Objective: Bamboo forest is a unique forest type in China with significant ecological, economic, and social values. Its spectral feature is often confused with those of other forest types in the same distribution region. It is thus challenging to accurately mapping bamboo forest distribution using remote sensing technology. This study aims to improve the accuracy of mapping bamboo forest by developing newly time-series remote sensing indices (TSI) and combining them with the random forest algorithm, and thus provide a new technical approach for bamboo forest resource monitoring. Method: Training samples for bamboo forest, evergreen forest, deciduous forest, grassland, building, bare land, water body and road were selected through visual interpretation. Based on the Sentinel-2A imagery from 2022–2023, spectral differences between bamboo forests and other cover types were firstly analyzed. Then three single-band (i.e. R_c, RE1_c, and SWIR_c) and two multi-band TSIs (MVI_c and NDWI_c) were innovatively developed to distinguish bamboo forests from other forest types, and four feature sets schemes were designed, namely original bands + traditional indices (FS1), original bands + traditional indices + red-edge indices (FS2), original bands + traditional indices + TSIs (FS3), and original bands + traditional indices + red-edge indices + TSIs (FS4). The random forest classification algorithm was used to compare the effect of FS1, FS2, FS3, and FS4 on the accuracy of mapping bamboo forest, and the importance of TSI in mapping bamboo forest distribution was analyzed. The area of bamboo forest derived from interpreted thematic map were validated against statistics from the 2021 China Forest and Grassland Ecological Comprehensive Monitoring and Evaluation Report. Result: In the four combination schemes, the overall accuracy ranking of land cover classification is as follows: FS4 > FS3 > FS2 > FS1. The producer and user accuracy of bamboo forests are also the highest in FS4, with values of 0.95 and 0.85, respectively. The comparison results of the combination of schemes show that the introduction of TSI significantly improves the accuracy of bamboo forest extraction. The bamboo forest area extracted by FS4 has a better consistency with statistical data, and the root mean square error has decreased from 17.53 in FS2 without using TSI to 7.46. The ranking of feature value importance shows that the five constructed TSIs are all at the top of the importance ranking, and their relative importance is above 75%, indicating that the developed TSIs have important contributions in bamboo forest extraction. Conclusion: The newly developed TSIs play a significant role in mapping bamboo forest distribution, effectively distinguishing bamboo forests from other forest types. The TSIs based on multi-temporal imagery pose a great application potential in forest cover classification.

Objective: The major objectives of this study are to clarify the annual dynamics of energy fluxes and the energy balance in the Otindag Sandy Land of Inner Mongolia, reveal the seasonal and diurnal patterns of carbon fluxes, and explore how environmental factors influence carbon fluxes in this ecosystem. Method: An eddy covariance system and meteorological instruments were used to continuously in situ observe the carbon fluxes, energy fluxes, and environmental factors in the elm savanna ecosystem of the Otindag Sandy Land in Inner Mongolia throughout 2021. The nighttime partitioning of net ecosystem exchange (NEE), the energy balance closure method, and the Random Forest algorithm were used to calculate and analyze the variation characteristics of carbon fluxes, energy balance, and the impacts of environmental factors. Result: 1) The study found that in 2021, latent heat and sensible heat accounted for 48.6% and 41.5% of the net radiation in the elm savanna ecosystem, respectively, with an energy closure of 73%. 2) The annual NEE of the elm savanna was ?231.77 g·m^?2, the gross primary productivity (GPP) was 849.79 g·m^?2, and the ecosystem respiration was 603.36 g·m^?2. The study area served as a carbon source during January, February, November, and December, and a carbon sink during the other months of the year. The carbon sink strength was highest in July and August, with values of ?75.17 g·m^?2 and ?73.75 g·m^?2, respectively, accounting for 64.1% of the annual carbon sequestration. On a daily scale, carbon flux exhibited a typical unimodal variation, with a peak carbon sink of 0.220 g·m^?2 in summer. 3) At the annual scale, air temperature was the primary factor influencing carbon fluxes. At the seasonal scale, total solar radiation was the dominant environmental factor affecting NEE in spring, summer, and winter, with relative importance values of 47%, 37%, and 35%, respectively. In autumn, soil water content was the most influential factor, contributing relative importance values of 58%. For GPP, soil water content was the most significant driver across all seasons, accounting for 72% in spring, 46% in summer, 61% in autumn, and 32% in winter, followed by total solar radiation. Conclusion: The elm savanna has a much stronger carbon sequestration capacity than other grassland ecosystems in the same region, with soil water content being a key environmental driver of carbon fluxes. In the ecological restoration of the Otindag Sandy Land and the Horqin Sandy Land, the recovery of native elm savanna vegetation can provide dual benefits of sandy land rehabilitation and carbon sequestration increase.

