Currently,China's natural protected area system is undergoing a series of transformations,including spatial integration and optimization,refinement of management regulations,and improvement of laws and regulations,all of which have implications for the conservation of wildlife.This study comprehensively reviews the current distribution of Elaphurus davidianus populations within China's protected areas,identifying issues such as imbalanced habitat distribution,the "island effect" in conservation,overpopulation in key regions,lack of natural regulatory mechanisms,and increasing human-deer conflicts.Furthermore,it analyzes the impacts of functional zoning and regulatory changes in nature reserves,spatial layout adjustments in both nature reserves and wetland parks,and enhanced laws and regulations.Within the context of the holistic optimization of the natural protected area system,we propose tailored measures based on the actual conditions of E.davidianus conservation.These include establishing a multi-level,networked conservation spatial pattern,implementing refined population management based on ecological carrying capacity,innovating community co-management models,and enhancing the policy support system grounded in the latest legal frameworks.Such efforts will advance the conservation of Elaphurus davidianus toward a systematic,scientific,and high-quality development stage.

With the introduction of China’s mangrove-afforestation methodology,mangrove carbon sinks can now realize their value through the voluntary greenhouse-gas emission-trading market.The basic framework for a market-based mangrove-carbon-sink trading system has been preliminarily established,yet detailed operational rules are still missing.Substantively,the legal nature of Certified Emission Reductions (CERs) as tradable assets remains undefined,leaving the property-rights relationships among trading parties unregulated.Procedurally,mangrove-afforestation projects involve both the use of natural-resource rights and conservation obligations,but the underlying regulatory framework is inadequate.To address these issues,drawing on quasi-property right and ownership provisions,mangrove-carbon-sink rights should be recognized as jointly held by the participating entities,with benefit-sharing determined by mutual agreement.When applying for a mangrove-afforestation project,applicants must secure the relevant natural-resource use rights in accordance with the site’s specific geographical classification.

To achieve the “dual-carbon” goals,it is necessary to coordinate economic growth with the green,low-carbon transition.Forest carbon sinks offer both cost advantages and ecological benefits,making them an important pathway to achieving the “dual-carbon” goals.With a dynamic general equilibrium framework,we construct a four-sector general equilibrium model that includes traditional industries,carbon abatement technologies,carbon capture and storage(CCS) technologies,and forest carbon sinks.Through theoretical analysis and numerical simulations,we examine the optimal economic growth path under carbon-neutrality constraints and analyzes the mechanisms through which forest carbon sinks promote economic growth.The results show that:1) Under carbon-neutrality constraints,economic growth faces an “investment crowding-out” effect;incorporating forest carbon sinks into the policy toolkit can mitigate this effect and play a macroeconomic buffering role.2) The optimal carbon-neutrality investment path should follow the structure of technological endowments.When forest carbon sinks have a cost advantage,they should be prioritized;however,when the marginal costs of technology-based emission reduction and carbon sequestration approach those of forest carbon sinks,investment in technology-based emission reduction and sequestration rises rapidly in a nonlinear manner,exhibiting a “technology surge” characteristic.In responding to carbon-neutrality constraints,full use should be made of the cost advantages of forest carbon sinks.While their potential has not yet been fully realized,sound market-based compensation and incentive mechanisms should be improved to guide investment,thereby alleviating the short-term economic impacts of carbon-neutrality constraints at relatively low cost.At the same time,continuous efforts should be made to advance technological progress in emission reduction and carbon sequestration,strengthen technology reserves,and build a multi-pathway synergistic system,so as to promote the green transition and high-quality development in a manner that minimizes total social costs,thereby ensuring the achievement of China’s “dual-carbon” goals.

