【Objective】 This research aims to explore the impact of future climate change on predicted runoff trends in the Yangtze River basin and provide a basis for early flood warning and prevention measures in the Yangtze River basin and other regions. 【Method】 Temperature, precipitation and runoff in the Yangtze River basin from 1961 to 2014 were evaluated by using the multi-mode set average (MME) of the international coupled model intercomparison project phase 6 (CMIP 6) and the SWAT hydrological model and predicted under SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5 emission scenarios from 2020 to 2099.【Result】 (1) Compared with the single model, MME showed better performance in simulating temperature and precipitation during historical periods, with a correlation coefficient with the observation value was >0.90. Further, MME simulated the spatial distribution of temperature and precipitation well. (2) The MME analysis showed that during 2020 and 2099, temperature and precipitation increases in the Yangtze River basin under all scenarios were <50% and <20%, respectively. Simulated temperature under the SSP5-8.5 scenario was 1.23 ℃ higher than that under the SSP1-1.9 scenario, and 0.99 ℃ higher than that under the SSP1-2.6 scenario. (3) Overall, future annual runoff of the entire Yangtze River basin increased significantly and reached 40 380 m3/s under the SSP5-5.8 scenario at the end of the 21st century.【Conclusion】 Temperature, precipitation and runoff in the Yangtze River basin are predicted to increase in the future, whereas flood disasters under low emission scenarios are relatively less likely.
【Objective】 Small and micro wetlands provide several important ecological functions, such as habitat support for key species, biological transfer, hydrological regulation and water purification, education and rest. Wuxi City in China contains numerous wetlands, of which most over 8 hm2 have been protected in recent years. However, not all small and micro wetlands have been protected in Wuxi City, and research regarding spatiotemporal changes in these habitats under various factors is lacking. Thus, analyzing the temporal and spatial characteristics and driving forces of small and micro wetlands can provide a theoretical basis for wetland ecological restoration and protection construction.【Method】 Based on Landsat satellite images in 2000, 2010 and 2020, patch information of small and micro wetlands in Wuxi City were extracted using support vector machine classification and other methods. Combined with meteorological and land use data, the spatiotemporal evolution of small and micro wetlands in Wuxi City and its influencing factors were analyzed.【Result】 (1) Within the past two decades, the total wetland area in Wuxi City has decreased from 178 000 hm2 in 2000 to 104 000 hm2 in 2020. Among them, the total area of small and micro wetlands has decreased from 19 000 hm2 in 2000 to 15 000 hm2 in 2020. (2) In terms of spatial distribution, small and micro wetlands in Wuxi were mainly distributed in the county-level city Yixing, which accounted for 40.0% of the area of Wuxi City. Small and micro wetlands in Wuxi City predominantly consisted of natural wetlands, accounting for up to 61.0% and displayed marked seasonal variation characteristics. In 2020, the proportion of seasonal small and micro wetlands in the total area of small and micro wetlands was as high as 73.8%. (3) The dynamic of small and micro wetlands in Wuxi City were positively correlated with temperature and precipitation due to natural factors and human activities. Specifically, human activities had a significant impact on the decline of small and micro wetland areas, and the transformation between wetland and other land types accelerated the decline of wetlands.【Conclusion】 Wuxi City is rich in small and micro wetland resources, which are in rapid decline due to seasonal and land use changes. Thus, the protection and restoration of small and micro wetlands must be enhanced to mitigate the negative impacts imposed by different factors.
As the wildland-urban interface (WUI) becomes an increasingly important area of focus, the close relationship between human settlements and natural ecosystems such as forests has led to a high incidence of fires. Human activities play significant roles in the occurrence of fires in the WUI, and with rapid urbanization and the construction of forest cities, the complexity and severity of these fires have increased. This paper provides an overview of research progress on fires in the WUI, through literature analysis and case studies. At present, the concept of the WUI in China lacks clarity and standardization, highlighting the need for further research in this area. Future research should focus on expanding the database of interface fire cases and integrating satellite monitoring systems, video surveillance, and big data platforms to establish an early warning and monitoring system for the WUI. In addition, strengthening the research on fire behavior simulation and remote sensing monitoring, especially UAV fire behavior detection technology research on fire behavior simulations and remote sensing monitoring of WUI and unmanned aerial, remote-sensing monitoring and other new technologies will be crucial for providing effective solutions for fire prevention and control in the WUI. This will also contribute to the improvement of management measures, standards, and risk reduction strategies. Overall, the emphasis on new technologies and scientific research will provide a solid foundation for the management and reduction of fire risks in the WUI.
