Results] Leaf PM, PM_2.5 and PM_>2.5 per unit leaf area differed among species, by 8.6, 9.8, and 10.5 folds, respectively. Leaf PM, PM_2.5 and PM_>2.5 on the basis of per leaf, per plant and per unit green area also showed significant differences among species. The maximum difference reached up to 239, 198, and 285 (per leaf); 3 600, 4 100 and 3 600 (per plant); 18.3, 20.5 and 18.1 (per unit green area) folds. In general, the PM, PM_2.5 and PM_>2.5 retention amounts of different life form was in the order of tree > liana > shrub. For the species with different leaf habit, the evergreen species had a higher PM, PM_2.5 and PM_>2.5 retention amount per unit leaf area than that of deciduous species. However, the PM, PM_2.5 and PM_>2.5 retention amounts on the basis of per leaf, per plant and per unit green area were on the contrary. Platanus acerifolia, Salix babylonica, Acer truncatum, and Ulmus pumila were efficient species in capturing PM and its size fractions. Pinus tabulaeformis, Cedrus deodara and Buxus megistophylla had a medium ability to accumulate PM and its size fractions. Less efficient species were Berberis thunbergii, Buxus sinica, Ligustrum quihoui. [Conclusions] The amounts of PM and its size fractions captured by leaves on the basis of per unit leaf area, per leaf, per plant and per unit green area all showed significant differences among species. The ranking presented in terms of capturing PM and its size fractions can be used to select species for atmospheric PM pollution removal in the region of Beijing. Since the quantity of PM and its size fractions captured by leaves depends on the PM and its size fractions retention amount per unit leaf area and leaf area index, efficient plant species and plant configuration designs considering different life form and leaf habit can be used to decrease human exposure to the pollutants.

[Objective] This research was carried out to investigate the effects of sub-irrigation gradients on water use efficiency, morphology and nutrient status, and to provide a scientific basis for precision irrigation of containerized Quercus variabilis seedlings. [Method] Annual containerized seedlings of Q. variabilis using two container sizes (D40 container: volume 656 cm³, specification 6.4 cm×25 cm; D60 container: volume 983 cm³, specification 6.4 cm×36 cm) were treated with four sub-irrigation gradients (85%, 75%, 65%, 55% saturated medium weight) to investigate the changes of water consumption, growth, nutrient status and electrical conductivity (EC) of the growing medium.[Result] 1) The water consumption of containerized Q. variabilis seedlings decreased successively when sub-irrigation gradients dropped. The water use efficiency did not show similar patterns, but the higher sub-irrigation gradient had the higher water use efficiency. 2) The seedlings with sub-irrigation of 85% and 75% saturated medium weight reached the maximum values in height, diameter, stem biomass, root biomass and total individual biomass in all treatments, and no significant difference was found between these two sub-irrigation gradients, but higher or significantly higher than other treatments. 3) There was no obvious pattern among different treatments in nutrient concentration. However, the seedlings with sub-irrigation of 85% and 75% saturated medium weight had significantly higher nutrient content in plants or different organs than other treatments, and there was no significant difference between these two treatments in nutrient content. 4) The seedlings with large size containers had water consumption higher than those with small size containers, and displayed a better performance in morphology, biomass and nutrient content, however, no significant difference was found between different container sizes in nutrient concentration. 5) Sub-irrigation significantly increased the EC value of the upper layer of growing media. The EC value of the middle and lower layers of growing media was not significantly different from each other, but significantly lower than that of the upper layer. There was no significant difference among the treatments in the EC value of the upper layer of growing media. The EC value in our study was lower than the threshold EC value which causes harm to seedlings, and would not have harmful effect on seedlings. [Conclusion] The seedlings with sub-irrigation of 85% and 75% saturated medium weight content with D60 container had the highest water consumption and higher water use efficiency. There was no significant between these two treatments in height, diameter, biomass, and contents of nitrogen, phosphorus and potassium, but higher or significantly higher than other treatments. Their EC values in upper layer of growing medium were lower than the threshold EC value which causes harm to seedlings. Therefore, in terms of water saving and growth promotion, the optimal treatment was D60 container with sub-irrigation of 75% saturated medium weight.

