Objective: This study was aimed to understand age-related tree growth pattern and their relationship with climate factors, in order to provide a scientific basis for predicting forest dynamics under future climate change and for forestry management in response to climate change. Method: Based on the data of Qinghai spruce forest in 2 sample plots at respective altitudes of 2 800 and 2 900 m in Pailugou small watershed in the middle of Qilian Mountains, the basal area increment (BAI) at breast height was used to characterize the growth of trees. We present the responses of Qinghai spruce (Picea crassifolia) growth to climate change using a stand-total sampling strategy. All the trees in the 2 sample plots were divided into 3 age groups: young (30-60 a), middle-aged (60-90 a), and old (90-120 a).We analyzed the growth difference among the 3 age groups and its key influential factors during the periods of rapid warming (1980-2000) and warming hiatus (2000-2013). Result: During the period from 1980 to 2000, water stress resulted from rapid warming in the study area restricted the growth of trees of all the 3 age groups, the BAI slope of regression line was decline gradually -5.91 mm²·a^-1 (P < 0.01), -9.48 mm²·a^-1 (P < 0.01), and -14.97 mm²·a^-1 (P < 0.01) respectively for the young, the middle-aged, and the old. The percentage of positive correlation between the BAI of the old trees and the average standardized precipitation evapotranspiration index(SPEI) from the current May to August was the largest, indicating that the drought-limiting effect of the old trees was the greatest. From 2000 to 2013, the warming hiatus coupled with increase of precipitation resulted in a relatively warm and humid climate characteristics. As a result, the BAI of different age groups turned into a non-significant increase trend. The BAI slope of regression line was of the young and the middle-aged (2.27 and 2.45 mm²·a^-1, respectively) was greater than that of the old (1.02 mm²·a^-1). The percentage of significant negative correlation between the old trees and the average temperature of the current June was large. However, the percentage of significant positive correlation between the young and the middle-aged trees and the total precipitation from the last July to the current June and the average SPEI from May to August were large, indicating that after mitigation of drought the warming still has a certain restrictive effect on the growth of old trees. However, the total precipitation from the last July to the current June and the average SPEI from the current May to August promoted the growth of the young and the middle-aged trees. Conclusion: During the rapid warming period, the BAI decline rate of Qinghai spruce in the middle Qilian Mountains gradually increased with the increase of tree age. During the period of warming hiatus, BAI of all age groups resumed the increasing trend, and the BAI increase rate of the young and the middle-aged trees was greater than that of the old trees. During the rapid warming period, the impact of temperature and SPEI on the BAI of the old trees is stronger. While during warming hiatus period, the impact of precipitation and SPEI on the young and the middle-aged trees is greater.

Objective: This article aims to explore whether the forest park environment can relieve human tension, the differences in health benefits of different forest park environments and the impact of soundscape perception on the health benefits of forest park, and to further study on which soundscapes are important elements of restorative (positive benefits) soundscapes, in order to provide a basis for restorative soundscape design for forest park. Method: Fuzhou national forest park was chosen for the study, 20 videos (10 videos with voice and 10 without) on environment of the forest park were tested by 35 invited college students on the park campus. The Ergo LAB data platform was used for physiological data collection during the experiment. Soundscape perception questionnaire was used to evaluate soundscape perception of different samples. The median test was used to analyze the differences in health benefits of different forest park environments. Wilcoxon test was used to analyze the effects of forest park environment on stress recovery and the impact of soundscape perception on the health benefits of forest park. Moreover, optimal scale regression was used to determine the restorative soundscape elements. Result: Different forest park environments can effectively reduce the rare of skin conductance level (SCLr), heart rate(HR) and heart rate variability (LF/HF). But different forest park environmental health benefits were different. Green space sample plots S7, S9 and blue space sample plots S8, S10 health benefits were better. There were significant differences in SCLr among different forest park environments, but no significant differences in HR and LF/HF. The addition of soundscape can change health benefits of forest park environments. Except for the sample plots S5 where conversation and children's frolic sounds were more prominent, the health benefits of audiovisual combined stimuli were higher than single visual stimuli. Chirm, running water sound, cicadas chirp, and footsteps had a greater impact on SCLr. Chirm, running water sound, cicadas chirp and wind sound had a greater impact on LF/HF. Natural sounds such as chirm and running water sound had a greater contribution to the positive benefits(SCLr decreased, HR decreased, LF/HF decreased), while artificial sounds such as footsteps were the opposite. Conclusion: The forest park environment can relieve stress to a certain extent. The health benefits of different forest park environments are different. Blue and green spaces play an important role in improving the health benefits. It is worth noting that the soundscape of forest parks is also the key to restorative environmental design. Natural sounds such as chirm and running water are important elements of restorative (positive benefit) soundscape. In the future, the design of restorative environment should start from multiple dimensions and fully explore a variety of restorative environmental elements, in order to provide more convincing evidences for the design of restorative environment of forest parks.