【Objective】 In order to study a new way of biological control of pests on Populus pseudo-cathayana × P. deltoides leaves, the effects of compound inoculation with arbuscular mycorrhizal (AM) fungi on the resistance of P. pseudo-cathayana×P. deltoides leaves to Hyphantria cunea were investigated. 【Method】 One-year-old P. pseudo-cathayana × P. deltoides cuttings were inoculated with Rhizophagus intraradices (RI) and Funneliformis mosseae (FM) by single and mixed inoculation (M) in a greenhouse, with no inoculation (CK) as the control. The chemical defense ability of secondary metabolites, defense enzymes and protease inhibitors in poplar leaves was determined, and the larva of H. cunea was used as a bioassay object to determine its anti-insect effect.【Result】 In 120 days, the mycorrhizal infection rate, arbuscular growth rate and number of vesicles in the root of the M group were higher than those of the FM and RI groups. Meanwhile, the M group could improve the chemical defense ability of the leaves of P. pseudo-cathayana × P. deltoides to a certain extent. The contents of total alkaloids and cellulose and the activities of peroxidase (POD), catalase (CAT), lipoxygenase (LOX), polyphenol oxidase (PPO), chymotrypsin inhibitor (CI) and trypsin inhibitor (TI) in leaves were significantly higher than those in the RI, FM and CK groups (P<0.05). The food intake, fecal output, cellulase activity, acetylcholinesterase (AchE) activity and multifunctional oxidase (MFO) activity of the third instar larvae in the M group were significantly lower than those in the FM, RI and CK groups (P<0.05). The body length, food availability, trypsin activity, carboxylesterase (CarE) activity, and glutathione S-transferase (GSTs) activity of the third instar larvae were significantly higher than those of the RI and FM groups (P<0.05). The food consumption rate and α-amylase activity of the third instar larvae did not significantly differ from those of the RI group, and the body weight of the third instar larvae did not significantly differ from those of the FM group. Body weight, food intake, food consumption rate, cellulase activity, GSTs activity, CarE activity, AchE activity and MFO activity of the fourth instar larvae were significantly lower than those of the FM, RI and CK groups (P<0.05), the fecal output of the fourth instar larvae was significantly lower than that of the RI and CK groups (P<0.05), and the trypsin activity of the fourth instar larvae was significantly higher than that of the other three groups (P<0.05). The body length and food availability of the fourth instar larvae did not significantly differ from those of the RI group, and the α-amylase activity of the fourth instar larvae did not significantly differ from those of the FM and RI groups. The body length, body weight, food intake, fecal output, food utilization, α-amylase activity, cellulase activity, GSTs activity, CarE activity, and MFO activity of the fifth instar larvae were significantly lower than those in the FM, RI and CK groups (P<0.05). The food consumption rate of the fifth instar larvae was significantly lower than that in the FM and RI groups, and the AchE activity of the fifth instar larvae was significantly lower than that in the FM group (P<0.05). The trypsin activity of the fifth instar larvae was significantly higher than that of the other three groups (P <0.05).【Conclusion】 The mixed inoculation of RI and FM could induce the chemical defense performance of P. pseudo-cathayana × P. deltoides leaves in the aspects of secondary metabolites, defense enzymes, and protease inhibitors. The anti-insect performance of combined RI and FM inoculation was better than that of single RI and FM inoculation and no AM fungi inoculation and had certain inhibitory effect on the larva of H. cunea. In practical application, combined RI and FM inoculation can be prioritized.
