Objective: Intensive human activities have resulted in significant changes in aerosols and particulate matter content in the atmosphere, thereby posing an important impact on the total amount and proportion of global diffuse radiation. In this study, based on the clarification of the canopy photosynthetic parameters corresponding to the radiation components, the seasonal dynamics and the main biophysical regulators were explored to gain insight into the effects of diffuse radiation on the gross primary productivity (GPP) of a poplar plantation, providing a reference for the accurate assessment of ecosystem functions and carbon sink of plantations in the future. Method: The carbon cycling processes and biophysical factors of a poplar (Populus × euramericanacv. '74/76') plantation in Gongqing Farmland, Shunyi District, Beijing, were observed for the consecutive four years (2015—2018). A nonlinear fitting method was used to split the ecosystem maximum photosynthetic rate (A_max) and apparent quantum efficiency (α) into two components influenced by direct radiation (A_max,dir, α_dir) and diffuse radiation (A_max,dif, α_dif), respectively. Since the rectangle hyperbola light response model (Michaelis-Menten model) would appear unsaturated phenomenon when simulating GPP, GPP at PAR of 2 000 μmol·m^–2s^–1 was used as the maximum photosynthetic rate (A₂₀₀₀) in this study. Result: In this study, simulated diffuse radiation based on clearness index and solar altitude angle was found to be consistent with the measured values (slope 0.82, R² = 0.87, RMSE = 51.67 W·m^–2, P < 0.01). The α _dif, A_2000,dir and A_2000,dif of this poplar plantation during the growing season showed an increasing trend and then a decreasing trend. The α_dif and A_2000,dif were significantly higher than α_dir and A_2000,dir (P_α = 0.02; P_A2000 = 0.03). The α_dif/α_dir and A_2000,dif/A_2000,dir were 5.6 and 6.1, respectively, and the two ratios showed significant differences in summer. The growing season GPP showed a single-peaked variation pattern during the study period, and GPP was significantly correlated with A_2000,dif only (P < 0.01), and GPP showed a significant increasing trend with increasing PAR _dif/PAR_dir (P < 0.01). In summer, A _2000,dif was mainly influenced by T_a and increased with the increase of T_a (partial correlation coefficient = 0.74, R² = 0.49, P < 0.05); in spring and autumn, LAI dominated the change in A_2000,dif (partial correlation coefficient = 0.69, R² = 0.53, P < 0.01). In contrast, the Prestley-Taylor coefficient ( η) and clearness index (CI) had no significant effect on A_2000,dif in either spring and autumn or summer. Conclusion: α and A₂₀₀₀ show significant seasonal trends. The effects of diffuse radiation on A₂₀₀₀ and α are significantly higher than those of direct radiation, and are more pronounced in the middle of the growing season. The changes of A_2000,dif in spring and autumn, and summer are mainly dominated by biological factors (LAI) and environmental factors (T_a), respectively. A_2000,dif is the most critical factor regulating GPP changes, thus diffuse radiation is the key radiation component affecting photosynthetic productivity in this poplar plantation.

Objective: This study aims to clarify the overall morphological characteristics of urban tree canopy (UTC) patches in the urban area of Beijing, and reveal the spatio-temporal dynamics of UTC patch morphology during the urbanization process, so as to provide the scientific reference for the planning and construction of urban forest in the future. Method: In this study, we first extracted the UTC patches within the 6^th Ring road of Beijing in 2002, 2013 and 2019 based on the high-resolution remote sensing images, and then analyzed the composition of patch morphological characteristics with the morphological spatial pattern analysis (MSPA) method, and finally revealed the spatial discrepancy of UTC transition using transition matrix and the relative contribution index method. Result: The UTC within the 6^th Ring road of Beijing increased from 387.93 km² in 2002 to 771.14 km² in 2019, showing a large expansion of UTC during the study period. However, there existed differences between the period of 2002–2013 and 2013–2019. From 2002 to 2013 the UTC reached to 282.92 km², which was apparently larger than that from 2013 to 2019 (97.39 km²). Furthermore, the morphological composition was rather steady throughout the study period. The islet, core and bridge were the main morphological types of UTC patches, since the total area of these three types comprised of over 80% of UTC in 2002, 2013 and 2019. The edge, loop, branch and perforation were the secondary types. During the study period, the transition between other urban land types and the islet of UTC was the main transition type of UTC, accounting for 30% and 25% of the total UTC conversion area during the periods of 2002–2013 and 2013–2019, respectively. Nevertheless, there were differences in UTC dynamics between these two sub-periods. Between 2002 and 2013, the transition related to the core of UTC patches had a relatively large areal ratio (approximately 23.12%), while the transition related to the bridge of UTC patches had a relatively large areal ratio (approximately 35.22%) between 2013 and 2019. It was suggested that the UTC transition before 2013 was to a larger extent characterized as the dynamics of UTC core, while UTC transition after 2013 was characterized as the dynamics of UTC bridge. From the perspective of spatial changes, the transition related to the UTC islet mainly clustered within the 4^th Ring road, while the transitions related to the UTC core and bridge were located between the 4^th and 6^th Ring-road. Conclusion: In the past two decades, the UTC within the 6^th Ring road in Beijing has expanded, mainly due to the urban greening projects. The islet, core and bridge are the main morphological characteristics of UTC patches within the 6^th Ring road in Beijing. With the development of the city, the main transition type of morphological characteristics of UTC patches gradually changes from the transition related to the core to the transition related to the bridging. The transitions of UTC patch morphological features present a gradient distribution between urban and rural areas, that is, from the city center to the outside, the main transition type of UTC patch morphological characteristics changes from the transition related to the islet to the transition related to the core and bridge. In the future, urban forest construction should focus on maintaining and improving the connectivity between urban forest patches and strengthening the protection of remnant forest patches in the city center.

