The 3D modeling and visualization simulation technology for trees is essential tools for investigating forest structure and growth dynamics, and a key technology and foundation for carrying out precision forest management. This paper systematically reviews various tree 3D modeling techniques from different dimensions, including rule-based one-dimensional text descriptions, two-dimensional imagery, three-dimensional LiDAR point clouds, and multi-source data fusion approaches, and also summarizes the progress in the visualization and simulation of tree morphology, growth, and polymorphism. With an emphasis on current trends in 3D tree modeling, this paper focuses on the integration application prospects of generative artificial intelligence (GAI), multi-source data fusion, and large model technologies. It discusses future directions in personalized, diverse, large-scale, and intelligent 3D modeling of trees. In the context of rapid GAI development, a novel framework for intelligent 3D tree modeling is proposed, grounded in multi-source data fusion and powered by GAI. The paper further examines the enabling role of emerging technologies such as digital twins and the metaverse in expanding the applications of tree 3D models. It analyzes their functional requirements and potential across the entire lifecycle of trees, including breeding and cultivation, heritage tree conservation, landscape design, forest operations, ecological monitoring and disaster early warning, as well as ecosystem protection and restoration. Through 3D model simulations of trees, spatial and temporal constraints can be effectively overcome to support intelligent decision-making. These technologies offer critical support for precise and efficient forest management and ecosystem service restoration, provide novel research paradigms and intelligent approaches for tree breeding, monitoring, and conservation, and enable cross-modal data integration and mechanism discovery across the entire spectrum of forestry applications.

Objective: With unmanned aerial vehicle data, an object-oriented method was used to identify individual Caragana korshinskii in Ordos City. RF, SVR, and XGBoost machine learning algorithms were compared to achieve high-precision extraction of individual C. korshinskii and accurate estimation of the biomass, providing a reference for environmental protection and carbon storage research in arid areas. Method: By comprehensively utilizing UAV-borne multispectral and lidar data, and integrating spectral and vertical structure information, an object-oriented method was used to conduct high-precision extraction of individual C. korshinskii. On this basis, three machine learning algorithms of random forest (RF), support vector regression (SVR) and extreme gradient boosting decision tree (XGBoost) were compared to conduct remote sensing accurate estimation of biomass. Result: 1) The ultra-high-resolution image data was obtained by UAV, and the LSMS segmentation algorithm and SVM classifier were able to achieve high-precision identification of individual C. korshinskii. The segmentation accuracy of C. korshinskii in each sample plot was above 86%, the accuracy of the total sample plot was above 90%, the under-segmentation and over-segmentation errors were below 6%, and the overall classification accuracy reached 91.51%. 2) The Recursive Feature Elimination (SVM-RFE) method based on support vector machines identified 17 variables with high contributions to biomass modeling, including 2 planar features and 15 height variables. The cumulative contribution of height variables to biomass was significantly more than that of planar variables (8.7 vs. 1.39). 3) Compared to the RF and SVR models, the XGBoost model provided higher biomass estimation accuracy for C. korshinskii in the study area (R2 = 0.95, RMSE = 259.57 g, MAE = 157.51 g), especially when biomass was below 2 000 g. 4) The multiple vegetation vertical structure information extracted from UAV-LiDAR reflected the diversity and vertical complexity of internal vegetation growth, which was beneficial for improving biomass estimation accuracy. Additionally, integrating multidimensional height variables, such as mean absolute deviation, coefficient of variation, variance, and percentile height, for biomass prediction showed advantages over using a single maximum height variable. Conclusion: The combination of LSMS segmentation and SVM classification for individual shrub extraction offers a technical reference for identifying individual vegetation. The introduction of multi-dimensional point cloud height metrics for biomass estimation compensates for the lack of vertical structure information in C. korshinskii provided by single multispectral data, improving the accuracy of biomass estimation. The XGBoost model provides a new perspective and tool for small-scale shrub biomass estimation in arid regions. Additionally, the high-resolution imagery and point cloud data obtained from UAVs avoid damage to the local ecological environment, which is particularly important in the fragile sandy areas.

Objective: In this study, a forest pinecone detection method based on real-time detection transformer (RT-DETR) was proposed to address the challenges of complex forest environments, small pinecones with indistinct texture features, leading to insufficient detection accuracy and poor real-time detection performance. The RT-DETR model has been optimized to enhance detection performance. Method: Firstly, to improve detection accuracy, the original backbone network was replaced with the re-parameterized vision transformer (RepViT) to enhance feature extraction capability. Secondly, the high-low frequency feature interactions (HiLo) mechanism was introduced to improve the capture of fine texture details. Finally, the re-parameterized cross stage partial bottleneck with 3 convolutions (RepC3) module was optimized into the decoupled replicated bottleneck cross stage partial with 3 convolutions (DRBC3). The receptive field was significantly expanded by incorporating large kernel convolutions and dilated convolutions. Meanwhile, both RepViT and DRBC3 adopted structural re-parameterization designs, simplifying the model structure during inference, and thus improving detection efficiency. Result: The optimized RT-DETR model was tested on the pinecone image dataset collected from Dalai forest station in Jiamusi, Heilongjiang Province, China, and the result showed that all metrics of the model achieved optimal balance, with AP50 of 93.37%, a precision of 93.30%, and a recall of 92.65%. While AP50 improved by 5%, GFLOPs were reduced by 51%, the number of parameters decreased by 41%, and the real-time frame rate FPS significantly increased from 74.3 to 95.5, representing a 28% improvement. Conclusion: This optimization method significantly improves the accuracy, real-time performance, and efficiency of pinecone detection in forest environments, providing an effective solution for automated pinecone harvesting tasks in practical applications.

