[Objective] To clarify the driving factors of soil nitrogen mineralization in the acid rain region, a systematic experiment was conducted at the Jinyun Forest Ecosystem Research Station, Chongqing. The variation of soil mineral nitrogen (ammonium-and nitrate-nitrogen) content, input sources and nitrogen mineralization was explored based on the field data measured during 2012-2014. The results will provide the theoretical basis for in-depth study of soil nutrient cycling in the similar region, and improve forest management.[Method]A 20 m×20 m plot with five 4 m×4 m sub-plots inside was set up in the evergreen broad-leaved forest in the middle subtropical forest ecosystem in Jinyun Mountain in Chongqing. Samples in upper, middle and lower layers of the soil (0-15, 15-30 and 30-60 cm, respectively) were collected at the end of each month from April to September during the period of 2012-2014. Water samples of throughfall and stemflow were collected and soil respiration rates were measured simultaneously. The contents of ammonium-(NH₄⁺-N), nitrate-nitrogen (NO₃^--N) and total nitrogen (TN) were measured in the laboratory subsequently. Soil nitrogen mineralization rate was quantified using incubation experiment in situ.[Result] The contents of ammonium-and nitrate-nitrogen were significantly different among years, months (except in 2012) and soil layers(P<0.05). There was an increasing trend for the monthly variation in both ammonium-and nitrate-nitrogen content, which increased from April to September. The annual variation in ammonium-and nitrate-nitrogen content in the top soil layer was in the order:2013 > 2012 > 2014. The variation in ammonium nitrogen content among soil layers showed a order in middle > lower > upper, and the variation of nitrate nitrogen content among soil layers showed a decreasing trend with increasing soil depth. The monthly variation of soil ammonification and nitrification rates was unimodal or bimodal. The annual variation showed an order in 2013 > 2014 > 2012 generally. The soil ammonium-and nitrate-nitrogen content were significantly (P < 0.05) or extremely significantly (P< 0.01) correlated with each other among soil layers, but not correlated with the nitrogen input in the rainfall. There was extremely positive correlation (P< 0.01) between soil ammonification/nitrification rate and soil respiration rate, while pH was extremely negatively (P< 0.01) correlated with both soil ammonification and nitrification rates. When soil respiration was greater than 4 μmol·m^-2s^-1, soil ammonification and nitrification rates decreased obviously with the increasing pH. However, when soil respiration was less than 4 μmol·m^-2s^-1 and pH ranged between 3.70-3.75, soil ammonification and nitrification rates showed a slightly rising trend first and then followed by a decrease.[Conclusion] The soil mineral nitrogen content was significantly different among years, months and soil layers. The soil mineral nitrogen content was lightly affected by the nitrogen input (including ammonium nitrogen and nitrate nitrogen) in the rainfall, but more closely related to the nitrogen content in adjacent soil layers. The increase of soil pH value inhibited the soil ammonification and nitrification rates, and the degree of inhibition varied with the soil respiration rate. Therefore, in order to maintain soil fertility, it is necessary to pay attention to the variation of soil pH and understand the status of soil nitrogen mineralization in the forest ecosystem of acid rain zone in Southwestern China.

[Objective] [Objective]To better understand the spatial heterogeneity of photosynthetic characteristics in canopy of Larix kaempferi, photosynthetic parameters of needles were measured in different canopy layers. This study could provide a sound theoretical foundation for developing a canopy productivity model and accurately evaluating canopy productivity.[Method] The 8-year-old L. kaempferi was selected as the research material, and the canopy was divided equally into 8 canopy layers according to the canopy length from top to bottom. In each tree, only one south-oriented branch was selected in each layer, and the diurnal change of photosynthesis of needles was measured on each selected branch.[Result] The diurnal change of photosynthetic parameters in most canopy layers was similar. Net photosynthetic rate (P_n), transpiration rate (Tr), value of stomatal limitation (L_s), photosynthetically active radiation (PAR), air temperature (T_a) and vapor pressure deficit (VPD) showed a single peak curve, and the stomatal conductance (G_s) gradually decreased from morning. With the increase of canopy, photosynthetic parameters increased, and specific leaf area reduced, while T_a and VPD increased firstly, and then decreased from high to low position of the canopies. There were significant significant differences (P<0.05) in the photosynthetic parameters and the micro-environmental factors among different canopy layers. The P_n, PAR, G_s, and (Tr) had exponential function relationships with relative canopy height (R² ≥ 0.94), and the T_a and VPD had quadratic function relationships with relative canopy height (R² ≥ 0.79). The result of path analysis showed that PAR was a main factor influencing P_n, but the impact of T_a and air humidity was relatively limited.[Conclusion] Photosynthetic effective radiation and photosynthetic activity of mesophyll cells were the main environmental and physiological factors affecting the spatial variation of P_n in L. kaempferi canopy. P_n increased significantly with the increasing canopy, while P_n at the bottom of L. kaempferi canopy was negative, indicating that the part of canopy remained in the state of carbon consumption. Therefore, we suggest that the results can be used as the important indicator for artificial pruning of L. kaempferi larch, and also can be used as the important theoretical basis for developing canopy productivity model and estimating canopy productivity.

[Objective] This study aimed to investigate the concentration and distribution pattern of non-structural carbohydrate (NSC) in Phyllostachys glauca, a dominant species in limestone mountains, and the ecological significance.[Method]The NSC concentration and distribution characteristics of individual (whole plant)and component level (leaf, branch, stem, stump, rhizome and root) of P. glauca in three different soil moisture habitats (continuous soil, semi-continuous soil and sporadic soil) in the limestone mountain area of Northwest Jiangxi Province were measured and analyzed.[Result]The results showed that:1) At individual level, from continuous soil and semi-continuous soil to sporadic soil, the concentration of soluble sugars increased gradually with the decrease of soil water content, and the value in sporadic soil (3.32% ±0.20%) was significantly higher than that in continuous soil (2.52% ±0.17%) (P< 0.05). The starch and NSC concentration decreased initially and then increased, and the values in semi-continuous soil were all significantly lower than those in sporadic soil (P < 0.05). 2) At the component level, the concentration of NSC, soluble sugars and starch in leaves were the highest in the three habitats, followed by branches and roots, and relatively lower in stems, stumps and rhizomes. 3)With the decrease of soil water content, the increment of soluble sugars concentration in P. glauca roots was greater than that in other parts. Compared with the value in continuous soil habitat, that in semi-continuous soil and sporadic soil increased by 74.29%, and 39.35%, respectively. The distribution proportion of soluble sugars in the components with high physiological activity (leave and root) in sporadic soil habitat increased by 71.26% and 50.61%, respectively compared with that in continuous soil habitats, while the distribution proportion in the stored components of stems, stumps and rhizomes decreased.[Conclusion]Our studies indicate that P. glauca has a physiological mechanism to cope with drought stress by regulating the concentration and distribution of non-structural carbohydrate both at individual and component level. The NSC regulation behavior at the component level can reflect the physiological strategies of plants to cope with drought stress more deeply than that at the individual level.