For a transitional zone of arid and semi-arid ecosystems in northern China,the western region of Inner Mongolia plays a significant role in regional ecological security and sustainable development due to the spatiotemporal evolution and trade-off-synergy relationships of its ecosystem services.In response to the insufficient research on the 'long-term dynamic associations of multiple ecosystem services' in this arid-semiarid transition zone,this study conducted quantitative evaluations and relationship analyses.Using land use data for the years 1990,2000,2010,and 2020 in the western region of Inner Mongolia,and integrating the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) and Revised Wind Erosion Equation (RWEQ) models,we quantitatively analyzed the spatiotemporal differentiation of ecosystem services in western Inner Mongolia with carbon storage,soil retention,windbreak and sand fixation,and habitat quality,while Spearman correlation analysis was employed to reveal the trade-off and synergy relationships among ecosystem services.The results indicated that:1) In 1990—2020,the land use structure in western Inner Mongolia remained relatively stable,dominated by unused land and grassland,with significant conversions among cropland,grassland and water area.2) The spatial distribution of ecosystem services was primarily influenced by changes in ecological land use.Carbon storage initially declined and then increased,with a total decrease of 0.55%;soil retention first decreased and then increased,reaching a peak of 1.21×10⁹ t in 2020,with high-value areas concentrated in grasslands,croplands,and forest land;the areas with low windbreak and sand fixation expanded initially but sharply contracted by 2020,with high-value areas concentrated in the central-eastern region;habitat quality showed a decreasing-then-increasing trend,with low-value areas exceeding 60%,while high-value areas continued to shrink due to forest degradation.3) The trade-off and synergy relationships among ecosystem services were complex and dynamically changing,with overall synergy strengthening and trade-offs weakening.Carbon storage and soil retention exhibited stable synergies.There was a strong synergy between habitat quality and carbon storage.The synergistic trend of windbreak and sand fixation with soil conservation had emerged,and the relationship between carbon storage and habitat quality had shifted from weak trade-offs to no significant correlation.In the future,it is necessary to strengthen the regulation of conversions among unused land,cropland,and grassland with a focus on protecting forest land to prevent the reduction of high-value habitat areas,and to rely on the synergistic relationships among services to comprehensively enhance carbon storage,soil retention,and other functions.

To investigate the physiological response mechanisms of important economic herbaceous plants used in vegetation restoration in arid regions under drought stress,the annual herbaceous plant Corispermum squarrosum as the research object.Through pot experiment on water control,four different soil moisture treatments were established:control (CK),light drought (LD),moderate drought (MD),and extreme drought (ED).The soil moisture contents under these treatments were (90±5)%,(70±5)%,(50±5)%,and (30±5)%,respectively.The changes in gas exchange parameters and chlorophyll fluorescence parameters of Sami leaves under drought stress were analyzed..The results showed that:1)The photosynthetic physiology of C.squarrosum was insensitive to light drought.Compared with the CK,only the stomatal conductance(G_s)and the actual photochemical efficiency(Φ_PSII)in the LD were significantly reduced by 22.86% and 22.09%,respectively.2)Under the MD,C.squarrosum primarily exhibited significant gas exchange limitations.Compared to the CK treatment,the net photosynthetic rate(P_n),G_s,transpiration rate(T_r),and Φ_PSII decreased significantly by 61.04%,42.86%,62.50%,and 39.13%,respectively.While other parameters showed no significant difference between the CK and MD treatments.3)Under the ED,the gas exchange characteristics of C.squarrosum underwent significant changes.Compared to the CK treatment,gas exchange parameters P_n,G_s,and T_r in the ED were significantly reduced by 77.06%,60.00%,and 81.25%,respectively,whereas the water use efficiency(WUE)increased by 19.33%.For chlorophyll fluorescence parameters,the maximum photochemical efficiency(F_v/F_m),Φ_PSII,and photochemical quenching(q_P)decreased significantly by 28.24%,65.22%,and 54.84%,respectively.The reduction in Photosystem II activity was identified as the primary factor leading to the decrease in net photosynthetic rate under the ED treatment.Elucidating the changing characteristics of gas exchange and chlorophyll fluorescence parameters in C.squarrosum provides a solid theoretical basis for the selection of improved plant materials and vegetation restoration practices in arid and semi-arid regions.