Objective: The spatial structure of coniferous and broad-leaved mixed forest and evergreen broad-leaved forest in Tianmu Mountains was compared and analyzed, and the succession pattern from coniferous and broad-leaved mixed forest to evergreen broad-leaved forest was revealed from the viewpoint of spatial structure, so as to provide a basis for sustainable management of evergreen broad-leaved forest and coniferous and broad-leaved mixed forest. Method: A 1 hm² fixed plot was set up for evergreen broad-leaved forest and coniferous and broad-leaved mixed forest in Tianmu Mountains National Nature Reserve of Zhejiang Province in 2015 and 2016 respectively. The tree species, DBH and three-dimensional spatial coordinates of each tree were investigated. Python language and ArcGIS software were used to calculate the spatial structure index of the two forest types. Result: The plant density of evergreen broad-leaved forest and coniferous and broad-leaved mixed forest was 2850 and 1842 plants·hm^?2, respectively, and the former was 54.72% larger than the latter. The number of tree species in evergreen broad-leaved forest and coniferous and broad-leaved mixed forest was 89 and 66, respectively, and the former was 23 more than the latter. The number of dominant tree species in evergreen broad-leaved forest and coniferous and broad-leaved mixed forest was 14 and 4, respectively. Cyclobalanopsis glauca had the highest dominant position in evergreen broad-leaved forest, and Cunninghamia lanceolata had the highest dominant position in coniferous and broad-leaved mixed forest. In terms of spatial structure, the aggregation index of evergreen broad-leaved forest community was between [0.75, 1], and the tree distribution pattern belonged to weak aggregation, while that of coniferous and broad-leaved mixed forest was in the range of [1,1.38], and the tree distribution pattern belonged to weak uniform distribution. The mixing degree of the two kinds of forest communities was between [0.5 and 0.75], which was moderate mixing. The forest community competition index of evergreen broad-leaved forest was in the range of [28, 44], which belonged to moderate competition, while that of coniferous and broad-leaved mixed forest was in the range of [128, 28], showing low competition as a whole. Conclusion: The plant density, tree species and dominant tree species of evergreen broad-leaved forest are significantly higher than those of coniferous and broad-leaved mixed forest. Compared with coniferous and broad-leaved mixed forest, evergreen broad-leaved forest has lower mixing degree, more aggregated distribution and more fierce competition. The distribution patterns of 4 dominant tree species in coniferous and broad-leaved mixed forest are all aggregated distribution. Among the 14 dominant tree species in evergreen broad-leaved forest, except Torreya grandis, blue fruit tree and Pinus elliottii, the other 11 dominant tree species are all aggregated distribution. The dominant tree species of the two forest communities are more than moderately mixed, in which Pinus elliottii in the evergreen broad-leaved forest is intensively mixed, and the mixing degree of the dominant tree species increases in the evergreen broad-leaved forest with the decrease of the dominant tree species. but there is no significant difference in coniferous and broad-leaved mixed forest. The competition intensity of the same dominant tree species in evergreen broad-leaved forest is higher than that in coniferous and broad-leaved mixed forest. In forest management, it is necessary for evergreen broad-leaved forest to strengthen the tending of dominant tree species with aggregate reproduction characteristics, increase community mixing degree, reduce community competition intensity and aggregation degree, and improve community stability. The coniferous and broad-leaved mixed forest can be suitable to take measures of tending and promoting renewal, increasing community density and tree species diversity, and improving community mixing degree and tree spatial distribution uniformity, so as to promote community succession to evergreen broad-leaved forest.

Objective: Fertilization is a critical intensive management practice to increase the productivity of fast-growing tree species. Nutrient addition would increase soil nutrient resource availability, and thus benefit the tree growth, which may subsequently result in plasticity in tree growth as well. Although a large body of literature exists on the response of tree growth to nitrogen (N) fertilization, the influence of N supply on the plasticity responses of phenological characteristics and tree growth is still not well understood for fast-growing tree species. This study aims to clarify the phenological characteristics and growth plasticity of fast-growing tree species in response to fertilization, providing a theoretical basis for the development of efficient nutrient management strategies for fast-growing and high-yield forests. Method: A three-year fertilization experiment was conducted in Populus tomentosa plantations, which species is the main afforestation tree species for constructing fast-growing and high-yields plantations in northern China. The experiment included three N application rate treatments (115, 230, 345 kg?hm^?2a^?1) and a control treatment (0 kg?hm^?2a^?1), with a randomized complete block design with three replicates. The leaf area index (LAI), tree diameter at breast height (DBH), and biomass were measured consecutively during the experimental period. The relationships of the biomass allometric growth among different organs were also analyzed. Result: 1) The results showed that all experimental treatments exhibited approximately the same phenological characteristics of dynamics of LAI and stem growth rate during the experimental period: the growing duration of P. tomentosa at this site lasted about four and a half months, and the growth often began in mid-April and ceased in early September. The monthly DBH growth rate showed two peaks, the first peak occurred from late April to mid-May, and the second, a minor peak, was detected from late June to mid-July. However, both the DBH growth rate and LAI were higher in the fertilization treatments, especially at the late stage (August) of the growing season when the fertilized stands had 71.6% and 85.1% higher (P<0.05) DBH growth rate in 2011 and 2012, respectively. 2) The analysis results of the biomass allocation showed that: the slope of allometric function for wood biomass and DBH under CK and fertilization treatments was 2.4, indicating that the growth relationship between stem biomass and DBH was allometric. The increase in stem biomass allocation in the fertilization treatments was induced by accelerating ontogenetic development and was not due to the ‘true’ plasticity response of growth to N addition. In contrast, the slopes of the allometric function for leaf and root biomass under CK and fertilization treatments were 1.2 and 1.0, respectively, suggesting that the growth relationship between leaf and root biomass allocation was isometrical. Compared with CK, the value of the allometric constants of the allometric function of different fertilization treatments was significantly higher by 0.4-0.6 (P<0.05), suggesting more leaf biomass accumulated per unit root biomass under treatments than that in CK, indicating that fertilization increased the biomass allocation from roots to leaves and induced a ‘true’ shift toward more leaf biomass per unit root biomass. Conclusion: Consequently, under fertilization conditions, the growth plasticity responses of P. tomentosa not only include a ‘true’ plasticity, but is also strongly controlled by the ontogenetic development. The findings of this study can help us to better understand the response and adaptation strategies of fast-growing tree species to the variation of environmental nutrient availability. Furthermore, the study can also provide theoretical references for refining high-efficient nutrient management techniques according to the plasticity response strategies of plants.