[Objective] This study aimed to study the physiological and ecological response characteristics of Lycium barbarum to elevated atmospheric CO₂ concentration() in Ningxia, and to provide a theoretical basis for exploring the cultivation and breeding of wolfberry and other woody economic forests under the background of climate change.[Method] In this study, ‘Ningqi No.1’ cuttings were used as experimental materials, the changes of plant vegetative growth index, fruit morphological parameters, sugar content, active substance content and sucrose metabolism-related enzymes activity of fruits in response to elevated were determined by using an open-top chamber (OTC) experimental facility and equipped with a concentration automatic monitoring system to simulate and control.[Result] 1) The increase of by 0.5 times[(570±20) μmol·mol^-1] and 1 times[(760±20) μmol·mol^-1] significantly promoted the growth of L. barbarum plants. The net growth of seedling height was 11.67% and 18.65% higher than that of the control, and the ground diameter was 55.09% and 62.58% greater than that of the control, respectively. 2) Under the two elevated treatments, the transverse diameter of L. barbarum fruit in Ningxia increased by 4.56% and 7.71% respectively, and the weight of single fruit increased by 15.05% and 34.53% respectively, compared with the control. 3) Under the two elevated treatment, the fructose content of summer fruits (90 d after treatment) was slightly higher than that of CK, while that of autumn fruits (120 d after treatment) was 1.39% and 3.98% lower than that of control. During the treatment period, the contents of glucose and total sugars were lower than those in CK, especially under treatment with 1 times. The content of sucrose in summer fruits was lower than CK under the two treatments, but the autumn fruits were slightly higher than that of control fruits when the CO₂ concentration increased by 1 times. 4) The content of polysaccharides decreased compared with CK flavonse decreased 16.62% and 18.35% in autumn fruits, and the increase of by 1 times had greater impact. 5) Changes in the activity of sucrose metabolism-related enzymes of fruit were obvious with the two elevated treatments. Acid invertase and neutral invertase increased. Sucrose phosphate synthetase in the summer fruits increased significantly, but autumn fruit enzyme activity was lower than that in control. The change trend of enzyme activity in decomposition direction and synthesis direction was the same. During the summer period, they were all higher than the control, but in the autumn period lower than the CK.[Conclusion]Thus, long-term treatment with elevated promotes vegetative growth of L. barbarum, increases the weight of single fruit, vertical diameter and horizontal diameter, which is helpful to improve the appearance of fruits. However, the content of sugar and bioactive substances such as polysaccharides and flavonoids are significantly reduced, and the activity of sucrose metabolism-related enzymes activity changes, which affected the nutritional quality of fruits.

[Objective] The mechanism of histological changes between rootstock and scion during callus formation, proliferation and connection of transfusion tissue at different grafting periods was studied through histological observation of the healing process of walnut(Juglans regia) bud grafting, in order to provide theoretical guidance for the practice of grafting walnut and other woody plants.[Method] The buds of 12-year-old semi-lignified new shoots of J. regia ‘Xiangling’ were used as scions and 2-year-old walnut seedlings were used as rootstocks, bud grafting experiments were carried out on 40-47 days and 100-107 days after bud germination respectively by square bud grafting. Histological observation of healing process was carried out with the method of heterogeneous tissue of woody plants section established by our research group.[Result] The mode of healing between rootstock and scion 40-47 days after bud germination of walnut was consistent with previous reports. The cambium cells played a dominant role and the main histological changes during healing included:isolation layer formation (3 days)→cambium cell differentiation to produce callus (4 days)→callus connection (6 days)→original cambium repair and connection between scion and rootstock (12 days). It took 12-15 days to complete the healing, and the survival rate of grafting was 95.6%; In the process of healing 100-107 days after bud germination, a new way of grafting healing was found different from the conventional healing. The xylem ray cells played a leading role in this process, and the healing process went through isolation layer generation (3 days)→xylem ray cell differentiation to produce callus (4 days)→callus connection (9 days)→vessel differentiation (15 days)→new cambium formation and connection of xylem rays between scion and rootstock (25 days), it took 25-30 days to complete the healing process, and the survival rate of grafting was 61.7%; During the healing process, the isolation layer on the side of rootstock dissolves before the scion and disappears when the callus was connected, while the isolation layer on the surface of scion still existed when the callus was differentiated, until the new cambium was formed.[Conclusion] Besides the common mode of healing dominated by cambium cells, there was a new mode of healing dominated by xylem ray cells in the healing process of bud grafting in walnut, xylem ray cells dedifferentiated to produce callus, and further differentiated into vessel, cambium and xylem ray to complete the final connection. During this process, the callus mainly came from the xylem ray cells of the rootstock, and the isolation layer of the rootstock dissolved before the scion.

[Objective]To provide theoretical basis and genetic materials for the breeding of the Sapindus, a comprehensive assessment and selection of superior germplasms from natural germplasm resources of three species and one variety of Sapindus in China and Vietnam.[Method]Based on 200 accessions of Sapindus germplasm resources from S. mukorossi, S. delavayi, S. rarak and S. rarak var. velutinus in 14 provinces of China and 1 region of Vietnam were carried out on the basis of fruit and seed properties. Correlation analysis, cluster analysis and principal component analysis were conducted for a quantitative assessment of the germplasms using the 20 fruit and seed properties.[Result]1)The coefficient of variation of fruit and seed properties was 5.46%-38.19%, and the average coefficient of variation was 17.42%. Pericarp saponin content(38.19%), 100-seed kernel weight(30.23%)and 100-fruit pericarp weight(30.29%)were significantly different, while non-significant variation was found in fruit shape index (5.46%) and seed shape index (5.70%). The diversity index ranged from 1.47 to 2.04 with an average of 1.95. 2) 100-fruit weight showed a significant positive correlation with 100-fruit pericarp weight (0.927) and 100-seed weight (0.768), while 100-seed weight significantly and positively correlated to the 100-seed shell weight(0.863)and 100-seed kernel weight(0.635). On the contrary, there was a significant negative correlation between oil content and pericarp saponin content (-0.382). 3) Cluster analysis divided the germplasms into three groups according to the fruit size:small (group I), medium (group Ⅲ), and large (group Ⅱ). S. mukorossi mainly belongs to group I, and S. delavayi, S. rarak and S. rarak var. velutinus mainly belong to group Ⅱ, Ⅲ. Group Ⅱ is mainly distributed in the Guizhou and Yunnan province. 4) Based on the principal component analysis respectively for oil content, saponin content and integrated use, 3 categories each with 10 accessions of superior germplasms were selected mainly from S. mukorossi and S. rarak with an average gain of 36.85%.[Conclusion]The yield index had the largest variation range, represented by pericarp saponin content and 100-fruit pericarp weight. This provides abundant resources and great space for the breeding of Sapindus. The increased investment in saponin accumulation is at the expense of reduced investment in oil accumulation, which reflects the trade-off strategy of the Sapindus in specific ecological environment. The 3 categories each with 10 selected superior germplasm accessions for oil, saponin and integrated uses are widely distributed in Yunnan and Guizhou province. It is speculated that these areas have more suitable environmental conditions and better germplasms for the development of Sapindus industry.

