Objective: NH₄⁺-N and NO₃^--N are the main inorganic N forms absorbed and utilized by trees. As distribution of absorbable N forms in soil is subject to great spatial heterogeneity, different tree species tend to develop different preferences for nutrients and absorption strategies. This study investigated the preference behavior of N, root morphological traits, and seedlings growth in Cunninghamia lanceolata, Pinus massoniana, and Schima superba under N heterogeneous environments. The results should reveal the mechanisms of nutrient preference and N foraging strategy in response to N heterogeneous environment, and provide a scientific theoretical basis for different tree species configuration of the mixed broadleaf-conifer forest plantations. It may also contribute to silviculture practice to improve the N use efficiency and productivity of the plantations. Method: In this study, four N treatments with different N forms (NH₄⁺-N and NO₃^--N) and proportion were constructed with the self-designed root box culture system. The NH₄⁺:NO₃^- was 10:0 and 0:10 for the high hetero-N, 8:2 and 2:8 for the medium hetero-N, 6:4 and 4:6 for the low hetero-N, and 5:5 for the homo-N, respectively. The seedlings of C. lanceolata, P. massoniana and S. superba were subjected to the four N treatments in order to investigate the root growth and morphological traits, and seedlings growth after 180 days treatment. Results: (1) under the heterogeneous N supply treatments, the root length, surface area and biomass of C. lanceolata in NO₃^--N patches were greater than in the NH₄⁺-N patches, but the root length, surface area and biomass of P. massonina and S. superba in NH₄⁺-N patches were greater than in the NO₃^--N patches. There was no significant difference in root morphological traits between NO₃^--N and NH₄⁺-N nutrient patches under the homogeneous N supply. The total root length, surface area and biomass of the three species were as the follow:homogeneity < low heterogeneity < medium heterogeneity < high heterogeneity. For example, the root biomass under the treatment of high heterogeneity was 7.96%-20.15%, 3.47%-19.07%, and 4.49%-9.08% higher than that with the other three treatments, respectively. (2) The height, diameter and total biomass of the three tree species were as the follow:low heterogeneity > homogeneity > medium heterogeneity > high heterogeneity. For example, the biomass under the treatment of low heterogeneity was 5.40%-33.67%, 7.61%-31.24%, and 11.32%-36.61% higher than that of the other three treatments, respectively. The root to shoot ratio of the three species under the high heterogeneity treatment increased by 58.47%-92.68% compared with the treatment of homogeneous N supply Conclusion: Under the heterogeneous N supply, C. lanceolata tends to grow more and slender roots in NO₃^--N patches, but P. massoniana and S. superba tends to grow more and slender roots in NH₄⁺-N patches. The root length, surface area and biomass of the three tree species increased with the increase of heterogeneity, but the average diameter was smaller. The height, diameter and biomass of the three tree species were greatest in the environment of lower heterogeneity and homogeneous N supply. It is concluded that the C. lanceolata prefers to absorb and utilize NO₃^--N, while P. massoniana and S. superba prefer to absorb and utilize the NH₄⁺-N under the environment of heterogeneous N supply.

Objective: The objective of this study is to quantify the time-lag responses of net ecosystem exchange of CO₂ (NEE) to environmental factors in a Populus×euramericana plantation, in order to provid scientific evidence for improving the accuracy of estimating carbon source/sink in the ecosystem. Method: We used the eddy covariance technique and micrometeorological sensors to continuously measure NEE and environmental elements, such as air temperature (T_a), soil temperature at 5 cm depth (T₅), photosynthetically active radiation (PAR), vapor pressure deficiency (VPD) and soil volumetric water content at 25 cm depth (VWC₂₅), during the growing season (April-October) in 2014 in a P.×euramericana plantation adjacent to the Chaobai River in the northern China. We quantified the time-lag responses of NEE to these environmental factors by using regression analysis and wavelet cross-correlation analysis. Besides, partial correlation analysis and principal component analysis were used to evaluate the importance of time lag on the relationship between NEE and the environmental factors based on the determination coefficient (R²), Lin's concordance correlation coefficient (LCCC) and root mean square error (RMSE). Result: Our result showed that PAR was the dominant environmental factor regulating NEE. Additionally, VWC₂₅ had no significant effect on NEE (P=0.151 5) due to the high-level groundwater and sufficient water supply in this riparian ecosystem. Although NEE showed the same diurnal variation with PAR, it reached the peak 2.5, 2 and 2.5 h earlier than T_a, T₅ and VPD, respectively. Interestingly, there were no significant time-lag relationships between NEE and environmental factors at night. After eliminating the time lag, the partial correlation between NEE and T₅ was significant (P=0.0051) compared to the insignificant relationship before (P=0.224 8). Moreover, the principal component analysis indicated that the relationship between NEE and the climatic elements could be more accurately described by logarithmic regression model. After eliminating the time lag, the model R² and LCCC increased by 8.1% and 2.0%, respectively, and RMSE reduced by 0.417 μmol·m^-2s^-1. Conclusion: Therefore, the diurnal dynamics of NEE in this P.×euramericana plantation were controlled by T_a, T₅, PAR, and VPD with distinct time-lag phenomenon in the daytime. It is vital for eliminating time lag to evaluate the environmental effects on NEE and improve the model accuracy.

