Objective: This study performs convolutional neural network (CNN)-based residual correction of ERA5-Land precipitation data in subalpine forest regions of southwestern China and evaluates the applicability of the corrected data to hydrological modeling, aiming to provide a reference for precipitation data optimization and ecohydrological research in the region. Method: The upper reaches of Minjiang River in western Sichuan Province were selected as the study area, topographic factors and multiple meteorological variables were used as model inputs to construct a CNN-based residual correction model for ERA5-Land precipitation. Based on observations from 20 national meteorological stations in and surrounding the basin, a grid-to-station spatial matching method was used to evaluate the accuracy of the original and corrected ERA5-Land data and the IMERG, CMORPH-BLD, and CMA-RA/Land precipitation products. The distributed hydrological-soil-vegetation model (DHSVM) was then used to compare the runoff simulation effects driven by the different precipitation datasets and evaluate the applicability of the corrected data to hydrological modeling. Result: 1) Among the four original precipitation products, ERA5-Land exhibited relatively good overall performance, and its temporal variations were generally consistent with ground observations. However, it overestimated light precipitation, underestimated heavy precipitation, and overestimated total precipitation over the study area. 2) The CNN-based residual correction method substantially reduced the systematic bias of ERA5-Land while preserving its original data characteristics. For light precipitation, the percentage bias (PBIAS) of the corrected ERA5 Land data decreased from 104.94% to 33.92%. Across all precipitation intensity classes, the corrected ERA5-Land data exhibited higher correlation coefficient (CC) and lower normalized root mean square error (NRMSE) than the IMERG, CMORPH-BLD, and CMA-RA/Land products. 3) Among the DHSVM runoff simulations driven by the different precipitation datasets, the corrected ERA5-Land data produced the best performance, with an overall Nash–Sutcliffe efficiency (NSE) of 0.66 during the study period and relatively stable performance across years. 4) The IMERG, CMORPH-BLD, and CMA-RA/Land products underestimated winter snowfall over the study area to different extents, which delayed the simulated rise of spring snowmelt runoff. The corrected ERA5-Land data showed the smallest underestimation and the best spring snowmelt runoff simulation, with an NSE of 0.38, outperforming the other products. Conclusion: The CNN-based residual correction method effectively reduces the systematic bias in ERA5-Land precipitation and improves DHSVM runoff simulations driven by the corrected data. The corrected ERA5-Land data can provide a relatively reliable precipitation dataset for ecohydrological research in the sub-alpine forest regions of southwestern China.

Objective: This study aims to functionally characterize the PdHyPRPs genes in the nationally approved elite variety of Populus × euramericana ‘Bofeng 3’, and generate novel salt-tolerant poplars by CRISPR/Cas9-mediated editing of PdHyPRPs. Method: With the tomato SlHyPRP1 amino acid sequence as a query, PdHyPRPs family genes were screened from the Populus deltoides reference genome. The gene structures and their protein types were analyzed through bioinformatics methods such as phylogenetic tree construction and homologous protein sequence alignment. Quantitative real-time PCR was employed to analyze the expression patterns of PdHyPRPs genes in leaves, stems, and roots of P. × euramericana ‘Bofeng 3’, and their responses to drought and salt stress. The homologous cloning method was used to obtain the coding sequences (CDS) of PdHyPRP1 and PdHyPRP2. CRISPR/Cas9 and homologous recombination techniques were used to construct gene editing and RNAi vectors targeting PdHyPRP1/2, which were then introduced into P. × euramericana ‘Bofeng 3’ by Agrobacterium-mediated transformation, to obtain PdHyPRP1/2-edited, PdHyPRP1/2-RNAi, and PdHyPRP1/2 overexpressed lines. Under salt stress, the contents of superoxide anion (O₂^–), hydrogen peroxide (H₂O₂), and malondialdehyde (MDA) in leaves and roots of each line were measured to evaluate salt tolerance and verify gene function. Result: A total of 15 PdHyPRP genes were identified in P. deltoides, with 360 to 1317 bp CDS. Each gene contained a single exon, encoding 119?438 amino acids. The encoded proteins all possessed an N-terminal signal peptide, a proline-rich repeat region, and a C-terminal 8-cysteine motif (8CM), belonging to the typical 8CM protein family and clustering into six evolutionary branches. Expression analysis revealed that, except for PdHyPRP13, 14 genes were expressed in leaves, stems, and roots of P. × euramericana ‘Bofeng 3’ and were induced by salt and drought stress, but with tissue specificity. PdHyPRP4, PdHyPRP5, PdHyPRP6, PdHyPRP7, and PdHyPRP8 showed high and relatively stable expression across all three tissues, while PdHyPRP1, PdHyPRP2, PdHyPRP9, PdHyPRP11, and PdHyPRP12 were mainly highly expressed in stems and roots. Under NaCl stress, the expression patterns of PdHyPRP1 and PdHyPRP2 exhibited similar expression patterns across three tissues, showing upregulation under low concentration stress and an initial upregulation followed by downregulation over time under high concentration. However, under PEG stress, their expression patterns varied among leaves, stems, and roots. PdHyPRP1 and PdHyPRP2 were successfully cloned from P. × euramericana ‘Bofeng 3’, with 840 bp and 597 bp CDS, respectively. Dual-gene editing and silencing vectors were constructed, and two edited-lines and two RNAi-lines simultaneously targeting PdHyPRP1 and PdHyPRP2 were obtained. Salt tolerance evaluation demonstrated that compared to the wild type, both edited- and RNAi-lines displayed milder leaf damage and significantly reduced accumulation of O₂^–, H₂O₂, and MDA in leaves and roots (0.60–0.85 times and 0.60–0.86 times of wild-type, respectively), indicating an improvement in salt tolerance. Conclusion: A total of 14 PdHyPRPs are expressed in leaves, stems, and roots of P. × euramericana ‘Bofeng 3’ with tissue specificity and respond to drought and salt stress. PdHyPRP1 and PdHyPRP2 play negative regulatory roles in salt stress response of P. × euramericana ‘Bofeng 3’, and their mutation or silencing can enhance salt tolerance by reducing reactive oxygen species accumulation and membrane lipid peroxidation. The PdHyPRP1/2 editing vector has been successfully constructed, and PdHyPRP1/2-edited lines of P. × euramericana ‘Bofeng 3’ with improved salt tolerance are obtained, providing new germplasm and target genes for stress resistance breeding in poplar.