[Objective] This study was to reveal the characteristics and key control mechanism of annual stem cross-section area increment(RAI)longitudinal distribution of Pinus tabulaeformis, to verify the application effects of Cortini et al. (2013) modeling method and model form on developing RAI longitudinal distribution model of Pinus tabulaeformis, and to choose the stem positions whose RAI could represent the RAI at whole stem level and could predict annual volume increment and leaf biomass effectively.[Method] 312 cross-sectional disks were obtained along the stem from 27 destructively sampled trees varying in age from 10 to 98 a in 9 stands,the RAI data obtained from annual ring width measurement on disks was used to analyze the RAI longitudinal distribution patterns of sampled trees,and the patterns were compared with the theoretical patterns to reveal key control mechanism. The RAI longitudinal distribution model of Pinus tabulaeformis was developed according to the method of Cortini et al. (2013), and its application effect was verified and evaluated according to the goodness of fit. The differences between the RAI at different stem positions with that at tree level, and the relationship between RAI at different stem positions with annual volume increment and leaf biomass of single tree was analyzed in the different RAI longitudinal patterns and at the overall level to determine the ideal positions and relationship models.[Result] The RAI longitudinal distribution included two patterns according to the distribution difference in stem middle segments, the RAI distribution in effective crown segment and butt swell segment was close to the theoretical patterns derived from water transport and mechanical support theory respectively, the consistency of distribution in middle stem segment with theoretical patterns varied with sample trees. The model of RAI longitudinal distribution for Pinus tabulaeformis could explain 82.76% of the longitudinal variation of RAI. The difference between the RAI at effective crown base with that at the whole stem level was lower than that at other stem positions, the relationship between the RAI at breast height with the single-tree leaf biomass was better than that at other positions, the relationship between the RAI at breast height with annual volume increment varied with RAI longitudinal distribution pattern, which was better than other locations or slightly worse than that at the ideal location.[Conclusion] The water transport and mechanical support requirements determined the RAI longitudinal distribution of effective canopy and butt swell segment respectively, their relative importance and biological environment factors determined RAI distribution of middle stem segment. Cortini et al. (2013) modeling method and model form was reliable to develop RAI longitudinal distribution model of Pinus tabulaeformis. The RAI at effective crown base was highly representative of that at whole stem level, the RAI at breast height was effective predictive variable, but was defective to represent RAI at whole stem level and to predict annual volume increment.

[Objective] The camellia weevil, Curculio chinensis (Coleoptera:Curculionidae), is a host-specific parasite of camellia seeds and has caused huge economic losses in China. Despite its economic impact, the genetic diversity is rarely understood. In this study, based on the genetic differentiation and structural variation of mitochondrial ATP synthase gene of C. chinensis in different regions, the influence of environmental selection pressure, especially the geographical altitude, on the genetic diversity and the phylogenetic structure of different geographical populations of C. chinensis was studied, and the changes of bases as well as their amino acid sequence structure of ATP synthase gene in adapting to environmental pressure were discussed, which is important to provide theoretical basis for establishing a control strategy of this pest.[Method] The populations of camellia weevil at different geographical altitudes were collected from the main oil-tea production areas. The specific primers of ATP synthase gene were designed and the ATP synthase gene was amplified by PCR. Genetic diversity and phylogenetic structure were estimated based on ATP gene sequences, and the structural differences of amino acids sequences and frequency were moreover analyzed.[Result] Genetic diversity and the phylogenetic structure of C. chinensis were inferred using the sequences of ATP synthase gene among different geographical populations. Thirty-two haplotypes (NCBI:MH560360-MH560391) in 119 individuals from all the sample regions in China were obtained. There was no obvious regularity in the genetic diversity differentiation of various geographical populations of camellia weevil (Nucleotide diversity π:0.000 86-0.048 03). The population expansion of camellia weevil was not significant (Tajima's D<0, P>0.05; Fu's Fs>0). Based on the geographical altitudes, all the samples of camellia weevil can significantly divided into two branches (F_st=0.374, P<0.001) under different selection pressures (Choice index:ω_{high altitude}=1.65, ω_{low altitude}=2.26, LRT P<0.001). ATP8 gene in the samples of low altitude branch (36 conservative sites) was more conservative compared to that in high altitude branch (27 conservative sites), and acidic amino acid utilization rate in high altitude branch was higher than that in low altitude branch, which might be related to the increase of protein stability, oxygen binding efficiency and oxidative respiratory efficiency of insects to adapt to high altitude.[Conclusion] The differentiation degree of ATP synthase gene in C. chinensis populations is low, but there is significant adaptation evolution to geographical altitude.

In this study, a new species, Nematus pumila Liu, Li & Wei, sp. nov. (Hymenoptera:Tenthredinidae:Nematinae), from China is described. The larvae feed on leaves of Ulmus pumila and even can defoliate an entire tree with high densities, and recurrent defoliation can cause major dieback. This work laid a foundation for identification, monitoring and control of the forest pest. The new species is very similar to N. sheni Wei, 1999, but can be distinguished from the latter by the following characters:labrum, pronotum and tegula of the new species are entirely black; fore tibia, basal 3/4 of middle tibia and basal 3/5 of hind tibia have white maculae; The ratio of width to length of postocellar area is approximately 1.9; fore wing has no Rs vein; petiole of hind anal cell is 1.2 times as long as cu-a; lancet with 15 annuli, serrulae with proximal part distinct, distal teeth big and strong; 1^st-11^th sutures with ctenidia, the longest ctenidium of lancet is 2/3 length of annulus; radix 0.7 times as long as lamnium. N. sheni Wei, 1999 is recognized as follow:labrum yellowish white; the posterior margin of pronotum, basal margin of tegula yellowish brown; greater part of the ventral side and basal 1/4 of the dorsal side of fore and middle tibiae, basal 1/3 of hind tibia yellowish white; postocellar area approximately 3.0 times broader than long; vein Rs of fore wing vestigial; lancet with 23 annuli, serrulae with proximal part indistinct, distal teeth small; 2^nd-15^th sutures with ctenidia, the longest ctenidium of lancet is 1/3 length of annulus; radix 0.4 times as long as lamnium. The genomic DNA of the new species was extracted by using the DNeasy Tissue Kit (Qiagen, Valencia, CA), and the sequence data of the mitochondrial gene cytochrome oxidase (COI) were obtained by sequencing, and the length was 810 bp; another 10 COI sequences of known Nematus, Pristiphora, Stauronematus species are available in GenBank and used in phylogenetic analyses with that of the new species. The results of nucleotide composition of the all 12 COI sequences showed that the content of A+T was 65% and higher than that of G+C. Phylogenetic tree of Nematus and related genera species based on Bayesian phylogenetic analysis of COI sequences was constructed, and the results showed that all the Nematus species form a monophyletic group, and Nematus is the sister group of Pristiphora. The holotype and all paratypes of the new species are deposited in the Insect Collection of Central South University of Forestry and Technology, Changsha, Hunan, China (CSCS).