Objective: Aiming at the problems of small sample size and non-wall-to-wall remote sensing auxiliary data when generating annual estimates in forest inventory (such as forest aboveground biomass, AGB), based on the hybrid estimation method and Monte Carlo simulation method, the actual inference ability of the hybrid estimation method to solve this problem and the response law of the method to the sample size were explored, the inventory sample size was optimized, and the relationship between the two types of statistical inference methods (based on wall-to-wall remote sensing auxiliary data and based on non-wall-to-wall remote sensing auxiliary data) was clarified to provide a methodological theoretical reference for generating annual estimates in forest inventory. Method: The hybrid estimation theory was used to break through the bottleneck of improving sampling accuracy under the conditions of small sample and non-wall-to-wall remote sensing auxiliary data. Based on the complete data of the 9thnational forest inventory in Genhe Forestry Bureau, different sample sizes of plots m₁ and remote sensing auxiliary data sample sizes m₂ were designed to simulate the small sample size and non-wall-to-wall remote sensing auxiliary data. The conventional model-based and design-based statistical inference methods were introduced for comparison to explore the inference efficiency of the hybrid estimator and its response to the sample size. At the same time, based on the variance analysis of the Hybrid estimator, the mathematical relationship between the Hybrid estimator and the CMB estimator is revealed from the variation rules of the variance components and the formula connection. Result: 1） When the sampling intensity of the Hybrid estimator is 100%, the total variance is equal to the model variance, which is consistent with the inference results of the CMB estimator. 2） When sample plot $ S_1 $ is complete, the variance calculated by the model-based method is only about 51.95% of the variance based on the design method, and the model-based inference accuracy is improved by 2.04% compared with the design-based inference accuracy. 3） When the Hybrid estimator infers the estimates of AGB in the study area, if the sample size m₁ remains the same, the inference accuracy of the Hybrid estimator is basically stable after m₂ is about 12 800 (0.127%), and the inference accuracy has an inverted J-shaped nonlinear relationship with the sample size of the sample plot and auxiliary data. Considering the survey cost and the stability of the results, the best cost-effective sample size for inferring the estimates of AGB is about $ {m}_{1}=40 \left(41\%\right) $ and $ m_2=12\ 800\left(0.127\%\right) $. 4） The Hybrid estimator is based on about 1/5 sample plots of the 9th National Forest Inventory of Genhe Forestry Bureau and 0.127% of the non-wall-to-wall free remote sensing auxiliary data samples, and has achieved an inference accuracy of nearly 90% (87.16%). Conclusion: 1） The CMB estimator can be regarded as a special case of the Hybrid estimator. In actual forest inventory, the method of inferring estimates can be adjusted according to accuracy requirements and cost constraints. 2） In the Hybrid estimator, the variance component derived from the model dominates the uncertainty of inference, which means that increasing the measured sample size, using high-precision auxiliary data (such as lidar data), and optimizing modeling methods will be powerful means to reduce its inference uncertainty. 3） Based on the inverted J-shaped nonlinear relationship between the Hybrid estimator inference accuracy and the sample size of sample plots and auxiliary data, the cost-effective sample size for Genhe Forestry Bureau to infer the annual forest resource estimates is determined to be $ {m}_{1}=40 \left(41\%\right) $, $ m_2=12\ 800\left(0.127\%\right) $. Compared with traditional design-based and model-based statistical inference, it has significant improvements in accuracy and cost, and can better meet the needs of county's annual forest management inventory. 4） For the national forest annual monitoring system, the Hybrid estimator reaches nearly 90% (87.16%) of the inference accuracy in the small-scale area (Genhe Forestry Bureau), based on about 1/5 of the field samples and 0.127% of non-wall-to-wall remote sensing auxiliary data. The inference accuracy can be further improved by improving the quality of auxiliary data and optimizing modeling methods. It has the potential to generating annual estimates innational forest inventory based on annual field plots.

Objective: The purpose of this study was to improve the light conditions of the Korean pine saplings under the forest by simulating the cutting of the canopy layer of the secondary forest, so as to promote the growth and development of the Korean pine saplings and accelerate the recovery process of the secondary forest. Method: According to distance control and growth quality, Korean pine saplings were selected from the core area in a 1 hm² large plot of Mongolian oak secondary forest. Individual openness optimization schemes with different thresholds (K_T =1, 1.5, 2) were used to control the openness of target Korean pine saplings under the forest. The openness optimization scheme is implemented through a two-level iterative optimization method, encompassing both tree and stand levels. At the tree level, the objective is to ensure that the openness of each target Korean pine sapling meets the predefined threshold value. Simultaneously, at the stand level, the optimization involves controlling a specific target Korean pine sapling while taking into account other target Korean pine saplings within the stand. The changes of non-spatial structure (total diameter classes, total species and canopy density) and spatial structure (uniform angle index, neighbourhood comparison and mingling) of stands before and after simulated cutting under different openness thresholds were compared, as well as the differences in openness and openness change rate of Korean pine saplings under different treatments. Result: A total of 145 target Korean pine saplings were selected by distance control and growth quality. The target Korean pine saplings were 1.1?4.9 m in DBH, 1.5?4.7 m in height and 0.6?1.7 m in crown radius. When K_T was 1, 1.5 and 2, the target Korean pine saplings reach the openness condition after cutting 14, 130 and 262 canopy trees for 3, 6 and 8 rounds respectively. After the optimized cutting simulation, the openness of Korean pine saplings was improved as a whole: when K_T was 1, the openness increased by 5.7% on average compared with the control, but there was no significant difference; when K_T was 1.5, the openness was 44.7% on average higher than that of the control, with significant difference; when K_T was 2, the openness was 107.7% on average higher than that of the control, with significant difference. Pre- and post-simulated harvesting activities exhibited no alterations in the total diameter classes and total species within the forest stand. Moreover, spatial structural metrics exhibited minimal changes. Under three different thresholds of openness (K_T = 1, 1.5, 2), the stocking intensity of harvesting is 1.5%, 15.6%, and 37.2% respectively. Compared with the canopy density of the control (CK) at 0.646, the canopy density under the three openness thresholds (K_T = 1, 1.5, 2) decrease by 0.5%, 13.3%, and 33.1% respectively. Conclusion: The two-level iterative optimization method for the openness index of Korean pine saplings improved the light conditions of Korean pine saplings under the forest, while maintaining the stability of most stand structures, and the openness threshold K_T =1.5 was better than K_T =1 or 2. The optimization methodology introduced in this research enables the determination of key parameters, including the total count of cutting rounds, the number of cutting trees within each round, the openness regulation route of each target Korean pine sapling and the distribution of cutting trees under different openness thresholds. This comprehensive framework offers invaluable guidance for shaping the post-replanting thinning strategy of Korean pine saplings and informs best practices for managing secondary forest ecosystems.

Objective: This study aims to analyze the temporal and spatial changes of vegetation resilience in Inner Mongolia Autonomous Region and the impacts of extreme climate on vegetation resilience, revealing the trend and mechanisms of changes in vegetation resilience under extreme climate conditions. Method: Vegetation coverage and vegetation resilience in Inner Mongolia from 2004 to 2023 were assessed with the constructed kernel normalized vegetation index (kNDVI) dataset based on the satellite (MOD 13 Q1 V6.1) and early warning indicators. In addition, based on the daily meteorological data from the U.S. National Centers for Environmental Information (NCEI), 15 extreme climate indices such as extreme temperature and extreme precipitation were calculated for the region. On the basis of a comprehensive analysis of the spatial and temporal characteristics of extreme climate, Pearson correlation analysis and geographical detectors were used to quantitatively assess the impacts of extreme climate on the vegetation resilience in Inner Mongolia. Result: 1) Approximately 85.63% of the areas in Inner Mongolia showed an increasing trend in vegetation coverage, while the vegetation coverage in the Daxinganling forest area and the western edge desert area had a decreasing trend. Approximately 57.46% of the areas in Inner Mongolia showed an increasing trend in vegetation resilience, and the spatial trend showed the pattern of increasing in the eastern and the grassland area at the southern end of the Daxinganling and decreasing in the Daxinganling forest area and the western desert and desert grassland area. 2) From 2004 to 2023, the extreme warmth index showed an increasing trend, with an increase in extreme high temperature events. The extreme intensity and frequency precipitation index showed an increasing trend, and extreme precipitation events were enhanced in intensity and frequency. 3) The correlation between extreme climate indices and vegetation resilience showed obvious spatial heterogeneity, intensity indices such as TNx and TXx showed a positive correlation with vegetation resilience in more than 60% of the region, and extreme low temperature indices (TN10p and TX10p) were mostly positively correlated with vegetation resilience in the western desert area and the Daxing'anling forest area. 4) TN90p and TX90p contributed significantly to resilience enhancement in the eastern steppe zone. The extreme precipitation indices, such as RX5day, RX1day, R20mm, and R10mm, showed significantly positive correlation with vegetation resilience in the central and eastern areas, and had a high explanatory power for vegetation resilience, indicating that the intensity and frequency of extreme precipitation had a greater influence on vegetation changes in Inner Mongolia. Conclusion: The spatial heterogeneity of vegetation resilience and climate extremes in the Inner Mongolia Autonomous Region is obvious, and the main factor affecting vegetation resilience is the extreme precipitation events and vegetation resilience is most sensitive to extreme precipitation intensity. Therefore, in future strategies for vegetation protection and restoration, priority should be given to the stability and sustainability of ecosystems, with full consideration of the climatic characteristics and vegetation restoration potential in different ecological zones, and more attention to water resource management and extreme climate change.