Objective: Larix principis-rupprechtii is one of the main tree species for plantations in north China, but its natural regeneration is generally poor. It is therefore important to identify the main limiting factors and explore practical techniques to promote the natural regeneration. Method: In the mid October of 2018, five sites in Liupan Mountains of Ningxia, China, were selected, each of which 5 habitat types were chosen according to canopy closure (near-mature forests, forest gaps, forest glades, forest edges, and young forests grown by farmland conversion program). A sample plot with a size of 12 m×12 m was set up for each habitat type, and within each sample plot 5 treatments, i.e., cutting grasses, completely removing humus layer after grass cutting, digging holes to expose mineral soil after humus removal, opening ditches into mineral soil after humus removal, and the control (without any treatment). The completely randomized block design was used, and each block was arranged parallel to the contour line. A total of 25 plots, each containing 5 treatments with 3 replications. Larch seeds were sowed by broadcasting (100 seeds·m^-2) after the plantation floor was treated, and two treatments of covering the ground with nylon mesh and not covering as control were employed to evaluate the effect of nylon mesh-covering on seedling density by preventing birds and rats from eating seeds. We counted the number of remaining seedlings in June of 2019 for statistical analyses. Result: In the case of no mesh-covering, the mean seedling density was 2.7 plants·m^-2 for the young forests, 1.8 plants·m^-2 for the forest edges, 1.4 plants·m^-2for the forest gaps, 1.3 plants·m^-2 for the near-mature forest, and 0.8 plants·m^-2 for the forest glades; the mean seedling density was 2.1 plants·m^-2 for the opening ditches, 1.9 plants·m^-2 for the digging holes, 1.8 plants·m^-2 for the humus removal, 1.3 plants·m^-2 for the grass cutting, and 1.1 plants·m^-2 for the control. The highest mean seedling density among the 5 treatments in each habitat type was 4.1 plants·m^-2for the opening ditches at the forest edges, 3.6 plants·m^-2 for the grass cutting in the young forests, 2.4 plants·m^-2 for the opening ditches in the forest gaps, 2.1 plants·m^-2 for the digging holes in the near-mature forest, and 1.3 plants·m^-2 for the digging holes in forest glades, respectively. Furthermore, we found that mesh-covering can increase seedling density of all treatments significantly. The mean seedling density of each treatment in the near-mature forests was increased by 2.3 plants·m^-2 for the humus removal, 1.0 plants·m^-2 for the opening ditches, 0.5 plants·m^-2 for the control, 0.5 plants·m^-2 for the digging holes, and 0.5 plants·m^-2 for the grass cutting, respectively, with a range of increase of 0.5-2.3 plants·m^-2. The mean seedling density of each treatment in the young forests was increased by 2.3 plants·m^-2 for the humus removal, 1.7 plants·m^-2 for the opening ditches, 1.3 plants·m^-2 for the digging holes, 0.6 plants·m^-2 for the grass cutting, and 0.3 plants·m^-2 for the control, with a range of increase of 0.3-2.3 plants·m^-2, showing a similar scope of increase in the near-mature forests. Conclusion: The important factors restricting seedling under larch forests include animal browsing, humus layer too thick to hinder roots into mineral soil, weed competition, shading by over-dense canopy, etc. We herein propose an integrative measure to significantly increase seedling density of larch: thinning to create a medium canopy shading habitat or selecting such existing habitats (e.g., not-closed young stands, forest edges, forest gaps), removing humus layer completely or opening ditches in large areas, and covering nylon mesh after seeding to prevent animal browsing.

Objective: The full length sequence of EuCPI gene was cloned from Eucommia ulmoides seed kernel and its structural characteristics were analyzed. The stress resistance function of EuCPI and its impact on the growth and development of Tenebrio molitor were explored. The results can provide a theoretical basis for further study of the stress-resistance mechanism in the future. Method: The RNA of E. ulmoides kernels was extracted and reverse transcribed into cDNA, the full-length cDNA sequence of EuCPI gene was amplified by RACE technology; the physicochemical properties and structural functions of the encoded protein were analyzed and predicted by using bioinformatics websites; the fragment containing EuCPI gene was inserted into pET28a to construct a prokaryotic expression recombinant vector, and the recombinant protein was investigated by SDS-PAGE, Western Blot, and protein purification tests; to preliminarily identify the effect of EuCPI gene on Escherichia coli, the differences in growth curves under salt and high temperature stress between E. coli containing EuCPI gene and control group were explored using recombinant prokaryotic expression system; in addition, the effect of EuCPI gene on the growth and development of T. molitor was studied by feeding T. molitor with the induced E. coli containing EuCPI gene. Result: The full-length sequence of EuCPI gene was 547 bp(GenBank accession number: MT702592), the gene contained a 309 bp open reading frame (ORF), encoding 102 amino acid residues. The predicted molecular weight of the putative protein was 11.17 kDa with the isoelectric point(pI) of 6.41. The protein was a stable and hydrophilic protein, the instability index was 27.73 and the total average hydrophilicity was -0.416. The amino acid sequence analysis showed that EuCPI protein had no transmembrane structure and no signal peptide, mainly composed of 50% α-helix, 36.27% random coil, 11.76% extended chain and 1.96% β-sheet, which belonged to the cysteine proteinase inhibitor family. Phylogenetic tree analysis showed that EuCPI protein had high homology with CPI of Quercus suber. The recombinant protein with the size of 15.29 kDa was induced and purified by the constructed prokaryotic expression vector pET28a-EuCPI. The growth curve of high temperature stress showed that the E. coli containing EuCPI gene was basically the same as that of the control group in the first 10 hours at 37℃, however the growth rate of the BL21(DE3) E. coli containing EuCPI gene was significantly greater than that of the control group in the first 10 hours at 42℃ and 50℃, and the control group showed significant growth inhibition. The salt stress test on solid medium showed that with the increase of NaCl concentration, both the test group and the control group showed growth inhibition, but the number of colonies containing EuCPI gene was significantly more than that of the control group, especially at 0.75 mol·L^-1, the former had more single colonies survived and the latter had no single colonies survived. Under 0.25 mol·L^-1 NaCl concentration in the first 8 hours, the growth curve of salt stress in liquid medium showed that the growth rate of the BL21(DE3) E. coli containing EuCPI was significantly faster than that of the control group displaying obvious growth inhibition. The forage tests showed that the body mass of T. molitor fed containing EuCPI gene decreased, while the body mass of the control group increased (P < 0.01). Conclusion: The EuCPI gene can improve E. coli tolerance to high temperature and salt stress, and the recombinant bacteria containing EuCPI gene can inhibit the growth and development of T. molitor