Evaluation and optimization of forest spatial structure are pivotal for enhancing forest quality and providing scientific references for forest management decisions.This study investigated two Picea crassifolia forest plots with distinct structural characteristics in the Helan Mountains,Ningxia.Large-scale spatial data were acquired via UAV LiDAR,enabling the calculation of spatial indices:the uniform angle index (W),neighborhood comparison (U),and the Hegyi competition index (I_c).Spatial structural characteristics were analyzed.The results show that:1) In both plots,tree distributions were predominantly random with minimal clustering;the frequency of size dominance classes showed no significant differences;competition was primarily null to low intensity.2) In the stand spatial structure optimization simulation,153 trees (8.8%) and 204 trees (11.2%) were harvested in sample plots 1 and 2,respectively.After optimization,the angular scale decreased by 7.35% and 5.60%,the size ratio decreased by 7.11% and 9.46%,the competition index decreased by 37.5% and 28.57%,and the number of canopy gaps increased by 6 gaps (covering 8 800 m²) and 11 gaps (covering 7 200 m²),respectively.UAV-LiDAR enables rapid and precise spatial data acquisition.Spatial indices (the uniform angle index,neighborhood comparison) effectively guide structural thinning prescriptions and gap-based regeneration strategies,improving understory conditions and promoting forest regeneration.

In order to investigate the variation of cone and seed morphological traits of Pinus sylvestris var.mongolica in the northwest area and their relationship with the environment,we used the cones and seeds of P.sylvestris var.mongolica forests from the following four locations as experimental materials:Dengkou County,Bayannur City,Inner Mongolia Autonomous Region;Ejin Horo Banner,Ordos City,Inner Mongolia Autonomous Region;Minqin County,Wuwei City,Gansu Province;and Honghua’erji Town,Evenk Autonomous Banner,Hulunbuir City,Inner Mongolia Autonomous Region.We studied the effects of climate and soil on cone and seed morphological traits of Pinus sylvestris var.mongolica.The results indicated the following:1) The variation coefficients of cone and seed morphological traits in the four regions ranged from 1.60% to 48.22%.The inter-regional variation coefficient was higher than that within the same region.The variation of cone morphological traits was always higher than that of seed morphological traits.2) The order of cone morphological traits from large to small in the four regions was as follows:Honghua’erji Town,Ejin Horo Banner,Dengkou County,Minqin County.3) The cone length (CL),seed length (SL),and samara length (TL) of P.sylvestris var.mongolica were significantly positively correlated with hydrolyzed nitrogen (AN) and available phosphorus (AP) (P<0.05),but the seed weight (SW) and seed volume (SV) were negatively correlated with AN and AP.4) The aridity index (AL) was negatively correlated with most cone and seed morphological traits,while the average annual precipitation (AAP) was positively correlated with many cone and some seed morphological traits.In general,the 12 environmental factors had an contribution rate of up to 99.99% for the cone and seed morphological traits of P.sylvestris var.mongolica.The contribution rate of meteorological factors was 88.10%,and that of soil factors was only 11.89%.The AAP had an contribution rate of up to 86.40% for the variation in cone and seed morphological traits of P.sylvestris var.mongolica across the four regions,indicating that AAP was the key environmental factor driving the phenotypic variation of cones and seeds.