[Objective] Platypus parallelus (Coleoptera:Platypodidae) is an important quarantine pest, it is increasingly intercepted by some China Entry-Exit Inspection and Quarantine Bureaus. This species is native to Central America but has established its populations in Hainan Province, China. Its further northern expansion across Qiongzhou Strait is of great concern, posing threats to forestry and environment to mainland China. Predicting its potential distribution can provide reference for interrupting its transmission and early monitoring.[Method] Based on the information resources platform of animal and plant inspection and quarantine in China, the interception records of P. parallelus at entry ports in China were retrieved and counted. According to the current distribution records of bark beetles, two groups of climatic variables (5 environmental variables and 9 environmental variables) were selected to compare the local ecological space of bark beetles with that of China. The niche conservativeness of bark beetles in the process of invasion in China was tested. Based on the two groups of environmental variables, niche models were constructed in the native Central American region and transferred to China. China and other countries and regions in the world will test the mode Classical native classical ecological niche model approaches were used to predict its potential distributions in China.[Result]P. parallelus are mainly captured in imported timbers from the import of wood products at the ports of Yangtze River Delta and Pearl River Delta. The ecological space occupied by beetles in China overlapped with that occupied by their native land; and their niche was conservative during its invasion in China. Comparing to native space, there are large vacancy of ecological space in China, where indicated that high invasion potentials might exist. In niche model prediction, compared with the prediction based on nine environmental variables model, the prediction based on five environmental variables was more conservative. The model results based on two sets of variables showed that the suitable habitats for bark beetles are mainly distributed Central America, central areas in South America, central Africa, and northern Australia. In China, Hainan, Taiwan and Guangdong provinces are suitable to P. parallelus invasion. In addition, Yunnan and southern Guangxi are also susceptible to P. parallelus.[Conclusion] Most of regions in Hainan, Taiwan, Guangdong, Yunnan, and Guangxi, together with the coastal areas in Fujian, have high invasion risk, and these areas are mostly concentrated in coastal areas, with frequent trade activities, which is conducive to the establishment and spread of the pest in the invaded areas. These high-risk areas should carry out early warning and monitoring to prevent its expansion from Hainan to the mainland or secondary invasion.

[Objective] Chrysaster ostensackenella ((Lepidoptera:Gracillariidae) is an important alien invasive pest newly discovered in Yantai, Shandong Province in 2008 and severely damages Robinia pseudoacacia, an important economic greening plant in China. Prediction of the suitable areas can provide a basis for promoting the efficiency of quarantine, supervision and control of the pest.[Method] In this study, data of 11 distribution locations of C. ostensackenella in China were collected, and nine environment variables with correlation coefficients <|0.9|were screened from 19 environment variables downloaded from WordClim between 1970 and 2000 by ArcGIS 10.0. Then the data were converted into the ASCⅡ format data required for MaxEnt, and the model was set to cloglog output format, outputting file type was ASCⅡ and linear features. To improve the accuracy of the predictive effects and reduce the level of uncertainty, a 10-times cross-validation was set up in the model and repeated 10 runs to get the average values. The contribution rate of each environment variable to the potential geographic distribution in this model was analyzed by Jackknife method, and the optimal simulation results were transformed and classified in ArcGIS10.0, that is, the habitat suitability indexes of C. ostensackenella in China were divided into four categories:non-suitable areas, low suitable areas, middle suitable areas, high suitable areas. Finally, the distribution map of different extent suitable habitats of the insect was obtained. The future distribution areas of C. ostensackenella were predicted using RCP 8.5 climate data of 2050 and 2070. The model precisions of MaxEnt were evaluated by areas under the ROC curve and True skill statistics.[Result] Under current climatic conditions, the high and middle suitable areas of C. ostensackenella were mainly concentrated in Shandong and its neighboring provinces (Liaoning, Beijing, Tianjin, Hebei, Shanxi, Henan, Anhui, Jiangsu), as well as in parts of Sichuan and Yunnan; Under the future climate conditions, by 2050, the middle and high suitable regions of C. ostensackenella under RCP 8.5 climatic conditions would be larger than those in present and spread to the southwest. By 2070, the suitable regions also would enlarge obviously and move to the northeast. Compared with the predicted results in 2050, the high suitable area decreased slightly. The Jackknife test indicated that annual precipitation, precipitation of wettest quarter, min-temperature of coldest month had a great contribution to the distribution of C. ostensackenella. The range of the optimum annual average precipitation is 382.08-1 135.81 mm, with the optimum of 753.85. The optimum wet season precipitation is 241.61-693.86 mm, with the optimum of 464.55 mm, and the optimum minimum temperature in the coldest month is -16.96-6.36℃ with the optimum of -5.5℃. The AUC and TSS values are 0.957±0.052 and 0.8±3.05, respectively, which indicates that the prediction accuracy of the model is excellent.[Conclusion] According to the results of this study, it is known that the pest is a major threat to black locust, R. pseudoacacia in China, and a high attention should be paid by the relevant afforestation and plant quarantine departments.

[Objective] In this study, Pinus yunnanensis is used as the material to analyze the propagation rule of the acoustic emission(AE)signal in samples under different moisture content conditions, and to discuss the response of moisture content to AE signal waveform, which could provide the basis for the location of AE source of P. yunnanensis and the basic data for nondestructive testing of wood internal defects.[Method] The most common P. yunnanensis in Yunnan Province, is used as raw material, containing four kinds of water-bearing states,those were, absolute dry, air-dried, green timber and water-saturated. According to the NI high speed data acquisition equipment and the LabVIEW software, the wood AE signal acquisition platform is set up. Then, the AE signal is collected on the surface of four kinds of wood samples by the simulation of AE source under lead core fracture. Meanwhile, the time difference method is used to calculate the average velocity of four kinds of water condition, and wavelet analysis is used to decompose and reconstruct the AE signal waveform, then soft threshold quantization method is applied for removing each channel coefficient and the high frequency coefficients quantized, and removing non-primary energy signals in order to extract the weak acoustic emission signal from the noise.[Result] In the experiment, the surface wave signals were mainly received by the sensors. With the increase of moisture content, the AE signal waveform and average sound speed of P. yunnanensis are greatly attenuated on the surface. Under absolute dry state, the time domain waveform of AE signal reaches 5.2 V, and the average sound speed can reach 4 208.77 m·s^-1, while the amplitude of the signal waveform is only 0.6 V, and the average sound speed is decreased to 1 414.07 m·s^-1 in water-saturated state. The amplitude and average rate of signal waveforms are ±4 V, ±2 V and 2 328.73 m·s^-1, 3 331.79 m·s^-1, respectively, in air-dried and green timber states, and the average sound velocity difference between each water bearing state is in the range of 876.98-1 003.06 m·s^-1. Moreover, the AE signals submerged in noise can be extracted by the method of wavelet analysis. Thus, the AE signal of four kinds of samples is obtained, and the range of frequency waveform is between 40 and 150 kHz, while the peak value of waveform appears at about 110 kHz in the air dry state, and the other three are peaked at about 50 kHz.[Conclusion] The increase of moisture content significantly changes the AE signal and propagation characteristics of P. yunnanensis, and its signal waveform and average sound speed are positively proportional to the decrease of moisture content. From the comparison of time-frequency diagram of signal before and after wavelet transform, it can be seen that the wavelet transform has obvious advantage in signal noise reduction processing, not only a lot of noise in the signal was removed, but also the useful signal was not damaged, moreover, the signal integrity was guaranteed. On the other hand, to a greater extent, the analysis error is reduced, which gives experimental data support for the research of P. yunnanensis AE source location and internal non-destructive testing. As an AE signal of acquisition and analysis platform, the result of this study could provide the necessary theoretical evidence for the research of AE characteristics of P. yunnanensis with different moisture contents in process of compression deformation and failure.