【Objective】This research aims to determine the actual threat level and prioritize the conservation of rare and endangered plants in the Wuyishan National Nature Reserve in Jiangxi Province, provide a reference for the conservation of these plants in the nature reserve.【Method】Using the line transect method combined with historical literature, the endangered coefficient, genetic value coefficient, and species value coefficient were used to quantitatively analyze the conservation priorities of 113 rare and endangered wild plants in the Wuyishan National Nature Reserve in Jiangxi Province. The relationship between the rare and endangered plants of Wuyishan in Jiangxi Province and five adjacent areas, namely Wuyishan in Fujian Province, Tianmushan in Zhejiang Province, Lushan in Jiangxi Province, Wanchaoshan in Hubei Province, and Jinfoshan in Chongqing City, were compared using the Sorensen similarity coefficient.【Result】(1) There were 113 species of rare and endangered plants in the reserve, belonging to 47 families and 85 genera. Among these, there were 6 species classified as National Class Ⅰ, 15 species as National Class Ⅱ. 20 species were classified as Jiangxi Province Class Ⅰ, 11 species as Jiangxi Province Class Ⅱ, 55 species as Jiangxi Province Class Ⅲ, and 12 species endemic to Jiangxi. (2) According to the quantitative analysis of conservation priority, 17 species (15.04%) were assessed as first class, 41 species (36.28%) as second class, 54 species (47.79%) as third class, and 1 species (0.89%) as fourth class. (3) The similarity coefficient between Wuyishan in Jiangxi Province and the five adjacent areas were about 30%. However, Wuyishan in Jiangxi Province owned more rare and endangered plants (38 species) and a higher proportion of species per unit area (0.24), indicated a higher conservation value.【Conclusion】 The excellent habitats and abundant rare and endangered plants in Wuyishan in Jiangxi Province indicate a high conservation value. The assessment and classification of the 113 rare and endangered plants more accurately reflect their current situation in the Nature Reserve, providing a reference for effective conservation plans for threatened species.
【Objective】 The Songhua River wetland is the most important ecosystem barrier in Harbin. This paper quantitatively studied the evolution and main influencing factors of the landscape pattern of the Songhua River wetland ecosystem in Harbin over the past 20 years, and we aim to provide a reference for wetland planning. 【Method】 Choosing the Harbin basin and its surrounding ecological area as the research object, Landsat remote sensing images from 2000, 2005, 2010, 2015 and 2020 were processed with the help of the GIS platform. The Fragstats software was used to analyze the regional landscape pattern index and explore the spatio-temporal evolution characteristics of the landscape pattern. Finally, SPSS was used for the statistical analysis of the factors affecting landscape pattern. 【Result】 (1) From 2000 to 2020, the water area (including wetland) continuously increased, while the cultivated-land area continuously decreased, which was the primary change feature of landscape pattern in the study area. The decreasing cultivated land was the main contributing factor of increasing water area, grassland, construction land, forest land and other land areas at 343.142 1, 2.484 9, 94.041 9, 35.469 0 and 1.980 0 km2, respectively; among them, the growth rate of water area, grassland, forest area and other land area exceeded 100%, and the area expansion showed an upward trend. (2) From the perspective of plaque types, the degree of fragmentation of each plaque increased to varying degrees during the 20 years, and the wetland landscape type structure tended to be complicated. From the landscape-level perspective, the overall landscape richness has increased, but the connectivity was poor, and the degree of external interference was relatively significant. (3) Urban economic development, climate and industrial structure were the main driving factors to stimulate the change of landscape pattern of the Songhua River wetland in Harbin. With the establishment of the Songbei District and the rise of tourism, relevant infrastructure has crowded the space of some water areas (including wetlands) along the river; wetland marshes and cultivated land have been divided into numerous patches, the overall landscape pattern tends to be fragmented, and human drivers have gradually become the dominant factors. 【Conclusion】 The landscape type of the Songhua River wetland in Harbin is a complicated structure. As human influence factors become more profound, the fragmentation degree of water patches increases, there is a serious loss of cultivated-land area, and the contradiction between cultivated-land protection and ecological protection remains prominent.