Objective: To accurately quantify the response of the sap flow density of Platycladus orientalis plantations in the mountainous areas of Beijing to extreme soil drought, and to clarify its water use strategy in response to extreme drought stress, so as to provide a scientific basis for the coordinated and comprehensive management of forest and water in mountainous areas of Beijing under the background of climate change. Method: During the growing season of 2024 (May - October), the plantation of P. orientalis, the main local afforestation tree species, was selected in Wuzuolou Forest Farm in Miyun District, Beijing, and fixed a sample plot of 20 m×20 m was set up. The change characteristics of P. orientalis sap flow density in the growing season was continuously monitored by a thermal diffusion sap flow probe, and meteorological factors and soil moisture in 0?40 cm soil layer (expressed as relatively extractable soil water REW) were simultaneously observed, and the change characteristics of sap flow density and the response to environmental factors were analyzed. Result: 1) In the 2024 growing season, there was a continuous 73-days (May 1 to July 12) extreme soil drought, the REW was extremely low at 0.11 during the 73-days, accompanied by continuous high temperature and strong solar radiation intensity. Drought reduced the sap flow density of P. orientalis, maintaining a low level throughout the drought period, with an average value of 0.004 4 mL·cm^?2min^?1, which is significantly lower than the average sap flow density during non-drought periods in the growing season (0.020 2 mL·cm^?2min^?1) (P<0.01). 2) Drought stress diminished and no longer significantly affected the differences in sap flow density among weather types such as sunny, cloudy, and rainy days during the drought period (P > 0.05). Daytime rainfall during the drought period caused a temporary increase in sap flow density, resulting in a slightly higher average sap flow density on rainy days (0.0049 mL·cm^?2min^?1) compared to sunny and cloudy days, which were 4.3% and 16.7% higher, respectively. 3) Drought altereed the diurnal variation pattern and day-night ratio of sap flow density. During non-drought periods, the diurnal variation pattern of sap flow density on sunny and cloudy days follows a “unimodal” pattern, with the diurnal sap flow density accounting for over 95% of the total. However, during drought periods, the diurnal variation of sap flow density on sunny and cloudy days exhibits a “trough” pattern, and the diurnal sap flow density proportion significantly decreases to 44% and 51%, respectively. Daytime rainfall during drought periods can alter the diurnal variation characteristics of sap flow density, showing an increase with the increase in daytime rainfall. The diurnal variation pattern may also revert to a “unimodal” pattern, and the daytime sap flow density ratio gradually increases. 4) The sap flow density of P. orientalis was mainly affected by the meteorological factors (solar radiation intensity, vapor pressure deficit, precipitation) during the drought period. In non-drought periods, the sap flow density was affected by a combination of soil moisture and meteorological factors. Conclusion: Under extreme soil drought stress, P. orientalis significantly reduced its sap flow density and changed the diurnal variation characteristics of sap flow density. During the drought period, the sap flow of P. orientalis was basically not measured during the daytime, but the sap flow used to supplement the water storage of the tree was measured at night. The results showed that P. orientalis had strong drought resistance, and the diurnal variation mode and day-night ratio of sap flow density were changed by closing the stomata during the day to reduce the sap flow density to reduce transpiration water consumption and maintaining a high sap flow density at night to supplement the water storage of the tree, so as to form a higher adaptability to the drought stress environment. Therefore, for arid sunny slopes with thin soils that are highly susceptible to drought stress, planting drought-tolerant P. orientalis should be prioritized. Stand-density regulation and other silvicultural measures should be implemented to reduce canopy transpiration and stand evapotranspiration, thereby sustaining a fundamental forest water balance. This study elucidates the water-use strategies employed by P. orientalis under severe soil-drought stress, thereby providing a theoretical basis for developing climate-adaptive, forest-water-coordinated management schemes.