[Objective] The research of multi-scale spatial distribution pattern and associations of forest landscapes has become a hotspot in landscape ecology. The purpose of this paper was to analyze the spatial distribution pattern and associations of the main forest landscapes in Daxing'an Mountains, which can contribute to clarify the formation and maintenance mechanism of forest landscapes in this area and also can provide some insights for healthy management of the forest landscapes. [Method] Based on the data of forest resource inventory in Pangu forest farm in Daxing'an Mountains in northeastern China, the spatial distribution pattern and associations of the main forest landscape types (natural Larix gmelinii forest, natural Betula platyphylla forest, natural coniferous mixed forest and natural mixed broadleaf-conifer forest) were characterized by using the O-ring statistics within Programita software and kernel density function within ArcMap software. [Result] The result of kernel density function indicated that the mean patch density for each forest type were 0.73-1.57 km^-2, and the spatial variation coefficient were up to 99.75%-119.67%, which both illustrated the distribution of the four forest landscapes were significantly clumped in spatial dimensions. The O-ring statistics showed that the main forest landscape types were significantly clumped at small scale, and tended to be in random distribution with the increase of scale. Spatial associations showed that there were negative correlations at small scale, non-correlations at medium scale, and positive correlations at large scale among different forest landscapes. Forest cutting and forest fire are the major driving forces for the change of forest landscape in the study area. [Conclusion] Our assessment indicated that the forest landscapes in this area have presented the trends of fragmentation during the recent 100 years, due to the long term forest harvest, forest fires and other interference factors. Therefore, in order to establish and maintain a healthy and stable forest ecsystem from the level of landscape, we suggested that the following four measures should be adopted: 1) For restoring the forest vegetation, the continuous forestation mode and random forestation mode should be employed in small and large scales, respectively; 2) For selection of tree species, native species should be given priority, and spatial configuration of these species should also be given attention; 3) For forest harvesting, selective cutting and intermediate cutting should be used; 4) Finally, more attentions need to be paid to the effects of human activities (e.g., forest harvest, silviculture and roads construction) on the forest landscapes.

[Objective] The aim of this study is to provide the theoretical basis for optimizing the stand spatial structure and for developing its ecological, economic and cultural functions by analyzing and evaluating the stand spatial structure of Cunninghamia lanceolata ecological forest.[Method] Neighbor trees of the object one was determined based on the Voronoi diagram, and Stand spatial structure index was calculated based on the measured data in eighteen permanent sample plots and the retest data in nine permanent sample plots of Cunninghamia lanceolata ecological forest of different age groups(young, half-mature and near mature)in Fushou Forest Farm of Hunan province. Mingling index, neighborhood comparison, uniform angle index, competition index, stand layer index and open degree of stand were selected to analyze their spatial structure characteristics before and after thinning and replanting. Meanwhile, adopted multiplication division method making a multi-objective programming for each spatial structure parameter, the evaluation index of stand spatial structure was put forward. Making reference to target and technical index of near-natural transformation of plantation and using the integration of qualitative and quantitative methods, the evaluation index values of stand spatial structure were divided into five grades.[Result] Before thinning and replanting, stand layer index and mingling index was generally low, indicating that mingling degree of tree species was low, the stability of the stand vertical space structure was weak, and the use of vertical space of trees was underutilized. Also, neighborhood comparison of DBH of the stands was closed to moderate state, the numbers of trees in diameter classes were distributed uniformly, and there was minor difference between individual trees, uniform angle index of the stands was belonging to the intermediate state of uniform and random distribution, which was not ideal horizontal distribution pattern of the stands. The open degree of young forest was high, but that of half-mature and near mature forest was low, indicating that growth space of young forest was sufficient, but half-mature and near mature was lack of growth space. As Cunninghamia lanceolata grown and developed, the competition index of stands showed an increasing trend,indicating that the competition pressure among individual trees was gradually increasing with the growth of tree age. The evaluation index of stand spatial structure of Cunninghamia lanceolata ecological forest of eighteen permanent sample plots was 0.185 9-0.364 7, belonging to the evaluation grade 1 and 2 accounting for 11% and 89% of the total sample plots respectively, without the sample plots belonging to the grade 3, 4 and 5, illustrating that the spatial structure of Cunninghamia lanceolata ecological forest was far from ideal spatial structure, and need to optimize the stand spatial structure. However, after thinning and replanting, the stand layer index and mingling index were increased significantly, the degree of difference among individual trees became apparent, and the growth space of juvenile and medium became more sufficient. The evaluation index of the stand spatial structure of Cunninghamia lanceolata ecological forest of nine retest sample plots was 0.346 2-0.613 1, belonging to level 2, 3 and 4 of evaluation grade accounting for 11%, 78% and 11% of the total retest sample plots respectively, which illustrated that the spatial structure of Cunninghamia lanceolata ecological forest of different age groups was improved obviously.[Conclusion] There were unreasonable factors in the stand spatial structure characteristics could be found by analyzing the stand spatial structure, which provided basis for management measures to optimize the spatial structure. The evaluation index of stand spatial structure was put forward, it explored a new approach to the ideal spatial structure of Cunninghamia lanceolata ecological forest and provided the theoretical basis for the evolution of the ecological forest improving mainly Cunninghamia lanceolata plantation toward ideal structure. According to the evaluation results of spatial structure of Cunninghamia lanceolata ecological forest in the research area, it was objectively reflected the actual situation of its spatial structure before and after thinning and replanting.