Objective: To further understand the role of fine roots in forest soil, the distribution of fine roots in three natural forests of Qinling Mountains and their relationships with soil physical and chemical properties were characterized in order to provide a scientific baseis for ecological management and forest restoration in Qinling Mountains. Method: Soil columns were sampled from three natural forests of Qinling Mountains, namely Picea asperata forest, Betula albo-sinensis forest and mixed forest of P. asperata and B. albo-sinensis. The relations between root parameters (fine root biomass, fine root length density, fine root volume and fine specific root length) and soil properties (soil organic matter, soil porosity, soil density, soil nitrate nitrogen, soil ammonium nitrogen and soil moisture) were studied. Result: Soil physical and chemical properties of the three natural forests showed vertical stratification along the soil profile. The organic matter content, porosity, nitrate content, ammonium content and moisture all decreased with increasing soil depth. Soil density increased with the increase of soil depth. The fine root indexes of the three natural forests decreased with the increase of soil depth. Fine root biomass mainly concentrated in humus layer, auouating for more than 69% in the humus layer for all the three natural forests, which also had the highest fine root length density, fine root volume and fine specific root length, where was 3.76-4.85, 2.63-3.80, 1.26-1.67 times as high as that in illuvial layer, and 11.13-14.98, 6.32-16.01, 1.76-3.28 times as high as that in parent material layer. Among the three forest stands, the fine root length densities in layers of mixed forest were the highest (its mean value was 0.45 cm·cm^-3); the fine root length density, fine root volume, and specific fine root length in layers of the P. asperata forest were the lowest (the mean value were 0.26 cm·cm^-3, 0.88 mm^-3·cm^-3, 0.60 cm·g^-1respectively). The result of correlation analyses showed that there were extremely significant or significant correlations between root parameters and soil properties (soil organic matter, soil porosity, soil density, soil nitrate, soil ammonium and soil moisture) of the three natural forests. Among them, positive correlations between fine root biomass, fine root length density, fine root volume and soil organic matter were the highest (the r value were 0.813, 0.795 and 0.784 respectively); and negative correlations with soil density were the highest (the r value were -0.715, -0.658 and-0.683 respectively). The principal component analysis showed that soil organic matter, soil nitrate, soil density, soil porosity, soil moisture, and soil ammonium contents were the first principal components affecting the distribution of fine roots in natural forests. The path analysis showed that soil organic matter had the greatest direct effect on fine root biomass density; soil moisture had the greatest indirect effect on fine root biomass density, mainly through the effect of soil organic matter. Conclusion: The root parameters of the three natural forests in Qinling Mountains decreased with the soil depth. The fine roots were well-developed and concentrated in the humus layer of forest soil. Among the three forest stands, the fine roots of mixed forest were the most-developed, and the fine roots of P. asperata forest were the least-developed. The root distribution was affected by soil factors, and the extent of influence of those factors were ranked in the order of organic matter > nitrate content > density > porosity > moisture > ammonium content. Soil organic matter directly affected fine root biomass density, while soil moisture indirectly affected fine root biomass density through the influence of soil organic matter. Therefore, in the process of ecological management and forest restoration in Qinling Mountains, biological characteristics of fine roots should be taken into account, with appropriate deployment of different tree species, and sufficient attention to the accumulation of organic matter in forest soil to maintain forest productivity and enhance the function of forest ecosystem.

Objective: In order tooptimizethe structure of the urban forestsand to improve thermal environment, canopy structure indices related to comfort of microclimate were constructed and screened. Method: One dimension canopy structure indicators(including leaf area index, mean tilt angle of leat, canopy thickness, under branch height, ratio of canopy thickness to tree height, and the permeability of the canopy), highly correlatedwith urban forest cooling effect, were selected to construct multidimensional canopy structure indices on the basis of both air flow and energy exchange in and out of the forests. Furthermore, correlation analysis was used to select canopy structure indices with high explanation to the microclimate comfort in the forests. Result: The one dimension canopy structure indicators were weakly correlated with the comfort degree in the forest (S) and the relative variationin comfort (S_d), whose explanatory power to S was between 0 and 30.5%and the explanatory power to S_d was between 0 and 53.5%; The multidimensional canopy structure indices significantly improved the interpretation to S and S_d, which were 0 to 37.5%and 30.9% to 55.1% respectively; The synergistic effect on S of the structure index for vertical heat diffuse and the structure index for horizonta heat diffuse was 43.5% relatively large. The synergistic effect on S_d of the vertical canopy index and the canopy vertical evenness index was 63.9%, the highest, among others. Conclusion: The comfort and the relative variationin comfortin urban forests are influenced by several structureindicators and indices jointly. The multidimensional canopy structure indices (including structure index for vertica heat diffuse, structure index for horizontal heat diffuse, comprehensive structure index for heat diffuse, vertical canopy index, canopy uniformity index, canopy vertical evenness index and comprehensive canopy index), constructed in this paper are highly correlated with comfort degree and its relative variation, providing a reference for the optimization of urban forest structure.

Objective: The study was conducted to reveal the slope locational differences and monthly dynamics of soil carbon and nitrogen contents and hydrolase activities in natural forest of Pinus sylvestris var. mongolica Litv. The correlation between carbon/nitrogen contents and hydrolase activities, and the effect of soil temperature and moisture. Method: The study was performed in a natural forest of Pinus sylvestris var. mongolica located in Mohe Town, Daxing'anling Region. In the middle of every month from May to October, 2018, three blocks (20 m×30 m) in every slope location (upper slope, middle slope, lower slope) were selected as sample region. Three sampling points were selected in every sample region. Soil temperatures at depths of 2.5 cm, 7.5 cm, 15 cm, 25 cm were measured after removing litters. Soil samples at different depths (0-5, 5-10, 10-20, and 20-30 cm), on different slope locations, and in different months were collected by excavating soil profiles. Subsequently, the moistures, organic carbon contents, total nitrogen contents, and hydrolase (urease, protease, sucrase, and cellulase) activities of soil samples were determined in laboratory. Result: Result showed that the contents of carbon and nitrogen were decreased with the increase of soil depth, and increased with the lowering the slope locations, and the highest contents of both were showed in September. The soil organic carbon contents in the soil layers of depth 0-5, 5-10, 10-20, 20-30 cm were 68.53-80.38, 40.28-46.66, 15.86-21.08, and 1.91-13.79 g·kg^-1 respectively, and soil total nitrogen contents in these layers 5.34-5.96, 2.98-3.68, 2.35-2.61, and 1.54-1.75 g·kg^-1 respectively. However, organic carbon contents and total nitrogen contents among slope locations did not show great differencs (P>0.05). Additionally, activities of urease, protease, sucrase, and cellulase were decreased with soil depth, urease and sucrase maintained higher activities in a lower slope location, but the protease, cellulase did the opposite. Furthermore, hydrolases always showed their highest activities in July or August. Finally, the results also indicated that contents of soil carbon and nitrogen were significantly and positively correlated with activities of detected soil hydrolytic enzymes (P < 0.01); soil carbon and nitrogen contents were significantly and positively correlated with soil moisture (P < 0.01); and soil temperature was significantly and positively correlated with soil carbon content (P>0.05), but negatively correlated with total soil nitrogen content (P < 0.05). Conclusion: The study demonstrated that soil carbon/nitrogen contents and hydrolase activities in P. sylvestris var. mongolica forest maintains a common pattern that 0-5 cm > 5-10 cm > 10-20 cm > 20-30 cm; contents and activities at different slope locations were indistinguishable (P>0.05); the highest soil carbon and nitrogen contents were found in September; and the highest hydrolase activities were found from July to August. It also proved that contents of carbon and nitrogen were significantly correlated with hydrolytic enzyme activities (P < 0.01); ant the soil temperature and moisture had significan affects on the carbon and nitrogen contents and hydrolase activities (P < 0.05).