Objective: This study aimed to construct a growth model of diameter at breast height(DBH) for Chinese fir plantations based on competition and climate factors, and analyze effects of competition, climate factors and their interactions on DBH growth. The results were expected to provide a reference for the growth of reserved trees after thinning and selective cutting under climatic changes. Method: Based on the permanent sample plots in the south of Jiangxi Province, the potential increment equation with multiplicative modifiers was used to construct DBH growth model. The quantile regression technique was used to model the potential DBH increment, and seven environmental factors(mean temperature, maximum temperature, minimum temperature, precipitation, accumulated temperature greater than 5℃, elevation, slope) were used to describe the effects of site quality on potential increment. Parameter significance and variance inflation factor were chosen to determine environmental factors, which could be the independent variables. Exponential function form was used to construct modifier functions. Competition variables included in the modifier functions were three stand-level and three tree-level competition indices(2 distance-independent indices and 1 distance-dependent index). The interactions between the selected best competition index and five climate factors on good-of-fit of growth models were also considered. According to model evaluation, the model with the best good-of-fit was selected to add plot-level random effect parameters, and then used to analyze the effects of competition, climate and their interactions on DBH growth of Chinese fir plantations. Model evaluation criteria included mean absolute error(MAE), relative mean absolute error (RMAE), and mean predicted error(MPE). Result: Elevation, minimum temperature and precipitation during investigation intervals showed significant effects on the potential DBH increment for Chinese fir. The potential increment would reach the maximum when DBH was 20 cm. Minimum temperature and precipitation during investigation intervals showed positive effects on the maximum of potential DBH increment, but elevation showed a negative effect. Compared with DBH growth models based on the other competition indices, the models with distance-independent indices showed the best good-of-fit, and followed by the models with distance-dependent indices. After containing the interactions between climate and competition, the good-of-fit of models was improved. Compared with the models which only included competition indices in modifier functions, MAE of growth models with interactions decreased 0.60%-18.69%, MPE decreased 0.12%-9.72%. The model included the interactions between basal area in larger trees as the competition index and mean temperature, maximum temperature and minimum temperature as climate factors showed the best good-of-fit, thus the model was selected to add plot-level random effect parameters to construct the final model. The final model had a good good-of-fit, and MAE was 0.071 1 cm, RMAE was 20.37%, MPE was 4.90%. The final model showed that temperature could increase the modifying effects of competition on potential DBH increment, except for the trees with a little competitive pressure or with a large competitive pressure. Conclusion: The quantile regression could present a good effect when used to model the potential increment. The interactions between climate and competition could improve the good-of-fit of DBH growth model. Therefore, if climate changed dramatically, we recommended that the interactions between competition and climate should be considered into individual tree growth model.

Objective: This study was carried out to compare different effects of multiple source data on forest dynamic forecasting. The patterns of parametric uncertainty and predictive uncertainty were analysed and quantified to illustrate the processes of information fusion. Changes in model accuracy and reliability were also assessed to reveal the differences in the characteristics of data, which also was expected to provide directions for further data collection. Method: Multi-period (i.e. 1990, 2005 and 2012) and multi-type (i.e. temporary plots, permanent plots and stem analysis) of inventory data of Pinus tabulaeformis were collected in Qinling Mountains. A simple variable-density stand-level model with a low data requirement was selected. Under a Bayesian framework of information fusion, we analysed the relations between traditional forest inventory data and empirical growth and yield models. The joint posterior parametric distributions were constructed using MCMC sampling technique in order to quantify the uncertainty in the forecasts of forest dynamics. On the one hand, the changes in the probability distributions of both parameters and predictions were compared for multi-period inventory data; on the other hand, the multi-type data were tested considering their impacts on model performances. The data-model updating loop was achieved by the relation between the priori and the posteriori, which meant that the joint posterior parametric distribution in the former experiment was continuously used as the prior information for the latter experiment. The integration of multiple source data was based on the assumptions of the independent likelihood for sampling and observing error in each dataset. To avoid the biases from erratic observations and outliers, the likelihood of error structure applied a heavy-tailed normal distribution. The heteroscedasticity of errors was considered using an automatically changing variance in likelihood during iterations. Result: With the new dataset continuously obtained, the marginal and joint parametric distribution kept changing. In general, the parametric uncertainty decreased along with the increase of the kurtosis in the probability distribution, resulting in a decreasing predictive uncertainty. In comparison with parameterization from inventory in 1990, the model calibrated with data from 2005 and 2012 showed an obvious lower predictive uncertainty during the mature stage, while the asymptotic parameter was shifted to higher values. The distinctions of predictions among various datasets revealed the advantages and drawbacks of different inventory datasets. The information from stem analysis tended to a higher prediction of average height for mature stand, when compared with plot sampling. The temporary plots and permanent plots differed in the sampling method and the observation quantity, which made the forecasts of stand basal area present distinctively. The model based on continuously updating and multi-source data performed the highest precision and accuracy. Conclusion: One challenge of forest growth and yield modeling is that sampling and observing errors vary with datasets. Even with the same set of optimal parameters, the advantages and drawbacks in different datasets might lead to a distinctive pattern of uncertainty. The probabilistic information could demonstrate both the accuracy of models and the lacking information of data, which would reveal the further direction of model development and data collection. The case study chose a specific Bayesian approach to demonstrate the complete logic of data-model loop and processes of information fusion.