[Objective] Mitochondrial ATP synthase exists in the plasma membranes of bacteria, thylakoid membranes of chloroplasts and the inner membranes of mitochondria, and is described as a splendid molecular machine, and a key enzyme for energy conservation in mitochondria. The proton motive force generated across the membrane by electron flow is used to drive the ATP synthesis from ADP and inorganic phosphate. The Japanese pine sawyer, Monochamus alternatus Hope (Coleoptera: Cerambycidae), is a longicorn beetle that is notorious as a vector of the pinewood nematode, Bursaphelen chusxylophilus (Steiner etBuhrer) Nickle, which causes pine wilt disease. This beetle is widely distributed in East Asian countries, including Japan, China and South Korea, vectoring the pine wilt disease there. The objective of the present study is to provide molecular information and references for further researches on insect ATP synthase gene, and physiological and toxicological functions of the ATP synthase gene of M. alternatus. [Method] An expressed sequence tag (EST) from Monochamusalternatus cDNA Library was amplified by 3' rapid amplification of cDNA ends. The cloned gene was characterized by splicing with the EST, open reading frame(ORF)research and Blast homologous comparison. ProtParam tool and DNAMAN software were used to analyze the characteristics of deduced protein and construct phylogenetic tree, respectively. The expression characteristics of the cloned gene at different developmental stages and in different parts of adults and larval tissues of M. alternatus were analyzed by real time quantitative PCR. [Result] A cDNA with 1133bp length was cloned, containing a 89 bp at its 5'-UTR, a 294 bp at its 3'-UTR, and an ORF of 750 bp which codes for ATP synthase D subunit designated as MaATPSE (GenBank accession number: KM101044). The MaATPSE encodes 249 amino acid residues, and the deduced molecular weight, isoelectric point and stability coefficient are 28.21 kDa, 9.40 and 31.13, respectively. The MaATPSE contains 3 serine phosphorylation sites, 4 threonine phosphorylation sites, 2 tyrosine phosphorylation sites and 1 glycosylation sites. The MaATPSE has 87% identity with Tribolium castaneum, 83% identity both with Bombyx mori and Drosophila melanogaster, respectively. M. alternatus and T. castaneum are on the same branch in phylogenetic tree, and there is a long genetic distance between M. alternatus and non Coleoptera insects. The relative expression level of MaATPSE in pupae and larvae was 3.70 times and 2.65 times of that in adults, respectively. There was a significant difference in expression among different developmental states (P<0.05). The MaATPSE was expressed in various tissues of larvae, the expression in fat body was highest, and 5.94 times of that in control, and the expression in body wall and hemolymph ranked the second, and was 3.93 times and 2.88 times of that in control, respectively. The expression in midgut and Malpighian tubules was relatively low, and was 0.24 times and 0.28 times of that in control, respectively. There were significant differences in MaATPSE expression among various larval tissues, except that between Malpighian tubules and midgut (P<0.05). The relative expression level in adult head, abdomen, antennae, feet, wings and thorax was 2.24, 3.09, 3.52, 3.39, 4.45 and 0.68 times of that in control, respectively. There were significant differences in MaATPSE expression among various parts in adults (P<0.05). [Conclusion] The Monochamus alternatus ATP synthase D subunit gene containing 5'-UTR, 3'-UTR and a complete ORF was cloned in this study. The MaATPSE and ATP synthase of T. castaneum are the most similar at amino acid level. The MaATPSE is extensively expressed in the larvae, pupae and adults, in various tissues of larvae and parts of adults of M. alternatus.

[Objective] The Japanese pine bast scale, Matsucoccus matsumurae (Kuwana) (Homoptera: Matsucoccidae), is an important invasive species and a destructive pest of pine forests in China. In this paper, the occurrence time, morphological characteristics, living habits and natural enemies of M. matsumurae at different developmental stages in three climatic regions in China were investigated to provide a basis for well monitoring the development and population dynamics, and determining the most appropriate control period. [Method] Three representative climate zones associated with the distribution status of M. matsumurae in China were chosen, i.e. Jinhua in Zhejiang Province (ZJJH), Qingdao in Shandong Province (SDQD) and Fushun in Liaoning Province (LNFS). The sampling sites were set in the forests infested by M. matsumurae. Continuous surveys in the forest and microscopic examination in a laboratory were conducted from 2011 to 2013. [Result] 1) M. matsumurae reproduced two generations a year in the three climatic zones and overwintered at the 1^st-instar nymph period, but their developmental durations in the three climatic zones were different. In ZJJH, the post-hibernation nymphs emerged in early March, while, the post-hibernation nymphs emerged in late April or early May in SDQD and LNFS. The populations of LNFS began to overwinter in October, but the populations of ZJJH did not overwinter until December. These differences were related to the local temperature. 2) The morphological and wax secretion characteristic of the females and males of M. matsumurae were varied at different developmental stages. Newly hatched 1^st-instar nymphs possessed developed antennae and legs, but did not secret wax substance on their surface. After settling under the bark crack, the 1^st-instar nymphs began to secrete white wax substances on their surface. The 2^nd-instar nymphs without antennae, eyes and legs were called "pearl-shape stage". After a period of feeding in spring, the insect body became enlarged and exposed to outside of the bark. The insects with white wax secretions were easily visible and were called "patent period". The 3^rd-instar nymphs possessed developed antennae and legs, and could crawl freely to search for pupation place. Then the nymphs secreted white wax filaments from the wax glands on the body surface to form wax cocoon. In the wax cocoon, the insects underwent two stages, prepupa and pupa. The male adults had a pair of antennae and compound eyes on head, and a pair of fore wings, while the hind wings degraded into poisers at thorax. There was a cluster of long wax filaments secreted from a group of columnar tubular ducts at the tergum of abdominal segment VII, and a copulatory organ at the posterior of the abdomen. The female adults were similar to the 3^rd-instar nymph in morphology, but their thorax and abdomen were larger. At the initial stage, the female adults were not covered by obvious wax secretion, after mating, they secreted wax filaments to form egg sacs. 3) There were 59 species in 14 families of the predators of M. matsumurae listed in China, of which, Anthocoridae in Hemiptera, Chrysopidae in Neuroptera and Coccinellidae in Coleoptera were preponderant.[Conclusion] The present study described the developmental process and morphological changes of M. matsumurae in all instars, especially, the characteristics of the pearl-shape stage and patent period of the 2^nd-instar nymphs, wax filament secretion, cocoon construction and pupation of the male 3rd-instar nymphs, eclosion, courtship and mating behavior of the male adults, egg sac formation and oviposition of the female adults. It was found that the developmental duration of each stage of M. matsumurae in the three climatic regions was different. The time for post-hibernant and overwintering varied dependent on the local temperature changes. The critical period for controlling the insect is from the emergence period of the 2^nd-instar nymphs to the active period of the male 3^rd-instar nymphs and the female adults. The preponderant natural enemies of M. matsumurae were lady beetles in spring, and flower bugs and lacewing flies in summer and autumn.