Objective: This paper aims at studying the diversity of endosphere bacterial and fungal microbiome in roots and stems of Populus alba×P. berolinensis grown in three different sites, and the results would provide scientific basis for the study of interactions between plants and microorganisms. Method: The roots and stems of poplar were collected from three different sites:Changweizi village of Linyuan town in Daqing city, Cuohai farm in Qiqihar city and Hancunhe Dongying nursery in Fangshan District. After surface disinfection, microbial DNA was extracted and sequenced by Illumina MiSeq using 16 s rRNA and internal transcribed spacer amplicon (ITS) amplifiers to determine the bacterial and fungal communities associated with the different plant habitats and niches. Results: According to the 97% sequence similarity cut-off level, the reads of bacteria and fungi were clustered into 1541 and 240 OTU, respectively. In comparison with the database, we found that Actinobacteria, Betaproteobacteria, Alphaproteobacteria, Gammaproteobacteria and Bacteroidia were the dominant endophytic bacteria, and the fungal community was dominated by Dothideomycetes, Agaricomycetes, Sordariomycetes and Tremellomycetes. The results of alpha and beta diversity showed that the stem endophytic communities of poplar in Beijing, Daqing and Qiqihar were obviously clustered and could not be distinguished. However, the endophytic community of roots was dependent on plant organs and growth environment. The Mantel test results showed that pH, and soil organic matter (SOM) contents and potassium (K) content were significantly correlated with the microbial communities (P < 0.05). However, the nitrogen (N) and phosphorus (P) content did not appear to be important factors explaining the variance in the communities of poplar root endophytes. We identified the core microbiome in the different organs of poplar grown in different environmental conditions, and obtained a total of 23 core bacteria OTU belonging to 6 classes, and 22 core fungi OTU belonging to 7 classes, respectively. Species indicator analysis revealed seven root endophytic bacterial indicator OTUs:Actinophytocola, Actinoplanes, Pseudonocardia, Rhodomicrobium, Streptomyces, Variovorax and Bradyrhizobium; five stem endophytic bacterial indicator OTUs:Bifidobacterium, Dialister, Faecalibacterium, Micrococcus and Rhodococcus; two root endophytic fungal indicator OTUs:Leptosphaeria and Ilyonectria; three stem endophytic fungal indicator OTUs:Pleosporales, Alternaria and Endosporium. The UpSetR results showed that 51 (3.30%) OTUs of bacteria were shared by 6 groups, and the unique OTU of 6 groups accounted for 4.54-15.44%; one (0.42%) OTU of fungi was shared by 6 groups, and the unique OTU of 6 groups accounted for 2.92-29.17%. Conclusion: The bacterial and fungal community structure depends on the pH, the soil organic matter content and potassium (K) content. Each plant organ represents a unique ecological niche for the endophytic communities. Finally, we have identified the indicator operational taxonomic units (OTU) and core microbiome associated with the different ecological niches of Populus and different environmental conditions. The results provide a basis for further study of host-microbial interactions with the identified abundant OTU of Populus.

Objective: The aim of this paper is to study the effect of heat treatment on phenolic content and antioxidant activity of Camellia oleifera seeds. Method: C. oleifera seeds were heated by hot air, infrared radiation and microwave radiation. After the heating treatment, the changes of polyphenol content and antioxidant activity in C. oleifera seed oil and the cake were analyzed. Result: The results showed that the changes of polyphenols and antioxidant activity in pressed oil of camellia seeds heated by three methods were similar. The total phenol content in oil changed little after heating at low temperature (90 and 120℃ in hot air and infrared, 245 W, 420 W and 560 W microwave). After heating at high temperature (150 C in hot air and 700 W microwave), the polyphenol content and antioxidant ability of camellia seed oil increased obviously. At the end of heating, the content of polyphenols reached 26.84, 94.34 and 84.51 μg·g^-1, respectively, which was 2.8, 12.4 and 11.0 times higher than the unheated control, and the antioxidant activity (%, ABTS^·+) reached 48.91%, 96.29% and 97.01% respectively, which was 6.11, 13.0 and 13.1 times higher than control. The variation of polyphenols in pressed cake C. oleifera seeds is similar to that in camellia oil. Total phenol content and antioxidant activity did not change much after low temperature heating, while it increased after high temperature heating for a period of time. At the end of heating, total phenol content increased by 14.4%, 42.5% and 34.45%, respectively, and the antioxidant activity (%, ABTS^·+) increased by 27.9%, 46.2% and 32.1%, respectively. The change of antioxidant activity of polyphenols in the cake was different after infrared heating at different temperatures, but the change trend was similar to that of polyphenols content. The increase of polyphenol content in the cake after heating may be due to the hydrolysis of cell wall, the increase of phenolic dissolution, or the release of bound phenols. The increase of the antioxidant activity (%, ABTS^·+) may also include the contribution of other polar antioxidants (methanol/water extraction) such as Maillard reaction products induced by heating. The specific reason remains to be further studied. Conclusion: High temperature heating of Camellia oleifera seeds can improve the polyphenol content and antioxidant activity of C oleifera seed oil and the cake. The thermal efficiency of the three heating processes is microwave > infrared > hot air. In production practice, short-term high temperature heating of infrared can be used to increase the phenol content of camellia oil. The results of this study provide a theoretical basis for exploring the mechanism of physicochemical changes of C. oleifera seeds during processing, and a technical support for the processing technology of C. oleifera seed oil.