Objective: This study aims to investigate the evolution patterns and driving factors of the effective saturation value and sequestration potential (defined as the percentage of the difference between the effective saturation value of actual mineral-associated organic carbon (MAOC) and its sequestration potential (the percentage of the difference between MAOC effective saturation value and actual content to effective saturation value) in Pinus massoniana plantations with stand development, so as to provide a scientific basis for carbon sink enhancement management. Method: P. massoniana plantations with different ages (young: 6 a, middle-aged: 13 a, near-mature: 29 a, mature: 38 a) in the hilly region of central Hubei Province were taken as the research object, and the plantations were subjected to a long-term field nutrient addition incubation experiment. The density-particle size fractionation method was used to quantify the dynamic changes of MAOC in the 0–10 cm soil layer of different age groups, evaluate the MAOC effective saturation value and sequestration potential, and identify the driving factors. Result: 1) Under natural conditions, the MAOC content in mature plantation (22.29±0.38 g·kg^–1) was significantly higher than that in near-mature (14.89±0.86 g·kg^–1), young (14.14±0.30 g·kg^?1), and middle-aged (11.82±0.69 g·kg^–1) plantations. 2) The MAOC effective saturation value in middle-aged plantation (19.29±0.55 g·kg^–1) was significantly lower than that in young (23.81±0.31 g·kg^–1) and mature (25.41±1.71 g·kg^–1) plantations. The MAOC sequestration potential significantly decreased with stand development, and had the lowest value observed in mature plantations 3) As soils approached MAOC saturation, the nitrogen and phosphorus contents in the mineral-associated fractions significantly increased across all age groups, while the C∶N and C∶P ratios significantly decreased. 4) The MAOC effective saturation value was primarily driven by the C∶P ratio of the mineral-associated fraction (R²=0.55, P<0.01), whereas soil specific surface area was the key factor determining the sequestration potential (R²=0.62, P<0.05). Conclusion: This study indicates that MAOC sequestration potential is highest in young plantations and lowest in mature plantations. In forest management, the long-term carbon sequestration function of P. massoniana plantations can be enhanced by quantitatively regulating soil nutrients to improve the C∶P ratio of the mineral-associated fraction.

Objective: The study aims to investigate differences in root and leaf functional traits of understory woody plants with different mycorrhizal types in subtropical evergreen broad-leaved forests, reveal whether mycorrhizal types influence root and leaf traits, and examine how soil factors affect root and leaf traits in arbuscular mycorrhizal and ectomycorrhizal plants. This research aims to provide a theoretical basis for understanding how mycorrhizal types drive coordinated variations in aboveground-belowground functional traits and the environmental adaptation strategies of plants. Method: Five arbuscular mycorrhizal (AM) and five ectomycorrhizal (ECM) tree species coexisting in a subtropical evergreen broad-leaved forest were selected as the study subjects. Leaf and root functional traits, along with soil properties, were measured and analyzed to clarify the differences in root and leaf functional traits among plants with different mycorrhizal types and to elucidated the relationship between trait variation and soil factors. Result: AM tree species had significantly higher leaf water content, specific leaf area, specific root length, and specific root area, and significantly lower leaf mass per area, leaf carbon content, root tissue density, root branching ratio, branching intensity, and root carbon content than those of ECM species. AM tree species tended to adopt a “low-input, fast-return” resource acquisitive strategy, that is, they rapidly acquired resources through high specific leaf area and low leaf mass per area. ECM species follow a “high-input, slow-return” resource conservative strategy, characterized by low specific leaf area and high leaf mass per area, and they acquired resources more slowly but possessed stronger defensive capabilities. Root trait variation also involved a “do-it-yourself-mycorrhizal investment” collaboration axis, which included independent roots development (high specific root length and specific root surface area) and investment in mycorrhizal symbiosis (high branching intensity and reliance on mycorrhizal symbiosis for resource acquisition). AM species rely on high specific root length and specific root surface area to enhance their root systems’ ability to acquire soil nutrients and water, while ECM species enhance resource acquisition by increasing root branching to promote symbiosis with fungi. The correlations between leaf and root traits were different between the two mycorrhizal types. In AM species, specific leaf area was significantly positively correlated with root branching intensity, reflecting coordinated aboveground-belowground resource acquisition strategies. However, in ECM species, these relationships were mostly non-significant, suggesting a decoupled pattern. Soil factors exerted differential regulatory effects on the allocation of root and leaf traits assembly between the two mycorrhizal types. Under low pH and low inorganic nitrogen conditions, AM species increased specific leaf area and specific root length. Under high pH and low nitrate conditions, ECM species increased root tissue density and branching traits. Soil dissolved organic carbon was positively correlated with specific root length and specific root surface area in AM species (P<0.05), and positively correlated with specific leaf area (P<0.05) in ECM species, and negatively correlated with leaf carbon content in ECM species (P<0.001). Conclusion: The mycorrhizal type derives the differentiation of leaf and root traits along the resource “acquisitive-conservative” economic spectrum and the “do-it-yourself-mycorrhizal investment” collaboration axis. The soil pH and nitrogen availability are key environmental filters modulating root-leaf trait variation.

Objective: This study aims to reveal the response patterns of stand daily transpiration to canopy structure and environmental factors and their differences across slope positions, so as to facilitate precise coordinated forest-water management at the slope-scale. Method: Three fixed plots were established at three slope positions (upper, middle, and lower slopes) on a typical hillslope fully covered by Larix gmelinii var. principis-rupprechtii plantations in the semi-humid area of Liupan Mountains, Ningxia. During the growing season (from June to October) in 2023, the sap flow of the tree trunk was monitored, and the daily stand transpiration was calculated. Simultaneously, the volumetric soil moisture (VSM) in the 0–80 cm soil layer, the effective leaf area index (LAI_e) of forest canopy, and the potential evapotranspiration (PET) outside forest were monitored. Subsequently, the response function relationship was determined based on the outer envelope of the scatter plot between daily stand transpiration and every single factor for each slope position. A daily stand transpiration model reflecting the influence of multiple factors for each slope position was established through multiplicative coupling. The model was calibrated and validated using measured data. The slope-position differences in the response of daily stand transpiration to each dominant factor were quantitatively analyzed. The stand daily transpiration changes under climate change scenarios were simulated, and the LAI_e regulation schemes required to maintain a target transpiration level were determined. Result: 1) The average daily transpiration of stands during the study period exhibited a clear difference among slope-positions, i.e., it at the middle slope (0.85 mm·d^?1) was not significantly higher than that at the upper slope (0.72 mm·d^?1), but significantly (P < 0.05) higher than that at the lower slope (0.67 mm·d^?1). 2) The response of daily stand transpiration to key factors includes a quadratic function that first increases and then decreases with rising PET, and an exponential function that firstly increases with rising VSM and LAI_e but later gradually levels-off. 3) A daily stand transpiration coupling model that simultaneously accounts for the effects of PET, VSM, and LAI_e across all slope-position plots explains approximately 85% (78%–89%) of the variation in daily stand transpiration, effectively reflecting the combined influence of multiple factors. 4) Model-based simulation analyses indicate that there are slope position differences in change slope (or sensitivity) of daily stand transpiration with varying key factors, and PET shows middle slope > upper slope > lower slope, VSM shows middle slope > upper slope > lower slope, and LAI_e shows middle slope > lower slope > upper slope. Under a scenario where future climate change causes a 15% increase in PET, the reduction of forest transpiration to its original level to mitigate ecological water consumption would require an slope position specific reduction of LAI_e (27.4% at upper slope, 25.8% at middle slope, and 16.6% at lower slope). Conclusion: There are differences in the stand daily transpiration and its response sensitivity to major driving factors among slope positions in L. gmelinii var. principis-rupprechtii plantations. Therefore, it is necessary to implement precise forest-water coordinated management with slope position differences.