[Objective] Plant growth-promoting rhizobacteria (PGPR) are rhizosphere inhabitants that can promote plant growth and suppress diseases. The study of PGPR effect on photosynthetic characteristics will provide scientific basis for application potential under drought stress and technical support for afforestation and vegetation ecological restoration in arid environments. [Method] A pot experiment was conducted in order to evaluate the effects of PGPR on the photosynthetic characteristics under drought conditions. A dominant species of PGPR with the ability to produce cytokinins, namely Bacillus cereus L90, was selected to use in this study. Walnut (Juglans regia) seedlings were inoculated with B. cereus L90 and then subjected to moderate soil drought stress. The net photosynthesis rate (P_n), stomatal conductance (g_s), intercellular CO₂ concentration (C_i) and chlorophyll (Chl) content of the walnut seedlings were measured with a LI- 6400 portable photosynthesis system and a portable chlorophyll meter. [Result] The results indicated that drought stress and B. cereus L90 inoculation had significant effects on the P_n, G_s, C_i and Chl content of walnut leaves. Compared with the control, the P_n and G_s under drought stress (DS) were significantly decreased by 21.78% and 29.47%. However, the decreases with inoculation of B. cereus L90 were only 11.62% and 23.84%, respectively. Therefore, B. cereus L90 inoculation was able to relieve negative effects of DS on G_s and P_n. The relieving effect of B. cereus L90 inoculation on DS increased along with the prolonged period of stress after the initial stage of drought. The C_i of walnut leaves in DR treatments decreased significantly at the initial stage, and then continuously elevated, whereas the G_s continuously declined. The result suggested that the reductions in net photosynthetic rate resulted from both stomatal and non-stomatal limitations. In B. cereus L90 treatment, C_i and G_s decreased continuously, indicating that the P_n reductions mainly resulted from stomatal limitations. The Chl contents of leaves decreased with drought stress. In the late period of drought stress, the chlorophyll content of walnut seedlings in DR treatment significantly decreased 9.22%, compared with the control. However, the chlorophyll content with inoculation of B. cereus L90 was 9.49% higher than that of the DS. B. cereus L90 inoculation could significantly decrease the decomposition of chlorophyll content under drought stress. In re-watering after DS, the P_n, G_s and Chl content were still lower than the control, by 9.46%, 10.29% and 5.86%, and the C_i was higher than the control by 8.72%. However, re-watering the drought-stressed seedlings inoculated with B. subtilis increased P_n, G_s and Chl contents to the control’s level, and the contents were higher than the DR seedlings by 7.01%, 12.15%, 5.81%, respectively. The photosynthetic ability of B. cereus L90 inoculated seedlings was more easily recovered to the level of control after re-watering.[Conclusion] The present study demonstrated that P_n, G_s and Chl content of walnut leaves significantly decreased due to water stress. Cytokinin-producing, B. cereus L90 inoculation under drought conditions could alleviate non-stomatal limitations and interfere with the suppression of net photosynthetic rate. Additionally, L90 is conductive to the photosynthetic ability recovery of walnut leaves after re-watering.