Objective: This study was executed to predict the biomass growth of Larix olgensis based on 3-PG model in order to provide the basis for studying its growth rules. Method: The data used in this article was obtained from 5 plots of experimental forests continuously observed for 28 years and 24 plots with 3 re-measurements. The stem density, DBH(diameter at breast height), volume and biomass of each plot in different times were calculated using the biomass calculation formula for each component (leaf, stem and root). The physiological parameters of the 3-PG model of L. olgensis were calibrated by density data. And the parameter values were determined based on soil data and meteorological data through parameter calibration, iterative fitting and sensitivity analysis. The result accuracy was examined by calculating coefficient of determination (R²), mean error(ME), mean absolute error(MAE), mean relative error(MRE), and root mean square error(RMSE). Two factors, the canopy quantum efficiency(alpha) and minimum biomass fraction of NPP to roots (pRn), were chosen to procced sensitivity analysis. Then, the growth biomass of L. olgensis was predicted under the conditions of the fertility ratings(FR) being 0.2, 0.4 and 0.6. Result: 1) The prediction results were reliable and the coefficient of determination (R²) was above 0.77. The absolute values of MRE of all the other indicators were within 10.97%, except for the foliage to stem biomass ratio with a value of 25.6%. 2) The sensitivity analysis showed that alpha and pRn were the key parameters of the model with high sensitivities. 3) The predicted biomass growth in this study was consistent with the growth mechanisms of plants under different FRs. At the same time, the biomass of larch was increased with the growth of FR. Conclusion: After the parameter calibration based on field data, the 3-PG model could simulate the biomass growth of L. olgensis well and be used as an effective forest management tool. For the 3-PG model of L. olgensis, alpha and pRn might be the key parameters affecting the prediction results.

Objective: Exploring the spatial distribution of site productivity and analyzing its relationships with environmental factors for Larix principis-rupprechtii plantations are crucial for the effective forest management in the north area of Hebei Province. Method: Based on data from 1 179 forest inventory plots distributed across this area, we established multiple linear regression (MLR), random forest(RF), regression Kriging(RK) and geographical weighted regression Kriging(GWRK) models with topographic, climate and soil factors. Through model evaluation, the optimal model was selected to predict the spatial distribution patterns of site index(SI) for L. principis-rupprechtii plantations. The relationships between the distribution pattern of SI and environmental factors were analyzed by correlation and partial correlation analysis. Result: The major environmental factors influencing site productivity of L. principis-rupprechtii plantations in the study area included elevation(DEM), precipitation of the driest month(BIO14), total soil nitrogen and phosphorus(TN and TP). The values of goodness of fit of the two geostatistical models(RK and GWRK) were similar and both significantly higher than those of MLR and RF models. In contrast to RK model based on global regression, the GWRK model based on local regression had a higher fitting accuracy with R²=0.780, AIC=160.533, RMSE=1.593 m and MAE=1.113 m. The GWRK model based on local regression had a highly predictive power to predict SI of L. principis-rupprechtii plantations in the study area. SI was more sensitive to the variation of topographic and soil factors and less sensitive to the variation of the climate factors across regions with different site productivity classes. Conclusion: The site with a high growth suitability for L. principis-rupprechtii might tend to occur in the northwest area with a higher elevation, relatively high BIO14 and suitable soil TN and TP contents. However, the site with a low growth suitability for L. principis-rupprechtii were found in the eastern and southern areas with a lower elevation, relatively low BIO14, and unbalanced TN and TP contents. It might be feasible to mitigate the negative effects of environmental factors on growth and productivity of L. principis-rupprechtii plantations through silvicultural activities or appropriate nitrogen and phosphorus addition in the study area.

Objective: This research aimed to explore the changes of phosphate-dissolving ability of Pseudomonas fluorescens at its strain JW-JS1 and the colonization dynamics in rhizosphere and mycorrhizosphere of poplars, to reveal the phosphate-dissolving mechanisms of this strain and further elucidate its interaction mechanisms with ectomycorrhizal fungi, so as to provide a theoretical basis for developing and exploiting the compound microbial fertilizer for poplar. Method: A liquid fermentation experiment was conducted to investigate the changes of soluble phosphorus contents, pH, and titratable acid contents in the broth of P. fluorescens JW-JS1. Kinds and concentrations of organic acids in the broth were also determined by HPLC. The stable marker of antibiotic rifampin was screened by using the rifampin-resistant mutant method, and the colonizing dynamics of mutant strain in rhizosphere and mycorrhizosphere of poplars were investigated by root irrigating method. Result: 1) The results showed that the soluble phosphorus contents in broth of JW-JS1 gradually increased with the time. Correlation analysis showed that the pH was negatively correlated with soluble phosphorus contents (r=-0.889^**), while the titratable acid contents was positively correlated with soluble phosphorus contents (r=0.958^**). 2) The total amounts of organic acid secreted by JW-JS1 (434.39 mg·L^-1) was significantly higher than that of control (25.94 mg·L^-1) (P < 0.05). Five kinds of organic acids were detected in the broth, including oxalic acid, tartaric acid, citric acid, maleic acid and fumaric acid. Among them, the amounts of oxalic acid (273.69 mg·L^-1) was significantly higher than that of other kinds of organic acids, which was about 63.01% of the total organic acid concent. 3) A strain of with 30 μg·mL^-1rifampicin resistance was selected. Compared with wild strain, there was no obvious change in colony morphology and phosphate-dissolving ability of JW-JS1^Rif strain (P < 0.05). 4) The strain of JW-JS1^Rif could effectively survive and maintain a certain colonizing population in the rhizosphere and mycorrhizosphere of poplar, and the colonizing population was a downward trend as the time of inoculation was prolonged, and the colonization dynamics were basically consistent. After 50 days of inoculation, the colonizing population was 5.2×10⁴ cfu·g^-1 and 4.5×10⁴ cfu·g^-1, respectively. Conclusion: The phosphate-dissolving ability of P. fluorescens JW-JS1 is closely related to the pH, titratable acid contents and organic acid in the culture medium, especially oxalic acid secreted by the strains may play an important role in the phosphate-dissolving process. P. fluorescens JW-JS1 can stably survive in the rhizosphere and mycorrhizosphere of poplar. The above results indicate that P. fluorescens JW-JS1 and Xerocomus chrysenteron are ideal materials for constructing functional compound microbial fertilizer for poplar.