Objective: This study aims to develop a carbon-sink-oriented management system that is adapted to the ecological characteristics of natural forests in Zhejiang Province, and accurately quantify the key parameters and operational measures required to maximize carbon sequestration. The system is designed to provide a scientific basis for the management of natural forests and the improvement of carbon sink capacity in Zhejiang Province. Method: The entire natural forests across Zhejiang Province were used as the research object. Based on the data from the 9th (2019) National Forest Resource Inventory in Zhejiang Province and permanent-plot remeasurements conducted in 2023, a total of 1 307 permanent natural-forest plots unaffected by harvesting, fire, pests, or disease were selected to establish tree growth, mortality, and ingrowth models. Multidimensional covariates such as diameter at breast height (DBH), tree-species diversity, diameter-class diversity, and stand basal areacross-sectional area at breast height were incorporated to construct a transfer matrix growth model for natural forests in Zhejiang Province, achieving accurate simulation of stand dynamics. Based on the equilibrium theory for stand diameter distributions, 27 candidate equilibrium curves were generated as management targets by coupling three key parameters. Each curve represented a combination of post-harvest stand cross-sectional area at breast height (B), maximum retained-tree DBH (D), and adjacent diameter ratio (q). The tested values were 30, 35, and 40 m²·hm^–2 for B; 35, 40, and 45 cm for D; and 1.3, 1.5, and 1.7 for q. The transition matrix growth model was used to conduct dynamic simulation of 50-year growth and management with 10-year cutting cycles, and surplus trees removed during each intervention. The optimal carbon-sequestration scenario was selected using the equilibrium index (var), carbon stock (C), and annual carbon-stock increment (ic). Result: 1) The transition matrix growth model based on the 30% independent test setperformed well (RMSE=0.64 m²·hm^?2; MAE=0.62 m²·hm^?2). DBH, tree-species diversity, and other covariates significantly affected tree growth, mortality, and ingrowth. 2) Twenty out of the 27 candidate equilibrium curves attained equilibrium. The optimal curve was defined by B=40 m²·m^?2, D=45 cm, and q=1.3. 3) Under the guidance of the optimal curve, in simulating the growth of forest stands, a stable diameter-class structure dominated by oak species would be formed after 50 years, with carbon stock reaching 237.85 t·hm^?2, and significantly enhancing carbon-sequestration performance. Conclusion: This study develops a natural-forest carbon management framework integrating a transition matrix growth model with equilibrium curves. The optimal parameter combination is determined, which can jointly promote stand structural stability and carbon sequestration. This framework provides technical support for shifting natural-forest management in Zhejiang from passive protection to proactive carbon-sink enhancement.

Objective: This study aims to develop stand-level mortality and ingrowth models for natural Pinus massoniana forests in Zhejiang Province, and identify the key factors influencing stand dynamics, so as to provide a theoretical basis for the sustainable management of P. massoniana forests in this region. Method: Based on the data from the 5th (1994), 6th (1999), 7th (2004), and 8th (2009) Continuous Forest Inventories in permanent sample plots of Zhejiang Province, a total of 389 sample plots of natural P. massoniana forests were selected, with 311 used for model simulation and 78 for validation. The Kendall’s tau-b correlation coefficient was used to screen stand and site factors. Six types of generalized linear models, including the Poisson model (Poisson), the negative binomial model (NB), the zero-inflated Poisson model (ZIP), the zero-inflated negative binomial model (ZINB), the Hurdle-Poisson model (HP), and the Hurdle-negative binomial model (HNB), were constructed to fit and compare the stand mortality and ingrowth processes. The fitting performance of each model was compared using Akaike information criterion (AIC), Bayesian information criterion (BIC), –2 times the log-likelihood (–2logL), and the Vuong test. The prediction performance was evaluated using mean absolute error (MAE) and root mean square error (RMSE). Result: 1) The ZINB model demonstrated the best overall performance for both mortality and ingrowth simulations. 2) The negative binomial series models (NB, ZINB, HNB) showed significantly better fit than their corresponding Poisson series counterparts (Poisson, ZIP, HP), with comparable performance observed between the ZIP and HP models, and a slight advantage of the ZINB model over the HNB model. 3) Stand mortality was primarily influenced by stand density, stand basal area at breast height, broad-leaved tree basal area at breast height, and elevation. 4) Stand ingrowth was mainly affected by stand density, stand basal area at breast height, and broad-leaved tree basal area at breast height. The site factors showed no significant influence on ingrowth. Conclusion: Stand density is a core variable that simultaneously regulate both mortality and ingrowth processes, but with opposite effects. The increase in the proportion of broad-leaved trees helps reduce mortality risk in P. massoniana stands and promotes its regeneration. It is recommended that practical forest management for P. massoniana should involve in rational control of stand density and appropriate enrichment planting with broad-leaved species, thereby maintaining the long-term health and productivity of P. massoniana forests.