Objective: The responses of photosynthetic process to drought stress and re-watering of the wild type and PtPIP1;3(GenBank accession No. MN795092 ptopip1.3) transgenic poplar variety '84K' (Populus alba×P. glandulosa '84K') were compared to analyze the limitation factors to photosynthesis in order to further understand the function of aquaporin PIP1 in regulation of CO₂ conductance and the influences on photosynthesis. Method: The wild type and PtPIP1;3 transgenic poplar variety '84K' were subjected to severe drought stress (The soil water content reaches 35% of the field water capacity) and re-watering. The gas exchanges and chlorophyll fluorescence parameters of the leaves were measured, with which the mesophyll conductance (g_m) and other relevant parameters were calculated. Then the regulation of aquaporin in CO₂ conductance and photosynthesis after drought stress and re-watering was analyzed. Result: Net photosynthetic rate (P_n), stomatal conductance (g_s) and transpiration rate (Tr) of transgenic poplars were significantly higher than those of wild type plants under normal watering regime. After six days of drought treatment, P_n of transgenic and wild type poplars started to decrease significantly, and the former decreased more rapidly than the latter and reached to the same level of the latter's on day 7 and the remaining time of drought treatment. During the 7-10 days of drought treatment, g_s, g_mand P_n of transgenic and wild type poplars were significantly lower than their own control (normally watered plants). So did photochemical quenching(q_P), actual photochemical efficiency of photosystem Ⅱ(Ф_PSII), electron transport rate(J_flu), Rubisco maximum carboxylation rate(V_cmax)and maximum electron transport rate(J_max). Photosynthesis of transgenic and wild type poplars were mainly limited by mesophyll conductance. After three days of re-watering, photosynthesis of transgenic poplars recovered more quickly and chlorophyll fluorescence parameters restored to the normal level, whereas, chlorophyll fluorescence of wild type poplars did not fully recover. Mesophyll conductance was still the main limitation factor, while biochemical limitation was the second major limitation factor. Conclusion: Mesophyll conductance was the main limitation factor of photosynthesis of PtPIP1;3 transgenic and wild type poplar '84K' during drought stress and re-watering. The photosynthesis of PtPIP1;3 transgenic poplar recovered quickly with re-watering after drought stress including the recovery of photosynthesis system II, which might help plants survive in nature wherein the stress stimuli is often transient but periodical.

Objective: To optimize the callus regeneration system for Eucommia ulmoides leaf explants, to assess the sensitivity of callus to Km and Cef, and to determine the optimum factor levels for Agrobacterium tumefaciens-mediated transformation, in order to allow for genetic transformation of adult plant of E. ulmoides. Method: Callus was induced from leaves of E. ulmoides adult plants. It was inoculated in different concentrations of MS medium, NAA and 6-BA to optimize culture conditions for adventitious bud induction and regeneration. In addition, different concentrations of Km and Cef were added to the culture medium to study callus sensitivity. Based on the obtained callus receptor system for leaves, an L₁₆ (4⁵) orthogonal array experiment was conducted to explore the effect of different conversion factors on Agrobacterium-mediated transformation efficiency. Transformation with an optimum combination of factors was used to obtain Km-resistant buds, which were assessed as transformants by GUS histochemical staining and PCR. Result: MS medium at 3/4 strength promoted the induction and growth of adventitious buds in E. ulmoides. The optimum medium for induction of adventitious buds in callus was 3/4MS + 0.27 μmol·L^-1 NAA + 4.4 μmol·L^-1 6-BA, with induction rate of 83%±10.0%; The optimal medium for adventitious bud rejuvenation was 3/4MS + 0.054 μmol·L^-1 NAA + 4.4 μmol·L^-1 6-BA, with an average growth length of (2.47 ±1.33) cm. Sensitivity testing of antibiotic and bacteriostatic agents showed that in the selected medium for genetic transformation, the optimal concentrations of Cef and Km for screening were 200 mg·L^-1 and 70 mg·L^-1, respectively. The orthogonal test showed that the optimum combination of factors for Agrobacterium-mediated transformation was 5 days of pre-culture, 10 min of infection time and 3 days of co-cultivation. Genetic transformation of about 200 calli was carried out using the optimum instantaneous conversion system, and three Km-resistant buds were obtained. GUS histochemical staining showed that the GUS gene was expressed in these Km-resistant buds, and PCR analysis demonstrated the presence of the NPTⅡ gene. Conclusion: For E. ulmoides callus, this study defined an adventitious bud induction medium, 3/4MS+0.27 μmol·L^-1 NAA + 4.4 μmol·L^-1 6-BA, and an adventitious bud rejuvenation medium:3/4MS + 0.054 μmol·L^-1 NAA + 4.4 μmol·L^-1 6-BA. Agrobacterium-mediated transformation of callus involved 5 days of pre-culture, 10 min of infection time and 3 days of co-cultivation, and the selection medium, 3/4MS + 0.054 μmol·L^-1 NAA + 4.4 μmol·L^-1 6-BA + 200 mg·L^-1 Cef + 70 mg·L^-1 Km. Three resistant buds were obtained using this system. PCR analysis and GUS histochemical staining indicated that T-DNA had been integrated into the genome of these Km-resistant buds. This report demonstrated that genetic transformation could be studied in a mature E. ulmoides tree, laying a foundation for studying gene functions and for objective-specific improvement of E. ulmoides.

Objective: This paper proposed a prediction method of total iron content (TIC) in Dalbergia odorifera leaves based on vegetation index and multi-spectral texture features, in order to provide an alternative approach for the diagnosis of heavy metal nutrition of precious tree species. Method: In this paper, D. odorifera saplings were subjected to four levels (CK, F1, F2, F3) of iron treatment. At the end of treatment, the leaves were collected, and multi-spectral images were obtained, from which vegetation indexes and texture parameters, such as texture parameters mean value (TFMV) and texture parameters variance (TFV), were extracted and calculated, and the relationship between the variables and TIC was analyzed. The variables significantly correlated with TFC at 0.05 and 0.01 levels were screened out by significance test. Then, correlation analysis (CA), principal component analysis (PCA), average impact value (MIV) and genetic algorithm (GA) were used for secondary screening. The results were used as input variables of particle swarm optimization-back feedback neural network (PSO-BPNN) to analyze and compare the prediction values. Results: 1) In the CK ~F2 gradient range, the growth amount of tree height, crown width and stem increased with the increase of iron application, while under gradient F3, the growth amount of tree height and crown width decreased and growth of stem increased significantly. 2) With the increase of leaf TIC, band B first decreased and then increased; band G was contrary to band B; band R first decreased and then increased, and then remained stable; bands RE and NIR showed a trend of rise all the time; With the increase of TIC, different changes occurred in different bands. In band B, the spectral reflectance in level CK, F1 and F2 decreased but that in level F3 increased. In band G, the changes were contrary to band B. In band R, the spectral reflectance in level CK and F1 decreased, while it in level F2 increased, and maintained stability in level F3. bands RE and NIR showed an upward trend in all levels. 3) Most VI and TIC were correlated at 0.01 and 0.05 levels. TFMV and TFV were also able to reflect leaf TIC, but TFV was superior to TFMV in terms of correlation level and number. From viewpoint of band, the correlation between bands RE and NIR and TIC was better than other bands in vegetation index and texture features. 4) The results obtained by different screening methods were different, among which CA and GA had the best and similar evaluation indicators. But the prediction values of GA in the range of 150-300 mg/kg were lower than the measured values, which is not suitable for field fertilization guidance. (5) The prediction results obtained by vegetation index alone were inaccurate, and the goodness of fit and prediction accuracy were improved by adding texture parameters. By comparison, the variance of texture parameters had a greater impact on the accuracy of the model. It was shown that the degree of dispersion of leaf texture could be used as a good auxiliary information for predicting TIC. Conclusion: Gradient fertilization of F1 and F2 can promote the growth and biomass accumulation of Dalbergia odorifera. According to the experimental data, the optimum total iron content in leaves is 150-300 mg/kg. In addition to vegetation index, MPV as an auxiliary factor can improve the goodness of fit and prediction accuracy of the model. The CA-PSO-BPNN method can be effectively applied to field fertilization guidance and provide more accurate prediction for monitoring the heavy metal content of precious tree species.