Objective: The recognition of forest images taken with the unmanned aerial vehicle (UAV) It is an the important technology using the unmanned aerial vehicle (UAV) images for pest automatic monitoring and early warning tree recognition for the automatic pest-control warning system in a forestry. An approach on object detection based on deep learning was used to accurately recognize and locates small-scale infected trees in high-resolution forest UAV images are accurately recognized and located through deep learning object detection technology. Method: The images of pine forest infected by Dendroctonus valens from Liaoning Province were chosen used as the experimental data. The UAV forest image dataset was constructed by images taken from the a height of 180-240 m and annotated by open source software LabelImg. Because the instance size of UAV forest images dataset in this paper is far smaller than general datasets, a small infected trees detector (SITD) is designed to improve the ability of recognition and localization for small object, since the instance size of UAV forest images dataset in this paper is far smaller than general datasets. Firstly, based on the framework of single shot multi-box detector (SSD), the prediction module is built from conv3_3 and tailored according to the size of the target tree in the image, then the generation method of default boxes is optimized. Secondly, the base feature map is transformed into the enhanced feature map by the feature enhance module, thus generating the base and enhanced prediction module are generated by using base feature maps and enhanced feature maps which is transferred by the feature enhance module. Finally, dual loss functions are used to facilitate the feature learning. Result: The method of small object detection based on deep learning can realize UAV remote monitoring of for forest pests, and accurately detect small and dense infected trees in UAV images accurately. In this paper, five SITD models with different structures and other object detection frameworks as SSD, FSSD and RFBNet are used to trained and tested with on UAV forest image dataset, were compared by and average precision (AP) and Precision-Recall curve are selected as evaluation indexes. The proposed method achieves the average precision of 92.62% using the UAV images captured in our study, which gets a gain of 69.71% compared to the original SSD300, and higher than the other three frameworks. Conclusion: Experimental results demonstrate that the method of small object detection based on deep learning can realize automatic detection of infected trees, and simplify the monitoring process for forest pests, and which can improve the warning ability of forest pests.

Objective: Phenylalanine is a precursor of many plant compounds that are essential for plant reproduction, growth, development, and defense against different types of stress. Phenylalanine biosynthesis pathway is one of the most important secondary metabolic pathways in plants. In the phenylalanine biosynthesis pathway, the cinnamate 4-hydroxylase (C4H) and 4-coumarate CoA ligase (4CL) are involved in the core reaction of phenylpropane metabolism. Lymantria dispar is a major forest pest in the world. In this study, our objective is to explore the effects of Lymantria dispar herbivore on key enzymes in phenylalanine biosynthesis pathway of Populus simonii×P. nigra for inducing defense, and to provide genetic materials for promoting host resistance by genetic engineering method. Method: The full length of C4H and 4CL was cloned by RT-PCR technology and its characteristics were analyzed in this study. The phylogenetic trees of C4H and 4CL were constructed by Neighbor-joining method, respectively. The activities of C4H and 4CL were compared by using spectrophotometry under the treatment of Lymantria dispar herbivore and mechanical wounding. The expression of C4H and 4CL genes under the two wounding treatments was determined by real-time RT-PCR technology. Result: Two C4H genes (namely C4H-1 and C4H-2) belonging to p450 family and one 4CL from multi-domain protein superfamily (AFD_class_I) were cloned and identified from the transcriptome of Populus simonii×P. nigra. The open reading frames of the full-length genes were 1 518-1 740 bp, encoding 505-579 amino acid residues with the molecular mass of 58.00-63.03 kD and theoretical pI of 5.63-9.09. Phylogenetic analysis showed that the C4H-1 of Populus simonii×P. nigra was clustered into a group with that of P. alba. The C4H-2 of Populus simonii×P. nigra was clustered into a group with that of P. tomentosa, P. tremuloides, P. trichocarpa×P. deltoides and P. trichocarpa. The 4CL of Populus simonii×P. nigra is closely related to that of P. trichocarpa×P. deltoids and P. trichocarpa. The results showed that the L. dispar herbivore induced the increase of C4H-1, C4H-2 and 4CL gene expressions by 6.86-, 1.15- and 1.50- fold of the control, respectively. Moreover, mechanical wounding induced up-regulation of C4H-1 gene, however inhibited down-regulation of C4H-2 and 4CL genes with 1.80-, 0.71- and 0.60- fold of the control, respectively. Both L. dispar herbivore and mechanical wounding could induce activities of C4H and 4CL enzymes, and the induced activity of C4H and 4CL enzymes by herbivore was significantly higher than that of mechanical wounding. Conclusion: L. dispar herbivore can significantly induce the increase of C4H and 4CL activity in Populus simonii×P. nigra, which may be due to the increased expression of C4H-1, C4H-2 and 4CL genes, respectively. The above results indicate that L. dispar herbivore is involved in the induced defensive response of phenylalanine biosynthesis pathway in Populus simonii×P. nigra. The results provides a basic theory for further understanding the resistance mechanism and lignin biosynthesis to defend L. dispar herbivore in Populus simonii×P. nigra.