Objective: In this study, the application of pressure sensing was researched in the tree ring detection with micro-drilling resistance. A pressure sensing micro-drilling resistance tree ring detection method based on spoke-type pressure sensor is proposed and designed, which provides an effective way to improve the reliability and accuracy of micro-drilling resistance annual ring detection. Method: The movement process and stress conditions of the micro-drill needle in the micro-drilling resistance tree ring detection device were analyzed, and the principle of pressure sensing micro-drilling resistance tree ring detection was proposed. A special spoke-type pressure sensor was designed based on resistance strain gauges and full-bridge circuits for achieving pressure sensing micro-drilling resistance tree ring detection without changing the main structure of the existing micro-drilling resistance tree ring detection device. The stress situation of the spoke-type pressure sensor was simulated through finite element analysis. A comparative experiment was carried out on the disc samples using a micro-drilling resistance tree ring device that integrated the existing analog torque sensing method, digital torque sensing method and the spoke pressure sensor detection method proposed in this study. The tested results were converted into quantiles for standardized display, and the Spearman rank correlation coefficient was used to quantitatively analyse the consistency of the tested results obtained by different methods. The accuracy of tree ring detection was obtained by manual interpretation and disc comparison. Result: The comparative experimental analysis showed that the spoke pressure sensor micro-drilling resistance method had high signal quality and detection sensitivity. In the Larix olgensis tree ring detection experiment, the average Spearman rank correlation coefficient of the detection signal of the spoke pressure sensor method and the digital torque sensing method was 0.769, and the detection accuracy was 95.16% and 96.39%, respectively, which verifies the feasibility of the spoke pressure sensor method. In the Cunninghamia lanceolata experiment, the average Spearman rank correlation coefficient was 0.364, and the detection accuracy was 87.79% and 85.47%, respectively. The analysis results of different samples showed that under certain circumstances, the spoke pressure sensor method was able to obtain better tree ring detection performance than the digital torque sensing method, and detect some ring information that could not be recognized by the digital detection method. The composite accuracy of L. olgensis and C. lanceolata was 96.62% and 89.15%, respectively, which were 0.23% and 3.68% higher than the digital torque sensing method, and 1.46% and 1.36% higher than the spoke pressure sensor method, both of which were higher than the accuracy of the two individual detection methods. Conclusion: Experiments show that the micro-drilling resistance method based on spoke pressure sensor can effectively realize micro-drilling resistance tree ring detection. The introduction of this method provides a way to improve the reliability and accuracy of micro-drilling resistance tree ring detection by multi-sensor fusion and provides a basis for building multi-sensor fusion micro-drilling resistance tree ring detection technology.

Objective: This study aims to establish a transient gene silencing system in leaves, in order to elucidate the role of PHYTOENE DESATURASE (PDS) gene of Catalpa bungei, CbuPDS-5, in the carotenoid synthesis pathway of the leaves. Method: In this study, C. bungei was used as the research subject, and the PDS gene family members were identified in the C. bungei genome. The expression pattern analysis was conducted to determine the expression levels of CbuPDSs in various tissues of C. bungei. The homologous cloning method was used to obtain the cDNA sequence of CbuPDS-5 from C. bungei. The structure and classification of CbuPDS-5 were analyzed by constructing a phylogenetic tree and performing homologous protein sequence alignments. The homologous recombination technique was used to construct a TRV2-CbuPDS-5 expression vector, and the Agrobacterium-mediated injection method was used to infect the leaves of C. bungei to create gene-silenced lines. Meanwhile, phenotypic observation and real-time PCR were performed to analyze the effects of CbuPDS-5 silencing on C. bungei growth and leaf pigment synthesis. Result: Six PDS members were identified in the C. bungei genome, with significant differences in their expression levels in different tissues such as leaves and flowers. Among them, the CbuPDS-5, which exhibited the highest similarity to tomato CaPDS, was highly expressed in leaves, and selected as the target gene. The full-length CbuPDS-5 was 1 095 bp, with a 948 bp ORF encoding 315 amino acids. It contained a dinucleotide binding motif, however had an amino acid deletion in the C-terminal. The functional validation showed that new leaves exhibited distinct photobleaching symptoms in two months after inoculation, and repeated inoculations significantly increased the extent of leaf whitening. The qRT-PCR analysis confirmed a significant reduction in the relative expression level of CbuPDS-5 in leaves with exhibiting photobleaching symptoms. Conclusion: The experimental results have demonstrated that the VIGS system can be used for gene silencing in C. bungei. CbuPDS-5 can serve as an indicator gene for rapid verification of the efficiency and duration of transient systems in woody plants. Additionally, the creation of variegated C. bungei through CbuPDS-5 silencing enhances its ornamental value and provides a foundation for breeding dual-purpose varieties with both ornamental and timber uses.