【Objective】 The objectives of this study were to explore the temporal and spatial evolutions of wetland landscape in Changsha from 1999 to 2019, to comprehensively analyze the dynamic-change characteristics of wetland-landscape patterns in Changsha in the same period, and to explore the influence mechanism of natural and human factors on wetland-landscape patterns, so as to provide an important theoretical basis for the protection and rational utilization of wetlands in Changsha. 【Method】 Based on global surface water data (GSWD), combined with meteorological and hydrological data, this paper adopted the methods of wetland distribution information extraction, wetland type classification and landscape pattern index, aiming to achieve long-term and continuous monitoring of the dynamic evolution of annual wetland-landscape patterns in Changsha City from 1999 to 2019 based on the seasonal and fluctuating characteristics of wetlands. In addition, we analyzed the evolution trend of its long time scale, as well as the short-term fluctuation change characteristics. 【Result】 (1) Since 1999, the wetland area in Changsha has been overall increase, with permanent river being the main wetland type. From 2007 to 2009, there was a large fluctuation in wetland landscape, as represented by the transformation of permanent rivers and lakes to seasonal rivers and lakes, respectively, in the early stage, and by the reversal of fragmentation after 2008. The fragmentation degree of wetland-landscape pattern in Changsha continuously intensified until 2017 and later began to gradually recover. (2) The wetland-landscape pattern in Changsha was greatly affected by the natural factors such as precipitation and runoff from the Xiangjiang River and extreme freezing disasters that led to large fluctuations of the wetland-landscape pattern. The wetland landscape pattern in Changsha was also affected by human factors such as growing population and urban expansion that may lead to the intensification, but government policies and measures had a positive effect on wetland restoration. 【Conclusion】 It was feasible to use GSWD to extract wetland information. The wetland area in Changsha had continued to grow, among which permanent river was the main wetland type. The results from this study could provide important scientific references for the protection and rational utilization of wetlands in Changsha.
【Objective】 The objective of this study is to construct and optimize the ecological spatial network in Jiuquan City, aiming to enhance the quality of the ecological environment, harness regional ecological functions, and prevent desert expansion. 【Method】 By integrating remote sensing ecological index (RSEI) with the ecological spatial network, this study assessed the spatial pattern of landscape in Jiuquan City. By using complex network theory, the study identified weak ecological source areas and proposed optimization strategies. 【Result】 (1) The RSEI exhibited a spatial pattern in the Jiuquan City, with low values in the northern region and high values in the central and southern regions. (2) The potential ecological spatial network in Jiuquan City comprised 332 ecological nodes and 656 ecological corridors. Through the simulation of additional edges based on the region with the lowest RSEI, 242 edges were added, resulting in the inclusion of nine ecological stepping stones. (3) After the addition of edges, there was a noticeable improvement in the robustness of network nodes and connections, while the improvement in edge robustness was slight and not significant. 【Conclusion】 The optimization strategies of adding edges and stepping stones to weak ecological areas can enhance the stability and ecological restoration capacity of the ecological spatial network in Jiuquan City. The construction of new ecological corridors to enhance connectivity between source areas would facilitate regional ecological benefits and provide strategies for future ecological engineering projects in Jiuquan City.
【Objective】 The objective of this study was to explore the extraction of spatio-temporal distribution of aquatic vegetation in lake wetlands using Sentinel-1 and Sentinel-2 data. 【Method】 Hongze Lake National Wetland Park was chosen as the research area. Based on the combination of Sentinel-2 MSI images and Sentinel-1 SAR images, the object-oriented image analysis was used. The feature set was constructed by using EVSI, NDVI, SR feature index and contextual features between objects, as well as differences in the backscatter coefficients of the SAR images corresponding to differences in the height of the emergent vegetation types. A decision-tree model was established at the object level to classify the wetland, and the spatio-temporal distribution of the aquatic vegetation and the emergent vegetation in the Hongze Lake National Wetland Park was acquired. 【Result】 The classification accuracy and the Kappa coefficient of aquatic vegetation were observed to be 89% and 0.85, respectively, and that of the emergent vegetation was 85.2% and 0.76, respectively. The results showed that, compared with the results of the pixel-based analysis method, the accuracy of object-based image analysis was higher. The wetland aquatic vegetation was dominated by submerged and emergent vegetation; among the emergent vegetation, lotus leaves and reeds were dominant. 【Conclusion】 The methods proposed in this study were feasible, and the results could provide a scientific basis for managers and planners of wetlands.