Objective: The differences of soil physicochemical properties, enzyme activities, microbial residue carbon and their contribution to soil organic carbon (SOC) of Cunninghamia lanceolata plantation under different thinning intensities were analyzed, and a new regulation mechanism of soil physicochemical properties and enzyme activities on microbial residue carbon accumulation was revealed. It provides a scientific theoretical basis for the sustainable management of Cunninghamia lanceolata plantations, alleviating global climate change and achieving the goal of "carbon neutrality" in my country. Method: Taking the Cunninghamia lanceolata plantation in Guanzhuang state-owned forest farm in Fujian Province as the object, the soil samples of 0-10 cm and 10-20 cm in different thinning intensities (31%, 45%, 63%) were collected, and aminosugars were used as microorganisms. Markers of residues, to explore the effects of thinning intensity and soil depth on the accumulation characteristics of soil microbial residues. Result: 1) The contents of soil bacterial microbial residue carbon (MRC_B), fungal microbial residue carbon (MRC_F), and microbial residue carbon (MRC) all increased significantly with the increase of thinning The ratio of carbon to bacterial residues (MRC_F/MRC_B) decreased with the increase of thinning intensity; soil MRC_B, MRC_F, MRC, MRC_F/MRC_B decreased with the deepening of soil layer. 2) The contribution rates of soil MRC_B, MRC_F and MRC to SOC were 13.20%-18.99%, 28.42%-39.72%, and 41.62%-58.70% under different thinning intensities, and they all increased with the deepening of the soil layer. 3) In the 0-10 and 10-20 cm soil layers, SOC, total phosphorus (TP), available phosphorus (AP), microbial biomass carbon (MBC), dissolved organic carbon (DOC), nitrate nitrogen. The contents of (NO₃^?-N) and ammonium nitrogen (NH₄⁺-N) were in the order of heavy thinning > moderate thinning > weak thinning, while pH value and density decreased with the increase of thinning intensity. 4) Both thinning intensity and soil layer depth had significant or extremely significant effects on soil enzyme activity ( P<0.05). The content of polyphenol oxidase decreased first and then increased; and with the deepening of the soil layer, the activities of the four enzymes all showed a decreasing trend. 5) Structural equation modeling (SEM) analysis showed that soil chemical properties and enzyme activities were latent variables that had a greater impact on the carbon content of soil microbial residues in the 0-10 and 10-20 cm soil layers, respectively. The soil single factor that has a greater impact on the latent variable soil microbial residue carbon content is the soluble carbon (P=0.002) and ammonium nitrogen (P=0.066) content in the 0-10 cm soil layer, and the 10-20 cm soil layer is Peroxidase (P=0.002) and nitrate (P=0.034) content. Conclusion: With the increase of thinning intensity, soil physicochemical properties and enzyme activities of Cunninghamia lanceolata plantations changed significantly, and the content of soil various forms of carbon and microbial residue carbon increased continuously; the structural equation model was well fitted, and the latent variable soil microbial residue carbon content was mainly It is regulated by the latent variables of soil chemical properties (soluble carbon, ammonium nitrogen and nitrate nitrogen) and enzyme activity (peroxidase), so in Cunninghamia lanceolata plantation management, soil nutrients and enzyme activities can be improved by moderate management density , and increase the carbon content of microbial residues and their contribution to the SOC pool.

Objective: Paeonia suffruticosa ‘Luoyanghong’ is one of common varieties with flower forcing, however the flower fragrance is too strong, and can make people feel uncomfortable when it is placed indoors. The aim of this study is to explore effects of exogenous methyl jasmonate on the volatile components and content and to obtain a method to improve the aroma components of P. suffruticosa ‘Luoyanghong’ in greenhouse, so as to provide a reference for improving the economic benefits of peony. Method: The whole plant of P. suffruticosa ‘Luoyanghong’ grown in greenhouse was sprayed with methyl jasmonate solutions (50, 100, 200, 300, 400 μmol?L^?1). The dynamic headspace adsorption method in combination with gas chromatography-mass spectrometry technology was adopted to detect the volatile components and content of flowers at different flowering stages. Result: 1) A total of 26 volatile compounds were detected in P. suffruticosa ‘Luoyanghong’ in greenhouse at different flowering stages. There were 23 compounds in the plants without methyl jasmonate treatment and 25 compounds in the plants sprayed with methyl jasmonate solution. These volatile compounds could be divided into six categories: alcohols, esters, aldehydes, terpenes, benzene rings and hydrocarbons, among them the total release amount of hydrocarbons and benzene rings was relatively high. After being sprayed with methyl jasmonate, the content of the six compounds showed different trends at different flowering stages. 2) The analysis of aroma compounds found that the three compounds, 1,4-dimethoxybenzene, 2,4-di-tert-butylphenol and methyl jasmonate, showed relatively high levels in most samples, which could be regarded as the main aroma component of P. suffruticosa ‘Luoyanghong’ in greenhouse. 3) After being sprayed with methyl jasmonate solution, the content of 1,4-dimethoxybenzene decreased, while the content of 2,4-di-tert-butylphenol and methyl jasmonate increased. The best concentration for methyl jasmonate solution was 100 μmol?L^?1. Conclusion: Application of 100 μmol?L^?1 methyl jasmonate solution can change the aroma components and content of the P. suffruticosa ‘Luoyanghong’ in greenhouse, so as to solve the uncomfortable feel problem of P. suffruticosa ‘Luoyanghong’ because of its strong fragrance when it is placed indoors.