[Objective] Temperature is an important factor affecting fuel moisture and is frequently used for fuel moisture prediction. Fuel surface temperature is used in physical or quasi-physical moisture models instead of air temperature, thus, a conversion from air temperature to fuel surface temperature is required. Currently commonly used conversion models such as Byram & Jemison mdoeland Van Wagner model are statistically based models with varied applicability at different regions. In this study, we intend to answer following questions: 1) What are differences between air temperature and fuel surface temperature at different areas? 2) How about the applicability of these conversion models at different regions? 3) What is the deviation of fuel moisture prediction using these conversion models? [Method] Air temperatures at 1.5 m height in a Korean pine stand and a larch stand were measured using a automatically weather station in Maoershan Forest Farm in Harbin, Heilongjiang Province. The fuel surface temperatures at 1, 2, 3 and 4 cm above ground surface were measured at the same time using thermocouples. Temperature observation was conducted for ten days in the Korean pine stand and four days in the larch stand. Moisture contents of the fuels at 1 cm above surface ground were monitored at 1h intervals at two sites in each stand for a successive 24 h. Comparison of air temperature and fuel surface temperature at different heights were conducted. Deviation of fuel surface temperature computed using the two conversion models was evaluated. Applicability of the two models was assessed based on the deviation. Influences of conversion of fuel surface temperature from air temperature using the two models on direct estimation accuracy of fuel moisture via a model proposed by Catchpole et al. were evaluated. [Result] 1) There exist differences between air temperature and fuel temperature, that is, fuel temperature is lower than air temperature in daytime but higher at night. 2) The two conversion models have deviation of more than 3℃, however it cannot reflect the bidirectional differences of air temperature and fuel temperature at daytime and night. 3) Models for direct estimation of fuel moisture established using air temperature and using fuel temperature calculated from the two conversion models have similar accuracy. [Conclusion] Temperature computed from the two conversion models is higher than the measured values in field with much greater deviation, indicating that temperature conversion is not suitable in this study area. It is not necessary to convert air temperature to fuel temperature, but using air temperature directly at 1h intervals for direct estimation of fuel moisture. It can still not determine which one is better to establish fuel moisture mode by using air temperature or fuel surface temperature and further investigation is required. Another important task for future research is developing new temperature conversion models which can truly reflect daily differences between air temperature and fuel surface temperature.

[Objective] According to the environment conditions and the growing characteristics of the bush, the function of ground surface following was required for cutting mechanism of bush stumper with flexible connecting and lifting. A crawler self-propelled desert shrub stumper was developed to provide technical support for the effective utilization of shrub resource. [Method] The optimized design scheme of crawler self-propelled shrub stumper was confirmed based on field trip of Kerqin Sandy of Inner Mongolia, and the design of the suspension cutting machine overall structure and key parts was accomplished with design methods of 3D solid modeling technology and virtual prototype technology etc. The sampling survey method was applied when doing statistical calculation of shrub distribution density and biomass in the forest experiments. [Result] Considering the characteristics of shrub and the overall environment of sand, the working head was designed into an inverted V-shape based on the characteristics of shrub root. The application of hoisting chain, support rollers and flexible connection makes the cutting device floating on the ground while going up and down. The design and manufacture of the suspension type shrub stumper were completed, including the selection of traction and drive mode, the design of cutting device and profiling mechanism, etc. The cutting device was suspended at the front of the hydraulic crawler tractor. Operating speed of this prototype, of which shape size is 1 200 mm long, 900 mm wide, 1 150 mm high, is 3.5 km·h^-1, moving speed of it is 5 km·h^-1. The rotating speed of circular saw blade cutting tool is 3 600 r·min^-1. The maximum clearance from cutting device to the ground is 900mm, with a common cutting stubble height of 50mm. After finishing the design and manufacture, the test run of the prototype was launched in a forest farm named Xing Longzhao, landed on Kerqin sandy land in Tongliao City of Inner Mongolia. There are 266 700 hm² of lobular caragana shrub. Moreover there are 2 000 hm² of this shrub on this forest farm. The test area is 10 m wide and 90 m long, with a total area of 900 m². At the same time, a statistical survey was conducted, the number of cut shrub and the amount of branches were measured. The statistical data shows that the actual distribution density of the bushes of the region is 811 bundle ·hm^-2, the biomass wet weight and dry weight are 6 012.44 kg·hm^-2 and 3 763.22 kg·hm^-2, the average sediment deposition of each shrub is 0.5 m³, of which the crown diameter is 3.1m and the average height is 1.9m. The moisture content of shrubs before sprouting is 34.71% by the way of kiln dried. All the surveys above provided basic data for the resource and energy utilization of shrub tending slashes.[Conclusion] A prototype of shrub stumper powered by hydraulic driven rub crawler tractor was designed and manufactured. A shrub stumping trial using the machine was carried out in Kerqin sand area of Inner Mongolia. The test showed that efficiency of the machine shrub stumping was 243 shrubs·h^-1 with 50 mm cutting height and less than 3% split of reserved stumps. The new sprouts of shrub stumps were five to ten times of reserved stumps and the new stumps glow more than 1.2 m in the summer and autumn investigation. The machine are suited the requirement of shrub stump reproduction in desert sand area.