Objective: This study aims to explore the leaf functional traits and their combinations among woody plants of different life forms in the mountainous region of northeastern Beijing, and systematically analyse the ecological strategy differences of dominant woody plants, providing reference for elucidating the environmental adaptation mechanisms of different life forms in this region. Method: Twenty dominant woody plant species were selected from 19 typical woody plant communities in the mountainous region of northeastern Beijing. A combination of field surveys and laboratory-based physicochemical analyses was used to systematically investigate the 12 typical leaf functional traits and their relationships in three life form types of woody plants—shrubs, deciduous broad-leaved trees and coniferous trees to reveal the trade-off strategies of those woody plants. Result: 1) The leaf area (LA), specific leaf area (SLA), leaf nitrogen content (LNC) and leaf phosphorus content (LPC) of coniferous trees were significantly lower than those of deciduous broad-leaved trees and shrubs, while the leaf thickness (LT), leaf carbon content (LCC), carbon-to-nitrogen ratio (C∶N) and carbon-to-phosphorus ratio (C∶P) of coniferous trees were significantly higher than those of deciduous broad-leaved trees and shrubs, implying that the deciduous trees had higher construction costs and higher nitrogen and phosphorus utilization efficiency in their leaves. 2) The SLA of all dominant woody plants was negatively correlated with leaf dry matter content (LDMC), while LNC was positively correlated with LPC, indicating a trade-off between investment in leaf photosynthetic capacity and physical defense structure. Nitrogen and phosphorus elements in leaves synergistically promoted plant growth, and the demands for nitrogen and phosphorus elements among woody plants in similar habitats did not exhibit specific variations with life forms. 3) There was significantly positive correlation between LT and LDMC in deciduous broad-leaved trees, there was a significant negative correlation between LT and LDMC in coniferous trees, and there was no correlation in shrubs. This variation can be attributed to the fact that the thicker leaves of deciduous broad-leaved trees require a greater LDMC in order to provide the physical structural support. In contrast, coniferous tree leaves, despite their considerable thickness, were characterized by a lower nutrient content and a reduced degree of stomatal opening and water evaporation, which resulted in a lower LDMC. 4) Principal component analysis and permutational multivariate analysis of variance revealed highly significant differences (P<0.01) among woody plants of different life forms along both chemical and structural trait axes, with an explaining power of 63.84% for the first two axes. The results showed that shrubs tended to have high LNC, LPC and low LCC trait combinations, coniferous trees showed low LNC, LPC and high LCC trait combinations, while deciduous broad-leaved trees varied along the directions of larger LA, LDMC and smaller LT. Conclusion: There are significant differences in some leaf functional traits among woody plants with different life forms. The shrubs and deciduous broad-leaved trees tend to adopt a “fast investment-return” strategy, while coniferous trees adopt a “slow investment-return” strategy. This study provides essential data for understanding plant resource acquisition-adaptation strategies, and biodiversity conservation in the region.

Objective: To analyze changes in 1?3 order root traits and its the effects on height and collar diameter of seedlings grwon in soils with different drought stresses so as to reveal response mechanisms of 1?3 order root on seedling growth of tree species with large divergence in biological characteristics. Method: Taking one-year-old seedlings including Acer truncatum, Prunus davidiana, Quercus variabilis, and Koelreuteria paniculata as research objects, whose biological and ecological characteristics are quite different, a field experiment with different gradient of soil moisture was implemented in half control environment. The mean root diameter (RD), specific root length (SRL), specific root surface area (SRA), and root tissue density (RTD) of roots in order 1?5 were measured. The relative interaction index (RII) was introduced to evaluate the relative impact of drought intensity on seedling growth and root traits. Effects of soil drought on relative growth of seedling height (H) and collar diameter (CD) were analyzed, and mechanism effects of RD, SRL, SRA and RTD of lower order root on H and CD were studied. Result: H and CD of four tree species were significantly affected by soil drought (P<0.001), and the effects were remarkably shaped by tree species (P<0.001). The inter species differences are much greater than the inter drought gradient differences. In extreme drought treatment, H and CD of A. truncatum and K. paniculata were decreased, and P. davidianadeveloped thin and tall stem, while H and CD of Q. variabilis was increased. This growth pattern was obviously constrained by changes in RD, SRL, SRA, and RTD of lower order root. The correlation between root traits at the 4th and 5th order levels is low. The relative growth of seedling height and ground diameter are significantly positively correlated with RD and SRA of lower order roots (P<0.05), but significantly negatively correlated with SRL and RTD of lower order roots (P<0.05), Namely, seedling growth was determined by soil resources acquisition strategies to some extent. The higher H and CD of A. truncatum and K. paniculata was accompanied with higher RD and SRA of lower order root so that A. truncatum and K. paniculata adapted drought soil environment using soil acquirement strategy. While the lower H and CD of P. davidiana and Q. variabilis was accompanied with higher SLR and RTD of lower order root so that P. davidiana and Q. variabilis adapted soil drought environment using conservation strategy. Conclusion: The effects of soil drought on aboveground seedling height and collar diameter of trees is closely related to changes in root traits of lower order root, and this relationship is mediated by tree species. In drought soil environment, A. truncatum and K. paniculata acquired soil resources by large amount of fine root, hence the root development of A. truncatum and K. paniculata is fast investment, while the root diameter of P. davidiana and Q. variabilis is larger, therefore, the root development of P. davidiana and Q. variabilis is slow investment. In general, absorptive root development of the four tree species is drought avoidance.

Objective: Under the background of global warming, there is a lack of research on the hydraulics and carbon metabolism of Betula albo-sinensis (red birch), and the mechanism of death and lethal threshold due to persistent drought stress are still unclear. This study aims to explore the hydraulics and carbon metabolism characteristics of B. albo-sinensis under drought stress, revealing its lethal threshold and death mechanism, which is necessary for clarifying the survival and adaptive capacity of B. albo-sinensis in the context of global warming. It also provides theoretical reference for red birch seedling cultivation and forest management. Method: The present study was carried out on four-year-old B. albo-sinensis seedlings subjected to continuous drought stress, which was classified into four stages of stress according to the appearance of the leaf blades and physiological status (Stage Ⅰ, reaching the point of leaf turgor loss; Stage Ⅱ, leaf blade drooping prolapse; Stage Ⅲ, leaves starting to dry up; Stage Ⅳ, leaves completely yellow). After reaching each stage, the seedlings were rehydrated for 1 week, 2 weeks, and 4 weeks. During the period of drought stress and at specific stages of rehydration, the soil volumetric water content, predawn leaf water potential, midday water potential, leaf specific conductance, stem specific hydraulic conductance, stem hydraulic conductivity loss, and soluble sugars and starch contents in roots, stems and leaves were measured, and the total amount of non-structural carbohydrates (NSC) was calculated. Result: 1) The results showed that at four stages of drought stress, leaf predawn water potential decreased to –0.732, –1.32, –1.712, –2.23 MPa, respectively. In the final stage of stress, the stem specific hydraulic conductivity and leaf hydraulic conductivity decreased by 94.5% and 99.1%, respectively, and the loss of hydraulic conductivity was more than 88%. The soluble sugar content in each organ rose, starch content decreased, the soluble sugar to starch ratio increased, and the total root NSC decreased to 62.6%. There was a significant correlation between the soluble sugar and starch contents and the loss of hydraulic conductivity values (P<0.01). 2) After rehydration, the soluble sugar content in various organs of seedlings that experienced stage Ⅰ, Ⅱ and Ⅲ drought stress was significantly higher than that of the control group (P<0.05), and the water transport capacity of B. albo-sinensis seedlings was able to be restored. However the hydraulic traits of B. albo-sinensis seedlings that experienced stage Ⅳ stress could not be restored, and the NSC content of roots and stems was lower than the level of the control group. 3) The loss values of stem hydraulic conductivity of B. albo-sinensis seedlings at the four stages were 15.57% ± 0.61%, 49.49%± 5.03%, 77%± 2.52%, and 96.4%± 1.11%, and the mortality rates were 0, 0, 33.3%, and 100%, respectively. Conclusion: There is a coupling relationship between the hydraulic traits and NSC of B. albo-sinensis seedlings during drought stress, and B. albo-sinensis seedlings cope with the impact of sustained drought stress on water transport by dynamically regulating the carbon allocation pattern of each organ and converse starch into soluble sugars. After rehydration, the recovery degree of the hydraulic traits and NSC of B. albo-sinensis seedlings is affected by the degree of the previous drought stress. Hydraulic failure and carbon starvation co-occur during plant death, and B. albo-sinensis seedlings are already at risk of death at a value of 77% loss of stem hydraulic conductivity.