Natural education is an important starting point for the construction of ecological civilization,and the professional skills of natural education tutors are key elements that drive the high-quality development of the natural education industry and affect the effectiveness of experience. A questionnaire survey was conducted and analyped,with SPSS 24.0 software.The exploratory factor analysis was used extract,the core dimensions of natural education tutors' skills. Then,multiple linear regression analysis and difference tests were applied to evaluate the relationship between each core dimension and emperience effectiveness,analyze the differences in tutors' skill evaluations among experiencers with different demographic characteristics,and explores the key factors influencing the effectiveness of natural education activities. The results show that:1) The core dimensions of natural education tutors' skills include ecological literacy and basic skills,curriculum design and interactive perception skills,as well as guiding exploration and interpretation skills.2) The tutors' ecological literacy and basic skills,as well as their skills in guiding exploration,thinking and explanation,can exert a significant positive impact on the experience effectiveness. By contrast,there is no statistically significant correlation between the tutors' curriculum design and interactive perception skills and the experience effectiveness.3)There are significant differences in experiencers' evaluations of tutors' curriculum design and interactive perception skills based on their educational levels;4) Overall,participants gave high ratings to all three dimensions of the tutors' skills,indicating that the groups participating in natural education activities expressed a high level of satisfaction with the tutors' professional competencies. Nevertheless,there is still room for further improvement. Enhancing tutors' ecological literacy and basic skills,as well as their skills in guiding exploration,thinking guidance and explanation,and providing differentiated natural education experiences,is conducive to optimizing the design of natural education courses,improving the teaching quality of tutors,and holds great significance for promoting the professional development of natural education.

To investigate the characteristics of the bryophyte community and flora and provide a basis for the protection and management of the forest in Mount Jigong National Nature Reserve in Henan Province,a survey was carried out from 2019 to 2022,and the characteristics of the bryophyte community and flora were analyzed.To further understand the characteristics of the bryophyte flora in Mount Jigong National Nature Reserve,a comparative study was conducted with 15 other research sites in China.The results showed that:1)A total of 254 species(including 240 species and 14 varieties)belonging to 108 genera and 51 families of bryophytes were found in Mount Jigong National Nature Reserve,and the mosses were the dominant species(210 species).There were 193 newly recorded species of bryophytes.2)The 254 species of bryophytes could be divided into 4 communities,including the hydrophytia community(22 species),petrophytia community(176 species),geophytia community(133 species),and epixylophytia community(130 species).The number of species did not vary greatly at different altitudes but varied greatly in different forest types.The overall species diversity was higher in the core proteced zone than in the general control zone.3)There were 10 types of bryophyte flora in Mount Jigong National Nature Reserve,predominantly belonging to the North Temperate element(38.01%),East Asia element(28.96%),and Temperate Asia element(13.57%),with other elements accounting for a relatively low proportion.4)Comparing with the 15 research sites,the results showed that the bryophyte flora of Mount Jigong National Nature Reserve was the most similar to that of the northern study areas and was different from that of the southern study areas.Therefore,the bryophytes in Mount Jigong National Nature Reserve are characterized by extremely rich species and obvious temperate characteristics in the flora.

Investigating the functional traits and construction costs of leaves in endangered plants is crucial for understanding their adaptive strategies,deciphering endangerment mechanisms,and formulating effective conservation measures.We systematically examined the functional traits including leaf fresh weight,dry weight,length,area,specific leaf area,dry matter content,and nitrogen content,and construction costs of mature leaves from different leaf positions (upper,middle,lower) in adult Terminalia myriocapra trees in Simao district,Pu’er,aiming to elucidate their resource use strategies and adaptation mechanisms at the leaf level.The results showed that:1) Significant differences were found in functional traits among leaf positions,with the middle leaves exhibiting the highest values in fresh weight,dry weight,length,and area,followed by upper and lower leaves.2) Significant correlations were observed among leaf functional traits,indicating synergistic and trade-off relationships.3) The construction cost per unit mass was positively correlated with leaf fresh weight,dry matter content,and nitrogen content,but negatively correlated with specific leaf area.4) By the principal component analysis,the lower leaves tend towards a conservative resource-use strategy,middle leaves towards an acquisitive strategy,and upper leaves represent an intermediate strategy.The results systematically revealed the differentiation of functional traits and allocation strategies of construction costs across leaf positions in T.myriocapra,providing new evidence at the leaf level for understanding its ecological adaptation and endangerment mechanisms,and offering a theoretical basis for the conservation and sustainable utilization of T.myriocapra.