[Objective] Through the comparison among the estimated result of the soil organic carbon density in the spruce (Picea asperata) and red birch (Betula albosinensis) natural forests in the Xinjiashan Forest Farm in Qinling Mountains with different estimation method, we tested the improvement of the new method on estimation accuracy by subtracting the root volume.[Method] The organic carbon densities of the mineral soil layers (top soil layer, core soil layer and subsoil layer) and organic soil layers (non/semi-decomposed layer namely L + F and fully decomposed layer of litter namely H) were estimated separately. For the estimation of the organic carbon density in the mineral soil layer, the estimation accuracy is improved by deducting the root volume of trees based on the existing method. The method for estimating the volume content of roots in each layer contains 4 steps as follow. Firstly, the root biomass of a single tree was estimated with the regression equations proposed by the previous study, which is multiplied by the growth density of the forest to obtain the total biomass of the roots per unit area of the forest land; secondly, by measuring the biomass and the volume of a partial sample of the root system,the density of the partial root sample is calculated to represent the density of the whole root system; then, the total root volume of the forest area per unit area is calculated by dividing the total biomass of the roots per unit area of the root system by the density of the root system; Finally, according to the distribution result of the root system along the depth obtained in previous studies, the total root volume per unit area is distributed to each soil layer and the content of root volume is calculated. For the estimation of the carbon density of the organic soil layer,the volume of the base of the trunk contained in the organic soil layer is subtracted, which is calculated with the mean ground diameter. In addition, due to the extremely uneven distribution of different components in the organic soil layer, the different components in the litter (organic soil layer) are carefully grouped according to the source organs and physical forms, and the organic carbon content of each component is determined.[Result] Thicknesses of top soil layer (A), core soil layer(B) and subsoil layer(C) were 19.10, 14.20, 31.03 cm and 18.57, 15.13, 28.13 cm for the spruce and the red birch, respectively. The SOC contents in A, B and C horizons were (44.56±3.72) g·kg^-1, (25.63±1.77) g·kg^-1 and (10.79±2.28) g·kg^-1 respectively for spruce;they were (34.11±5.46) g·kg^-1, (19.06±4.95) g·kg^-1 and (11.02±3.86) g·kg^-1 respectively for red birch. The carbon contents of various components in organic soil layer of the two stands were significantly different (P < 0.05). The organic carbon contents of spruce cones, moss, tree branches and roots in litters were greater than 600 g·kg^-1. Followed by the organic carbon contents of leaves, which were (458.90±46.81) g·kg^-1 for spruce forest and (420.72±55.66) g·kg^-1 for red birch forest. The organic carbon contents of other undistinguishable fine particles was the minimum which were less than 300 g·kg^-1. The root volumes in A, B and C horizons were 66.81 (3.5%), 20.69 (1.5%) and 9.18 (0.3%) m³·hm^-2 respectively for spruce, and they were 50.57 (2.7%), 31.75 (2.1%) and 17.22 (0.6%) m³·hm^-1 respectively for red birch. The carbon density of organic soil layers was 4.26 kg·m^-2 for spruce, less than that of the original method by 0.73%; H and L+F layers accounted for 84% and 16% respectively; the carbon density of mineral soil layers was 16.58 kg·m^-2, less than that of the original method by 2.13%. The carbon density of organic soil layers was 3.49 kg·m^-2 for red birch, less than that of the original method by 0.48%; H and L + F layers accounted for 90% and 10%; the carbon density of mineral soil layers was 14.06 kg·m^-2 for red birch, less than that of the original method by 1.61%.[Conclusion] The estimated total organic carbon densities of soil in spruce forest and red birch forest decreased by 1.85% and 1.39% respectively after deducting the content of root volume, which suggested that the currently-estimated forest soil carbon storage might be generally higher than the actual value.

[Objective] The use of poplar veneer for the preparation of Cee-sections thin-walled timber structure can be used to investigate its axial compression performance and buckling deformation mode to provide the basis for the use in architecture.[Method] Based on the cross-sectional form of cold-formed thin-walled section steel, the impact of Cee-sections thin-walled timber structure of the assemble pattern, glass fiber cloth(GFC),curling, thickness and other factors on Cee-sections thin-walled timber structure short column axial compression properties can be explored.[Result] The result showed that the average ultimate loads of assemble pattern along the grain of veneer, assemble pattern surface layer cross grain and core layer along the grain of veneer and assemble pattern grain staggered of veneer were 12.5,14.6 and 12.97 kN respectively. The section validity of the GFC-poplar veneer composite Cee-sections thin-walled timber structure specimen is large overall, ranging from 46.46% to 50.21%. Compared assemble pattern surface layer GFC and core layer along the grain of veneer with assemble pattern surface layer cross grain and core layer along the grain of veneer, when replaced the transverse bending veneer with GFC, the average cross-sectional area reduced by 26.90%,the mass reduced by 5.17%,but the limit load increased by 8.63%. Compared assemble pattern outer angular surface layer GFC and core layer along the grain of veneer with assemble pattern surface layer GFC and core layer along the grain of veneer,the limit load reduced by 34.17%,and the local buckling occurred at the middle of the flange and web. Assemble pattern surface layer GFC and core layer along the grain of veneer, lip width 25 mm assemble pattern surface layer GFC and core layer along the grain of veneer and lip width 50 mm assemble pattern surface layer GFC and core layer along the grain of veneer groups had the same assemble pattern and the lip dimension were respectively 0, 25 and 50 mm, corresponding to the actual ultimate bearing capacity were 15.86,16.76 and 18.98 kN. Compared with lip width 50 mm assemble pattern surface layer GFC and core layer along the grain of veneer, the thickness of the core layer of the lip width 50 mm assemble pattern surface layer GFC and core layer along the grain of thickening veneer group increased by 52.96%, the average weight per meter increased by 33.33%, and the ultimate load increased by 90.31%.[Conclusion] Assemble pattern surface layer cross grain and core layer along the grain of veneer is more reasonable than assemble pattern along the grain of veneer and assemble pattern grain staggered of veneer in the same layer blank of Cee-sections thin-walled timber structure, and its axial bearing performance is good. When GFC is used instead of the striated curved veneer, the axial bearing capacity of Cee-sections thin-walled timber structure can be enhanced and the plasticity failure mode can be showed. Only partly pasting GFC on the surface corner of Cee-sections thin-walled timber structure can't improve the axial bearing performance of no curling Cee-sections thin-walled timber structure. The curl has a strengthening effect on the axial bearing capacity of Cee-sections thin-walled timber structure, and the axial bearing capacity of the specimen increases with the increase of curl size in the range of 0-50 mm lip width. With the increase of Cee-sections thin-walled timber structure core along the monolithic board thickness, C profile specimen axial load capacity also increased.