【Objective】 Pinus massoniana is the main coniferous tree species in subtropical China and P. hwangshanensis is the main constructive species in subtropical mid-montane region of the eastern China. Both species coexist at horizontal level but exhibit distinct vertical distributions. The objective of this study is to investigate the distribution patterns of P. massoniana and P. hwangshanensis forests and provide a theoretical basis for the scientific management and conservation of these forest resources. 【Method】 The study was focused on eight typical distribution areas in the eastern subtropical region of China. Non-metric multidimensional scaling analysis (NMDS) and multivariate regression trees (MRT) were employed to explore the differences in community structure and the main influencing factors between the two pine forests. Additionally, a linear mixed-effects model was used to quantify the response of species diversity indices to abiotic factors. Based on the principles for compiling the Vegegraphy of China, a preliminary quantitative classification of P. massoniana and P. hwangshanensis forests was performed. 【Result】 Significant differences were observed in the community structures of P. massoniana and P. hwangshanensis forests, with elevation identified as the primary influencing factor. Mean annual temperature had a significant effect on species richness within both communities, while mean annual precipitation had the most pronounced impact on overall species richness. Elevation exerted a significant influence on the evenness of the two communities. The preliminary vegetation classification resulted in the identification of six associations for P. massoniana forest and five associations for P. hwangshanensis forest. 【Conclusion】 Altitude variations shape the differences in community structure between P. massoniana and P. hwangshanensis forests and directly or indirectly influence species diversity in these communities. The vegetation classification highlights the diversification of vegetation types in the two pine forests and provides a reference for future classification efforts.
【Objective】 Aiming to address the phenomena of low contrast, low saturation, and hue shift in unmanned aerial vehicle (UAV) photography images of forestland under hazy conditions, this study proposes a de-fogging method for UAV images adapted to forestland aerial photography scenes based on Resnet. 【Method】 The UAV images in woodland scenes were characterized by texture features and rich high-and low-frequency information. GFF information transfer modules were attached to each layer of the backbone network to transform feature maps into weight maps for filtering and sending to other layers, and thresholds were set at the receiving end to avoid the adverse effects of redundant information. Then, the global defogging effect was enhanced by dense links to improve the defogging quality in high- and low-frequency image regions. Finally, defogging experiments were conducted on a test set of woodland UAV images with fog. 【Result】 The average structural similarity of DHnet on the test set of woodland images was 0.83, and the average peak signal-to-noise ratio was 22.3 dB, which represented improvements of 4.8% and 39.3%, respectively, compared with the Resnet method. 【Conclusion】 The algorithm can effectively reduce tonal shift and remove residual fog, improving the color fidelity and detailed information retention of aerial woodland fog images obtained by UAV photography.
【Objective】 Plant height is a fundamental component of plant ecological strategies. This study aims to elucidate the phylogenetic conservatism of maximum plant height in Chinese angiosperms, investigate its variation across taxonomic groups and geographic regions, and explore its associations with environmental factors. 【Method】 Using data on the maximum plant height and geographic distribution of 20 295 Chinese angiosperm species, this study assessed the phylogenetic conservatism of maximum plant height among different growth forms, taxonomic groups, and vegetation zones. The study analyzed the correlation between the phylogenetic signal (Pagel’s λ) and factors such as latitude, temperature, and precipitation. 【Result】 The maximum plant height of Chinese angiosperms exhibited a strong phylogenetic conservatism (Pagel’s λ = 0.893). Among them, herbaceous plants showed slightly lower phylogenetic conservatism compared to woody plants, while six orders including Fabales exhibited phylogenetic signals higher than 0.9. The phylogenetic signals of all plants and woody plants displayed a unimodal relationship with latitude and temperature but showed a negative correlation with precipitation. The latitudinal pattern of phylogenetic signals in herbaceous plants was less pronounced, instead showing a multi-peak relationship with temperature and precipitation. 【Conclusion】 The maximum plant height of Chinese angiosperms demonstrated a clear geographic pattern in terms of phylogenetic conservatism, but the trend varied among different growth forms. Overall, the phylogenetic conservatism of maximum plant height of angiosperms and woody plants was stronger in middle latitudes compared to both high and low latitudes.