To investigate the potential of synergistic active-passive remote sensing for estimating forest aboveground biomass (AGB),with the central urban area of Guangzhou as the study area,31 multi-source remote sensing features (including 6 SAR features and 25 optical features) were extracted through Sentinel-1 SAR data and Sentinel-2 multispectral imagery.Combined with field-measured AGB,six machine-learning (ML) regression models (Random Forest,Support Vector Machine,Extreme Gradient Boosting,k-Nearest Neighbors regression,AdaBoost,and Linear Regression) were used to develop forest AGB inversion models.The results showed that:1) The Visible Atmospherically Resistant Index Green (VIGreen) performed prominently in forest AGB inversion,ranking fifth in feature importance in the Random Forest (RF) model;different polarization combinations also contributed significantly to AGB inversion;2) Across different dataset combinations,the RF model achieved the highest accuracy among the six regression models;3) Models using only optical data outperformed those using only SAR data;4) Fusion of SAR and optical data produced substantially higher AGB inversion accuracy than using SAR or optical data alone:compared with SAR-only features,the coefficient of determination (R²) increased by 0.48 and the root mean square error (RMSE) decreased by 3.73;compared with optical-only features,R² increased by 0.14 and RMSE decreased by 2.08.Therefore,ML approaches that integrate optical and SAR data can effectively improve the accuracy of forest AGB inversion.

With the increasing problems of the ecological environment,the assessment of damage to forest ecological services and functions has gradually become an important issue in the construction of environmental rule-of-law.However,there is no such evaluation index system for the damage to forest ecological services and functions in Guangdong Province.Using the analytic hierarchy process (AHP) method,we constructed an assessment system for forest ecological environment damage,which is approximately equivalent to the loss of forest ecological services and functions and is suitable for fast evaluations at small spatial scales.By absorbing existing assessment methods of forest ecosystem service functions,we combined the six major ecological function zones in Guangdong Province and utilized expert scoring and the analytic hierarchy process to establish a new evaluation index system,including regulatory services,support services,and supply services.Through weight analysis,the regulatory service in the Nanling Mountain District had a high weight of 0.507,highlighting its core role in water conservation and pollution purification.The weight of support services in the central Guangdong region was 0.475,reflecting that soil and water conservation was crucial for maintaining the ecological security of the region itself.Supply services had a prominent weight in coastal areas (0.412),mainly due to the high economic value and biodiversity conservation functions of mangrove forests in this region.Therefore,through the AHP quantitative evaluation,there were differences in the dominant service types of different ecological functional areas,and protection strategies should be formulated according to local conditions.This result would provide a scientific basis for the protection and ecological restoration of forest resources in diverse regions across Guangdong Province,and points out the need to further optimize the objectivity of evaluation indicators and improve the legal framework to enhance the operability and scientificity of the damage assessment of forest ecological services and functions in the future.

To meet the requirements of conducting a pilot study on surveying methods of ancient tree groups in Jilin Province,with the paired data of tree age and diameter at breast height (DBH) of 4,235 sample trees obtained from the 2nd National Census of Ancient and Notable Trees and the National Biomass Survey Surveying and Modeling Program,we developed DBH average growth models for individual trees of ten major tree species or groups (spruce,fir,Korean pine,larch,Mongolian oak,birch,elm,linden,aspen,and walnut) in Jilin Province by using the three common growth functions,involving Richards,Logistic and Gompertz,and the thresholds of DBH for identifying ancient trees of each tree pecie or group were determined.The results showed:1) Among the commonly used growth functions,the Richards function was found to be the most effective for fitting DBH growth models;2) The values of the coefficient of determination (R²) of the DBH growth models for the ten main tree species groups were all above 0.7,and the values of the total relative error(TRE) were within ±3%.The established models may be referred to determine the DBH thresholds of ancient trees and to estimate the age of ancient trees during the 3rd National Census of Ancient and Notable Trees in Jilin Province;and the modeling approach and the method for determining the DBH thresholds of ancient trees can be used as references for other provinces.