Objective: This study analyzed the leaf-soil ecological stoichiometric characteristics and plant homeostasis differences of typical revegetation in different arid areas of the Loess Hilly Region. From the perspective of plant nutrient utilization strategies and homeostasis maintenance ability, it aimed to identify suitable revegetation types for different arid levels. By analyzing the nutrient cycling processes driven by the ecological stoichiometric characteristics and plant homeostasis differences of typical revegetation in different arid areas, it provided a scientific basis for vegetation optimization and soil nutrient management in the Loess Hilly Region of China. Method: Along the aridity gradient from south to north of the Loess Plateau, 17-year-old Robinia pseudoacacia (RP) plantations, shrublands, and abandoned land were selected in Fuxian County (aridity level 0.641), Baota District (aridity level 0.718), and Mizhi County (aridity level 0.764) for the purpose of examining the carbon (C), nitrogen (N), and phosphorus (P) content and stoichiometric properties of both leaves and soils. The interrelationships between these components and the homeostatic characteristics within the leaves were further analyzed. Result: 1) The leaf carbon and nitrogen contents of RP plantations were respectively lower and higher than those of other vegetation restoration types. The leaf phosphorus content and soil carbon to nitrogen ratio of abandoned land were the highest, while the leaf soil carbon to phosphorus ratio and soil nitrogen to phosphorus ratio of shrubland were the highest. In terms of soil characteristics, soil carbon to nitrogen ratio, and soil carbon to phosphorus ratio of abandoned land were generally higher than those of other vegetation restoration types. Soil nitrogen content and soil nitrogen to phosphorus ratio were lowest in RP plantations. However, soil phosphorus content in RP plantations was significantly higher than that in shrublands and abandoned land. 2) With increasing aridity, the carbon and nitrogen contents of leaves in Baota District were respectively 8.77% and 6.64% lower than those in Fuxian County, while the phosphorus content was 34.25% higher. In Mizhi County, the carbon and nitrogen contents of leaves were respectively 1.01% and 44.53% lower than those in Fuxian County, while the phosphorus content was 16.02% higher. As aridity increases, the trends in the soil carbon to phosphorus and soil nitrogen to phosphorus ratio of leaves were similar to those of carbon and nitrogen, showing initial decreases followed by increases and overall declines, respectively. In contrast, the soil carbon to nitrogen ratio showed an increasing trend. 3) Soil carbon content (7.47, 3.44, and 2.67 g·kg^?1on average in Fuxian County, Baota District, and Mizhi County, sane blow), nitrogen content (averaging 0.66, 0.36, and 0.37 g·kg^?1), and the soil carbon to nitrogen ratio (averaging 11.62, 9.62, and 7.59), soil carbon to phosphorus ratio (averaging 14.89, 9.25, and 6.64), and soil nitrogen to phosphorus ratio (averaging 1.37, 0.99, and 0.92) all tended to decrease with increasing aridity. In contrast, soil phosphorus content (averaging 0.501, 0.36, and 0.40 g·kg^?1) first decreased and then increased. 4) An increase in aridity intensifies nitrogen limitation on vegetation growth, while the shift from abandoned land to forest land increases phosphorus limitation. Mantel analysis shows significant correlations between leaf and soil carbon, nitrogen, and phosphorus contents and their stoichiometric ratios at different levels. Aridity has a greater impact on leaf and soil indicators than vegetation type and soil depth. 5) Different revegetation types show distinct abilities to maintain foliar chemical stoichiometric homeostasis. Leaf carbon in all vegetation types exhibits absolute homeostasis. Leaf nitrogen and phosphorus in abandoned land and shrubland show weak homeostasis or sensitive characteristics. The soil carbon to phosphorus ratio of abandoned land leaves is sensitive or weakly homeostatic, while the soil carbon to nitrogen and soil nitrogen to phosphorus ratios of RP and shrub leaves are sensitive. Conclusion: Aridity is a key environmental factor regulating the leaf-soil carbon, nitrogen, and phosphorus stoichiometric characteristics of revegetation. RP plantations can more effectively maintain foliar homeostasis under different aridity levels in the Loess Hilly Region, showing stronger adaptability than shrublands and abandoned land, and can be the main tree species for vegetation restoration and reconstruction in this area. In areas with higher aridity and in abandoned land, nitrogen fertilizer should be applied, while in relatively humid shrublands and forests, nitrogen and phosphorus fertilizers should be added.