[Objective] This paper attempted to answer the question of what specific impact on households' capital input and labor input in forest management could be caused by engaging in different forest management types. The concerns are of important significance in enhancing forest resource growth and forestry sustainable development.[Method] This research conducted a sample survey of 500 forestry farm households, 50 villages, and 10 counties in Jiangxi Province. By applying quantitative regression method, the research analyzed the impacts of partnership management and joint shareholding management on households' capital input and labor input in forest management.[Result] Partnership management had a statistically positive influence on households' participation in capital investment in forest management with a coefficient of 1.013. It also significantly impacted the intensity of capital input. The coefficients were 4.174 for total input and 1.909 for per unit input, respectively. Joint shareholding management had a promoting effect on the amount of labor use in forest management, with coefficient of 0.521 for total input and 0.180 for per unit input. In addition, the impact of logging quota policy could be positively regulated by joint shareholding management. Partnership management and joint shareholding management significantly reduced the restrictions on labor input from long distance to township in mountainous areas. Rural households' human capital characteristics, forest land resource characteristics, and finance ability characteristics had diverse effects on households' investment in forest land management.[Conclusion] Partnership management and joint shareholding management can promote household forest management investment. However, the development of partnership management and joint shareholding management is relatively low. What is more, the impacts of partnership management and joint shareholding management on capital input are different from those on labor input. Therefore, in order to promote the sustainable development of forestry, it is necessary to guide the standardization and procedure of partnership management and joint shareholding management. Especially in remote mountainous areas, we should take the advantages of plentiful members and wide information sources of partnership management and joint shareholding management. Meanwhile, coordinated reform of collective forest tenure and forest infrastructure should be improved, so as to incent farmers to participate in forest management.

[Objective] Through the comparison among the estimated result of the soil organic carbon density in the spruce (Picea asperata) and red birch (Betula albosinensis) natural forests in the Xinjiashan Forest Farm in Qinling Mountains with different estimation method, we tested the improvement of the new method on estimation accuracy by subtracting the root volume.[Method] The organic carbon densities of the mineral soil layers (top soil layer, core soil layer and subsoil layer) and organic soil layers (non/semi-decomposed layer namely L + F and fully decomposed layer of litter namely H) were estimated separately. For the estimation of the organic carbon density in the mineral soil layer, the estimation accuracy is improved by deducting the root volume of trees based on the existing method. The method for estimating the volume content of roots in each layer contains 4 steps as follow. Firstly, the root biomass of a single tree was estimated with the regression equations proposed by the previous study, which is multiplied by the growth density of the forest to obtain the total biomass of the roots per unit area of the forest land; secondly, by measuring the biomass and the volume of a partial sample of the root system,the density of the partial root sample is calculated to represent the density of the whole root system; then, the total root volume of the forest area per unit area is calculated by dividing the total biomass of the roots per unit area of the root system by the density of the root system; Finally, according to the distribution result of the root system along the depth obtained in previous studies, the total root volume per unit area is distributed to each soil layer and the content of root volume is calculated. For the estimation of the carbon density of the organic soil layer,the volume of the base of the trunk contained in the organic soil layer is subtracted, which is calculated with the mean ground diameter. In addition, due to the extremely uneven distribution of different components in the organic soil layer, the different components in the litter (organic soil layer) are carefully grouped according to the source organs and physical forms, and the organic carbon content of each component is determined.[Result] Thicknesses of top soil layer (A), core soil layer(B) and subsoil layer(C) were 19.10, 14.20, 31.03 cm and 18.57, 15.13, 28.13 cm for the spruce and the red birch, respectively. The SOC contents in A, B and C horizons were (44.56±3.72) g·kg^-1, (25.63±1.77) g·kg^-1 and (10.79±2.28) g·kg^-1 respectively for spruce;they were (34.11±5.46) g·kg^-1, (19.06±4.95) g·kg^-1 and (11.02±3.86) g·kg^-1 respectively for red birch. The carbon contents of various components in organic soil layer of the two stands were significantly different (P < 0.05). The organic carbon contents of spruce cones, moss, tree branches and roots in litters were greater than 600 g·kg^-1. Followed by the organic carbon contents of leaves, which were (458.90±46.81) g·kg^-1 for spruce forest and (420.72±55.66) g·kg^-1 for red birch forest. The organic carbon contents of other undistinguishable fine particles was the minimum which were less than 300 g·kg^-1. The root volumes in A, B and C horizons were 66.81 (3.5%), 20.69 (1.5%) and 9.18 (0.3%) m³·hm^-2 respectively for spruce, and they were 50.57 (2.7%), 31.75 (2.1%) and 17.22 (0.6%) m³·hm^-1 respectively for red birch. The carbon density of organic soil layers was 4.26 kg·m^-2 for spruce, less than that of the original method by 0.73%; H and L+F layers accounted for 84% and 16% respectively; the carbon density of mineral soil layers was 16.58 kg·m^-2, less than that of the original method by 2.13%. The carbon density of organic soil layers was 3.49 kg·m^-2 for red birch, less than that of the original method by 0.48%; H and L + F layers accounted for 90% and 10%; the carbon density of mineral soil layers was 14.06 kg·m^-2 for red birch, less than that of the original method by 1.61%.[Conclusion] The estimated total organic carbon densities of soil in spruce forest and red birch forest decreased by 1.85% and 1.39% respectively after deducting the content of root volume, which suggested that the currently-estimated forest soil carbon storage might be generally higher than the actual value.