Objective: Based on the fact that the local compression deformation of straight tenon and mortise joints under bending is relatively large and the bending stiffness and load bearing capacity are low, the concept of "cross-laminated timber" was referenced to develop suitable pre-reinforcing methods for straight tenon and mortise joints. This study was carried out to investigate the effects of locally cross-laminating on the structural performance of straight tenon and mortise joints, and put forward a reasonable pre-reinforcement methods and relevant parameters in order to provide theoretical and practical supports for the application of traditional tenon and mortise joints in modern timber structure projects. Method: 18 straight mortise and tenon joints were manufactured with glulam of No.1 Douglas fir (Pseudotsuga menziesii) lamination, of which some were treated with 4 different reinforcing methods. All of the joints were tested under monotonic loading. The failure modes and working curves were observed, and the moment carrying capacity and initial stiffness were obtained. The constitutive model of wood under complex stress state was developed and finite element(FE) model was developed. The tests were simulated by FE methods and the model was verified by comparing the predicted deformation modes, load-displacement curves, moment and stiffness with the test results. Then parametric study was conducted to investigate the effects of locally cross laminating on the structural performance of the straight tenon and mortise joints. Result: It was observed that compression deformation perpendicular to grain at the upper surface near the tenon end and the lower surface near the beam was the most critical for the untreated tenons. By locally cross laminating, the compression deformation perpendicular to gain could be effectively reduced. It was found that the initial stiffness of the joints increased from 14.0% to 36.9% for different reinforcing configurations, and the moment carrying capacity of some specimens increased while some specimens decreased. The predicted results from FE model were correlated well with the test results. With the increase of width of the cross-laminations, the stiffness of the joints firstly increased and then decreased, however, the moment presented an opposite trend. With the increase of thickness of the cross-laminations, the stiffness of the joints increased while the moment decreased. For the tenon and mortise in this study, it was recommended to take a rate of thickness of cross-lamination to the tenon width of 0.25 and a width of 210 mm as the optimum solution, respectively. Conclusion: The rotational stiffness of straight tenon and mortis joints could be improved by the locally cross laminating. By choosing appropriate parameters, the ultimate moment could also be increased. The structural performances of the straight tenon and mortise joints could be further improved by using materials like bamboo scrimber and steel plates, which might have a higher strength and ductility, instead of wood laminations.

Objective: This study was carried out to analyze the pigment component, stability and antioxidant activity of the heartwood of Dalbergia bariensis with the aims to provide theoretical basis and technical support for making full use of the resources of D. bariensis and also to provide reference for the efficient utilization of similar rosewood resources. Method: Pigment was extracted from the processing waste(shavings) of D. bariensis heartwood, and the constituents and properties of the pigment were explored. Ultra-high performance liquid chromatography coupled to Q Exactive quadrupole-Orbitrap mass spectrometry (UPLC-Q-EXACTIVE-MS) was used to isolate and identify the pigment. The content of main components in the pigment was determined. The effects of pH, metal ions, temperature and ultraviolet irradiation on the stability of pigment were investigated. The scavenging ability of the pigment to DPPH and ABTS radicals was also studied by using ascorbic acid(Vc)as positive control. Result: 19 flavonoids were identified from the heartwood pigment of D. bariensis, including orientin, puerarin, vitexin, isorhamnetin, pelargonidin, cyanidin, hispidulin, chrysin, glycitein, cirsimaritin, sakuranetin, naringin, genistein, malvidin, diosmetin, medicarpin, formononetin, maackiain, and 6-hydroxyflavone, of which the relative content of formononetin was 2.27%. The pigment had a good stability under acidic conditions, but a poor stability in alkaline conditions, and precipitation appeared after pH>9. K⁺, Na⁺, Ba²⁺, Ca²⁺ and Mg²⁺ had a little effect on the pigment. Al³⁺ had a color enhancement effect on the pigment. Gr⁶⁺, Cu²⁺ and Fe³⁺ made the pigment precipitate and had a great destructive effect; the pigment was stable when heated at high temperature for 2 hours. The pigment color could be enhanced by long-time high temperature heating, and the pigment color could be slowly enhanced by ultraviolet irradiation. The pigment could scavenge DPPH radicals and ABTS radicals. Conclusion: The main components of the pigment from the heartwood of D. bariensis are flavonoids. The pigment is stable in acidic to neutral environments, unstable in alkaline condition, unstable in the presence of Gr⁶⁺, Cu²⁺ and Fe³⁺. High temperature heating and long-time irradiation might have a great influence on the stability of pigments, which have a certain antioxidant capacity.

Objective: In the late stage of the collective forest tenure reform, the improvement of the forest allocation efficiency encountered new problems, and the existing research results and the practical exploration did not provide effective answers. At the same time, the change of the external environment promotes the increase of non-farm employment of farmers, the opportunity cost of forestry investment increases. This paper mainly explores the relationship between non-farm employment and the forestry production division, and provides policy references for accelerating the construction of the forestry production division system and effectively promoting the development of the forestry specialization, and enriches studies on forestry division theory. Method: Firstly, we divide the influence of the non-farm employment on the farmers' decision into the substitution effect and the income effect. Based on the theoretical basis, we analyze the influence of the non-farm employment on the farmers' forestry production division. Secondly, we use farmers' data from Fujian province and select the binary Probit model to verify the significant relationship between the two. Thirdly, we select the tool variable of "does the village people have the habit of going out to work?" and use the Ⅳ-Probit model to solve the endogenous problem. At the last, the robustness test is carried out by replacing the key variable "non-farm employment income" with "non-farm employment number". Result: The empirical analysis of Ⅳ-Probit model showed that: at the significance level of 1%, the non-farm employment income of farmers and the non-farm labor force who does not live at home both have significant positive impact on the division of the forestry production. Firstly, the more non-farm employment income farmers have, the less capital constraint they have to participate in the division of the forestry production, the more obvious the substitution effect. Secondly, the non-farm employment farmer who does not live at home has a higher opportunity cost of the forestry production, they are more likely to choose the division service. At the same time, at the significance level of 10%, the proportion of surrounding farmers participating in the division of labor and the level of family income in the village have significant impact on the division of labor in the forestry production. In addition, the robustness analysis shows that the above results are stable. Conclusion: 1) The non-farm employment of farmers has a role in promoting the division of labor in the forestry production. With social and economic development, the income of the non-farm employment and the number of non-farm employment labors who do not live in their homes will increase. It is the future trend of the further deepening the development of the division of labor in the forestry production. 2) The higher the proportion of farmers involved in the division of labor, the lower the transaction cost of the division of labor in the forestry production, and the more likely farmers are to participate in the division of labor in the forestry production. Therefore, it is necessary to strive to construct the service system of the forestry production division of labor, build an information platform of the forestry production division service, establish a mechanism of multi-sectoral integration and formulate forestry policies with multiple departments to promote the development of the forestry division of labor steadily and orderly.