Objective: Grassland caterpillars, Gynaephora spp. (Lepidoptera:Lymantriidae), attack many plants in the Sanjiangyuan Nature Reserve which is in Qinghai-Tibet Plateau. For protecting the vegetation there it is essential to control the pests with non-pollution techniques. We investigated the insect natural enemies of the caterpillars and tried to use them for biocontrol. Methods: We collected pupae of G. qinghaiensis which is widely distributed in the Reserve and brought them to lab for rearing parasitoids.Then the parasitism rate was counted and the natural enemies were classified. Results: A new parasitoid species, Pteromalus sanjiangyuanicus Yang (Hymenoptera:Pteromalidae), was found parasitizing the pupae of Gynaephora qinghaiensis during the survey by taxonomic study. In this paper, the morphological characteristics of the new species of parasitoid were described in detail, and clear color photos of morphological characteristics were provided. The basic information of its biology and distribution is also provided. Meanwhile, a key to distinguish the new species from the closed species P. qinghaiensis Liao 1987 is provided. The characters below are different from the latter species:Female antennae black-brown only with base part of the scape dark-yellow; metasoma dark-brown with slight purple luster; all coxae having same color with mesosoma and others yellow-brown; notauli appearing at anterior 1/3 of mesonotum and although they are weak but distinct; forewing with marginal vein 1.3 times as long as stigmal vein; dorsellum with a sharp carina which like a "V" and its anterior part concave with about 10 short longitudinal carinae in concave area, length of the area about as long as frenal area of scutellum (22:24) medially; propodeum with median carina exist at basal 1/3 although it is weak; upper mesepimeron reticulate and not smooth and shining. Male antennae dark-brown and metasoma only 0.8 times as long as mesosoma. Conclusion: In the present survey, a new parasitoid species has been found and is a new natural enemy which has high potential for biocontrol of the caterpillar. The types of the new species are kept in the Insect Collection, Chinese Academy of Forestry, Beijing, China.

Objective: In order to explore the cooperative mechanism to degrade lignin between Monochamus alternatus and its gut bacteria, the lignin-degrading function of Serratia marcescens, a dominant bacterium living in the larval gut of M. alternatus, was studied. Method: Liquid kraft lignin medium was used to cultivate this bacterium. The degradation of lignin by S. marcescens was measured by the method of microtitration and the characteristic of lignin-degradation enzyme (LiP). Meanwhile, influences of different culture conditions on enzymatic activity of Lip, a dominant lingin-degrading enzyme which was produced by S. marcescens, had been studied. Result: It was showed that the accumulated degradation rate of the kraft lignin by S. marcescens was up to 94.12% in ten days, and the highest enzymatic activity was reached on the 4th day after inoculation. This bacterium could produced lignin peroxidase(LiP), manganese peroxidase(MnP) and laccase(Lac) in medium of lignin, and the enzymatic activity of LiP was highest, followed by MnP and Lac, and the daily variation tendency of the former two kinds of enzymes were similar with the degradation rate of lignin in the medium. The optimal medium contained 3 g·L^-1 lignin, 5 g·L^-1 yeast extract as organic nitrogen sources, 0.20 g·L^-1 Mg²⁺, 0.40 g·L^-1 Ca²⁺, 0.15 g·L^-1Fe²⁺, 0.04 g·L^-1 Mn²⁺, 0 g·L^-1 K⁺, and the optimum condition is pH value of 5.0. Conclusion: S. marcescens had strong ability to degrade lignin through producing LiP and MnP. The LiP enzymatic activity could be significantly affected by the concentration of lignin, pH, kinds and concentrations of nitrogen source, concentrations of mental irons.

Objective: Based on the survey of nest site characteristics, nest defensive behavior and reproduction result of Chinese sparrowhawk, the mechanism of nest selection and reproduction efficiency of Chinese sparrowhawk are analyzed, and the influence factors on breeding success rate are revealed in order to provide valuable advices for its conservation. Method: According to the different defensive intensity, we divided nest defensive behaviors into 4 levels, and counted numbers of calls of birds within 10 min. We measured the parameters of nest site, including specie of nest tree, nest height above ground, diameter at breast height, altitude, area of tree-crown, slope position, slope gradient, slope aspect, front view of nest, nest distance fromroad, building, or water, vegetation characteristic within 20 m radius sample circle around nest tree. The data were analyzed with SPSS 23. Result: In 2016 and 2017, we found totally 51 nests of Chinese sparrowhawk, among which 35 nests were monitored byinfrared camera, and 661 306 monitoring photos were taken. In 2016, the hatching rate was 71.4%, and the fledging rate was78.2%. In 2017, the hatching rate was 82.5%, and the fledging rate was 61.5%. Through the inspection of the monitoring photos in the infrared camera, it is found that the main reason of the breeding failure of Chinese sparrowhawk was that the eggs or nestlings were preyed on, and the predators included King rat snake (Elaphe carinata)(n=9 nests), Eurasian jay(Garrulus glandarius)(n=1 nest), Siberian weasel (Mustela sibirica)(n=1 nest), and Crested goshawk (Accipiter trivirgatus)(n=1 nest). The farther the nest tree was from road, the more the male cried (r=0.68, n=12, P < 0.05, Spearman), and the higher the female's nest defense level (r=0.42, n=42, P < 0.01, Spearman). Breeding success rate was negatively correlated to the distance from nest tree to road(r=-0.45, n=47, P < 0.01, Pearson), the other factors did not have a significant positive correlation to breeding success rate or hatching rate. The closer the nest tree was to building(r=-0.56, n=47, P < 0.01, Pearson) and road(r=-0.35, n=47, P < 0.05, Pearson), the higher the height of the nest from the ground was. Linear regression analysis of the nest height (y, m) and the distance from nest to building(x, m) showed a relation:y=12.75-0.01x(R²=0.32, n=47, P < 0.01). The principal component analysis showed that there were 8 main factors affecting Chinese sparrowhawk's nest site selection. The size of nest trees and forest quality around nest site played key roles in nest selection, human activity area and water source also influenced nest selection partly. Conclusion: Chinese sparrowhawks tend to nest far away from human activities, but by adapting to human activity, the nesting near to road had a higher fledging rate. Chinese sparrowhawks with stronger nest defensive behavior tend to nest far away from anthropic zone. Chinese sparrowhawks close to the human activity area will choose to build their nests at a higher position. Chinese sparrowhawk usually nests in big tree in leafy forest with rich species of trees, sparse grass and shrub, and near to water source.