Objective: This study aims to empirically test the causal effect and mechanism of national park pilot construction on biodiversity, and resolve theoretical disputes over whether the national park pilot can effectively promote, so as to provide a scientific basis for improving the spatial layout of national parks and the policy system for biodiversity conservation. Method: The bird observation data in China were used to construct bird richness indicators, based on panel data from 266 cities at the prefecture level and above (2011—2023). A difference-in-differences (DID) approach was applied to systematically to evaluate the impact of national park pilots on avian biodiversity. PSM-DID was used to alleviate the sample selection bias. Parallel trend tests, placebo tests, and exclusion of concurrent policies were used to verify robustness. Heterogeneity analysis was conducted on geographic location, endangerment level, and migratory habit. Mechanism analysis was conducted to identify three pathways: forest protection quality, government environmental governance, and public environmental awareness. An extended analysis with spatial econometric models was used to test spatial spillover effects. Result: 1) The impact of national park pilot construction on avian biodiversity was significantly positive at the 1% level. This result remained robust after PSM-DID, placebo tests, and exclusion of concurrent policies. 2) Heterogeneity analysis showed: in the impact of national park pilots on avian biodiversity, the positive effect was significantly stronger in central and western regions than in eastern regions; the improvement of non-endangered bird populations was greater than endangered ones; the improvement of resident bird communities was more than migratory ones. 3) Mechanism analysis indicated that national park pilot construction promoted biodiversity by increasing forest coverage and stand quality, strengthening local government environmental governance, and raising public environmental awareness. 4) Extended analysis found a significant positive spatial spillover effect, improving bird diversity in adjacent cities. Conclusion: The pilot construction of the national park system serves as an effective pathway for enhancing avian biodiversity conservation. In the phase of deepened advancement, efforts should be directed toward optimizing the spatial layout of the national park system, and establishing a long-term driving mechanism that integrates habitat protection, governmental governance, and public participation in a triadic synergy. At the regional strategic level, priority should be given to establishing new parks in the central and western regions, while formulating differentiated species-specific conservation plans for endangered species and migratory bird assemblages. Concurrently, it is imperative to break down administrative boundary barriers and build a cross-regional collaborative protection network of ecological corridors, so as to fully unleash the spatial spillover effects of the national park pilots and achieve systematic enhancement of conservation.

Objective: This study aims to develop an efficient prediction system that does not require genotypic data through multi-dimensional phenomics analysis, reveal the key phenotypic characteristics of early-fruiting Juglans regia (walnut), and provide clues for deciphering their genetic linkage relationships, so as to offer a methodological reference for investigating the formation mechanisms of other special groups in woody plants. Method: A total of 156 typical and closely related mature walnut samples from mature trees preserved at the National Long-term Scientific Research Base in Aksu, Xinjiang were targeted, and 31 early-fruiting and 8 late-fruiting germplasm resources were selected for phenotype identification. According to international standardized measurement protocols, a total of 31 phenotypic traits were systematically determined, covering four categories: stem/branch morphology, leaf characteristics, bud development, and fruit external quality. A multi-dimensional integrative strategy was used for data analysis. Firstly, orthogonal partial least squares-discriminant analysis (OPLS-DA) was applied to reduce the dimensionality of high-dimensional phenotypic data and identify discriminatory variables. Then, analytic hierarchy process (AHP) was used to assign weight coefficients to each variable. Finally, grey relational analysis (GRA) was integrated to construct a synergistic model incorporating multi-parameter interactions. The entire workflow, from data processing to model construction, was automated via custom Python scripts. This analytical framework operated entirely on phenotypic data, achieving classification and prediction of complex traits without reliance on genotypic information. Result: The multivariate analysis was used to identify 13 core phenotypic parameters significantly associated (P<0.01) with early-fruiting traits in walnut, covering fruit traits (nut weight, nut transverse diameter, and shell thickness), leaf traits (second leaflet pair-petiole angle below terminal leaf, leaflet width, basal leaf length, basal leaf area, basal leaf-petiole angle, terminal leaf area, leaflet area, and basal leaf width), stem/branch trait (short-shoot internode length), and mixed bud trait (mixed bud insertion position). The model constructed based on these parameters achieved 90.81% classification accuracy on an independent validation set, demonstrating strong predictive power of the selected phenotypic markers for early-fruiting traits and confirming the reliability of this genotype-free prediction system. Furthermore, the directionality of correlations with early-fruiting traits was clarified: nut transverse diameter, basal leaf area, basal leaf-petiole angle, leaflet area, and mixed bud insertion position showed positive correlations with the formation of early fruiting traits, while nut weight, shell thickness, and internode length showed negative correlations. Conclusion: This study has identified the core phenotypic traits of early-fruiting walnuts and elucidated the basis for their trait formation. The established phenotypic marker screening system provides a standardized method for early selection of early-fruiting germplasm without requiring genotypic data. Furthermore, the proposed multi-dimensional analytical framework is applicable not only to deciphering genetic mechanisms in walnuts but also extensible to characterizing other special groups in woody plants, thereby providing phenotypic-level theoretical support for germplasm utilization.

Objective: Ａ comprehensive evaluation was conducted on growth, wood property, and stress resistance traits of Picea abies clonal population in Xiaolongshan, Gansu Province. The genetic structure, genetic diversity, and trait genetic parameters of the population were characterized based on genome-wide SNP markers, thereby providing a basis for elite clone selection and core breeding population construction. Method: A total of 136 P. abies clones were used as the experimental material to determine 15 growth, wood property and stress resistance traits. At the same time, 31 285 high-quality SNP markers retained after quality control were used to analyze population structure, genetic diversity, heritability, and genomic estimated breeding values. On this basis, the phenotypic variation, trait correlations, membership function analysis, principal component analysis (PCA), and a multi-trait comprehensive index were further integrated to comprehensively evaluate and screen the multiple traits of the clones. Result: 1) The P. abies clonal population showed a certain degree of genetic stratification. At K = 2, it could be preliminarily divided into two subgroups, with most clones exhibiting mixed ancestry. Population genetic diversity parameters, including effective allele number (N_e), observed heterozygosity (H_o), expected heterozygosity (H_e), Shannon-Wiener diversity index (I), and polymorphic information content (PIC), indicated that the population retained a certain level of genetic variation; however, H_o was lower than H_e, suggesting that the observed heterozygosity was lower than the expected level. 2) The coefficients of variation for the 15 traits ranged from 8.31% to 36.65%. Tree height (H) was most strongly correlated with diameter at breast height (DBH) (r = 0.85). Starch content was significantly positively correlated with soluble sugar content, but significantly negatively correlated with nitrogen and phosphorus contents. Heritability varied markedly among traits. Starch content, phosphorus content, budburst stage (BS), and wood density (Pilodyn value) showed relatively high heritability; modulus of elasticity, leaf dry weight (LDW), and DBH showed moderately high heritability; whereas H, chlorophyll content (CC), and nitrogen content showed relatively low heritability. 3) Using three selection methods at a 10% selection intensity, the overlap of elite clones was relatively high for growth and wood property traits but low for stress resistance traits. After retaining H and DBH, PCA of the remaining 13 traits identified seven key indicators, namely H, DBH, LDW, Pilodyn, MOE, CC, and BS. Except for H and CC, all of these key traits showed moderate or higher heritability. 4) Based on the comprehensive evaluation of these seven traits, 13 elite clones with stable overall performance were identified. Furthermore, the population could be divided into three groups based on the seven key traits, with the 13 elite clones mainly clustered in Group I. These integratively selected elite clones were distributed across different branches of the SNP-based phylogenetic tree, indicating that they covered a relatively broad genetic background while maintaining breeding potential. Conclusion: Although the P. abies clonal population showed limited overall genetic differentiation, it still retained a certain level of genetic diversity and exploitable genetic variation. The multi-trait selection strategy integrating phenotypic evaluation with molecular genetic parameters can facilitate the coordinated improvement of growth, wood property, and stress resistance, improve the stability and accuracy of elite clone selection, and provide a basis for core breeding population construction and subsequent parental optimization.