Objective: Constructing a multi-view plant phenotypic information collection platform, image data of seedlings under water and fertilizer stress were obtained at fixed time intervals, and phenotypic parameters were extracted from morphological changes to characterize the stress response to water and fertilizer stress of Salix suchowensis seedlings, providing reference for cultivating seedling and managing water and fertilizer accurately. Method: This paper constructed a multiple view phenotypic information collection platform and proposed a seedling phenotypic extraction method based on time sequence images by adopting the approximate stitching algorithm to realize the local image effective joining together into a complete image, phenotypic information such as plant height and major branch diameter extraction algorithm and plant height visualization algorithm were put forward based on image multiple points of view. In this paper, a water-fertilizer experiment was carried out with Salix suchowensis as the research object, and water and nitrogen factors were set up, including two levels of normal water treatment and drought stress treatment, and six levels of nitrogen concentration. The changes of plant height and main branch diameter of Salix suchowensis under time series were compared and observed. Result: 1） Compared with the traditional direct mosaic algorithm and violent mosaic algorithm, the approximate image mosaic algorithm proposed in this paper has better adaptability on the multi-perspective phenotypic information collection platform, and can eliminate the stitching traces well and realize the seamless image mosaic. 2） The deterministic coefficient R² of the plant height algorithm proposed in this paper is 0.96 under multi-view images, and that of the main branch diameter extraction algorithm under multi-perspective images is 0.74, which solves the problems of inaccurate measurement of plant height and un measurement of main branch diameter caused by plant leaf occlusion under single-perspective conditions. 3) In the time series of the whole growth cycle, the changes of average plant height and main branch diameter of Salix suchowensis seedlings with time were significantly affected by different water treatments. Under normal water treatment, the average plant height and main branch diameter of Salix suchowensis seedlings were 33.6 cm and 2.49 mm respectively. The average plant height and main branch diameter of Salix suchowensis seedlings were 22.8 cm and 2.25 mm, respectively. The average plant height and main branch diameter under normal water treatment were 47.4% and 10.7% which were higher than those under drought stress. 4） In the time series of the whole growth cycle, average plant height and main branch diameter of Salix suchowensis seedlings showed differences under gradient nitrogen fertilizer, and plant height and main branch diameter increased first and then decreased with nitrogen content. Under normal water treatment, except T5 treatment group, the average plant height and average main branch diameter of other groups were higher than CK treatment group, and T2 treatment group had the highest growth rate, which was 1.92 cm·d^?1 and 0.075 mm·d^?1. Under drought stress, the average plant height in T1 and T2 treatment groups was higher than that in CK treatment group, and the average growth rate in T2 treatment group was the highest, which was 1.05 cm·d^?1 and 0.035 mm·d^?1. Conclusion: The method based on continuous image sequence is reliable and practical in monitoring seedling phenotypic characteristics. When nitrogen content is insufficient, the plant growth rate will slow down, and when nitrogen content is excessive, the plant growth rate will be inhibited and even seedlings will be burned. Considering the two growth indexes of plant height and main branch diameter, T2 treatment group (urea 0.1 g per pot, urea 0.1 g per pot on the 40th day of cuttage planting) was the best fertilization index under normal water treatment.

Objective: This study aims to establish a quantitative analysis method for the culm form characteristics of Phyllostachys edulis ‘Yuanbao’, and provide a basis for its further study and development and utilization. Method: In this study, a set of approaches was established to quantitatively measure and analyze the internodal length, internodal skew length, internodal diameter, internodal concave depth and internodal oblate index of Ph. edulis ‘Yuanbao’, and the stem shape characteristics of the experimental forest population of Ph. edulis ‘Yuanbao’ planted in Huanggongwang Forestry Garden in Fuyang District, Hangzhou, Zhejiang were tested with these approaches. Result: The results showed that in the range of internodal numbers from 1^st to 30^th, the average internodal length of Ph. edulis ‘Yuanbao increased along with the internodal number, reaching 11.06 cm at the 30^th internode, which amounted to 36.87% of Ph. edulis at the same internodal number. The adjacent internodes alternately skewed to each other in its culms, namely, the length of the same internode varied at different directions, and the internodal length at the two branching sites were the longest or the shortest alternately, while the internodal length on its vertical sites of the branching site changed subtly and was close to the average. Internodal skew length at the base and upper part of culms was shorter, while the skew length of the 9^th to 14^th internodes in the middle of the culm was longer. The average internodal diameter decreased along with the increase in the internodal numbers from 1^st to 30^th. The internodes were usually concave on both sides, the concave depth was lower at the base part, and gradually increased along with the internodal number, reaching the deepest at 10^th to 23^rd internode, and then gradually declined along with the internodal number ascending. In other words, the 1^st to 2^nd internodes concaved slightly at the both branching-sides, and there was no concave on internode between the 2^nd and 3^rd internodes. Subsequently, the concave directions rotated after this site, and the subsequent internodes concaved at the directions vertical to branching site, namely, the 3^rd to 30^th internodes concaved at the sides vertical to branching site, with the deepest depth in internodes from the 10^th to 23^rd. Except 1^st and 2^nd internodes, the upper half of each internode had a wider diameter than the lower half of each internode for 3^rd to 30^th because their lower parts were concaved. The culms were oblate, and the 1^st and 2^nd internodes were near round with subtly oblate at direction vertical to branching site, and the oblate index in upper half was larger than that in lower half of each internode. The oblate direction rotated at a site between 2^nd and 3^rd internodes, and the 3^rd to 30^th internodes were oblate at branching direction with oblate index in upper half smaller than lower half in each internode. The culm’s oblate index enhanced gradually from 3^rd to 15^th internodes, reaching greatest at 15^th to 23^rd internodes, and declined gradually from 23^rd to 30^th internodes, reaching nearly round at the 30^th internode. Rubbing and photo profiles showed waving nodes in the culms. Conclusion: In this paper, a protocol has been established for the measurement and analysis of the skewed and concaved internodes, and oblate culms in Ph. edulis ‘Yuanbao’, which could promote the development of bamboo culm form research, and make up for the shortcomings of the previous method that can only be used for round culm. Detailed and accurate quantitative information of the culm form characteristics of Ph. edulis ‘Yuanbao’ is obtained through this protocol, providing a basis for its further scientific research and development and utilization, as well as a reference for the study of other distinctive bamboos.