[Objective] The objective was to explore the differences of respiration rates in the soil and soil components of the mixed plantations of Cunninghamia lanceolata and broadleaved trees in northern Fujian Province in China under different harvesting intensities, to identify the main influencing factors of the seasonal variation in total soil respiration rate, and to provide a scientific basis for studying the impact of regional forest harvesting on soil respiration rate.[Method] Experiments were carried out in a mixed plantation of C. lanceolata and broadleaved trees in northern Fujian Province in August 2011. Selective harvesting at three intensities:medium (34.6%), high (48.6%), and extra-high (67.6%) and clear cutting were performed, and non-harvesting was used as control. The respiration rates of soil and its components, soil temperature and moisture at a depth of 5 cm were measured using a Li-Cor 8100A infrared gas exchange analyzer from July 2016 to July 2017 (5 years after harvesting).[Result] As assessed in 2016, in the non-harvesting control plot and selective harvesting plots, the total soil respiration rate reached its maximum in July and minimum during January to March; 5 years after clear cutting, the total soil respiration rate reached its maximum in June and minimum in November. There was no significant difference (P > 0.05) in respiration rate in the mineral soil between the harvested plots at different intensities and the non-harvested control. The respiration rates of litter and roots did not differ significantly between the selective harvesting and the non-harvesting (P > 0.05), but significantly decreased by 0.93 μmol·m^-2s^-1 and 0.53 μmol·m^-2s^-1 under clear harvesting (P < 0.05) compared to the non-harvesting (1.45, 1.11 μmol·m^-2s^-1). The total soil respiration rate did not differ significantly between the selective harvesting at different intensities and non-harvesting plots (P > 0.05), but compared to non-harvesting (4.39 μmol·m^-2s^-1), the total soil respiration rate significantly increased by 1.64 μmol·m^-2s^-1 under clear harvesting (P < 0.05). Soil temperature did not differ significantly between the selective harvesting at different intensities and the non-harvesting (P > 0.05), but compared to the non-harvesting (18.52℃), the soil temperature significantly increased by 4.7℃ under clear harvesting (P < 0.05). Soil moisture did not differ significantly among medium intensity, high intensity, and non-harvesting conditions (P > 0.05), but compared to non-harvesting (30.67%), the soil moisture significantly decreased by 2.17% and 3.98% at the extra-high intensity of harvesting and the clear cutting (P < 0.05). The total soil respiration rate could be best described by the exponential model of soil temperature. The model that fit temperature best explained 77.8%-83.3% of the variation in the total soil respiration rate under selective harvesting and non-harvesting conditions, and 35.5% of the variation in total soil respiration rate under clear harvesting. The temperature sensitivity (Q₁₀) of the total soil respiration rate was in the range of 1.77-2.72 under selective harvesting and non-harvesting conditions, and it was 1.47 under clear cutting conditions.[Conclusion] 5 years after harvesting, selective harvesting at different intensities and non-harvesting had no significant difference in the respiration rates of soil and its components. The respiration rate of the litter, the root, and the total significantly decreased under the clear cutting. Selective harvesting at different intensities did not change the regularity of seasonal variation in total soil respiration rate. The maximum and minimum values of seasonal variation in total soil respiration rate appeared early under the clear cutting. In the study area, the seasonal variation in total soil respiration was mainly controlled by soil temperature.

[Objective] It is of significance to investigate the temporal variations of microclimate and the extent of human comfort in forests for developing rational management strategies, assessing the ecological benefit of urban recreational forests, and providing guidance for local residents to choose befitting time and clothing for recreation in the forests.[Method] Three typical plantation forests for recreational purposes nearby the highest peak of Huishan National Forest Park in Wuxi City were selected to compare the differences of microclimate and the extent of comfort between forests and open area with no forest. The three forests planted in the 1980s and 1990s were respectively of Cinnamomum camphora, Pinus elliotii on the southern slope, and Quercus variabilis on the northern slope. A site on a cement road on the mountain ridge was taken as the control. The air temperature, air relative humidity and wind velocity were measured in the field during the day time (5:00 am-19:00 pm) on calm sunny days in the spring, summer, autumn and winter, respectively. Comfort index and weather index for clothing thickness were calculated to quantify the seasonal and diurnal variations of microclimate and extent of human comfort.[Result] The results showed that seasonal variations of temperature in all forests exhibited a greater extent in summer than in spring, autumn, and winter while the air relative humidity in summer and autumn were greater than that in spring and winter. The highest wind speed in the C. camphora stand and P. elliotii stand occurred in summer but Q. variabilis stand and the control site were in autumn. There was no significant difference in the extent of human comfort among different forests in the same season and the most comfortable season for all forests were in spring. Single-peak diurnal variation of air temperature was found in all forests with temperature peak from 11:00am to 15:00pm and troughs from 5:00am to 7:00am in all the four seasons. However, the daily variation of air relative humidity exhibited an opposite trend. Large fluctuations in wind speed demonstrated by peaks and troughs respectively occurring during 5:00am-9:00am and 13:00pm-15:00pm, The daily extent of human comfort peaked in spring, autumn and winter during 11:00am-15:00pm while dropped to the lowest values in summer. The extent of human comfort of the three forests was improved significantly in summer but not in winter. The longest period of climate reached the comfort level in each forest was in spring (11:00-17:00), followed by autumn (11:00-15:00) and summer (5:00-7:00), yet the weather was extremely uncomfortable in winter. The weather index for clothing thickness (WICT) of all forest stands was 1 in summer and 7 in winter. In spring, the WICTs were different among the forest stands, with 5 for C. camphora stand, 4 for both P. elliotii and Q. variabilis stand, and 3 for the control site. In autumn, the WICT was 4 for the control site and Q.variabilis stand, and 5 for C. camphora and P.elliotii stand.[Conclusion] The three mature plantation stands all played a cooling and humidifying effect in spring, while the P. elliotii stand showed an effect of wind speed reduction in all seasons. The seasonal and diurnal variation trends of microclimate factors and the extent of human comfort among three recreational forests indicated that microclimate was biophysically regulated in summer, and the climate in spring was the most comfortable for human.

[Objective] This study aimed to investigate the ecological effects of root exudates input on herb species from seed germination and seedling growth.[Method] We performed an experiment on acceptors(Trifolium repens and Medicago sativa) in which in situ exudates were collected from Picea asperata seedlings.[Result] 1) Root exudates decreased the germination rate, germination vigor and germination index of the two herb species seeds, and significant differences were observed on the M. sativa seedlings. 2) Similarly, both the fresh weight and dry weight of two herb species seedlings were decreased under root exudates treatments, and significant differences were also observed on M. sativa seedlings. 3) Root exudates additions reduced the total length, total surface area and total volume of two herb species seedlings. Among them, significant differences were found only for the total length. 4) Synthesis effect was a vital index of allelopathy. Further analysis showed that the synthesis effects of root exudates on seed germination and seedling growth of two herb species seedlings were negative. And the allelopathy to M. sativa was stronger than that to T. repens. 5) The analysis of root exudates showed that numerous phenolic acids were found in the root exudates of P. asperata seedlings.[Conclusion] 1) Our result manifested that the root exudates from P. asperata seedlings had obvious inhibitory effects on the seed germination and seedling growth of the herb species. 2) Numerous phenolic acids in the root exudates maybe one of major reasons for the observed inhibiting effects of root exudates.