Objective: This study aims to establish a reliable core germplasm population of Phyllostachys edulis (Moso bamboo), promoting its effective utilization and facilitating molecular genetics research. Method: In this study, a total of 432 P. edulis germplasm accessions were targeted, and a stepwise systematic clustering analysis was conducted based on 15 phenotypic traits with an overall sampling rate of 10%. The sampling scheme for core germplasm was optimized from multiple dimensions, by incorporating two genetic distance calculation methods, three sampling techniques, and seven clustering algorithms. After determining the optimal sampling scheme, eight sampling proportions were set to screen the best overall proportion, and the effectiveness of group-based sampling was compared with direct sampling without grouping. Finally, the representativeness of the core germplasm was comprehensively evaluated through a multi-indicator assessment system. Result: The study found that a combination of 10% sampling ratio, priority sampling method, Euclidean distance method, and minimum distance method was the optimal strategy for constructing the core germplasm of P. edulis. The core germplasm constructed by ungrouped sampling (NGcore) exhibited a higher variance difference percentage (VD) than that constructed with grouped sampling (LCore and PCore), indicating better performance. T-tests, coincidence rate tests, and principal component analysis of the phenotypic traits demonstrated that the selected 43 core accessions effectively avoided genetic redundancy and adequately represented the original germplasm. Conclusion: This study has successfully constructed a core germplasm that represents the phenotypic diversity of the original P. edulis germplasm, laying a foundation for the collection, conservation, and effective utilization of germplasm resources.

Objective: In this study, through genome-wide identification and bioinformatics analysis of PagTMK gene family of Populus alba × P. glandulosa, PagTMK10 gene that is highly expressed in young stems, cambium and xylem was selected to explore its effect on height and radial growth. This study aims to help for further elucidating the mechanism of auxin signaling pathway in stem growth. Method: Bioinformatics and the related software were used to identify the PagTMK10 gene family members. The expression of PagTMK10 gene in young stems, young leaves, young roots, terminal buds, mature stems, old roots, root tips, vascular cambium, xylem and phloem was analyzed by real-time fluorescence quantitative PCR. The plant P_pagTMK10::GUS promoter vector and overexpressing 35S::PagTMK10 vector were constructed by using the PagTMK10 promoter and coding region sequences, respectively. The 84K poplar transgenic materials were created by Agrobacterium-mediated method and used to identify the effects of PagTMK10 gene on poplar height and radial growth. Result: A total of 10 TMK homologous genes were identified in 84K poplar genome, among which PagTMK10 gene was homologous to AtTMK1. The relative expression of PagTMK10 gene was higher in young stems, cambium and xylem. The expression location of P_pagTMK10::GUS transgenic poplar overlapped with that of P_pagDR5::GUS (auxin response reporter gene), and the main expression sites were in terminal buds, cambium and primary xylem. It is speculated that the PagTMK10 gene affects height and radial growth through auxin induction. The number of sprouts and growth rate of truncated PagTMK10-OE seedlings grown in soil were significantly greater than that of the control seedlings. It was found that the 12th internode cambium and primary xylem, plant height and basal diameter of 45 days old transgenic lines (#10, #49) that overexpressed PagTMK10 gene increased by 53.7%, 40.3%, 22.09% and 20.12%, respectively, compared to the control. The height and basal diameter of the 6 months old transgenic lines increased by 19.42 and 16.53%, respectively, compared to the control. Conclusion: PagTMK10 gene is associated with auxin expression site, and mainly expressed in terminal buds, cambium and primary xylem, affecting height and radial growth. This study can lay a foundation for further revealing the molecular mechanism of PagTMK10 gene involved in stem growth of 84K poplar.

Objective: In this study, a research was conducted on the ploidy, ornamental characters, and petal volatile components of floral blotches rose cultivars, for exploring and utilizing the breeding value of these cultivars, so as to provide a theoretical reference for the selection of parental plants and their hybrid offspring. Method: In this study, 13 modern rose cultivars with floral eyes were used as materials to identify their ploidy by flow cytometry. According to the ornamental characteristics of modern rose and the test guide of specificity, consistency and stability of new varieties of Rosa, 25 phenotypic traits were screened, and analyses were carried out on phenotypic diversity and correlation. The floral components of its petals were identified by gas chromatography-mass spectrometer. Result: 1) Nine varieties, including ‘Pastel Babylon Eyes’, ‘Sunshine Babylon Eyes’, ‘Bull’s Eye’, ‘Eyes for You’, ‘Queen Babylon Eyes’, ‘Eyeconic Lemonade’, ‘Amethyst Babylon’, ‘Sunset Babylon Eyes’, and ‘Princess of Phoenicia’, are tetraploid, and 4 varieties, including ‘Coral Babylon Eyes’, ‘Fancy Babylon Eyes’, ‘Xizi Xiawu’, and ‘Alissar, Princess of Phoenicia’, are presumed to be tetraploid. 2) The tested varieties had rich phenotypic diversity, with a diversity index of quality traits ranging from 0.54 to 1.67, and a coefficient of variation ranging from 20.34% to 190.00%. The diversity index of quantitative traits ranged from 1.41 to 1.95, with a coefficient of variation of 8.09%–60.73%. 3) There were extremely significant correlations (P<0.01) between 17 pairs of traits, such as flower diameter and petal length, and there were significant correlations (P<0.05) between 14 pairs of traits, such as floral blotch area and the ratio of floral blotch area to petal area. 4) Through European cluster analysis, the 13 rose germplasm resources could be divided into 3 groups according to flower traits, leaf traits and plant height. 5) In the principal component analysis, the cumulative contribution rate of the first 3 principal components reached 60.7%, and the characteristic factors were mainly leaf size, leaf shape, flower color, petal size, flower diameter, floral blotch area, stamen number, crown and plant height. 6) A total of 72 volatile components were identified in petals of 13 rose varieties, which were rich in species but low in overall content. Among them, terpenes were the most diverse types in volatile substances, and aldehydes were the most highest content in volatile substances. According to the floral composition, 13 modern rose cultivars with floral blotches were also divided into three groups. Conclusion: The modern rose cultivars with floral blotches have a high proportion of tetraploid, rich phenotypic and floral composition diversity, providing important genetic resources for directional breeding.