[Objective] Evaluation of forest ecological security of 31 provinces, municipalities and autonomous regions of China, and analysis of its changing trend are conducive to know the situation of forest ecological security in 31 provinces, municipalities and autonomous regions, and differences among them. The study was to provide a scientific basis for establishing policies to improve the ecological environment based on the local conditions. [Method] Based on the PSR model, improvements were made to develop an indicators system of evaluation of forest ecological security. The indicators system was applied in the evaluation of forest ecological security in 31 provinces, municipalities, autonomous regions using the entropy method based on the yearbook data from 1999 to 2012. [Result] In the forest ecological carrying capacity indicators, the weight of resource indicator (0.536) and the complexity indicator (0.188) were significantly greater than others, indicating that the status of forest resources and complexity of the forest ecosystem was the main reason for variation among different years in the forest ecological carrying capacity in the provinces. In the human behavior indicators, the negative effect of human pressure on forests(0.995)was greater than the positive effect(0.005)brought by the maintenance of forests. Between 1999 and 2012, the comprehensive evaluation of forest ecological safety displayed a trend of increase, indicating an evident improvement of forest ecological safety in China. But there were still some provinces, such as Shanghai, Tianjin, Ningxia, Qinghai showed a far lower value (around 0.35 on average of 3 representative years) of the comprehensive evaluation than the national average ( 0.546), measures need to be taken to prevent degradation of the forest ecosystem.The comprehensive evaluation of the large provinces in forestry such as Jilin and Yunnan, far higher than those of Ningxia and Shanghai. The differences among provinces of forest ecological safety has now become increasing. In the evaluation of forest ecological safety, the forest ecological carrying capacity plays a main role followed by the role of human activities. [Conclusion] The overall situation of forest ecological security in China tended to improve, however, there are big differences among provinces, municipalities and autonomous regions. The main factors causing changes in forest ecological security are the quantity and quality of forest resources. Protection of existing forests, especially the natural forest should be strengthened.Attention needs to be given to optimization of stand structure and specie composition, persistence to sustainable development, and reduction of destruction to forest resources.A pre-warning mechanism for forest ecological security should be established to prevent deterioration of forest ecological security.

Low temperature stress limits the geographical distribution of many wild plant and crops, and reduces their productivity. There are huge differences in survivability of trees to low temperature stress. Chilling sensitive trees from tropics and subtropics are irreversibly damaged at temperature condition higher than freezing point, while those species originated from temperate-zone can withstand extreme freezing conditions. In recent years, the analyses of physiological and biochemical response characteristics, transcriptome, proteome and metabolome of chilling sensitive trees and temperate-zone trees under low temperature stress have been rapidly developed, which from various levels have elucidated the physiological and molecular mechanisms that woody plant regulating low-temperature response and freezing tolerance. These analyses provide important reference for molecular breeding of freezing-tolerant woody plant by using anti-freezing related genes. Under the low temperature stress of 1—10℃, chilling sensitive trees would appear disorders physiological processes in water status, mineral nutrition, photosynthesis, respiration and metabolism, and hence lead to chilling damage, and even death. Calcium signal transduction pathway is the important signal transduction pathway during low temperature response process. ABA is involved in the regulation of plant stress response gene by transcriptional activation of ABA-dependent transcription factor. Regulation of low temperature response transcription can be divided into CBF pathway and non-CBF pathway. CBF regulates the expression processes of downstream target genes: related receptors of plant cell membrane first perceive environmental signal and transmit it to cell nucleus. The signal is perceived and transducted through Ca²⁺ and MAPK and induces expression of CBF, which will activate the promoter of cold-response gene and trigger cold response mechanism (gene activation), and the transcribed mRNA is translated into various proteins. These gene products participate in physiological processes of changing the composition of membrane, antioxidant enzyme activities, content of osmotic substances, which will improve cold resistance. On the other hand, CBF gene expression is also regulated by some upstream transcriptional factors, including Ca²⁺ signal way and ICE1-CBF cold response way. Mechanism and metabolic pathway of chilling acclimation in trees are much similar to freezing acclimation in trees, but the latter may be more complicated, because it needs to face extreme and abnormal temperature variance. The antifreeze protein induced by cold during freezing acclimation has strong activity to inhibit ice recrystallization; Dehydrin and LEA protein protect cellular by osmoregulation; Heat shock protein (HSP) regulates protein folding and transportation, and restores activity of modifying enzyme; antioxidant enzyme system scavenges oxygen free radical and hydrogen peroxide; early light-induced protein (ELIP) takes parts in the high light stress acclimation process, which plays important roles for antifreeze mechanism of trees. In the field of tree's freezing tolerance, comprehensive analysis of the transcriptional factor and functional genes shall be emphasized in the future; the development mechanism of freezing tolerance induced by environmental signal such as light, temperature, etc. shall be more thoroughly study; expression mechanism and function of important proteins under low temperature stress shall be explained by combination of proteomics methods and other technology to integrally reveal the surviving mechanism of woody plants under low temperature stress.