Objective: Leaf area is an important parameter in evaluating a plant's ability to photosynthesize and how well it can adapt to its surroundings. The tiny and dense growth of spiny leaves causes numerous difficulties in the traditional measurement of leaf area. Therefore, the aim of this study was to construct a rapid and accurate model for measuring the leaf area of the spiny leaves in Juniperus chinensis cv. Pyramidalis. Method: The leaf length (LL), base width (LBW), maximum leaf width (LW_max) and leaf thickness (LT) of 1 270 leaves from J. chinensis were measured using a vernier caliper, and the leaf area (LA) was determined through leaf image using Photoshop CS5 software. Then the relationships between the morphological indexes and leaf area were analyzed to further construct an estimation model of leaf area for the spiny leaves of J. chinensis using SPSS statistical software. Result: LA had the greatest coefficient of variation (CV=0.301) among the five morphological indexes and ranged from 7.307–7.556 mm² (95% CI). LA was significantly and positively correlated with LL and LW_max (r=0.858, 0.794). The optimal multivariate linear regression model for LA was Y=?3.879+0.718 X₁+5.679 X₂?1.177 X₃ (R²=0.914, RMSE=0.667, AIC=2060.969), where X₁, X₂ and X₃ were LL, LW_max and LBW respectively, with a prediction accuracy of 96.21%. The optimal univariate model for LA was based on LL, Y=?1.686+1.003 X (R²=0.725, RMSE=1.191, AIC=3238.133), with a prediction accuracy of 91.16%. Conclusion: This study provides a concise method for accurately estimating the area of spiny leaf of J. chinensis and a basic data for studying the relationship between spiny leaf traits.

Objective: The lack of chromosome physical markers seriously hinders the development of cytogenetics research in the genus Carya. In this study, we used the whole genome sequencing data to develop some oligonucleotide type chromosomal physical markers and established a development method of oligonucleotide probes for Carya cathayensis, in order to provide reference for the related research of other species in Carya. Method: The repetitive sequences in the genome of C. cathayensis were analyzed by the Tandem Repeat Finder software and filtered out according to the principle of Period size greater than 4, Copy number more than 100, and Period size * Copy number more than 3 000. About 60 oligonucleotide probes were designed and synthesized, and then these probes were further analyzed and screened by the technology of fluorescence in situ hybridization in C. cathayensis, C. hunanensis, C. tonkinensis, C. dabieshanensis, C. kweichowensis, C. illinoinensis and C. sinensis. Result: 1) The oligonucleotide probes of sht-2, sht-3, sht-4, sht-5, sht-5S and sht-45S were able to produce fluorescence signals in C. cathayensis. The probes of sht-2, sht-3, sht-4 and sht-5 had the same distribution patterns on the chromosome, and there were two pairs of signals with different fluorescence intensities. The sht-45S produced one pair of signals on the C. cathayensis chromosome, while sht-5S only had one signal site on the single chromosome of C. cathayensis. These probes were all located in the near centromere region of the chromosome. 2) Among the two pairs of signal sites of sht-5, the stronger pair was completely overlapped with the distribution of the signal sites of sht-45S on the chromosome of C. cathayensis. 3) The distribution positions of 45S rDNA and sht-45S on the chromosomes of C. cathayensis were completely overlapped, and the positions of 5S rDNA and sht-5S were also completely overlapped. 4) The oligonucleotide probe of sht-5 was able to produce fluorescence signals in C. hunanensis, C. tonkinensis, C. dabieshanensis and C. kweichowensis, and the distribution patterns were similar with C. cathayensis. However, there were no signals produced by sht-5 in C. illinoinensis and C. sinensis. 5) The oligonucleotide probes of sht-5S and sht-45S were able to produce fluorescence signals in C. hunanensis, C. tonkinensis, C. dabieshanensis, C. kweichowensis and C. illinoinensis, but no signals in C. sinensis. 6) The probe of sht-45S only had one pair signal sites on the chromosome of C. hunanensis, C. dabieshanensis and C. kweichowensis, and their distribution patterns were similar. The sht-45S produced two pairs of signals sites on the chromosome of C. illinoinensis, which located in the near centromere region of two pairs of homologous chromosomes. 7) The probe of sht-45S only had one pair signal sites on the chromosome of C. tonkinensis, C. kweichowensis, C. dabieshanensis and C. illinoinensis, and the signal sites were located in the near centromere region of homologous chromosomes and had the similar distribution patterns. However, there were two different distribution patterns in C. hunanensis. The first distribution pattern only had one single fluorescence signal site, and the second pattern had two different intensities of signal sites, which all located in the near centromere region of chromosomes. Conclusion: 1) The oligonucleotide probes of sht-2/3/4/5, sht-5S and sht-45S can be used as physical markers for C. cathayensis, C. hunanensis, C. tonkinensis, C. dabieshanensis and C. kweichowensis. 2 ) The oligonucleotide probes of sht-5S and sht-45S can replace the plasmid probes of 45S rDNA and 5S rDNA to analyze the chromosomes of C. cathayensis, C. hunanensis, C. tonkinensis, C. dabieshanensis, C. illinoinensis and C. kweichowensis.