Objective: Based on the progeny determination data from genetic design trials involving cross-breeding between Pinus elliottii and P. caribaea, this study analyzed the genetic variation patterns of growth traits in the hybrid pine. The superior parents with high combining ability and hybrid combinations with heterosis were screened, aiming to provide a reliable theoretical basis and material foundation for developing hybrid breeding programs and selecting elite families in P. elliottii × P. caribaea. Method: A total of 27 P. elliottii × P. caribaea families (6 × 5 testcrossing design, with missing 3 combinations) were used as research materials, and the tree height, diameter at breast height (DBH), and wood volume of the 15-year-old trees were measured. The genetic parameters were estimated through analysis of variance. The parental evaluation and selection of superior hybrid combinations were conducted by analyzing combining ability and calculating heterosis. Result: The average values of tree height, DBH, and timber volume of 15-year-old hybrid pines were 18.87 m, 22.64 cm, and 0.42 m³, respectively, with average heterosis of 9.42%, 19.29%, and 87.62%, respectively. There were extremely significant differences in DBH and timber volume among paternal, maternal, and their interaction effects, while tree height only showed significant differences among maternal parents. The heritability for tree height, DBH, and volume was 0.26, 0.29, and 0.27, respectively, indicating moderate genetic control. For tree height traits, the parent interaction was greater than the maternal effect, which was in turn greater than the paternal effect. The general combining ability (GCA) effect exceeded the special combining ability (SCA) effect. For DBH and volume traits, the variance component of the parent interaction was close to the sum of the maternal and paternal effects. The paternal effect was significantly greater than the maternal effect, and the SCA effect exceeded the GCA effect. The paternal additive contribution to DBH and volume was significantly higher than that of the maternal parent, while the maternal parent contributed more to tree height than the paternal parent. The GCA range of the maternal parent for tree height, DBH, and wood volume was –1.2119?0.8338 m, –3.1639?2.2895 cm, and –0.1223?0.1005 m³, respectively, while the paternal parent GCA ranged from –0.8299?0.5333 m, –3.4347?2.3379 cm, and –0.1292?0.1040 m³, respectively. S7 and H3 had the highest GCA, being the optimal maternal and paternal parents, respectively. The SCA ranges for tree height, DBH, and wood volume were –1.6523?1.4606 m, –4.5242?3.6855 cm, and –0.1855~0.1305 m³, respectively. The hybrid combination of S6×H3 had the highest SCA. Five high-yield stable hybrid families were selected based on comprehensive absolute growth, parental combining ability, and intra-family variation, which were S6×H3, S16×H22, S6×H8, S7×H9, and S13×H8, and their average genetic gain of 9.26% in volume and an average better-parent heterosis was 171.78% in volume. Conclusion: P. elliottii × P. caribaea exhibits strong rapid growth potential and high heterosis in the central Guangxi region. The interactions between parental lines exert a greater influence on growth traits than the individual parental effects. The heterosis observed is primarily driven by dominant and epistatic effects, with additive effects playing a secondary role. The maternal parent exerts a stronger influence on tree height growth than the paternal parent, while the paternal parent has a greater effect on radial growth than the maternal parent. The above conclusions provide a reliable theoretical basis for formulating the breeding program of P. elliottii × P. caribaea. Additionally, three key breeding parents of P. elliottii and P. caribaea, and five superior families of P. elliottii × P. caribaea were selected, providing high-quality materials for P. elliottii × P. caribaea breeding and the promotion of superior varieties.

Objective: With integrating national county-level epidemic data of China from 1982 to 2023, spatiotemporal scan statistics and regression models were employed to to systematically reconstruct the transmission pathway of pine wilt disease (PWD) in China over past 42 years, identify key evolutionary stages, quantify the heterogeneous effects of drivers of recent hotspot outbreaks, and reveal differences in driving modes among regional hotspots, thereby providing a scientific basis for formulating differentiated and precise prevention and control strategies. Method: SaTScan was used to perform spatiotemporal scan statistics based on the discrete Poisson model. The temporal unit was year, and both the maximum spatial and temporal scanning windows were set to 30%. A total of 999 Monte Carlo simulations were conducted to identify significant hotspots (P<0.05). A binary logistic regression model was separately constructed for the three temporally overlapping spatiotemporal clusters identified during 2015—2023 (located in central-southern China, the Shandong Peninsula, and eastern Liaoning, respectively). The dependent variable was whether PWD occurred at the county level (1=occurred, 0=not occurred). The independent variables were the number of spatially neighboring epidemic counties (NEIGHBOR), mean temperature and precipitation from June to September (TEMP_MEAN, PREC_MEAN), normalized difference vegetation index (NDVI), tree cover (TC), and regional gross domestic product (GDP). The Hosmer–Lemeshow test was used to evaluate model goodness-of-fit. Result: 1) Spatiotemporal evolution pathway: a total of 9 significant hotspots were detected, exhibiting a four-stage transition pattern. During 1982—1988, only one significant hotspot was identified at the Jiangsu–Anhui border (RR=3.39), reflecting early local clustering of the epidemic. During 1989—1999, two clustering centers formed in the Yangtze River Delta (RR=12.22) and the Pearl River Delta (RR=8.66). During 2000—2014, the epidemic expanded into the central-western inland, with a new significant hotspot in the Wuling Mountains. During 2015—2023, there was a trend of a trend of “northward expansion and westward advancement”. A significant hotspot identified in the Hunan–Hubei–Jiangxi border region (RR=14.15), and northern epidemic areas were established for the first time in the Shandong Peninsula and eastern Liaoning, showing a multi-point outbreak pattern. 2) Common driving mode: the spatial neighbor effect was significant in all three hotspot regions (P<0.05), but its intensity varied: the NEIGHBOR odds ratios for central-southern China, the Shandong Peninsula, and eastern Liaoning were 2.606, 2.359, and 1.627, respectively. This indicates that for each additional epidemic county in surrounding areas, the odds of local epidemic occurrence were 1.627–2.606 times the reference level, suggesting that local diffusion is a common driver across the three hotspot regions. 3) Regionally heterogeneous dominant factors: precipitation in the central-southern hotspot showed a significant negative effect, suggesting that high-humidity environments might reduce the risk of PWD transmission by inhibiting vector insect activity. In the Shandong Peninsula hotspot, NDVI was the strongest positive factor, with a standardized odds ratio of 9.33, indicating that host vegetation density might be a key habitat screening factor for colonization and outbreak in this region. In the eastern Liaoning hotspot, the June–September mean temperature was the dominant limiting factor, indicating that temperature suitability is a fundamental prerequisite for colonization at the high-latitude frontier. Conclusion: This study constructs, for the first time, a national-scale long-term analytical framework, revealed the four-stage invasion and diffusion pathway of PWD (coastal introduction-regional spread-inland jump-northward outbreak), and clarifies the driving mode of “spatial neighbor effect as a common fundamental driver, with regional habitat factor heterogeneity dominating outbreak intensity”. This research provides a key scientific basis for formulating precise prevention and control strategies. In particular, emerging northern epidemic regions need to strengthen climate early warning and source interception, while established epidemic regions should optimize monitoring layouts according to dominant factors.