Objective: This study aims to rank the importance of stopover sites of Siberian cranes at different spatial scales, and identify conservation gaps and propose management recommendations, based on the analysis of migration strategy and distribution pattern of Siberian cranes in the past 20 years. Methods: Using the satellite tracking data of ten Siberian Cranes in 2016 and 2017, four types of stopover sites were divided based on the different stopping days. The rank of each staging area was evaluated synthetically with the weighted assignment. The conservation gaps were identified and migratory routes were mapped using the spatial analysis function of ArcGIS 10.2. Results: There was no significant difference in migration parameters between spring and fall season, such as migration distance, staging frequency, staying duration and migration legs. A total of 62 and 104 stopover sites were screened in spring and fall seasons, belonging to 23 and 27 staging units/areas of five staging regions, respectively. Of which, only nine and 13 important stopover sites were identified in spring and fall seasons, including the known stopover sites in Zhalong, Momoge and Xianghai National Nature Reserves(NNRs) and their surrounding areas in the western Songnen Plain, and the Yellow River Delta of the North China Plain. Tumuji NNR of the western Songnen Plain, and Wolong Lake Provincial Nature Reserve and the eastern Keerqin Sandy Land of Liao River Plain were newly recognized. Important, common and temporary stopover sites and resting sites were outside the existing protection system by 36.4%, 37.5%, 40.7% and 72.4%, respectively. In general, the western Songnen Plain is the most important staging areas both in spring and fall. In spring, the Liao River Plain is the second important and the Yellow River Delta is the third important. The two staging regions are in the opposite situation in fall. The stopover sites in the middle and lower reaches of the Yangtze River are more important in fall than those in spring, while those in Daxing'an Mountains are the opposite. Conclusion: The migration mode of Siberian Cranes is the energy minimization strategy. The migration route likes the number '8' shape, where western Songnen Plain and Liao River Plain are located in the narrow bottleneck. The crane adopts the facultative migration, using hopping strategy in a large proportion of potential refueling sites and skipping strategy in order to bypass a poor quality stopover site. In the past 20 years, the distribution of stopover sites in China experienced a remarkable change. Liao River Delta was not the important stopover site in recent years, while the eastern wetland of Keerqin Sandy Land in Western Liao River Plain is the newly discovered important staging region. To ensure migration safety and long-term survival of Siberian Cranes, it is suggested to strengthen the supervision of the important stopover sites in the surroundings of current protected areas using the existing management institutions. For the important staging sites with small and scattered wetland area, it is recommended to establish a conservation community, such as the eastern wetland of Keerqin Sandy Land. The interdepartmental and interregional joint protection and management mechanism is proposed for temporary stopover sites and resting sites in North China Plain, and the middle and lower reaches of Yangtze River.

Objective: With the advent of the era of big data, ecological data is emerging in large numbers, but there are data missing phenomena in the process of collection and transmission, resulting in incomplete data, which brings difficulties for subsequent analysis and application. In order to improve the integrity and accuracy of data, it is important to find a suitable data filling method. In this study, the stem moisture data of a plant was used as the object. For the missing data on the same data segment, the different data filling methods were compared to verify the validity and accuracy of the LSTM model to fill the stem moisture data. Method: The integral data of stems water of Lagerstroemia indica planted in Haidian District of Beijing in June 2017 were selected as experimental data, and some data were manually deleted as missing data. The missing parts were filled by interpolation method, RNN neural network and LSTM neural network respectively. The results were compared with the original data and analyzed. Based on the error distribution of neural network predictive value error which increases with the delay of the prediction time, this paper proposed a method of adding late data processing on the basis of neural network prediction value:Prediction was implemented from the forward and reverse two directions of missing data, and the predicted values were multiplied by a set of weight values decreasing according to the prediction time, and then added together. In combination of the advantages of the two prediction directions, the prediction accuracy could be further improved. Result: Among the three methods, the RNN and LSTM neural network methods had obvious advantages compared with the traditional interpolation methods. The accuracy of the interpolation method decreased rapidly when the missing value increases, while the neural network method decreased slowly. When the error between filled value and real value was set within 2% as the accurate, the filling accuracy of the interpolation method was less than 50%, the RNN method was between 50% to 60%, and the LSTM method reached 80% or more; When the error between filled value and real value was set within 4% as the accurate, the filling accuracy of the interpolation method was 60%, the highest accuracy of the RNN method reached to 90%, and the accuracy of the LSTM method was more than 95%. When the weight processing was added on this basis, ,the accuracy of the LSTM prediction result was 97% within 2%, and 100% within 3%. Conclusion: This paper innovatively adopts the bidirectional comprehensive prediction method based on LSTM model, which significantly reduces the influence of cumulative error in long-term prediction on prediction results and improves the accuracy of prediction data. Compared with the other two kinds of data filling methods, the data filling method based on LSTM Neural network has a greater advantage in the long-term missing time series data filling.

Objective: The excellent flexibility of bamboo is due to its microstructure. Having a deeper understanding of the flexibility of bamboo from the micro-level and exploring the morphological changes of bamboo under bending is of important significance. It might provide some bases for the bamboo bending mechanisms and its utilization. Method: Bamboo strips were taken as the research object. The morphological changes of parenchyma cell in the tensile layer were observed by scanning electron microscope(SEM) during cycle loading. For this purpose, parenchyma cell deformation, stress-strain curves of parenchyma cell and parenchymatous tissue, as well as the changes of the cell recovery were analyzed. The deformation of parenchyma cells among different portions was also evaluated. Result: With the increase of the load, parenchyma cell in the tensile layer was stretched in the longitudinal direction, wherea the cell was slightly compressed in the radial direction. The parenchyma cell recovered after unloading. Crease occurred among the parenchyma cells when the bamboo strip was bending. The maximal length strain and width strain of parenchyma cell reached 1.03% and 0.71%, respectively. At the same portion, the length and width recovery of parenchyma cell was 30.96% and 5.93%, respectively. The maximum length strain of parenchymatous tissue was 0.72%. Conclusion: Image-Pro Plus could be used to analyze the cell morphology and observe the deformation directly. Parenchyma cell in the tensile layer was stretched in the longitudinal direction and compressed in the radial direction, respectively. The strain and recovery of parenchyma cell were both larger in the longitudinal direction than those in the radial direction. The parenchyma had a better elasticity in the longitudinal direction.