Objective: This study aims to identify the compound pathogens causing anthracnose of Camellia oleifera and to screen effective fungicides for compound pathogens on C. oleifera, in order to provide targeted strategy for controlling C. oleifera anthracnose. Method: Leaf samples with anthracnose symptoms were collected from C. oleifera plantations in Hunan, Guangxi, Guangdong, Jiangsu and Hainan Provinces, China. Tissue separation method was used to isolate and purify the pathogenic fungi, and the morphological characteristics combined with and multi gene phylogenetic analysis were used to identify species. The composite infection experiments were used to study the relationship between pathogenic fungi and pathogenicity. The mycelial growth rate method was used to determine the indoor virulence of fungicides such as prochloraz, difenoconazole, azoxystrobin, picoxystrobin, fluopyram and boscalid to pathogens of C. oleifera. Result: 1）The result showed that a total of 186 isolates were obtained from 106 symptomatic lesions, among which 130 isolates of Colletotrichum genus were the main pathogens, followed by 18 isolates in Pestalotiopsis genus, 28 isolates in Neopestalotiopsis genus, 4 isolates in Pseudopestalotiopsis genus and 6 isolates in Alternaria genus. There were 55 lesions from which only species of Colletotrichum genus were isolated, and 51 lesions from which both Colletotrichum species and other pathogens were isolated. There were 51 lesions from which multiple pathogens with different species in the same genus or from the different genus were simultaneously isolated. There were 7 combinations of different strains isolated: different species of Colletotrichum genus, Colletotrichum sp. and Pestalotiopsis sp. or Neopestalotiopsis sp. or Pseudopestalotiopsis sp. or Alternaria sp., Colletotrichum sp., Pestalotiopsis sp. and Neopestalotiopsis sp. or Alternaria sp. 2）Further co-infection experiment showed that the lesion size caused by inoculation with mixed strains was significantly larger than that caused by inoculation with single strain, indicating that there was synergistic effect of compound infection of Colletotrichum sp. and other pathogens in C. oleifera anthracnose lesions. 3）The virulence test results showed that difenoconazole and prochloraz had the strongest inhibitory effects on Colletotrichum, Pestalotiopsis and Neopestalotiopsis pathogens of C. oleifera, with EC₅₀ mean values of 0.011 to 0.555 μg·mL^?1. Azoxystrobin and picoxystrobin had the highest indoor toxicity to Pestalotiopsis and Neopestalotiopsis, with an average EC₅₀ from 0.007 to 0.020 μg·mL^?1, but had weak inhibitory effect on Colletotrichum. Boscalid and fluopyram had almost no inhibitory effects. Conclusion: The results indicate that there is compound infection of Colletotrichum sp. and other pathogens in anthracnose lesions of C. oleifera, and prochloraz and difenoconazole can be used as the main fungicides to control C. oleifera anthracnose caused by compound infection of pathogens.

Objective: Pagiophloeus tsushimanus (Coleoptera: Curculionidae) is a serious wood borer on Cinnamomum camphora, which has rapidly outbroken in Shanghai . Linalool and eucalyptol are important terpene metabolites in C. camphora, and also constitute the chemical defense system in C. camphora. This study aims to explore the host selection and adaptation mechanism in the interaction between P. tsushimanus and C. camphora and clarify the development adaptability and detoxification mechanism that P. tsushimanus copes with the linalool and eucalyptol, so as to analyze the potential mechanism that P. tsushimanus obligates to C. camphora. Method: The newly hatched P. tsushimanus larvae were fed with linalool and eucalyptol for 3 days using residual film method and the sensitivity of P. tsushimanus larvae to the two terpenoids was determined. Linalool (10.0 mg·g^–1 and 19.7 mg·g^–1) and eucalyptol (5.0 mg·g^–1 and 15.2 mg·g^–1) were set for the long term feeding treatment, to measure the survival curve, developmental duration, body weight and other growth and development indexes of P. tsushimanus larvae in order to evaluate the phenotypic response of P. tsushimanus to the two terpenoids. The qRT PCR technique was used to determine the relative expressions of detoxification enzyme genes (CYP450, carboxylesterase, UDP-glucuronosyltransferase, Glutathione S-transferase and ATP binding cassette transporter) and insect cuticle protein genes in the 4^th instar larvae of P. tsushimanus. Result: Linalool and eucalyptol significantly inhibited growth and development of P. tsushimanus larvae under the long-term feeding of two mass fraction of the terpenoids and this inhibitory effect was correlated with the dose, that is, prolonged the developmental duration, reduced the weight and showed high mortality. Moreover, the larvae also exhibited high-frequency mortality before and after the molting period. Compared with eucalyptol, P. tsushimanus larvae showed stronger tolerance to linalool. The qRT-PCR results revealed that the expression of four cytochrome P450 genes were significantly up-regulated, four cuticle protein genes were up-regulated in P. tsushimanus treated with linalool and one UGT gene was significantly up-regulated in P. tsushimanus larvae treated with eucalyptol. Conclusion: The larvae of P. tsushimanus show different physiological adaptability to the two secondary metabolites. Meanwhile, the expression patterns of detoxification enzyme genes and cuticle protein genes in P. tsushimanus larvae are different under two secondary metabolites. The result also suggests that P. tsushimanus larvae could detoxify different plant secondary metabolites through different mechanism so as to achieve host colonization and population outbreak.