Objective: Based on the phenomenon that the Anoplophora glabripennis population in Guyuan, Ningxia preferentially infests Fraxinus pennsylvanicain mixed stands with Salix matsudana, this study compares the differentiation in host adaptability between this population and the population in Qiqihar, Heilongjiang, which mainly infests Acer negundo. The purpose of this study is to reveal the physiological mechanism underlying the adaptation of the Guyuan population to F. pennsylvanica and provide important physiological basis for regional monitoring and ecological management for different geographical populations of A. glabripennis. Method: A. glabripennis adults for this experiment were collected from the two regions: the Guyuan population (G) and the Qiqihar population (Q). The two populations were mainly fed on either F. pennsylvanica or A. negundo. In this study, four treatments were set up: Guyuan population fed on F. pennsylvanica (G-Y), Guyuan population fed on A. negundo (G-F), Qiqihar population fed on A. negundo (Q-F), and Qiqihar population fed on F. pennsylvanica (Q-Y). The nutrient and secondary metabolite profiles in the bark of one-year-old branches from both host plants were analyzed. Furthermore, we measured the selective feeding amount, oviposition of two populations feeding on two host plants, non selective feeding amount, survival time of two populations feeding on a single host plant, and midgut enzyme activities (digestive, detoxification, and protective enzymes) of the beetles under the different treatments. Result: 1) There was a significant difference in the bark composition between the two host species: A. negundo had higher moisture, cellulose, soluble sugar, and sesquiterpene content than F. pennsylvanica, while F. pennsylvanica contained more flavonoids and tannins than A. negundo. There was no significant difference in starch, protein, and alkaloid content between the two. 2) Behavioral and survival of A. glabripennis exhibited distinct population specificity. The Qiqihar population had a significant preference for feeding on A. negundo, with significantly reduced survival after feeding on F. pennsylvanica, and no oviposition behavior on the host. Although the Guyuan population also preferred A. negundo, there was no significant difference in non-selective feeding amount or survival duration on the two hosts and was capable of ovipositing on F. pennsylvanica. 3) There were significantly differences in the activities of digestive enzymes, detoxifying enzymes, and protective enzymes among different treatments, which reflected the activity of midgut enzymes was co-regulated by host plant and population origin. Digestive enzyme activities were correlated with host nutrient levels, while the activities of detoxifying enzymes and protective enzymes were primarily modulated in response to host secondary metabolites. Conclusion: There is significant differentiation in their physiological adaptability to the non-preferred host, F. pennsylvanica, between the two geographic populations. Both populations maintained a strong feeding and oviposition preference for A. negundo, while only the Guyuan population has developed a notable physiological tolerance and utilization capacity for F. pennsylvanica, through its efficient detoxification enzyme system, enabling completion of feeding, survival, and reproduction on this resistant host. This differentiation likely represents local adaptive evolution under long-term selection pressure from differing host environments. The findings provide crucial physiological insights for developing region-specific monitoring and ecological management strategies for A. glabripennis.

Objective: In this study, an analysis was conducted on the geometric morphology characteristics of right forewings of 16 species of noctuid adults, which aims to provide a morphological basis for the digital classification of moths and also conduct exploratory research on insect species in the field of axial analysis. Method: Firstly, the software tpsDig2 was used to extract local landmark coordinate data in a specific order. Secondly, the Procrustes superposition analysis was conducted on the topological structure differences within and between species, and explored the degree of morphological variation of different noctuids at different landmarks. Thirdly, the data of average configuration map were visualized to explore the axial specificity of 16 species of noctuids at different landmarks. The thin plate spline analysis was used to investigate the variation trend of landmark on the right forewing of noctuids. Finally, discriminant analysis was applied to build classification function to classify and identify the noctuid insects. Result: 1) The analysis of the topological structure of landmark space showed that 16 species of noctuids exhibited high homology within species, and significant differences existed between species. 2) The Procrustes superposition diagram revealed that 16 species of noctuids exhibited a significant dispersion trend at the the crossing points of radial vein R₄, elbow vein Cu₂, and buttock vein 2A with the outer edge of the moth wing, as well as at the the crossing point of radial vein R₁ base, while their distribution was more concentrated at the the crossing points of midrib M₁, M₂, and M₃ with the outer edge of the moth wing. 3) Axial specificity analysis showed that there were morphological differences between the horizontal and longitudinal directions of the crossing points of the wing veins around the wing chambers of 16 noctuids, indicating that the inter species differences in this region were mainly reflected in the horizontal direction, while there were no significant axial differences at the crossing points of the outer edge of the moth wings. 4) Thin plate spline analysis presented the changes in the wing parts of 16 species of noctuids corresponding to 15 landmarks on the right forewing, and found that noctuids belonging to the same genus had similar trends in changes. 5) The discriminant analysis accuracy of the test samples was 98.12%, with only 3 Trisuloides c-album mistakenly classified as Trachea atriplicis, while the remaining 16 species of noctuids were correctly classified. Conclusion: There are significant differences in the dispersion degree and variation trend of 16 species of noctuid moths at different landmark points on the wing veins. The interspecific differences at landmarks around the wing chamber are mainly reflected in the horizontal direction, while the differences in the horizontal and longitutional directions at the outer edge of the wing chamber are not significant. Combined with discriminant analysis, the effectiveness and reliability of geometric morphological characteristics of moth wings in the taxonomic identification of noctuid insects are verified.