【Objective】 The process of community establishment in Chinese fir (Cunninghamia lanceolata) artificial forest, as one of the most significant ecosystems and sources of timber in China’s subtropical regions, is crucial for understanding the coexistence of species and the maintenance of biodiversity in plantation forests. The objective of this study is to investigate the process of community assembly and underlying mechanisms of Chinese fir artificial forests in Chinese subtropical, and provide a theoretical basis for enhancing the stability of local biodiversity in the management of Chinese fir artificial forests. 【Method】 Data from 143 pure Chinese fir artificial forests with a wide age range (3-100 years old) in subtropical China were collected through literature search and field sampling surveys. The changes in community phylogenetic structure with forest age and breast height diameter were examined to explore the variations in environmental filtration, competitive exclusion, and stochastic processes during stand development. 【Result】 Overall, as the forest age increased, the net relatedness index (NRI) and net taxon index (NTI) of plant communities in Chinese fir artificial forests initially decreased and then leveled off. The phylogenetic structure transitioned from aggregation to stochastic processes and eventually tended to diverge. The changes in NRI were more significant than those in NTI. In the early stage of young stands, NRI and NTI were both higher than 0, indicating aggregation in the phylogenetic structure. Before stand maturity, NRI was lower than 0, and NTI was higher than 0, showing divergence at the community level and aggregation at the end of the evolutionary tree. After stand maturity, both NRI and NTI were lower than 0, indicating a divergent phylogenetic structure. The trend of phylogenetic structure with diameter at breast height (DBH) was consistent with stand age. 【Conclusion】 The community assembly of Chinese fir artificial forests is primarily driven by environmental filtration, followed by a period of stochastic processes, and ultimately dominated by inter-biotic interactions as the forest stand grows and develops. Implementing appropriate forest management measures for different stand ages is beneficial for the coexistence of local species and the maintenance of plant diversity in Chinese fir artificial forests.
【Objective】We aim to reveal the activity rhythms and clustering patterns of the Reeve’s muntjac (Muntiacus reevesi) population under anthropogenic disturbance in Lüconghu Provincial Wetland Park of Zhejiang Province, to provide a basis for the scientific conservation and management of ungulates.【Method】We used infrared camera trapping to monitor the population of M. reevesi from February 2021 to January 2022. The daily activity rhythm and group patterns were analyzed based on the data from 1 896 independent valid photos.【Result】 The daily activity rhythms of M. reevesi varied across seasons. The minimum area of the overlap of daily activity rhythm curves (DARCs) was observed between winter and spring (Δ = 0.79, P<0.01), with higher intensity and significantly earlier activity peaks detected in the dusk of winter. The daily activity rhythms of M. reevesi also differed along altitudinal gradients. The minimum area of the overlap of DARCs was found between 700-900 m and 1 100-1 300 m (Δ = 0.76, P <0.01), with only one peak of activity detected in the dusk at 700-900 m. Seven group patterns were identified. The solitary individual pattern had the highest proportion (92.95%), followed by the adult female with fawn group (3.47%) and one female and one male group (2.37%). The remaining four group patterns (two female, two male, one male with fawn, two female with fawn) only accounted for 1.21% of the valid detections in this study.【Conclusion】The M. reevesi in Lüconghu Provincial Wetland Park of Zhejiang Province, is a diurnal animal mainly active in the morning and dusk and is mainly solitary. Its daily activity rhythm showed significant differences in different seasons and altitude gradients, which may be mainly influenced by factors such as temperature, food resources, vegetation type, and human disturbance.