Objective: The LEAFY COTYLEDON1 (LEC1) gene is a transcription factor specifically expressed in plant embryos. The aim of this study is to explore the molecular mechanism of this gene in regulating high frequency somatic embryogenesis of peony, providing a theoretical basis for constructing an efficient and stable high-quality regeneration system and genetic transformation system of tree peony. Method: Based on the genome of Paeonia ostii and the transcriptome data from our laboratory, PoLEC1 gene was cloned from P. ostii, and the structure and phylogenetic analysis of its encoded protein was performed. The expression characteristics of PoLEC1 gene in different tissues and embryo development were analyzed by real-time quantitative PCR. PoLEC1 gene overexpression vector was constructed, and Arabidopsis thaliana was genetically transformed by inflorescence impregnation method to obtain T3 transgenic plants, and the phenotype of transgenic plants was observed. Result: PoLEC1 contained the CBFD_NFYB_HMF domain. Phylogenetic analysis showed that PoLEC1 was closely related to grape (Vitis vinifera) and cocoa (Theobroma cacao), and PoLEC1 gene was highly expressed in early and late embryonic development. It was expressed in all tissues of tree peony, with the highest expression in stems, followed by leaves. PoLEC1 was heterogeneically overexpressed in A. thaliana by Agrobacteria-mediated method. The results showed that there was no significant difference in leaf size between PoLEC1 transgenic plants and wild type plants. The number of leaves of PoLEC1 transgenic plants was slightly more than that of wild type, and PoLEC1 transgenic plants bolted later than wild type. Subcellular localization determined that PoLEC1 was localized in the nucleus and cytoplasm. Conclusion: PoLEC1 may be involved in somatic embryo development and flowering, providing important genetic resources for molecular breeding of peony.

Objective: In this study, an investigation was conducted on the effects of changing geomagnetic fields on the locomotor behaviours of Odontotermes formosanus and Reticulitermes chinensis, and the response of magnetic receptor genes to different magnetic field, in order to provide a theoretical basis for further elucidating the molecular mechanisms of the termite magnetic behaviours. Method: In this study, the effects of different magnetic field strengths (the strong magnetic field of 0.1 mT and elimination of the horizontal component of the magnetic field) on the locomotor behaviours of the worker termite R. chinensis and O. formosanus under light and dark conditions were investigated. The expression levels of two magnetic receptor genes response to different magnetic fields in two termite species were analyzed. Result: 1) Under light condition, the walking turn angle and angular velocity of O. formosanus increased significantly, but walking velocity and distance had no significant difference in the elimination of the horizontal component of the magnetic field. In the strong magnetic field (0.1 mT), walking turn angle and angular velocity of O. formosanus had no significant difference under light, but walking velocity and distance of O. formosanus increased significantly. Under darkness, walking turn angle, angular velocity, velocity and distance of O. formosanus increased significantly in the elimination of the horizontal component of the magnetic field. In the strong magnetic field (0.1 mT), walking turn angle, angular velocity, velocity and distance of O. formosanus had no significant difference. 2) The walking turn angle, angular velocity, velocity and distance of R. chinensis increased significantly in the elimination of the horizontal component of the magnetic field under light. In the strong magnetic field, walking turn angle, angular velocity, velocity and distance of R. chinensis had no significant difference under light. Under darkness, walking turn angle and angular velocity of R. chinensis increased significantly, but walking velocity and distance had no significant difference in the elimination of the horizontal component of the magnetic field. In the strong magnetic field, walking turn angle, angular velocity, velocity and distance of R. chinensis had no significant difference under light. 3) The expressions of (Cryptochromes 2, Cry2) and MagR were significantly increased under strong magnetic field (0.1 mT) treatment compared to geomagnetic field, but under elimination of horizontal component of magnetic field treatment, the expressions of Cry2 and MagR were significantly reduced in the two termite species. Conclusion: Regardless of whether it is under light or dark conditions, elimination of the horizontal component of magnetic field significantly increases the walking turn angle and angular velocity of the two termite species, suggesting that the magnetic field intensity affects the locomotor behaviour of termites. In addition, the expressions of Cry2 and MagR genes significantly increase under strong magnetic field (0.1 mT) treatment, while the expressions of the two genes significantly decrease under the elimination of horizontal component of magnetic field, indicating that Cry2 and MagR genes in termites can respond to the changes of magnetic field strength, implying that Cry2 and MagR genes may be involved in the regulation of magnetic sensing behaviours in termites.

Objective: Sinoscolia fengyang Wei et Niu is the major defoliator of the landscape plant species Pterocarya stenoptera in Beijing in recent years. Due to the damage of the pest, the host leaves occur a large number of yellowish-brown spotted, broken or defoliated ultimately, seriously threatening the healthy growth of P. stenoptera. In order to realize the sustainable management of the pest and protect the landscape and ecological environment of P. stenoptera, it is important to investigate the parasitic natural enemy resources of the pest, clarify the species, screen the dominant natural enemy species and carry out the application of biological control. Method: The damaged leaves by larvae of S. fengyang were collected from the north garden of Beijing National Botanical Garden, brought to the laboratory, and then were cultured at room temperature for the rearing of parasitoid wasp. When the adults emerged, they were collected, and specimens were examined based on the characteristics of traditional morphology and mitochondrial COI gene sequence. Result: A new parasitoid that parasitizes the larvae of S. fengyang was discovered, it belongs to the genus Closterocerus in the family Eulophidae (Hymenoptera), and here is named as C. sinoscoliae Jiang, Yao et Fu, sp. nov. The morphological characteristics of the new species were described in this paper. The color images and electron microscope photos of the external morphological characteristics of male and female were also provided. Meanwhile, based on the COI gene sequence of the new species, a phylogenetic tree with some other species of Closterocerus was constructed, and the taxonomic status of the new species was further clarified. Objective: In this study, a new species of the genus Closterocerus is discovered. It parasitizes the larvae of S. fengyang on P. stenoptera, and represents a potential parasitoid enemy for biological control.