Objective: This study explores the impact of material sensory characteristics on human psychological and physiological restoration in indoor environments, and analyzes the regulatory role of subjective impressions and comfort perception in the recovery process. The purpose of this study is provide empirical support for understanding the formation mechanism of restoration effects in real indoor environments, and provide theoretical basis and practical reference for the scientific selection and design application of wooden materials in biophilic architecture. Method: The coated and uncoated Chinese fir wall panels served as visual stimuli comprised, and solid Chinese fir board and melamine-impregnated paper-overlaid particleboard served as tactile stimuli. Three visual-tactile wooden environments with significant differences in comfort perception were constructed, and latex-painted walls and ceramic tiles were used as a control environment. Sixty-four university students were recruited to perform a cognitive fatigue-inducing task in each condition, and their electrocardiography (ECG) and electrodermal activity (EDA) post-task physiological responses were recorded using electrocardiography (ECG) and electrodermal activity (EDA). Psychological restoration was assessed with the state-trait anxiety inventory-6 (STAI-6), subjective vitality scale (SVS), and restoration outcome scale (ROS). Environmental perceptions were rated on Likert scales. ANOVA and non-parametric methods were used to compare the differences in physical and mental responses under different environmental conditions, and Spearman rank correlation analysis was used to examine associations between physiological indices and subjective evaluations. Result: Compared with the control environment, the short-term interaction between visual and tactile senses in the wooden environments significantly enhanced post-task parasympathetic activity. The high-frequency power (HF) of heart rate variability and root mean square of successive differences (RMSSD) in adjacent normal sinus intervals were both increased compared to the baseline period, and the amplitude was significantly greater than that in the control environment (P<0.05). The difference in surface gloss caused by wall coating did not produce significant physiological effects (P>0.05). Tactile contact with melamine-overlaid particleboard significantly reduced skin conductance level (SCL) (P<0.05), but did not cause corresponding change in perceived naturalness (P>0.05). Psychological restoration scores were positively associated with perceived naturalness, comfort, and preference (P<0.05). Increases in HF and RMSSD were also correlated with higher naturalness and preference ratings (P<0.05). Conclusion: Short-term interaction between visual and tactile senses in the wooden environments effectively facilitates psychological and autonomic recovery following cognitive effort, and its effects are not only related to the sensory properties of the material, but also regulated by individuals' subjective perception of the overall comfort and impression of the environment. Meanwhile, changes in the autonomic nervous system exhibit sensory specificity, with visual stimuli enhancing parasympathetic activity and tactile stimuli regulating skin sympathetic activity. These findings suggest that restorative effects arise from a synergistic integration of visually mediated psychological relaxation and tactile-mediated physiological modulation, rather than from a single dimension of perceived naturalness.

Objective: This study aims to systematically investigate the key constraints and underlying mechanisms affecting the realization of ecological product value in the “photovoltaics (PV) + ecological governance” project in Kubuqi, Inner Mongolia. Based on this analysis, it proposes targeted optimization pathways to deepen the theoretical understanding of practical challenges and provides decision-making references for the sustainable development of similar projects. Method: In this study, the Kubuqi “photovoltaics + ecological governance” project in Inner Mongolia was taken as a typical case. A qualitative research paradigm and grounded theory method were used to conduct open coding, axial coding, and selective coding to semi-structured interview data from 15 core or direct stakeholders. A cross validation was conducted by combining policy documents, enterprise materials, and field observation information. Result: The results showed that the Kubuqi “photovoltaic + ecological governance” project had generated multiple ecological products, including photovoltaic power generation, vegetation restoration, land improvement, ecological agriculture, carbon-sink enhancement, and ecological landscapes. However, the value of these composite products were yet not fully transformed into stable and sustainable economic returns. The main constraints were concentrated in four areas. 1) An inadequate policy and institutional environment, which manifested as a gaps between top-level design and grassroots implementation, mismatches between ecological governance matching policies and resource carrying capacity, ambiguous demarcation of ecological product property rights, absence of industrial support policies, and inconsistent standards and certification systems. 2) Natural and technological constraints, the severe water scarcity and infertile soils conditions in Kubuqi region posed fundamental limitations, and there were technical challenges including immature and poorly adaptable technologies such as under-panel planting, imbalances between costs and benefits, and insufficient long-term monitoring data and scientific research support. 3) Absence of multi-stakeholder coordination and benefit-sharing mechanisms, there existed functional fragmentation and insufficient collaboration exist among government departments. The primary motivation of photovoltaic enterprises—generating revenue from power production—was misaligned with ecological investment. Community and farmer participation remained low with limited benefit channels, and fair, transparent ecological benefit distribution mechanisms were lacking. 4) Cognitive and capacity limitations, there were misconceptions and cognitive biases among various sectors of society regarding ecological product value. There was a disconnect between academic research and frontline practical needs, while grassroots implementation units faced shortages of specialized personnel and supporting resources. Conclusion: To overcome these challenges, the study proposes a systematic optimization pathway that focuses on broadening diversified value realization channels. This involves transforming ecological value by developing eco-derived industries, creating tradable rights-based products, improving ecological compensation mechanisms, and establishing eco-tourism brands. Innovative approaches to project implementation and operational management are essential, including optimizing land transfer and consolidation models, exploring suitable integrated governance technologies, and establishing multidimensional project supervision and acceptance mechanisms. Ultimately, by strengthening policy coordination, technological innovation, and capacity building, a “value-added governance” model can be established, centered on multi-stakeholder collaborative governance and capable of facilitating the integration of governance with industrial development, thereby promoting the sustainable and large-scale realization of the value of ecological products.

Objective: This study aims to reveal the evolutionary game dynamics of participants in forestry carbon sequestration projects, identify the key parameters influencing their decision-making, and explore optimal policy combinations by comparing the marginal effects of different policy measures, thereby providing a theoretical basis and policy references for mitigating default risks in forestry carbon sequestration projects. Method: A four-party evolutionary game model involving enterprises, forest landowners, verification institutions, and the government was constructed to analyze the behavioral decisions and evolutionary paths of the participants at different stages of project development. Based on this model, published data on forestry carbon sequestration projects were incorporated with typical cases, and MATLAB R2021a was used to conduct numerical simulations. Result: The game system converges to different stable equilibria at different stages of project development. In the initial stage, enterprises may engage in the default behavior of land hoarding and subcontracting due to risk aversion or speculative motives, while forest landowners may choose to prematurely harvest carbon sink forests because of insufficient technical guidance and other factors. In the development stage, verification institutions may only review the completeness of submitted applications due to cost constraints. In the mature stage, with the gradual improvement of carbon sequestration methodology and the continuous strengthening of the regulatory system, enterprises and forest landowners would ultimately tend toward long-term voluntary cooperation, thereby ensuring the authenticity and sustainability of emission reductions from forestry carbon sequestration projects. Simulation results indicate that: 1) inequitable income distribution is a major driver for default by the participants, and policy interventions that alleviate information asymmetry between enterprises and forest landowners can significantly promote compliance; 2) compared with increasing the amount of fines, appropriately increasing the amount of default compensation is more effective in promoting enterprise compliance, while government subsidies can effectively improve the quality of verification by verification institutions; and 3) incentive policies such as government subsidies can effectively prevent project quality degradation resulting from lax government supervision. Conclusion: The national voluntary emission reduction trading information platform should be improved to alleviate information asymmetry. A market-oriented regulatory mechanism centered on “default-compensation” and supplemented by government rewards and penalties should be established, and government guidance should be strengthened to continuously advance research on carbon sequestration methodologies and the formulation of relevant standards. These measures can help mitigate default risks in forestry carbon sequestration projects and promote the sustainable development of the forestry carbon sequestration market.