Objective: Analyzing the variation characteristics and influencing factors of soil organic carbon (SOC) and its fraction carbon pools in Pinus massoniana plantations of different stand ages, to provide a reference for clarifying the SOC sequestration mechanisms in plantations. Method: This study investigated subtropical P. massoniana plantations across stand age classes: young (6 a), middle-aged (13 a), near-mature (29 a), mature (38 a), and over-mature (57 a). Explored age-dependent patterns of SOC and its fractions in the 0–10 cm soil layer, analyzed relationships between SOC fraction dynamics and key indicators (tree characteristics, soil chemical properties, and microbial biomass), and further discussed the underlying mechanisms of SOC sequestration in plantation ecosystems. Result: The SOC content in mature plantation was significantly higher than that in young plantation and middle-aged plantation. The dry mass fraction of mineral-associated fraction (72.98%) in mature plantation was significantly lower than young plantation, middle-aged plantation, near-mature plantation and over-mature plantation (92.67%–93.33%), while the dry mass fraction of light particle fraction (26.08%) and heavy particle fraction (0.93%) were significantly higher than young and middle-aged plantations. The organic carbon content of mineral-associated fraction in mature plantation was significantly higher than young, middle-aged, near-mature, and over-mature plantations, the organic carbon content of heavy particulate fraction was significantly lower than that in over-mature plantation, and the organic carbon content of light particulate fraction was significantly lower than middle-aged plantation. The organic carbon mass fraction of mineral-associated fraction in all age groups was > 50%, which dominated the accumulation of SOC. The organic carbon dry mass fraction of mineral-associated fraction in mature plantation (66.78%) was significantly lower than young, middle-aged, near-mature and over-mature plantations. Correlation analysis revealed that SOC content was significantly positively correlated with the dry mass fraction of light particle fraction, the dry mass fraction of heavy particle fraction and the mineral-associated fraction organic carbon content, and was significantly negatively correlated with the light particle fraction organic carbon content. Stepwise regression analysis showed that SOC accumulation was driven by forest floor litter, dry mass fraction of light particle fraction, dry mass fraction of heavy particle fraction and mineral-associated fraction organic carbon content (R²=0.98). The partial least squares model showed that the total effect of mineral-associated fraction (including organic carbon content and carbon-phosphorus ratio of mineral‐associated fraction) on SOC accumulation was the highest (0.91) during stand development. Conclusion: The mineral-associated protection mechanisms mediate the dynamics of soil organic carbon sequestration during stand development in P. massoniana plantations. In the mature plantation, synergistic effects between forest floor litter and SOC fractions facilitated highly efficient SOC sequestration.

Objective: The study aim to reveal the effects of soil physicochemical properties on the emission characteristics of biogenic volatile organic compounds from Cunninghamia lanceolata under forest fire smoke deposition. It further explores the post fire interactions among soil, vegetation, and the atmosphere, providing a scientific basis for ecological restoration and atmospheric environmental assessment after forest fires. Method: C. lanceolata seedlings from the state-owned forest farm of Youxi County, Sanming City, Fujian Province were selected as the research objects. A blank group, a low-concentration group, and a high-concentration group were set up to burn 0, 50, and 150 g of combustibles for flue gas treatment. At 7, 30, and 90 days after enclosed smoke exposure, the chemical composition and emission rates of plant volatiles were determined using a preconcentration system coupled with gas chromatography-mass spectrometry (GC-MS). Concurrently, changes in soil physicochemical properties were continuously monitored, and structural equation modeling (SEM) was employed to analyze the potential relationships among smoke concentration, the emission rates of biogenic volatile organic compounds from C. lanceolata, and soil physicochemical parameters. Result: 1) On day 7 after smoke treatment, smoke concentration had a significant positive effect on both nitrogen content and pH in the 10–20 cm soil layer. By the 30th day, it exhibited a significant negative effect on nitrogen content in that layer while maintaining a significant positive effect on pH. On the day 90, smoke concentration showed a significant negative effect on pH in the 10–20 cm layer. Over time following smoke treatment, with the exception of phosphorus in the 0–20 cm layer and carbon in the low concentration group of the 0–10 cm layer, which declined on day 30 and rebounded by day 90. The nitrogen content, pH, and electrical conductivity in the 0–20 cm layer, as well as carbon content in the 10–20 cm layer, all displayed a continuous downward trend. 2) Eight important olefins were released from C. lanceolata, including 1-butene, 1-hexene, trans-2-butene, cis-2-butene, 1-pentene, isoprene, trans-2-pentene and cis-2-pentene, among them, isoprene, 1-hexene, 1-pentene and 1-butene exhibited the highest emission rates. At 30 days post-treatment, the emission rates of biogenic volatile organic compounds from C. lanceolata showed differences among, which tended to converge by day 90. At 30 days post-treatment, smoke concentration exerted a significant negative effect on isoprene emission rate (P<0.01). By 90 days post-treatment, the emission rate of trans-2-butene was significantly lower than that of the control(P<0.01). In the low concentration treatment group, 1-butene emission rate was significantly elevated at 7 days post-treatment(P<0.01). 3) Forest fire smoke altered the physicochemical properties of the soil, among which nitrogen and phosphorus content, as well as soil pH, were closely associated with the emission of biogenic volatile organic compounds from C. lanceolata. Structural equation modeling showed that soil nitrogen content had a direct, significant positive effect on isoprene emission (P?<?0.001), while soil phosphorus content had a direct, significant negative effect (P?<?0.01). Additionally, soil pH exhibited a highly direct, significant negative effect on isoprene emission (P?<?0.001).【Conclusion】Under the context of forest fire smoke deposition, dynamic changes in soil physicochemical properties, especially soil nitrogen and phosphorus contents and pH, significantly regulate the emissions of biogenic volatile organic compounds such as isoprene from C. lanceolata. These findings enrich our understanding of the soil-plant-atmosphere interactions following forest fire and offer guidance for post fire ecological management: for example, moderate nitrogen supplementation can enhance plant antioxidant capacity, while judicious phosphorus application and pH adjustment help control biogenic volatile organic compounds emissions and mitigate regional air quality impacts.