Objective: In order to address the problems of limited workspace and difficulty in adapting to complex climbing environments for existing tree climbing robots, this study aims to develop a new type of claw-type tree climbing robot platform and climbing gait to expand the operating range of existing prototypes in tree trunk environments, replacing the forest researchers to carry out canopy level operations and reducing the safety hazards. Method: Based on the physiological characteristics and climbing mechanism of primate organisms, a three-armed clawed robot structure was designed, and the rationality of the design scheme was verified through the static simulation analysis. Two gait strategies, three-claw vertical climbing and dual-claw turnover, were proposed, and the workspace equations of the robot were deduced through geometric analysis to determine the maximum step length under each climbing gait. Adams dynamics simulation was used to verify the joint torque stability, and energy consumption was calculated to evaluate the range performance. Finally, field gait verification experiments were conducted using the prototype to assess the gait feasibility and the actual climbable range of the robot. Result: 1) The maximum deformation of the structure was at the sub-millimetre level, and the maximum equivalent stress in the material was 67 MPa. Theoretically, there will be no serious deformation or damage during operation, and its design and material selection meet the requirements. 2) The designed three-claw climbing gait was able to achieve a maximum step length of 210 mm, with a single gait cycle of about 4 minutes. 3) The dual-claw turnover gait was able to achieve a maximum of 51° around a tree pole turnover, with a single gait cycle of about 2.5 minutes. 4) According to the climbing range experiment, the robot was able to reach the trunk of about 61–136 mm in diameter, with an angle of about 40°–87° to the ground. 5) The endurance experiment showed that the lithium battery with a capacity of 9 800 mAh was able to continue to output the maximum working current after 30 minutes of continuous operation, and there was no obvious wear and tear on the key parts such as the joint rudder disc and the support frame of the robot. Conclusion: In this study, a new three-armed clawed tree-climbing robot and its climbing gaits are developed through the biomimetic design of primates. The robot is made of aluminum alloy and photosensitive resin material, with a total weight of about 2.5 kg. Based on the results of static simulation, the rationality of the dimensional design and the material selection is verified. Through the climbing range experiment, its adaptable diameter range accounts for about 68% of the experimental tree trunk range, and the climbable inclination angle can meet most of the climbing scenarios, and the climbing range can be further expanded by replacing the claws. After field experiments, the current power supply configuration can support at least 30 minutes of continuous climbing operation, and it can achieve continuous operation by replacing the battery in the woodland environment. The experimental results verify that the robot is able to climb with the designed gait, and shows a more ideal overall performance, which provides a new solution for assisting forest researchers to carry out high-altitude forest tree sampling and canopy monitoring.

Objective: This study aims to explore the axial compression performance of laminated bamboo grid sandwich panels, and propose a calculation formula for axial compression bearing capacity, so as to provide technical reference and theoretical basis for the application of laminated bamboo grid sandwich panels in engineering fields. Method: Four types of laminated bamboo grid sandwich panels with different aspect ratios were fabricated with laminated bamboo as raw material by partition method. In-plane axial compression tests were conducted on the specimens with hinged boundary conditions at both ends. The influence of aspect ratios on the bearing capacity, longitudinal strain, and lateral displacement of the specimens was investigated. Additionally, the failure modes and mechanisms of the specimens with different aspect ratios were examined. The reliability of the experimental results was validated through finite element simulation, and the applicability boundaries of the theoretical calculation formula were systematically delineated via parametric extension analysis. Result: The axial compression process of the laminated bamboo grid sandwich panels was categorized into three stages: elastic stage, elastic-plastic stage, and failure stage. The failure mode of specimens with aspect ratios of 1, 2, and 3 experienced local buckling, while those with an aspect ratio of 4 failed due to global buckling. Compared to the specimen with an aspect ratio of 1, the bearing capacity of specimens with aspect ratios of 2, 3, and 4 decreased by 7.92%, 12.18%, and 18.27%, respectively. The critical load calculation formulas for local and global buckling of sandwich panels, considering the effects of material anisotropy and core shear deformation, demonstrated excellent accuracy. The deviation between the calculated and experimental values of local buckling bearing capacity ranged from 0.86% to 2.83%, while the error between the calculated and experimental values of global buckling bearing capacity was within 8%. Parametric analysis demonstrated that the theoretical calculation formula exhibited high computational accuracy within the aspect ratio range of 1 to 7. The relative errors between the calculated values from the formula, the experimental values, and the finite element simulation values were controlled within 10%. Conclusion: As the aspect ratio increases, the bearing capacity of laminated bamboo grid sandwich panels decreases, and the failure mode changes from local buckling to global buckling. The theoretical calculations for the compressive behavior of laminated bamboo grid sandwich panels demonstrate high accuracy, providing reliable theoretical support for their engineering applications.

Objective: In response to the differences between the mechanical property testing methods, testing environments, and wood structure design methods of imported glued laminated timber (GLT) and China's standard specifications, a study was conducted on the mechanical property testing of imported GLT. The typical loading characteristics and failure modes of various specimens were summarized, and the strength standard values were determined to provide reference for the determination of strength design values of imported GLT. Method: Taking the GL24h European spruce (Picea abies) GLT used in the main exhibition hall of Tianfu Agricultural Expo Park as the object, the loading characteristics and failure mode of its raw materials were explored through small clear specimen mechanical tests. Based on the improvement of the current standard method, the strength standard value and design value of GL24h were determined and compared with the European standard EN 14080: 2013 and the“Standard for design of Timber structures”(GB 50005—2017), respectively. Result: Research has shown that the characteristic value of radial compressive strength of GL24h provided by EN 14080: 2013 is 4.60% higher than the experimental value, while the longitudinal compressive strength is 20.27% lower, and the longitudinal tensile strength, bending strength, elastic modulus, and radial shear strength are all about 50% lower. The design value of longitudinal compressive strength, radial compressive strength, longitudinal tensile strength, bending strength, and radial shear strength of GL24h determined by GB 50005—2017 were 9% higher than that determined by the improved γ_R-V_R envelope curve. Conclusion: When the load conditions where the timber structure building is located are known, a more accurate strength design values of imported timber can be calculated according to the reliability analysis results in the GB 50005—2017, combined with the actual load conditions. It is still necessary to further improve the method for determining the design value of strength of imported GLT.