[Objective] When large forestry equipment are in practice, it needs operator to make a lot of observation to determine due to the complexity of forest environments and the impact of obstacles, which result in intermittent operation, reducing operational efficiency. Especially in poor light conditions, it will greatly increase the risks for the operator. Based on 2D laser and images, harvesting targets in artificial forest were detected and identified in this study by using information fusion technology, which provided supplementary information to the operator to compensate for the lack of the human eyes. [Method] This paper presented a target detection method for artificial forest harvesting based on 2D laser and images. The main contents were: 1) Built harvesting target information collection system based on 2D laser scanner and thermal imager, where PC was applied to control the information collection. Also the collected signal pretreatment was conducted in this part. Then laser data, visible and infrared images were captured for targets. 2) Internal and external joint calibration was conducted between laser points and image to match them together, thereby obtaining the target area image we need at the same time to obtain the coordinate position of the target by the laser information, which provided the basis for subsequent target recognition. 3) Fused the visible image and infrared image. Fused image had richer information and reduced uncertainty caused by a single sensor. 4) According to the collected information, features including temperature, colors and shape were extracted to provide specific evidence for target identification. 5) On the basis of obtained features, a popular machine learning algorithms-support vector machineswas applied by training and learning with a number of samples to establish math model for features and targets. 6) The characteristic parameters of the mathematical model were optimized by 3 different optimization algorithms to improve recognition performance. [Result] Models with different optimizations were compared by ROC curves. Experiment results showed that the optimized model by GA used in this paper could recognize harvesting targets effectively and it’s correct rate could reach more than 96%. [Conclusion] Multi-sensor fusion technology was introduced into smart forestry equipment in this paper. Instead of the commonly used expensive 3D laser scanning system, 2D laser and images were combined and used. On the one hand, it saved the costs; on the other hand, for the 2D data, the data processing was faster. At the same time, the complementary among sensorsmade the measuring and identification more accurate. The results showed that the method used in this study could provide the information needed by forestry equipment operations, which improved operational efficiency and reduced operational risks.

[Objective] In this study, the distribution characteristics of throughfall under the Caragana tangutica shrub canopy and its influence factors were researched. The aims of this paper were to provide the basal data for quantitatively evaluating the eco-hydrology function of Caragana tangutica shrub in the Qilian Mountains as well as parameterized the hydrological model which relying on the ecological process. [Method] Based on the investigation of population characteristics, three representative Caragana tangutica shrubs were selected on the middle slope. The measurement radial sections along the branch radial direction were selected. Containers for rain water collection were installed at each radial section. The throughfall and its spatial distribution were measured after 12 rainfall events at the period with stable foliage volume. Then the relationship between throughfall and rainfall, as well as the spatial distribution pattern and its influence factors were analyzed. [Result] The throughfall under Caragana tangutica canopy exhibited evident differences in different rainfall events. In the observation period, the mean throughfall rate of individual shrub was 45.9%. There was a linear relationship(y=0.626 2x-1.018 1,R²=0.983) between throughfall volume and rainfall and a quadratic function relationship between throughfall rate and rainfall(y=-0.033 6x²+1.806 8x+34.094,R²=0.575 3). The throughfall rate exhibited an evident spatial heterogeneity and monotonously increased from 28.98% at 10cm distance to the shrub base to 62.19% at 90cm distance to the shrub base along the radial direction. Influenced by the canopy structure characteristics, the biggest increment was occurred at a distance of 30—50 cm, which accounted for 61% of the total increment. The spatial variable coefficient of throughfall rates along the radial direction were decreased with the increasing rainfall, which expressed more remarkable when the rainfall was less than 10 mm. The distribution pattern was also changed when the rainfall intensity was increased. When the rainfall intensity were 0.97 or 4.27 mm·h^-1, there was an evident difference of throughfall rates between 10—30 cm and 50—90 cm, while this difference could be weaken when the rainfall intensity was 25.06 mm·h^-1.[Conclusion] The throughfall features of individual Caragana tangutica shrub were influenced by characteristics of both rainfall and the canopy structural. The relationships between throughfall volume and rainfall as well as between throughfall rate and rainfall were in accordance with findings of correlational researches that conducted by predecessors. The general spatial distribution pattern of throughfall under the canopy was determined by the canopy features, while this pattern was also influenced by rainfall volume and rainfall intensity. The increase of rainfall or when the rainfall intensity reached a certain extent both can decrease the spatial heterogeneity of throughfall under the canopy.

[Objective] Amygdalus pedunculata is naturally distributed in Mu Us Desert. The tree has strong resistance, and its kernel has high oil content, therefore A. pedunculata is classified as a new type of woody edible oil plant resources. [Method] Understanding nutritional quality characteristics of A. pedunculata kernel, particularly fatty acids, will provide scientific basis for the breeding. In this paper, 31 A. pedunculata representative samples were selected according to their nut characteristics from Mu Us Desert. The variations of crude fat content and fatty acid composition were studied. The samples were extracted using Soxhlet extraction and the GC analysis based on AOAC996.06 method was used to analyze the fatty acid composition and oil content. [Result] The results showed that the crude fat content ranged from 46.08% to 61.61%, the average content was 54.58%. The kernel oil contained seven kinds of fatty acids: Palmitic, Palmitoleic, Stearic, Oleic, Linoleic, α-Linolenic and cis-11-Eicosenoic, among which the major fatty acids were oleic acid (34.94%) and linoleic acid (15.87%). The percentage of total unsaturated fatty acids in the oil varied from 96.44% to 98.31%, while percentage of oleic acid and linoleic acid content was as high as 93.09%. The percentage of saturated fatty acid was reached to 3.56%, and its major composition was palmitic acid. The lipid content was relatively stable, and the variation coefficient was only 8.10%. However fatty acid content changed greatly, coefficients of variation was 37.02% for linoleic acid and 8.77% for oleic acid. The variation coefficient of fatty acid components among different individuals in A. pedunculata population from high to low was linolenic acid (37.02%), cis-11-Eicosenoic (29.34%), stearic acid (25.39%), palmitoleic acid (21.83%), linoleic acid (20.34%), palmitic acid (14.44%), oleic acid (8.77%). This result indicated that the content of oleic acid and linoleic acid was not only high, but also stable, while the content of linolenic acid and cis-11-Eicosenoic was comparatively low and unstable. The total crude fat content was significantly correlated with the content of oleic acid, linoleic acid and unsaturated/saturated ratio, with the correlation coefficient of 0.68, 0.70, and 0.74, respectively. The total crude fat content was highly and negatively correlated with the content of linolenic acid and SFA, with the correlation coefficient of -0.52 and -0.68. MUFA was significantly correlated with the content of oleic acid, while PUFA was significantly correlated with the content of linoleic acid and the correlation coefficient were closed to 1.00. [Conclusion] A. pedunculata nuts have high content of crude lipid. The fatty acid composition was relatively simple, and mainly of oleic acid and linoleic acid. The content of oleic acid and linoleic acid was relatively stable, and positively correlated with the total crude fat content. These results would provide some guidance for breeding new oil varieties.