Objective: This study examined the correlation between the living habits of a newly recorded pest, the birch leaf miner, in Jilin, and the environment, in order to provide a strategic basis for controlling the dispersal of the pest. Method: A combination method of DNA molecular identification with morphological characteristics was used to clarify the taxonomic status of the insect. The indoor and field comparative observation methods were used to record the habits of the pest and describe various insect stages. A fixed sample survey was performed in the forest to assess the number of mature larvae, cocoons and adult moths in the soil before overwintering. The test plots were artificially watered at 3 days intervals to imitate the average monthly precipitation during the adult moulting season until adult moulting. We measured and recorded the effects of soil water content, soil temperature and soil chemical properties on moulting. Result: The results showed that the insect is Profenusa thomsoni, which was for the first time found to infest birch trees in Jilin. The insect had two generations a year in Jilin, with irregular generations. In early June, the emergence of adult occurred. The larvae were discovered in the lower leaves of birch trees, and the first generation of larvae was observed from late June to early July, during which most of the larvae shed their leaves and fell into the shallow soil layer, while a few of them pupated in the leaves and emerged as adults. From late August to early September, the mature larvae escaped from the leaves into the soil and made soil cocoons mainly in the 5–10 cm layer for overwinter. The first generation of adult pinnipeds started to lay eggs near the birch leaves, and the adults laid 4–6 eggs in a single leaf. The first generation of mature larvae pupated between the upper epidermis and the fence layer of birch leaves or on the soil surface. The second generation of adults migrated to the upper canopy to lay eggs after eclosion. The egg incubation cycle was 10 days and the larvae had 6 instars. In drought years, the eclosion was delayed in the field until rainfall, when the adults were able to successively moult. Through correlation and redundancy analyses between soil physical and chemical properties and adult eclosion in the following year, it was showed that soil water content was the key determinant of the occurrence and amount of birch leafminer pests, and a relatively high soil water content significantly promoted adult eclosion. There was a positive correlation between soil pH, nitrogen content, and eclosion rate, while soil temperature had little impact on adult eclosion after overwintering. The other factors, such as soil total carbon, nitrogen and phosphorus content, posed no impacts on the survival of last instar larvae of the birch leafminer in soil. Conclusion: The birch leafminer has been found for the first time in the Jilin area and has formed a regional infestation. In this study, the life history and soil ecological adaptations of the insect have been evaluated, and the spread of the insect is mainly restricted by environmental factors and soil water content, among which soil water content controls the amount and timing of adult eclosion, followed by soil pH and nitrogen content, while other physical and chemical properties basically presents little effect on adult eclosion after overwintering.

Objective: The purpose of the present study was to explore the foraging strategies of oriental storks ( Ciconia boyciana ) under different conditions, and their population distribution in two areas of Poyang Lake, so as to provide a theoretical basis for the protection of this species. Method: From December 2021 to March 2022, the foraging behavior of oriental storks in Poyang Lake National Nature Reserve and Wuxing Siberian Crane Conservation District was observed using the focal animal observation method. In 2015–2021 and 2012–2022, the population of oriental storks in East Poyang Lake National Wetland Park (PLNWP) and Nanji Wetland National Nature Reserve (NWNNR) at Poyang Lake was investigated in January of each year. Result: The mean water depth of oriental storks habitat was (17.22 ± 6.28) cm (n = 754). The water depths in level III and level II were the most common depth used by oriental storks, accounting for 51.33% and 35.94%, respectively. The storks’ foraging water depth was (14.64 ± 6.26) cm (n = 669), and the main water depths were H3 and H2, accounting for 43.20% and 37.52%, respectively. The foraging frequency was (6.58 ± 3.13) times·min^?1 (n = 334), the success foraging frequency was (0.2 ± 0.53) times·min^?1 (n = 334), the success rate of foraging was (3.36 ± 9.55)% (n = 334), and the step frequency was (20.15 ± 11.49) steps·min^?1 (n = 334). The step frequency at water depth I was significantly higher than that at water depth II ( P < 0.001), III ( P < 0.001), and IV ( P = 0.006), and the foraging frequency at water depth III was significantly higher than that at water depth I (P = 0.038). The step frequency in the morning was significantly lower than that at noon ( P < 0.001) and in the afternoon ( P < 0.001), and the step frequency at noon was significantly higher than that in the afternoon ( P = 0.017). The success foraging frequency ( P = 0.005) and success rate ( P= 0.006) in the afternoon were significantly higher than those at noon. The step frequency showed a highly significant negative correlation with water depth ( P< 0.001), and foraging frequency showed a highly significant positive correlation with water depth (P = 0.004). A total of 979 stork-time were recorded in PLNWP from 2015 to 2021, and 5 233 stork-time were recorded in NWNNR from 2012 to 2022. The population size of storks in NWNNR was greater and more stable than those in PLNWP. In PLNWP, the storks were mainly distributed in Niejia and Hanchihunan, and in NWNNR, they were mainly distributed at Sanhu Lake and Changhu Lake. Conclusions: Foraging parameters of Oriental Storks were different at different water depths an Foraging parameters of oriental storks are different at different water depths and periods. The results have demonstrated that the storks can adapt their foraging strategies quickly and flexibly depending on environmental variables such as water depth and period of time to guarantee that they obtain sufficient energy. The storks tend to have a concentrated distribution pattern in PLNWP and NWNNR and exhibit high requirements for its habitat environment. NWNNR can provide a stable habitat and foraging environment for this species; therefore, this site is of great significance for its protection.