Objective: To quantify public perception and preference towards the cultural ecosystem services of urban forest parks in Nanjing using online review data from social media platforms and field survey data. This will aid in enhancing public satisfaction and precise management, and facilitate the optimization and sustainable management of urban forest park ecological spaces. Method: Within typical forest parks in Nanjing, field research, social media data analysis, and natural language processing techniques were employed. Based on the “importance-satisfaction” analysis model, the public’s perception, preferences, and impacts on cultural ecosystem services were quantified. Result: 1) The public highly recognizes aesthetic appreciation and leisure recreation services but has lower satisfaction with emotional connection, inspiration acquisition, and cultural heritage services. There is a mismatch between supply and demand among these services, indicating an urgent need to enhance services catering to the public’s spiritual and emotional needs. 2) Younger individuals prefer educational and cognitive services and leisure recreation, while older individuals favor health promotion and emotional connection services. Men prefer leisure recreation and health promotion services, whereas women are more inclined towards aesthetic appreciation, educational and cognitive services, and emotional connection services. 3) Accessibility and usage frequency enhance social interaction, emotional connection, and health promotion services, highlighting the importance of improving accessibility within forest parks. 4) Different occupational groups have their unique needs and preferences for cultural ecosystem services, which can be leveraged by smart landscape systems to enhance service experiences and motivate public participation in park management and development. Conclusion: Visitors of different ages, genders, accessibility levels, usage frequencies, and occupational backgrounds exhibit significant differences in their preferences for cultural ecosystem services. Park management should adopt differentiated service strategies encompassing policy support, personalized services, technology integration, and community participation. These strategies will provide robust support for the scientific management and ecological space planning of urban forest park.

Objective: Slash pine (Pinus elliottii), loblolly pine (P. taeda), Caribbean pine (P. caribaea) and their interspecific hybrids are the main timber species introduced and domesticated from North America in China. In recent years, dozens of elite varieties of foreign pines have been approved. As the morphological characteristics of exotic pines are very similar at seedling stage, it is a challenge to distinguish these elite varieties. The purpose of this study is to construct a set of DNA fingerprints for foreign pine varieties, which can be used for the identification of different foreign pine species, and provide technical support for the management of germplasm resources and intellectual property protection of exotic pine varieties. Method: The 51K liquid phase probe microarray of slash pine and loblolly pine was used to capture SNPs of 38 elite varieties of exotic pines and their hybrids, and obtained their genotype data. The core SNPs in exotic pine germplasm resources were able to be efficiently identified through screening genetic parameters, such as minor allele frequency, deletion rate, heterozygosity and polymorphism information content. The number of SNP markers was further simplified based on PIC values to achieve the goal of efficiently identifying samples with a smaller number of SNPs. Result: A total of 60 567 SNPs loci were obtained by SNP locus capture and genotyping. Through strict control of minor allele frequency, deletion rate, heterozygosity and other parameters, 344 core SNPs were screened. The PIC value was further reduced to 20 SNPs, with which slash pine, loblolly pine, Caribbean pine and their hybrids were able to be efficiently distinguished. This approach was used to successfully establish DNA fingerprint profiles for 38 elite pine varieties. Conclusion: In this study, a DNA fingerprinting system for elite exotic pine varieties has been developed, and a method for identifying exotic pines and their elite varieties has been established. The research results can provide technical support for the protection of intellectual property rights, germplasm management, and pedigree analysis of elite varieties.

Objective: This study aims to reveal the genetic variation patterns of growth traits in open-pollinated families of Cupressus funebris (cypress), and assess the magnitude and mode of family and environment effects, and their interaction. Method: This study targeted the 8-year-old open-pollinated families of cypress established in three different environmental conditions in Kaihua (KH) forest station in Kaihua County, Shibawu (SBW) forest station in Chun’an County of Zhejiang Province, and Taizishan (TZS) forest station in Jingshan County of Hubei Province. The genetic variation patterns of growth traits were analyzed, and the parameters such as breeding values and heritability were estimated, and hereby to screen for families with rapid growth and strong stability, and to explore the impact of the main environmental factors at the experimental sites on the growth of cypress. Result: The genetic variation coefficients of growth traits (tree height, diameter at breast height, individual tree volume, and crown width) of cypress families ranged from 11.64% to 21.20%, with the greatest variation in individual tree volume. There were significant differences in the growth traits among sites, and among families, and the volume per plant of TZS was 124.64% and 171.93% higher than that of KH and SBW, respectively. The variation ranges of family heritability of KH, SBW and TZS were 0.30–0.73, 0.22–0.51 and 0.75–0.87, respectively. The independent culling method was used to select 2, 1, and 3 superior families respectively in the KH, SBW and TZS sites, with the top 20% of breeding values for diameter at breast height (DBH) and tree height as the criterion, and the genetic gains in individual tree volume ranged from 25.87% to 59.00%. The 7, 7, and 6 elite individual trees were selected from the KH, SBW, and TZS sites, respectively, based on a selection rate of 3% on phenotypic values for DBH and tree height, and the gains in individual tree volume ranged from 181.98% to 355.53%. Multivariate variance analysis and genetic parameters across multiple sites indicated that there was a significant family by environment (G×E) interaction effect on family growth traits. The variation range of B-type genetic correlation coefficients was from 0.05 to 0.71. Based on the BLUP-GGE biplot analysis of DBH and tree height, family 3, 7, and 12 were comprehensively selected as fast-growing and stable families, with an average individual tree volume gain of 27.74%. Key environmental factors such as sunlight duration, rainfall, soil exchangeable calcium content, soil organic matter content, soil available nitrogen, and soil acid-available phosphorus content at the experimental sites might be the critical factors affecting the growth of cypress. Conclusion: There is abundant variation in growth traits among cypress families, indicating that they are significant potential for genetic improvement. These traits are influenced by family genetics, environment, and G×E (genotype × environment) interaction. The comprehensive selection of fast-growing and stable families can provide a material basis for the promotion of cypress varieties across different locations.