Objective: Bamboo is widely used in traditional fields such as making of cutting boards, chopsticks and toys for children, however mildew negatively affects its various enterprises and consumers. The existing anti-mildew agents are mainly poisonous and easily leach out of the treated material. Enzymatic bio-catalytic oxidation can form a stable chemical bond between non-toxic iodine and bamboo to improve leaching resistance of iodine and enhance the anti-mold efficacy of bamboo at the same time. It also provides a new idea for the development of natural and non-toxic fungicides. Method: Using ABTS as mediator, potassium iodide was catalyzed by laccase and the liberated iodine was fixed on bamboo, and these led to improved leaching and mildew resistances. Fourier transform infrared(FTIR)and X-ray photoelectron spectroscopy(XPS)were used to study the changes effected by the treatments on the chemical constituents of bamboo. The effects of different concentrations of laccase on the antifungal properties of bamboo were studied by using 4-year-old bamboo samples as the experimental materials, and Trichoderma viride, Aspergillus niger and Penicillium citrinum strains as the test fungi. In order to know the fixation of the active ingredient in the bamboo, the content of iodine was determined by inductively coupled plasma mass spectrometry(ICP-MS), and the fixation rate of iodine in the bamboo was calculated. The anti-mold efficacy of the blocks before and after leaching was tested for the three mold fungi. Result: Laccase catalyzed iodine treatment of bamboo can effectively improve the anti-mildew effects of bamboo, and the participation of laccase in various weight percent (wt.%) showed better performances than the block treated with potassium iodide alone. The laccase treatment KI with a concentration of 4.8×10^-3 wt.‰ had the best resistance to Trichoderma viride, followed by Aspergillus niger and Penicillium citrinum that almost completely covered the samples after 21 days' treatment. The leaching experiment showed that the iodine fixation rate could be increased to 86.13% after the treatment of samples with laccase at the concentration of 4.8×10^-3wt.‰, while iodine fixation rate was only 37.47% after the block treated with potassium iodide alone. Potassium iodide had a limited anti-mildew efficiency in the environment of a mixture of the three fungi, but adding laccase could significantly improve the anti-mildew efficiency. FTIR and XPS analyses showed that laccase catalyzed iodine treatment could modify bamboo lignin forming C-I bond, but with less influences on cellulose and hemicellulose. Conclusion: Laccase catalyzed iodine could improve the mildew and leach resistances of bamboo which increase with laccase concentration. The immobilization rate of iodine in the blocks could be effectively improved by adding laccase to catalyze iodine. The results of comprehensive anti-mildew test showed that laccase catalyzed iodine treatment was significantly higher than for potassium iodide. This study not only broadened the application of laccase and other biological enzymes, but also provided a safe and reliable fungicide for bamboo products that directly get in contact with food or humans.

Objective: The aim of this paper was to analyze structural characterization and component, thereby to promote the efficient conversion of lignocelluloses biomass to fuel ethanol.[ Method: Pinus, Cunninghamia lanceolata and Fraxinus mandschurica were used as experimental materials, pretreated by sodium ethoxide(C₂H₅ONa)system under the condition of 121℃ and by Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD)to analyze chemistry components, structure properties and thermal stability.[ Result: The experimental results showed that the contents of cellulose, xylan and lignin all changed, to a different extent, in the three kinds of pretreatment materials, those were, the contents of cellulose and xylan both increased, whereas the lignin content decreased slightly. The cellulose content of the pretreated C.lanceolata showed a largest increment of 48.1%, average increased by 8.1%, and orderly followed by Pinus and F. mandschurica. From the lignin removal effects perspective, the pretreatments effect of Pinus were better, and the lignin content was decreased by 6.1%. From the experimental results, the conclusion could be obtained that softwood in sodium ethoxide pretreatment system reflected a better effect. In addition, the changed X-ray diffraction(XRD), Fourier transform infrared spectra of the reaction of LOI(crystallinity index)and HBI(hydrogen bond strength index)indicated a changed crystal of pretreatment materials, which suggested that pretreatment can increase the relative crystallinity.[ Conclusion: Enzymatic hydrolysis efficiency was studied by different changes of enzyme dosage and time. The experimental result further verified the result of C. lanceolata > Pinus > F. mandschurica, which might provide a theoretical foundation for energy conversion of woody biomass.

Objective: By revealing the demand price formation mechanisms and policy influencing factors for the purchase of forest carbon sequestration by emission reduction enterprises, the government will regulate and standardize the price trend of the forest carbon exchange market. It also ensures that the forest carbon sequestration price will be used to effectively guide the allocation of resources to the stakeholders and plays an increasingly important role for providing the basis. Method: It is based on directional distance function to calculate the average unit carbon emission reduction cost of 19 enterprises with 589 energy saving and emission reduction units in Shanghai thermal power industry in 3 consecutive years. Meanwhile, it's based on Benitez model to calculate the annual average unit carbon sequestration cost of the 20-year carbon sequestration project of Chinese fir plantation in Zhejiang Province. On this basis, considering various policy factors, this article uses Rubinstein model to analyze the forest carbon sequestration pricing mechanisms based on enterprises' demand for carbon emission reduction. Result: The average marginal abatement cost of thermal power plants in Shanghai was 312.66 yuan·t^-1, and the annual average unit carbon sequestration cost of the 20-year carbon sequestration project of Chinese fir plantation in Zhejiang Province was 217.24 yuan·t^-1. Based on the market trading environment and policy conditions currently assumed, the equilibrium price of the forest carbon market should be 234.5 yuan·t^-1. At the same time, the simulation analysis of the sensitivity of the forest carbon market equilibrium price to changes in the model parameters shows that:if the deduction rate increases from 5% to 15% when forest carbon sequestration does not exceed the company's baseline annual emissions, the equilibrium price of the forest carbon market will increase from 234.5 yuan·t^-1 to 269.1 yuan·t^-1; when the carbon tax rate rises from 1% to 5%, the equilibrium price will increase from 234.5 yuan·t^-1 to 303.7 yuan·t^-1; when the corporate social responsibility coefficient will increase from 0.55 to 0.95, the equilibrium price will drop from 234.5 yuan·t^-1 to 227.3 yuan·t^-1; when the buyer's market concentration of the emission reduction company increases from 1/19 to 1, the equilibrium price will drop from 234.5 yuan·t^-1 to 218.1 yuan·t^-1. Conclusion: The result shows that the changes of deduction proportion when the total amount of forest carbon sequestration is less than enterprises' standard annual carbon emission amount, carbon tax rate, corporate social responsibility coefficient and buyer's market concentration of carbon emission reduction enterprises are sensitive to the market equilibrium price of forest carbon sequestration. This conclusion not only provides a new approach for carbon emission reduction enterprises and forest carbon sequestration suppliers to take market measures and set the market price of forest carbon sequestration, but also presents a new method for the government to effectively implement ecological compensation policy within the framework of market.