Objective: The research compared the differences in secretion distribution, the types and relative contents of main chemical components between Qi-Nan agarwood and ordinary agarwood, and analyzed the antibacterial effect of the two kinds of agarwood on cigarette gas to provide a significant scientific basis for the quality assessment and rational utilization of Qi-Nan agarwood. Method: Taking 10 batches of Qi-Nan agarwood and 9 batches of ordinary agarwood as the research objects, the distribution of secretions was investigated using the microsection method, the chemical composition of the secretions was examined using gas chromatography-mass spectrometry(GC-MS) and the smoke components of incense sticks produced by Qi-Nan agarwood and ordinary agarwood were analyzed using headspace solid-phase microextraction coupled with gas chrom·atography-mass spectrometry(HS-SPME-GC-MS). Additional, the air disinfection effect test was used to test the inhibitory effects of smoke on natural bacteria, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Result: Both Qi-Nan agarwood and or ordinary agarwood generally accumulate their secretions in included phlocm and ray parenchyma cells. However, Qi-Nan agarwood has a higher organization ratio of these two organizations than ordinary agarwood. Qi-Nan agarwood has a substantially greater secretion content than regular agarwood. Also, the chemical composition of Qi-Nan agarwood and ordinary agarwood differs significantly. While Qi-Nan agarwood has a higher relative content of chromones than ordinary agarwood, the relative content of sesquiterpenoids in ordinary agarwood is lower. The majority of the chromones in Qi-Nan agarwood are 2-(2-phenylethyl)chromone and 2-[2-(4-methoxy)phenethyl]chromone, with a combined relative content of 77.3% compared to 1.5% in ordinary agarwood. Lastly, aromatic chemicals, sesquiterpenoids, and chromone derivatives made up the smoke produced by burning the Qi-Nan and ord agarwood incense sticks. The smoke composition comprises more aromatic compounds than the chemical composition of secretions, which is mostly made up of aromatic compounds in secretions, products of secretions cracked, and products of wood cracked. Moreover, Sagarwoodphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa are all strongly inhibited by the smoke of two types of burnt agarwood incense sticks, with a kill rate of more than 99%. Yet, the Qi-Nan agarwood incense sticks' antibacterial impact on natural bacteria in the air is superior than that of ordinary agarwood. Conclusion: The secretion characteristics of Qi-Nan agarwood and ordinary agarwood are significantly different and they are produced by different types of Aquilaria sinensis. Qi-Nan agarwood has a high secretion content and is rich in 2-(2-phenylethyl)chromone and 2-[2-(4-methoxy)phenethyl]chromone, and when it is burned to make incense, it has a strong antibacterial effect that is slightly superior to that of ordinary agarwood.

Objective: In order to expand the applicable range of the free square plate when testing the principal shear modulus of wood, this paper proposes a new method for dynamically testing the shear modulus of wood, namely the free square plate torsional modal method. Method: According to the unique first-order torsional mode characteristics and energy method of the wood free square plate, the relationship between the principal shear modulus of wood and the first-order torsional frequency of the free square plate is derived. First-order torsional modal frequencies of free-square plates were calculated using ANSYS for different tree species and different width-to-thickness ratios. Simulation and regression analysis were performed to obtain the modified equation between the principal directional shear modulus of wood and its first-order torsion frequency of the free-square plate (free-square plate torsion modal law equation). Result: The torsional mode characteristics of wood free slabs are divided into three categories according to the aspect ratio(l/b) of the free slab: l/b ≥3, l/b= 2 and l/b=1. The torsional mode shape of a free plate with l/b ≥3 varies along its long side curve, while it varies linearly along its broad side. The torsional mode shape of a free square plate (l/b=1) varies linearly along its long side and curves along its broad side. The torsional mode shape of a free plate with aspect ratio of 2(l/b= 2) varies curvilinearly along both its long and wide edges. Conclusion: The free square plate torsional modal method for testing the principal shear modulus of wood has a reliable theoretical basis. The square plate width-to-thickness ratio used to test the principal shear modulus of wood is in the range of 7-30 for the chordwise, radial and transverse square plates of wood, to reduce the limit of the width-to-thickness ratio of the opposite plate. The free square plate torsional modal method is suitable for testing both the principal shear modulus of wood and the shear modulus of wood composite panels and isotropic materials. Its effectiveness is verified by the free-bar torsional vibration method and the asymmetric four-point bending method. The method has the advantages of simple test operation and high-test accuracy. Theoretical analysis and experimental results both show that the shear modulus of wood composites and wood by the traditional free square plate torsional vibration method is low, and the low degree is related to the material type and the square plate width-to-thickness ratio.

Objective: This study explored the bleaching effect and influence of the second-generation biological complex enzyme on tung wood, and provided theoretical basis and scientific basis for the decolorization and biological improvement of tung wood and the development of tung wood pulping. Method: Paulownia elongata was used as the experimental material, and the cellulose second-generation enzyme (CTEC2) was used for pretreatment. The changes of color difference index and chemical components of samples before and after pretreatment were analyzed by controlling pretreatment time(60, 75, 90, 105 min), temperature(30, 50, 70 ℃) and pH value(3, 5, 7), The thermal degradation properties of the samples were analyzed by TGA(thermo gravimetric analysis), the changes of microstructure were investigated by SEM(scanning electron microscope), and the changes of crystallinity after pretreatment bleaching were measured by XRD(X-ray diffraction). Result: 1) Color determination: when the pretreatment conditions were pretreatment temperature 50 °C, pH value 7 and pretreatment time 105 min, the bleaching effect of paulownia wood was the best, and the brightness and whiteness were improved, and the bleaching effect will also be improved with the extension of pretreatment time. 2) Component determination showed that CTEC2 had the best pretreatment effect on Paulownia wood at 50 °C and pH 7. The relative content of cellulose increased by 10.76%, hemicellulose content decreased by 11.13%, acid-soluble lignin content decreased by 3.05%, acid-insoluble lignin content decreased by 4.22%, and extract content decreased by 1.15%. 3) From the TGA curve, the temperature corresponding to the maximum mass loss rate of pretreated paulownia wood increased, and the thermal stability increased. It can be seen from the SEM images that the pretreatment can effectively destroy the lignocellulose structure. XRD showed that the crystallinity of pretreated paulownia wood cellulose increased. Conclusion: CTEC2 can change the main chemical components of paulownia wood, reduce the content of lignin, hemicellulose and extract, so as to achieve bleaching and decolorization effect. The optimum conditions for bleaching pretreatment of paulownia wood were temperature 50 °C, pH 7 and pretreatment time 105 min.