Objective: This study aims to explore the mechanism of difficulty in differentiation and regeneration of embryogenic callus of Catalpa bungei under long-term subculture, so as to provide a theoretical basis for the differentiation and regeneration of somatic embryogenesis system and genetic stability of C. bungei. Method: The newly induced non-embryogenic callus, primary embryogenic callus and 7-year subcultured embryogenic callus were used as materials to analyze the cell ploidy, differentially expressed genes and endogenous hormone levels. Result: 1) Through chromosome counting, it was found that the chromosome number of the primary embryogenic callus maintained diploid status (2n = 40), while the chromosome number of the embryogenic callus continuously cultured for 7 years was doubled, and the chromosome number ranged from 80 to 162. The result of flow cytometry measurement showed that the DNA content of embryogenic callus that was cultured continuously for 7 years was 3 times higher than that of C. bungei seedlings, and the cell ploidy was hexaploid. 2) Through GO and KEGG enrichment analysis of transcriptome data, it was found that differentially expressed genes were significantly enriched in plant hormone activation signaling pathway, transcriptional regulation, MAPK signaling pathway, development process regulation and other pathways. Among them, SAUR, ARF, AUX/IAA and GH3 which respond to auxin signaling, abscisic acid receptor PYR/PYL, extracellular protein AGP, transcription factor ABI3 and other genes that promote somatic embryo differentiation were all down-regulated, while the expression of ethylene synthesis inhibitor ETO1 was up-regulated. 3) Endogenous hormone level analysis showed that the content of IAA and ABA in embryogenic callus that was cultured continuously for 7 years was significantly lower than that in newly induced embryogenic callus, which corresponded to the down-regulated expression of genes involved in plant hormone signal transduction. It is suggested that high levels of IAA and ABA may be the key to regulating somatic embryogenesis. Conclusion: In summary, it is speculated that chromosome doubling, abnormal expression of genes related to somatic embryogenesis and significant decrease of endogenous hormone levels in the embryogenic callus of C. bungei during long-term subculture may be the fundamental cause of its difficulty in differentiation and regeneration.

Objective: This study aims to investigate the reproductive efficiency of Nipponia nippon under captive conditions and its correlation with ages of male and female individuals, and to gain a more accurate understanding of the reproductive biological characteristics of the species, in order to guide the establishment of a stable captive population and promote the reintroduction programs for endangered species. Method: The data of natural breeding of N. nippon under two captive rearing conditions (conventional housing enclosures and rewilding training mesh cages) in Shaanxi Hanzhong Nipponia nippon National Nature Reserve was collected from 2018 to 2020, and used to explore the effects of ages of male and female individuals on reproduction performance of the N. nippon. Result: The overall differences in natural reproductive parameters of N. nippon under different captive conditions were not apparent, but they were influenced to varying degrees by individual age. The clutch size increased and then decreased with individual age (LM: t=-2.651, P<0.01). The females aged 4–9 years old produced significantly more eggs per clutch than younger (1–3 years old) or older (>10 years old) individuals (ANOVA: F = 5.713, P<0.05). The hatching success rate declined with age (LM: t =–2.405, P = 0.018), and the hatching rate of females aged 1–3 years old was significantly higher than those aged 4–9 years old (t-test: t = 2.751, P<0.05), but there was no significant difference in the number of fledglings. The results suggest that the influence of parental breeding experience under captive conditions may mainly manifest during the egg-laying process rather than during the hatching and rearing stages. In addition, the age distribution structure of breeding output from both male and female parent birds was similar. Conclusion: The age of parent birds significantly affects the natural breeding performance of captive N. nippon. Breeding pairs have less reproductive experience at the early stage of sexual maturity, resulting in a lower clutch size. However, after the age of nine, the breeding birds show reproductive senescence, and their reproductive output is also low. Based on the results of this study, it is recommend that when releasing N. nippon into the wild, individuals aged 2–3 years old should be primarily selected, while the release of individuals older than 9 years should be avoided.