Objective: In the process of ecological civilization construction, in response to insufficient incentives and structural imbalances faced by state-owned forest farms in undertaking the dual tasks of ecological protection and resource utilization, this study aims to examine how improved incentive mechanisms can enhance the developmental vitality of state-owned forest farms, thereby providing a reference for deepening incentive reform of state-owned forest farms and promoting their high-quality development. Method: Based on a review of the employee performance appraisal system in state-owned forest farms and local practices in performance-based incentives, a multitask principal–agent model was constructed to analyze the incentive structure associated with the dual tasks of state-owned forest farms from the perspectives of external and internal incentives. Comparative-static numerical simulations were then conducted to examine differences in behavioral responses among category Ⅰ public-welfare, category Ⅱ public-welfare, and enterprise-type state-owned forest farms under changes in key parameters. Result: 1) Compared with category Ⅱ public-welfare and enterprise-type state-owned forest farms, category Ⅰ public-welfare state-owned forest farms faced a more pronounced shortage of incentives for resource utilization. 2) Category Ⅰ and category Ⅱ public-welfare state-owned forest farms generally exhibited a stronger orientation toward ecological protection, but allocated relatively insufficient effort to resource-utilization tasks. 3) The existing appraisal weights, benefit-transmission mechanisms, and internal allocation arrangements are asymmetric across the two tasks, making external incentives more likely to be skewed toward ecological protection. 4) When ecological accountability is stringent and the transmission of resource-utilization signals and the realization of related performance-based rewards are relatively weak, information attenuation, ecological accountability pressure, and the compression of incentive differentials in internal allocation further amplify the external incentive bias. 5) The task substitutability and performance uncertainty would further exacerbate the incentive imbalance between the dual tasks of state-owned forest farms. Conclusion: Incentive mechanisms for state-owned forest farms should be optimized through coordinated improvements in external appraisal structures, benefit-transmission mechanisms, internal performance allocation, and differentiated appraisal systems. This study provides an economic explanation for the insufficient developmental vitality of state-owned forest farms and offers a theoretical basis for advancing their category-specific reform.

Objective: This study aims to quantitatively examine the spatial imbalance characteristics, network structure patterns, and driving factors of the two stages of production-processing in China’s Camellia oleifera industry, providing decision-making references for optimizing the division of labor and cooperation in major producing regions and improving the coordination efficiency between production and processing. Method: Based on panel data for 15 major C. oleifera producing provinces in China from 2014 to 2022, a two-stage additive network DEA model, a spatial gravity model, social network analysis (SNA), and QAP regression were comprehensively used to construct a bidirectional spatial association network of production?processing, systematically measure the efficiency of the two stages, characterize the network structure, and identify the key driving factors underlying spatial interactions. Result: 1) There was a significant efficiency mismatches exist between the production and processing stages in major C. oleifera production areas, forming two typical patterns:“strong upstream but weak downstream”and “weak upstream but strong downstream”. The average efficiency of raw material supply (0.63) was higher than that of processing (0.60), indicating pronounced mismatches in regional factor allocation and functional positioning. 2) The spatial network of the C. oleifera industry exhibits a radial diffusion pattern, characterized by a layout of“central production core–southwestern collaborative radiation–southeastern processing absorption”. From 2014 to 2022, the network density of the production→processing network increased from 0.338 to 0.386, and the number of ties rose from 71 to 81; the network density of the processing→production network increased from 0.333 to 0.390, and the number of ties rose from 70 to 82. However, the network efficiency of the production→processing network declined from 0.538 5 to 0.483 5, indicating a certain degree of path redundancy. 3) Geographic adjacency, mechanization level, and e-commerce development exerted stable positive effects on the formation of spatial associations, while the effects of planting area, urbanization rate, and economic development level varied across stages. In particular, the effect of planting area shifted from positive to negative as C. oleifera forests enter the full-fruiting stage. Conclusion: To alleviate the spatial structural imbalance between production and processing in the C. oleifera industry chain, efforts should focus on optimizing the regional division of labor and interprovincial cooperation mechanisms, improving post-harvest handling and logistics systems, and enhancing the coordination efficiency between the production and processing stages as well as the overall operational performance of the industry chain.

Plastic pollution has become a global environmental crisis, posing a serious threat to ecological balance and human health. As a substitute for plastic, bamboo serves as a key alternative pathway, contributing Chinese wisdom and solutions to global plastic pollution governance and establishing itself as another “diplomatic card” for China. China has abundant bamboo resources, mature processing technologies, complete industrial chain systems, and vast market scale, laying a solid foundation for the development of the bamboo substitution industry. This paper first systematically elaborates on the connotation of the green transformation concept of “bamboo as a substitute for plastic” and the current development status of diversified substitute products under this background. It then introduces in detail two main technical pathways for developing bamboo substitute products: the original-state utilization of bamboo and composite reconstitution. Based on these two pathways, a series of products have been successfully developed, including bamboo drinking straws, bamboo hangers, bamboo fiber lunch boxes, bamboo fiber automotive interior parts, bamboo winding composite pipes, bamboo water cooling fillers for cooling towers, bamboo film bags, and bamboo charcoal based fully biodegradable mulch films. These products have been promoted and applied in fields such as fast-moving consumer goods, transportation, building materials, packaging, and agricultural and forestry planting. By further developing technologies for the depolymerization and reconstitution of the main components of bamboo cell walls, the traditional limitation that “forming equals shaping” for natural materials has been overcome. This enables the transformation of bamboo into functional plastic reducing sheets and plastic reducing composite materials with optical, sound, thermal, electromagnetic management properties, significantly expanding the functional application boundaries of bamboo. Furthermore, in view of the current bottleneck issues facing the bamboo substitution industry, several considerations are proposed to stimulate the vitality of the domestic market for bamboo substitute products, shift future technological innovation from an “indicator oriented” approach to a “cost oriented” approach, and improve the quality inspection system. Ultimately, the goal is to transform the green concept of “bamboo as a substitute for plastic” into a green industry, providing a nature-based solution for global plastic pollution governance.