Objective: In this study, the effects of different irrigation quantity on the branching pattern and adaptability of biennial triploid Populus tomentosa plantation were investigated, in orderto provide theoretical basis for canopy management of triploid P. tomentosa plantation. Method: The branching patterns of 9 trees in a two-year-old triploid P. tomentosa plantation were measured under the sufficient drip irrigation, deficit drip irrigation and no irrigation treatment (CK). Result: The results showed that: 1) the average branch length and branching angle of the first-order branches of P. tomentosa were significantly affected by different irrigation quantity (P < 0.05). Under drip irrigation, the average branch length of the first-order branches was the longest (3.31 m) and the branching angle was the largest (59.81°). 2) The different treatments significantly affected branch diameter ratio (2∶1) (P < 0.05). The branch diameter ratio (2∶1) of control, full drip irrigation and deficit drip irrigation were 0.39, 0.51 and 0.39, respectively. 3) There were no significant differences inthe total branching rate and gradual branching rates of P. tomentosa among different treatments (P > 0.05). Under the conditions of sufficient drip irrigation, there were more new branches in the current year, and less new branches in CK treatment. Conclusion: In summary, the twig length, branching angle and branch diameter ratio of two-year-old P. tomentosa have strong plasticity and variability under different irrigation condition. When the soil moisture is sufficient, the number of branches of P. tomentosa increased, the first-order branches grow faster, the branching angle increased, and the overall branching rate was lower. The results of this study will be helpful to understand the branching pattern and the adaptive strategies of the poplar, and provide a theoretical basis for making the reasonable pruning measures.

Objective: The quality of seedlings directly affects the outplanting performance, and the density and row spacing configuration of seedlings affect seedling quality and yield. This study aimed to explore Populus tomentosa seedling growth, nutrient content and light interception in response to density and row spacing, and to select the suitable density and row spacing of P. tomentosa seedlings, in order to improve the quality of P. tomentosa seedlings and save the cost. Method: In this paper, three seedling densities (50 000(A₁), 41 667(A₂), 31 250(A₃) seedlings·hm^-2) and three kinds of row spacing (uniform row B₁ (row spacing 0.8+0.8 m), the narrow-wide rows B₂: (row spacing 0.6+1.0 m), and the narrow-wide rows B₃: (row spacing 0.4+1.2 m) were designed to explore the effects of seedling density and row spacing on growth, nutrient content, light interception of P. tomentosa. Result: 1) Density and row spacing had significant effects on seedling growth indexes. The seedling height, root biomass and biomass of A₂B₃ were the highest, with 294.65 cm, 151.92 g and 328.77 g, respectively. 2) Density and row spacing had significant effects on leaf nitrogen concentration of P. tomento sa seedlings. The leaf nitrogen concentration of A₃B₃ was the highest with a value of 16.43 g·kg^-1. Narrow-wide row planting significantly increased the nitrogen concentration in seedling stems and roots compared with equidistant row planting. 3) The interaction of density and row spacing configuration had no significant effect on canopy light interception (P > 0.05). However, row spacing significantly affected light interception and leaf area index (LAI) of P. tomento sa seedlings (P < 0.01). Narrow-wide rows 2 significantly increased light interception and leaf area index of P. tomentosa. The light interception and leaf area index of treatment B₃ were the highest, which were 0.87 and 3.59, significantly higher than those of treatment B₁. 4) Under different density and row spacing, light interception significantly affected the growth index of the seedlings (P < 0.05). Light interception was significantly positively correlated with seedling height, root collar diameter, aboveground biomass, underground biomass and total biomass of P. tomentosa (P < 0.01), and negatively correlated with stem/root (SR) (P < 0.05). Among them, light interception and biomass had the highest determinant coefficient, with R² reaching 0.408. Conclusion: Under different density and row spacing, light interception is the key factor affecting seedling height, root collar diameter, stem-to-root ratio and biomass. In general, the seedling growth indexes and nutrient concentration change with different density and row spacing. In terms of seedling quality, under the treatment of A₂B₃, the growth indexes and light interception of P. tomentosa are the best. As for the production economy, A₁B₂, A₁B₃, A₂B₂, and A₂B₃ are better.