Objective: This study aims to investigate the relationship between pollinating insects (bee, butterfly and gophers) and environmental factors in urban green corridors, providing a scientific basis for the conservation of urban pollinators and the construction and optimisation of urban green corridors in the future. Method: Five typical green corridors in the built-up area of Hefei City, Anhui Province were used as research objects, and correlation and regression analyses were carried out on the collected data of corridor environmental factors and pollinators’ diversity indicators, and a fitting model was constructed to explore the relationship between pollinators and environmental factors. Result: 1) A total of 5 860 pollinators, belonging to 3 orders, 17 families, 50 genera and 77 species, were recorded in 15 sample plots during the 6-month survey. Among them, Lepidoptera had the highest abundance, and the dominant families were Lycaenidae and Apidae. 2) The habitats of green railway corridors, high-pressure corridors, and river corridors were more attractive to pollinators, and there were large differences in similarity of the composition of pollinators among different types of green corridors. 3) Species richness, multiplicity, and Shannon index were significantly positively correlated with nectar plant richness, soil pH, flowering multiplicity of nectar plants, and bare ground coverage (P<0.05), and significantly negatively correlated with forest canopy closure, degree of human disturbance, and soil humidity (P<0.05). 4) The optimal fitting model showed that forest canopy closure, flowering multiplicity and richness of nectar plants in corridors were the important environmental factors affecting the survival and reproduction of pollinators. 5) The exotic invasive species in the corridor accounted for 21.92% of the total surveyed plant families, and some invasive plants had high nectar value for pollinators, however, which increased the risk of pollinators spreading non-native species through urban corridors. Conclusion: There are significant differences in the distribution of pollinator communities in different types of urban green corridors, and environmental factors such as flowering multiplicity and richness of nectar plants, canopy closure, and the degree of human interference are important factors influencing the characteristics of pollinator communities in urban corridors.

Objective: It is of great practical significance to clarify and analyze the performance theory, mechanism, and pathways of rural digitalization affecting the development of forestry new quality productive forces, to provide a scientific basis for digitally empowering the high-quality development of forestry and promote the construction of modern forestry industry system. Method: Based on the panel data of 30 provincial administrative units in China from 2012 to 2020, a comprehensive evaluation index system of rural digitalization level and forestry new quality productive forces development level was constructed. The two-way fixed effect model, intermediary effect model, and spatial Dubin model were used to empirically analyze the impact of rural digitalization on the development of forestry new quality productive forces and its mechanism. Result: 1) Benchmark regression results show that rural digitalization has a significant contribution to the development of forestry new quality productive forces, with the level of forestry new quality productive forces increasing by 0.0645 units for every 1 unit increase in the level of rural digitalization. This conclusion is still valid after a series of robustness tests. 2) The results of regional heterogeneity analysis show that rural digitalization can significantly promote the development of forestry new quality productive forces in eastern and western China. In areas with low development levels of forestry new quality productive forces, rural digitalization can significantly contribute to the development of forestry new quality productive forces. The results of dimensional heterogeneity analyses showed that the development of digital infrastructure and digital industry can significantly promote the development of forestry new quality productive forces with digital infrastructure contributing more, and the digital transformation of rural areas has a greater role in promoting new forestry labors. 3) The results of mechanism analysis show that rural digitalization can promote the development of forestry new quality productive forces by releasing technological innovation breakthrough effect, labor resource allocation effect, industrial upgrading driving effect, and resource management quality improvement effect. 4) The results of the spatial econometric model show that the level of rural digitalization has a significant negative spatial spillover effect on the development level of forestry new quality productive forces. The short-term and long-term indirect effects are significantly negative. Conclusion: From 2012 to 2020, the level of rural digitalization in China’s 30 provincial administrative units will continue to increase, which will have a significant effect on the development of forestry new quality productive forces, and the level of forestry science and technology innovation, the stock of forestry human capital, the level of advanced forestry industry structure and the intensity of environmental regulation will affect the development of rural digitalization in promoting the development of forestry new quality productive forces to a different extent. Therefore, provincial administrative units should continue to promote rural digital development, strengthen rural digital infrastructure construction, effectively promote digital industry development, actively encourage forestry technology innovation, enhance forestry human capital, continue to promote the advanced structure of the forestry industry, and optimize environmental regulations and moderately increase their intensity, to accelerate the development of forestry new quality productive forces in China.