[Objective] The secondary phloem from four species of three genera in the family Anacardiaceae (Rhus chinensis, Rhus potaninii, Pistacia chinensis, and Cotinus coggygria) were used to study the structural characteristics and patterns of distribution of various cells constituting the secondary phloem in different species. The structural characteristics of resin canals and their distribution were also clarified. This can provide a theoretical basis for studying the relationship between the development of plant secondary phloem, and the synthesis and structure of secondary metabolites,and to facilitate related evolutionary studies of Anacardiaceae plants.[Method] Bark samples were collected form Pistacia chinensis, Rhus potaninii, Cotinus coggygria and Rhus chinensis, the samples included vascular cambium, secondary phloem and periderm, but not secondary xylem. A comparative anatomical study of structural characteristics of the secondary phloem from four species in Anacardiaceae, and the composition and arrangement of its components in each, was meticulously conducted.[Result] The results showed that the secondary phloem of the four species in Anacardiaceae consisted of sieve tubes and companion cells, phloem parenchymal cells, phloem ray cells, resin canals and phloem fibres, which were arranged in a tangential band. However, some differences in the secondary phloem and resin canal structure among the four species were still observed. The conducting phloem and non-conducting phloem of the P. chinensis, R. potaninii and R. chinensis were clearly defined. Phloem ray cells in all species were arranged in a neat and vertical direction, except in R. potaninii, where they were obliquely distributed in the non-conducting phloem. The resin canal of R. potaninii was branched but not in the other three species, and only a small amount of fusion occurred between adjacent resin canals. There were a large number of phloem fibres in the secondary phloem of P. chinensis and C. coggygria, fewer in R. potaninii, and none in the phloem of R. chinensis.[Conclusion] The four Anacardiaceae species had noticeable differences in the secondary phloem cells and their resin canal structure. Rhus potaninii is the only species in Anacardiaceae found with branched resin canals, which provides a valuable basis for evolutionary studies of Anacardiaceae plants.

[Objective] TATA box-binding protein associated factor TAF10, as one of the basic transcription factors, plays an extensive and important biological role in the regulation of growth, development and stress response. Cloning and functional analysis of TAF10 homologous gene CpTAF10 in wintersweet (Chimonanthus praecox) may help to enrich the understanding of plant TAFs gene, and provide theoretical basis for the analysis of the mechanism of transcriptional regulation of the resistant formation of wintersweet.[Method] Based on the cDNA sequence of TAF family gene in wintersweet transcription database, we obtained the CpTAF10 gene and analyzed the sequence characteristics and evolutionary tree. The expressions of CpTAF10 in different tissues and flowering stages, and the changes of CpTAF10 gene expression under heat, cold, NaCl stress and ABA treatments were analyzed using real-time quantitative PCR. Meanwhile, the overexpression vector of CpTAF10 was constructed, and transformed into Arabidopsis thaliana via floral dipping method, phenotypes and stress tolerance of the homozygous transgenic lines were analyzed.[Result] The cDNA sequence of CpTAF10 is 712 bp, including 405 bp of ORF (open reading frame). The open reading frame of CpTAF10 encoded a protein composed of 134 amino acids. The theoretical molecular weight of this protein was 15.21 kDa, and the predicted isoelectric point pI value was 5.19. The CpTAF10 protein has high homology with other plant homologous proteins. The multiple sequence alignment shows that CpTAF10 protein belongs to the TAF10 homologous protein and contains the histone folding domain. The results showed that the CpTAF10 gene expressed in the roots, stems, cotyledon, young leaves, mature leaves and flowers of wintersweet, and the mature leaves had the highest expression level. CpTAF10 showed a fluctuating expression pattern in different flowering stages, and showed the highest expression in the senescence stage. The expression of CpTAF10 was induced in cold, salt stress and ABA treatment in wintersweet. The overexpression of CpTAF10 gene increased the germination rate of transgenic Arabidopsis seeds under salt stress. Compared with the wild type, the main root and lateral roots of the transgenic plants showed growth advantage to some extent under salt stress.[Conclusion] The expression of CpTAF10 gene can be induced under cold, salt stress and ABA treatment, and CpTAF10 gene may be involved in molecular regulation of stress tolerance in wintersweet. The overexpression of CpTAF10 gene in Arabidopsis significantly enhanced the germination rate and the growth advantages of root under salt stress, enhanced the salt stress tolerance in transgenic Arabidopsis to some extent.

[Objective] The non-disturbed forest age was estimated by the geographically weighted regression (GWR) model. The information of forest fire severity was obtained by using remote sensing data and history data of forest fire occurrence. Then the forest fire intensity was graded. The interaction between forest fire severity and forest type was discussed, and the age of disturbed forest was estimated. Finally, the spatial distribution of stand age in Heilongjiang province was obtained.[Method] In this study, Heilongjiang forest was taken as the study area, based on the multi-spectral data of the study area and the forest resources inventory data, stepwise regression method was used to extract five significant factors as the independent variables, including the remote sensing factors of Greeness, Wetness, stand average breast diameter (ADBH), stand average tree height (ASH) and Altitude. The GWR model was used to establish the stand age estimation model of non-disturbed forest. The global Moran I index was used to characterize the spatial autocorrelation of the model residuals. The spatial distribution map of non-disturbed forest age in the study area was drawn and the spatial distribution status of stand age was explored. Combining the location and area records of forest fires, visual interpretation of multi-spectral data was used to extract the burned area. Fire severity was divided into four classes according to the dNBR. The ArcGIS software was used to do an overlaying analysis on the fire severity map with vegetation type map. The fire severity map and vegetation type map were superimposed to discuss the succession of different forest types under different fire severities. When the stand age of disturbed forest was defined, the age of forest without tree species replacement remained unchanged. The stand with tree species replacement was classified its age as 0 in the year of forest fire occurrence, and accumulated from 1 at the beginning of germination of new dominant species, so as to deduce the age of forest after disturbance.[Result] The average age of non-disturbed forests in Heilongjiang was 48 years, with a standard deviation of 16 years. The R_adj² of the GWR model was 0.68, and the RMSE was 16.171 7. Moran I was used to test the residual of the model, and it was found that the GWR model was able to eliminate the spatial autocorrelation of residuals well. The overall spatial distribution of forest age in the study area was uneven, and the forest age in Daxing'an Mountains was generally higher than the average level of Heilongjiang forest area. Forest fires occurred mainly in Daxing'an Mountains and Xiaoxing'an Mountains areas in Heilongjiang Province in 2000-2010. According to dNBR, fire severity was divided into four classes:unburned, low, moderate and high. High severity burned area was 29 157 hm², moderate severity burned area was 180 268 hm², and low severity burned area was 318 507 hm². Larix gmelinii forest and Quercus mongolica forest had the largest burned area in the whole study area, accounting for 28.63% and 47.23%, respectively. According to the replacement of different forest types under different fire severities in the burned area, the age of disturbed forest was determined, and the spatial distribution map of disturbed forest age was plotted.[Conclusion] GWR model can effectively estimate the age of non-disturbed forest in Heilongjiang Province, and successfully reduce the spatial autocorrelation of residual. In the process of estimating forest age, forest fire disturbance factors were added to obtain more realistic spatial distribution data of forest age, which provided data support for forest NPP, NEP, forest carbon storage, forest biomass and other related research in Heilongjiang area.