Objective: Plants of genus Eurya are dominant species in the tropical and subtropical evergreen broad-leaved forest, which is traditionally considered as a strictly dioecious plant. However, bisexual plants exist in Eurya obtusifolia trees at Jinyun mountain in Chongqing in addition to the typical female and male plants. The morphology and structure of flower buds at different stages of differentiation and the differences and similarities of the differentiation process between bisexual flower buds and typical female and male flower buds were investigated to understand the whole process of flower buds differentiation in different sexes and their morphological characteristics in each differentiation period, to identify the critical period of sex differentiation of flower buds, and further to provide important morphological evidences for exploring the relevant mechanism of sex differentiation. Method: Typical flower buds of female, male and bisexual trees of E. obtusifolia were used as experimental materials. The changes of external morphology and tissue structure during flower bud differentiation were observed and analyzed using conventional paraffin section. Result: 1) The E. obtusifolia has 1-4 flower buds, located in the axils of new or two-year-old branches. 2) The differentiation of flower buds began in early August and basically completed differentiation in the middle and late December, lasting about 120 days. After that, the flower buds were dormant, and entered the initial flowering period from February to March of the next year. The flower bud differentiation time of bisexual flower buds was later than that of male and female flower buds. 3) The process of flower bud differentiation can be divided into 5 stages:bract differentiation, sepal differentiation, petal differentiation, stamen and pistil differentiation, and stamen and pistil formation. 4) In the process of flower bud development, the primordia of both male and bisexual flower buds appeared at the same time. The primordia of stamens in male flowers developed normally while the primordia of pistil stopped developing, and both stamen and pistil primordia in the bisexual flower developed normally. Only pistil primordium was found in female flower bud, but not stamen primordium. 5) In the early stage of the development of bisexual flowers, the development speed of pistil primordium was slightly faster than that of the stamen primordium. The development of pistil was consistent with that of the female flower, the base of carpel primordium healed and enlarged, the middle depression formed ovary and the top healed and extended upward to form style. The development of stamens was consistent with that of the male flower. The upper end of stamen primordium expanded to form anthers and the lower end formed short filaments. At the mature stage of pistil and stamen, the floral organs continued to grow and develop gradually. 6) The length-width ratio of flower buds of the three types of sexes showed an increase first and followed by a decrease during the whole process of differentiation. The male flower buds reached the highest value in the differentiation stage of the bracts, while the female flower buds and the bisexual buds peaked in the stamen and pistil differentiation stages. The dynamic changes of the external morphological characteristics(shape, color) of flower buds in the five differentiation stages were conical (green)→elliptical or approximately circular shape (green faded, deep purple) →round and fat (royal purple)→round, the top of male flower bud was round and blunt, the top of female flower bud and bisexual flower bud was gradually sharp (purple red gradually faded and green deepened)→oval (purple red completely faded, from tender green to yellowish green or brownish green). Conclusion: The flower bud morphology and internal tissue structure of three sexual expression plants of E. obtusifolia are consistent during bract differentiation, sepal differentiation and petal differentiation, but there is a significant difference in the pistil and stamen differentiation stage. The differentiation of bisexual flower bud is similar to that of male flower bud, both with pistil and stamen primordium appearing. It is clear that the key stage of sex differentiation is pistil and stamen differentiation, and there is a corresponding relationship between the external morphology of flower buds and the differentiation stages.

Objective: In this study, we investigated the characteristics and influencing factors of birds' and insects' sound in forests to understand the activity and spatio-temporal pattern of vocal communities in urban forest background.This study aims to further understand important landscape resources in urban forests and provide new ideas for the investigation and conservation of biodiversity. Method: Based on the biophony at 3 urban forest sites (foothills, river valleys and ridges) in the Yuanshan Park in spring, the sound signals quantified by species identification, frequency analysis, spectrum analysis and Acoustic Complexity Index (ACI).The environmental factors(vegetation composition, vertical structure, illumination, temperature, relative humidity, wind speed), were analyzed to identify the activity rule and mechanism of the vocal community. Result: The results showed that the spring forest soundscape in Shenzhen was composed of 3 kinds of sound, namely, the sound of birds, the sound of insects and the mixed sound of birds and insects. The dominant vocal communities were Red-billed Leiothrix (Leiothrix lutea), Light-vented Bulbul (Pycnonotus sinensis), Red-whiskered Bulbul (Pycnonotus jocosus), Common Tailorbird (Orthotomus sutorius), Malaysian Hawk-Cuckoo (Cuculus fugax) and Chestnut Bulbul (Hemixos castanonotus). Sounding community of insects was composed of Cicadas (Cicadidae), Crickets (Gryllidae) and Tettigoniidae. In terms of temporal change, the sound of birds in the sunrise and sunset period was dominant; the sound of birds disappears in night, while the sound of the insects became dominant. The rest of day was the mixture sounds of birds and insects. In addition, the relationship of forest soundscape with characteristics of vegetation communities (diversity, evenness, dominance, vertical structure and phenology) and meteorological factors were analyzed. The results showed that the spatial structure of the vegetation, the phenology of the shrub layer and the intensity of illumination had great influence on the bird's and insect's vocal activities in spring. The birds' and insects' vocal activities were the most abundant in the ridge where the vertical structure of vegetation was simple, and the phenology of shrub layer was obvious. Conclusion: The spring soundscape of Shenzhen is characterized by different sound elements at different time periods, showing abundant variation characteristics and obvious regularity. At the same time, the characteristics of the vegetation community and the meteorological factors have a significant influence on the vocal community. Through the study onthe characteristics of the soundscape and its influencing factors we can fully understand the forest landscape, provide data and theoretical support for the protection and utilization of forest landscape resources, and enable the citizens to enjoy the green welfare.