[Objective] Alcohol dehydrogenase and 2- keto acid decarboxylase are two key enzymes for isobutanol production. To construct a recombinant Escherichia coli strain for isobutanol production, the cDNA sequence of the two enzymes genes (adh2 and kivd) neede to be cloned from Saccharomyces cerevisiae and Lactobacillus lactis, respectively. The poplar hydrolysate was further used as a fermentation substrate to produce isobutanol with the recombinant E. coli to investigate whether the recombinant E. coli strain can utilize lignocellulosic materials to produce isobutanol. This study also intends to provide a research basis for the renewable production of isobutanol. [Method] We amplified the gene of adh2 by PCR with S. cerevisiae genome as a template and amplified the kivd with L.lactis genome as a template. We constructed the recombinant plasmid pSTV-29-adh2 and pSTV-29-kivd, and then transformed the plasmids into E.coli DH5α respectively, obtained the recombinant strains E. coli DH5α-pSTV-29-adh2 and E. coli DH5α-pSTV-29-kivd. Further, the tandem expression plasmid pSTV-29-adh2-kivd was constructed and then integrated into the E. coli DH5α for constructing the recombinant strain E. coli DH5α- pSTV-29-adh2-kivd. Isopropyl beta-D-thiogalactopyranoside(IPTG) was used to induce the recombinant strains E. coli DH5α for recombinant protein expression. Alcohol dehydrogenase and 2-Ketoisovalerate decarboxylase activities in E. coli DH5α-pSTV-29-adh2, E. coli DH5α-pSTV-29-kivd and E. coli DH5α-pSTV-29-adh2-kivd were measured. The amount of protein expression was analyzed with gray gel scan through SDS-PAGE. The fermentation of recombinant E. coli DH5α strains showed that the proteins encoded by adh2 and kivd were expressed simultaneously. The fermentation of recombinant E. coli DH5α strains was conducted in flask with glucose and poplar wood hydrolysate as fermentation substrates to produce isobutanol separately. The isobutanol concentration was detected by chromatography. [Results] The recombinant plasmid pSTV-29-adh2, pSTV-29-kivd and pSTV-29-adh2-kivd were verified by bacteria liquid PCR, enzyme digestion and DNA sequencing. The obtained fragment size was consistent with the size of target genes (adh2 and kivd) and plasmid vector pSTV-29, the results of adh2 and kivd gene sequencing were in complete accord with corresponding gene sequences in NCBI. The results indicated that the expression vector pSTV-29-adh2, pSTV-29-kivd and pSTV-29-adh2-kivd were successfully constructed. Protein content measurement and SDS-PAGE electrophoresis analysis showed that the proteins encoded by adh2 and kivd were respectively expressed in E. coli DH5α-pSTV-29-adh2 and E. coli DH5α-pSTV-29-kivd, and simultaneous expressed in E. coli DH5α-pSTV-29-adh2-kivd. In gray gel scan, the corresponding position of 40 kD (Adh2 protein molecular weight) and 70 kD (Kivd protein molecular weight) had obvious characteristics of protein bands, and the expression quantity of adh2 encoding protein exceeded that of kivd encoding protein, while the blank control strain didn't appear any protein characteristic bands. All of the results showed that the recombinant strains E. coli DH5α-pSTV-29-adh2, E. coli DH5α-pSTV-29-kivd and E. coli DH5α-pSTV-29-adh2-kivd were successfully constructed. In the fermentation experiments, only the E. coli DH5α-pSTV-29-adh2 could produce isobutanol with glucose and poplar wood hydrolysate as fermentation substrates, and the yields were 4.1 g·L^-1 and 0.14 g·L^-1, respectively. The strains E. coli DH5α-pSTV-29-adh2 and E.coli DH5α-pSTV-29-kivd didn ’t produce isobutanol. Thus, isobutanol could produce only with the adh2 and kivd expressed simultaneously in E. coli DH5α-pSTV-29-adh2-kivd. [Conclusion] The key genes of isobutanol synthetic pathway were expressed in E. coli and the recombinant strain E. coli DH5α-pSTV-29-adh2-kivd would utilize lignocellulose to produce isobutanol. This study offered an alternative strategy for isobutanol biosynthesis.