Objective: This study aimed to verify the applicability of the original Granier formula to calculate the liquid flux density of 107 fast-growing poplar trunks, in order to provide a basis for accurate calculation of tree transpiration. Method: In order to verify the applicability of the original formula of Granier, 107 poplar was taken as the test object, and the liquid flux density was actually measured by in vitro stem segment weighing method and whole-tree container weighing method on the basis of thermal diffusion trunk flow measurement technology. By establishing the statistical relation between the measured liquid flux density and the temperature difference Coefficient (K value) measured by the thermal diffusion method, the correction formula is finally formed. Result: Compared with the actual measurement values of the whole tree container weighing method and the indoor stem weighing method, the fluid flux density calculated by Granier's original formula is seriously underestimated, with error rates of -71.5% and -74.3%, respectively. The correction formulas established based on the real measurement values of the whole tree container weighing method and the indoor stem weighing method are F_d (fluid flux density, cm³·cm^-2 s^-1)=0.010 8K^{0.566 6}(R²=0.812 6) and F_d=0.019 17K^{0.952 8} (R²=0.940 3). According to the data collected on June 23 and 24, compare with the measured value of the whole tree container weighing method in the field under the natural condition, the value of Granier's original formula underestimates by 68.90%, while the whole-tree container weighing method underestimated only 2.95%, and the in vitro stem segment weighing method underestimated by 15.75%. Conclusion: Granier's original formula seriously under estimates the sap flow density of 107 poplar stems, which would cause great error. However, the corrected formula can reflect the relationship between the density of the liquid flux and the K value, and can accurately express the true liquid flow. Therefore, the liquid flux density of 107 poplar stem calculated by the Granier formula corrected based on the whole-tree container weighing method has higher accuracy.

Objective: Eucommia ulmoides is a traditional medicinal and rubber woody plant that is endemic to China. It is important to study the genes related to growth and development for breeding. Auxin response factor(ARF) is an important transcription factor in the auxin signaling pathways. Study of the role of ARF in E. ulmoides organ development has great values both in theory and practice. Method: Identification of putative EuARF genes from genome data and bio-informatics analysis were performed. The phylogenetic tree was generated using a multiple sequence alignment of the EuARF, AtARF (Arabidopsis thaliana ARF), OsARF (Oryza sativa ARF) and PeARF (Populus×euramericana ARF) proteins. RNA-seq data were used to analyze EuARFs expression profiles. qRT-PCR were used to analyze the expression patterns of these genes and miRNAs in organs at different developmental stages. Result: A total of 18 EuARFs were identified in the E. ulmoides genome. These EuARFs were divided into five classes by phylogenetic tree and predicted that eu-miR160s target EuARFs of class Ⅱ and eu-miR167s target EuARFs of class Ⅴ except EuARF8.2. The expression patterns showed that the expression of EuARFs in different growth stages of leaves was different, and the expression of EuARFs in class Ⅴ and EuARF19.2 in class Ⅵ were higher in 3 cm long growing leaves and unfolded young leaves. The qRT-PCR indicated that EuARFs expressed in organs (leaf, root and stem) at different developmental stages (young and mature). In addition, EuARFs were up-regulated in mature roots and down-regulated in mature leaves and stems. Meanwhile eu-miR160s was mainly expressed in young roots, and eu-miR167s was mainly expressed in mature leaves. Conclusion: A total of 18 EuARFs were identified in the genome of E. ulmoides. These EuARFs were expressed in organs (roots, stems and leaves) at different developmental stages (young and mature) under normal growth conditions. The expression level indicates that EuARFs in class V has a regulating role for seedlings growth and development and EuARF19.2 plays an important role in regulating the leaf growth.

Objective: Based on the principle of bidirectional selection and judgment, a method was proposed to reasonably match the individual tree information extracted from point cloud data(LiDAR) with the reference information measured by the field work. Method: Using airborne LiDAR point cloud data, individual tree information such as tree position, number, height, and crown diameter was extracted. Firstly, the candidate reference trees were selected according to the information of the LiDAR tree. Then whether such candidate trees were the most reasonable LiDAR trees from the reference tree or not were evaluated again. Result: The matching accuracy, the heights and crown diameters accuracy after matching were used as the accuracy indicators. Compared with the other three commonly used matching methods, the height accuracy of individual tree using the proposed matching method was increased from 75.21% to 91.01%, and the crown diameter accuracy was also increased from 60.50% to 68.64% under the conditions with the same matching accuracy. When the height and crown diameter accuracy were controlled with the same value, the proposed method improved the matching accuracy from 33.52% to 61.11% comparing to the traditional method. Conclusion: The proposed method in this paper could match the single tree information quickly and efficiently between the ones extracted by remote sensing and the reference information measured on the field work. Compared with the traditional method, it could show some superiority when used in high-density and multi-layer stands.

Objective: This study aims to explore the tolerance of emerald ash borer to a hot and humid environment and the possibility of colonization under high temperature and humidity conditions in southern China. Method: In this study, the survival rate of adults, the number of mature eggs per adult female, and the hatchability of fresh eggs were measured under different conditions of high temperature and humidity. Result: 1) Adults of emerald ash borer were relatively tolerant to constant high temperature and humidity. At 80% RH, both male and female adults were able to survive for more than 3 days at 38℃ when the relative humidity was 80%. The survival rate of males started to decrease on the third day at 41℃, while the mortality of females occurred only at constant temperatures above 42℃. Female adults were more tolerant than male adults, and females could survive for 24 hours at 43℃, while all males died within 12 hours. 2) Eggs of emerald ash borer could develop to maturity at 28℃, 38-43℃, 80% RH. The number of mature eggs per female at 38℃ and 41℃ were significantly more than that at 28℃. The number of mature eggs declined gradually with the increase of temperature when constant temperature was over 41℃, and no mature egg was observed at 44℃. 3) At 80% RH, eggs were easy to be infested by pathogens. However, some eggs still hatched at 28℃ and 38℃, but not at over 41℃. The egg hatchability decreased significantly under high temperature and humidity compared to the hatchability at 28℃. Conclusion: The results demonstrate that emerald ash borer has strong tolerance to high temperature and humidity, so that it is possible to survive and establish populations after being spread to some regions in central or southern China.