Objective: Improving the level of economic welfare of farm households is the main policy objective of collective forestland tenure reform. This paper tries to answer the impact of collective forestland tenure reform on the economic welfare of farm households, and reveals the mechanism of the welfare effect of collective forestland tenure reform based on the intermediary perspective of forestry production investment and off-farm employment, which is of great significance for optimizing the structure of household production and improving the economic welfare of farm households. Method: Based on the long-term tracking large-sample farm household survey data of 862 households in 18 counties (cities) of 9 provinces (regions) across China from 2003 to 2019, the mechanism of collective forestland tenure reform on the economic welfare of farm households is studied from the perspectives of investment in forestry production and off-farm employment, and the effects of collective forestland tenure reform on the economic welfare of farm households are estimated by using the difference in difference model and the mediation effect model. Result: 1) Collective forestland tenure reform can significantly increase the total income and consumption of farm households, which in turn will enhance economic well-being. 2) Increasing investment in forestry production and higher the degree of off-farm employment are the main pathways to realize the economic welfare of collective forestland tenure reform. 3) The economic welfare effect of collective forestland tenure reform on less economically developed areas and areas with higher forest resource endowment is greater; and the income-generating effect of the low-income level farm household group and the wealth effect of the middle-consumption level farm household group is more significant. 4) The promotion effect of collective forestland tenure reform on the economic welfare of farm households who have held forest right certificates for a longer period of time is greater than that of those who have held them for a shorter period of time, and the higher the proportion of collective forest land certificates, the greater the effect of improving the economic welfare of farm households. Conclusion: Collective forestland tenure reform can effectively improve the economic welfare of farm households, but the economic welfare effect of collective forestland tenure reform has a certain lag, and has obvious group and spatial and temporal heterogeneity. Therefore, it is necessary to continue to ensure that all forest land parcels of each farm household can obtain property rights certificates by confirming rights and issuing certificates, and to continue to maintain the long-term stability of the contractual relationship of collective forest land, as well as to implement precise assistance by accurately identifying the heterogeneity of the farm households’ groups, and to strengthen the forestry policy support and project tilting of economically underdeveloped areas and areas with high forest resource abundance in order to help promote the effective enhancement of the economic welfare of the farm households.

Objective: This study aims to investigate the mechanisms through which the new round of collective forest tenure reform (hereinafter referred to as“new forest reform”) affects the marginal growth of China’s wood-based forest product exports, thereby providing scientific evidence for deepening forest tenure reform and promoting the high-quality development of forest product trade. Method: Drawing on six-digit bilateral trade data from China Customs and the United Nations Trade Database from 2000 to 2022, this study employs a export ternary margins decomposition method to analyze export growth and constructs a year-province-destination country panel dataset. Taking the new forest reform as a quasi-natural experiment and using manufacturing as a control group, the study applies a double machine (DML) approach to evaluate the impact of the reform on the marginal growth of wood-based forest product exports. Result: 1) An increase in domestic timber supply substitutes for imported timber, with demand for imported timber being significantly more elastic than for domestic timber. 2) The new forest reform significantly increases the export share, extensive margin, and quantity margin of wood-based forest products, while significantly reducing the price margin. 3) The reform promotes marginal export growth by enhancing domestic timber supply and enabling domestic timber supply and enabling substitution of imports with domestic timber. 4) In terms of heterogeneity, the reform has a stronger positive effect on capital- and technology-intensive wood-based product exports compared to labor-intensive products, and its impact is more pronounced in southern forest regions than in non-southern regions. Conclusion: The new forest reform has a significant incentivizing effect on the forestry industry, effectively driving the marginal growth of wood-based forest product exports, reducing dependence on external timber resources, and strengthening national timber security. In the future, it is essential to enhance top-level design, leveraging the new forest reform to better coordinate natural resource management, industrial policies, and trade policies, thereby advancing the high-quality development of forestry.

Objective: The study aims to examine the impacts of the integration of digital economy and forestry industry (referred to as “Digital-Forestry Integration”) development level on the urban-rural income gap in 11 prefecture-level cities in Zhejiang Province, and the mechanisms, so as to provide scientific basis for the high-quality development of forestry industry and the common prosperity of all people in China. Method: Based on the panel data from 2015 to 2022 at the city level, this study empirically examines the impacts of Digital-Forestry Integration on the urban-rural income gap in Zhejiang Province using fixed effect models and mediation effect models. Result: 1) The baseline regression results show that the impacts of Digital-Forestry Integration on the urban-rural income gap shows an “inverted U-shaped” trend, initially widening and then narrowing, and the results are robust; 2) The results of the mechanisms analysis indicate that Digital-Forestry Integration affects the urban-rural income gap through employment and income effects; 3) The heterogeneity analysis indicates that the effect of Digital-Forestry Integration on the urban-rural income gap is more significant in areas with smaller income gaps, higher development levels of digital inclusive finance, and larger urban scales. Conclusion: From 2015 to 2022, the impacts of Digital-Forestry Integration development on urban-rural income gap in Zhejiang Province presents an initial expansion and then a reduction trend with regional heterogeneity observed and it influences the urban-rural income gap through employment effects and the income effects. Therefore, Zhejiang Province should continue to strengthen policy guidance and resource allocation, promote the deep integration of digital economy and forestry industry, and gradually narrow the urban-rural income gap.

Objective: This study aims to explore the effects of different root cutting methods and fertilization on the development of jujube tree roots, providing a research basis for the development of jujube orchard root cutting and nurturing machinery, and providing reference for the prevention and control of tree root degradation and fertilizer reduction technology. Method: Xinjiang Junzao trees were used as the research object, and an experimental method based on cylindrical spatialization was designed in a relatively limited experimental area. Five treatments and one control were set up for repeated experiments to determine the root system's rejuvenation characteristics after 6 months of experimental treatment. Result: 1) Both root cutting and fertilization were able to promote the germination of root system quantity. The root cutting treatment alone increased by 244.21% (P<0.01) compared to the control group, while the fertilization treatment alone increased by 69.82% (P<0.05) compared to the control group. 2) Cutting had a more significant effect on promoting new root germination than pulling apart, with a 119.65% increase in the number of newly germinated roots (P<0.01). The distance between new roots and the broken point by pulling treatment was 13.74 times that under cutting treatment (P<0.01). 3) Root cutting and fertilization had a synergistic effect, with the number of newly germinated roots increased by 26.57% (P<0.05) compared to root cutting alone and 156.56% (P<0.01) compared to fertilization alone. Conclusion: Different root cutting methods have different effects on root system rejuvenation, and the root cutting methods cause less mechanical damage to the roots than the pulling apart. Root cutting machinery should strive to achieve the effect of neat root cutting as much as possible. Root cutting plus fertilization is a potential technique for reducing fertilizer application, and the root cutting and nurturing machinery of jujube trees should also have the root cutting and fertilization functions.