Objective: Despite many scholars focusing on the evaluation of the policy effects of the natural forest protection (NFP), there is scarce literature focusing on the causal relationship between the implementation of the natural forest protection policy (NFPP) and new quality productivity of forestry (NQPF). To fill this research gap, we study the impact mechanism of the policy of NFP on NQPF in key state-owned forest areas, aiming to provide scientific basis for optimizing the policy of NFP and enhancing NQPF. Method: Based on panel data from 87 forest industry enterprises in key state-owned forest areas from 2011 to 2020, using efficiency based measure (EBM) model to calculate levels of NQPF and methods such as two-way fixed effects model, we conduct empirical analysis on the causal impact and mechanism of the policy of NFPP on NQPF. Result: 1) The implementation of the policy of NFP has a significant positive impact on NQPF in key state-owned forest areas, which still holds true after a series robustness checks. 2) The upgrading of the forestry industry structure, the transformation of the economic model, and the accumulation of human capital play a transmission role in the relationship between the policy of NFP and NQPF. 3) The policy of NFP has a more significant promoting effect on the development of NQPF in Inner Mongolia forest industry group, small-scale forest industry enterprises, and forest industry enterprises with larger forest areas. Conclusion: Natural forest protection policy significantly promote the development of forestry new quality productivity through the upgrading of forestry industrial structure, the transformation of economic model and the accumulation of human capital, and its influence is heterogeneous. Based on this, increase financial input in tianbao project policy, and develop more refined differentiation policy, to adapt to the specific needs of different regions, optimize the allocation of forestry resources, improve industrial efficiency, to accelerate the formation of forestry new quality productivity and cultivation, for the sustainable development of forestry to provide solid policy support and practical guidance.

Objective: Under the background of deepening the reform of forest right system and promoting moderate scale operation, this paper explores the influence mechanism and difference of management right security on the investment of large-scale households in forest infrastructure, aiming at improving the supporting policies of forest right system reform and promoting the establishment of diversified forest infrastructure supply system. Method: On the basis of theoretical analysis, based on the perspective of the security of management rights of large-scale households, this paper used the survey data of large-scale forestry households in China to analyze the impact of the security of management rights on the investment in forest infrastructure of large-scale households and its mechanism from three dimensions: standardization of transfer contract, maturity of transfer contract and conflict of forest land management with panel Tobit model. Result: The forest land management without forest right conflict has a significant positive impact on the forest infrastructure of large-scale households. A long-term and standardized transfer contract can encourage large-scale households to invest in forest infrastructure. There are differences in the investment structure of forest infrastructure among households with different characteristics. The incentive effect of management right security on the investment of forest infrastructure in the southern sample group is stronger than that in the northern sample group, and the incentive effect on the investment of forest infrastructure in the ordinary scale group is stronger than that in the large scale group.

Objective: This study addresses the disconnect between the theoretical framework of high-quality development in forestry and the practice of realizing the value of forest ecological products. By proposing an observable conceptual framework, it analyzes whether the realization of forest ecological product value facilitates high-quality development in key state-owned forest regions. The research aims to resolve crucial practical challenges associated with the value realization of forest ecological products and the advancement of high-quality forestry development under state-owned forest management systems. Method: The study optimizes the input-output indicator system for the efficiency of ecological product value realization in the Northeast state-owned forest regions. Using technologies and methods such as ArcGIS, equivalent factors, Super-SBM model, Super-Malmquist index, and coefficient of variation, it calculates the efficiency of forest ecological product value realization for 87 forestry enterprises in key state-owned forest regions from 2003 to 2020, which is an important criterion for the degree of high-quality development in forestry. Result: 1) The value flow of forest ecological assets in key state-owned forest regions is enormous, mainly composed of the value of forest support and regulation services, which aligns with the foundational requirements for green and high-quality development. By 2020, the value of support and regulation services reached 728.34 billion yuan, while supply services and cultural services amounted to 46.06 billion yuan and 37.70 billion yuan. However, the total output value of forest ecological products showed a trend of first increasing and then decreasing, dropping to 9.87 billion yuan in 2020, mainly due to the reduced output value of wood products. 2) The average efficiency of forest ecological product realization in key state-owned forest regions is low, and the goal of high-quality forestry development has not been fully achieved. From 2003 to 2020, the average efficiency of forest ecological product value realization was only 0.39, with the number of forestry bureaus reaching an effective level each year of less than 1/4 of the total area. By region, the Jilin Forestry Group had the highest efficiency in ecological product value realization, with an average of 0.63. In contrast, the Daxing’anling Forestry Group had the lowest efficiency, with an average of 0.32. 3) According to the total factor productivity(TFP) and its decomposition results, the average of total factor productivity(TFP) in key state-owned forest regions from 2003 to 2020 was 1.025. The mean of technical progress change(TC) was 1.042, and the innovation effect caused by technological progress was the main source of growth in the transformation of ecological product value in key state-owned forest regions. 4) The variation coefficient of different forestry groups first decreased and then increased, and the numerical gap in value realization efficiency expanded over time. In 2009, the overall variation coefficient was the smallest, at 0.81; by 2020, the variation coefficient was 1.38. Regional development was uncoordinated, with the forestry bureaus under the Jilin Forestry Group taking the lead in entering the stage of high-quality forestry development. Conclusion: By realizing the value of forest ecological products, key state-owned forest regions promote technological and organizational innovation as the driving force for development, cultivate ecological capital as a key element, implement innovative and green development concepts, and push forestry towards high-quality development. However, bottlenecks such as low output elasticity of ecological capital, significant regional development disparities, and limited sharing of development outcomes continue to constrain high-quality development in these regions. Addressing these challenges requires tailored and categorized policies tailored to local conditions to advance the realization of forest ecological product value. This study provides an observable conceptual framework and empirical evidence to support the implementation of the strategic directive to “cultivate new drivers for high-quality economic development” and promote context-specific approaches to realizing ecological product value.