【Objective】 Changes in landscape patterns and ecosystem service values (ESVs) in the Fuxian Lake basin are affected by the “Four Retreats and Three Returns” protection policy. Quantitatively understanding such changes can provide a reference for the protection of watershed landscapes. 【Method】 Four sets of remote sensing images taken from 2006 to 2021 (before and after the implementation of the “Four Retreats and Three Returns” protection policy) were selected for landscape classification, and the land use dynamics, transfer matrix and landscape pattern indices were calculated. The ESVs were evaluated using the equivalent factor method and the SPSS software package was used to analyze the correlations between the ESVs in the watershed and the landscape pattern indices. 【Result】 The results indicated that the forested and water system areas in the Fuxian Lake basin were small, while the construction land area was expanding before the implementation of the “Four Retreats and Three Returns” protection policy. The landscape pattern was also complicated and fragmented, with weak connectivity and low ESVs. After the policy was implemented, the forested area increased significantly, the expansion of construction land slowed significantly, and the rate of water system reduction decreased. The degree of fragmentation of the landscape pattern also decreased and the connectivity was enhanced. The ESVs in the basin increased significantly. (2) The ESVs in the Fuxian Lake basin were connected with the landscape pattern, and the total basin ESV was significantly positively correlated with CONTAGE and negatively correlated with SHDI and SHEI. Among the individual ESVs, supply services were significantly negatively correlated with LPI, regulation and support services were significantly positively correlated with CONTAGE and significantly negatively correlated with SHDI and SHEI, and cultural services were significantly positively correlated with CONTAGE. 【Conclusion】 Future studies should focus on the mechanism behind these changes and provide a reference for the next step in protecting and managing the Fuxian Lake basin.
【Objective】 As per the new era and the comprehensive development of territorial spatial planning and the proposed rural revitalization strategy, the evaluation of village development potential is basic to rural planning and construction. The evaluation is also the core link to village planning under territorial spatial planning and a key guide to the classification of villages. 【Method】 Taking “background explanation-potential evaluation-village classification-classification pattern-development strategy” as the research path, seven criterion layers and 19 indicator layers were constructed according to the structural framework of target layer-criterion layer-indicator layer. The weights of indicators were determined by AHP and the entropy weight method. Based on this, villages in Lingbi County in Anhui Province were classified. Next, the landscape pattern of classified villages was analyzed based on Fragstats. 【Result】 Lingbi County in Anhui Province was divided into four types of villages: agglomeration enhancement, suburban integration, characteristic protection and relocation and withdrawal. Agglomeration enhancement villages had the largest landscape area, the most complex landscape shape, and the highest landscape agglomeration degree. The patch integration degree of suburban-integrated villages was the highest with the best landscape connectivity. The landscape complexity of the villages of relocation and withdrawal was the highest. Corresponding development strategies were proposed for different village types. 【Conclusion】 Corresponding development strategies are put forward for different village types: agglomeration and upgrading villages have a certain scale, an important breakthrough for rural modernization. During construction, the village layout should be optimized, the internal structure of the village should be properly adjusted, the construction of the village infrastructure should be improved, and the village’s appearance should be improved. The relationship between protection and development should be fully considered, and the integrity, authenticity, and continuity of village characteristics should be emphasized. In the construction of suburban-integrated villages, we should make use of their location advantages, focus on improving the village’s internal facilities, optimize the spatial layout, and discourage continuous expansion. At the same time, the overall style of the village should be different from the urban landscape—industrial development should be combined with the characteristics of the villages, village resources should be integrated, and the docking and integration of urban and rural industries should be strengthened. As per different industries, block division is conducted to realize the centralized development of industry and the intensive development of land. The natural resources in the villages should be protected, and rational land use and local resources should be combined to build characteristic tourism projects to develop village tourism. The relocation and withdrawal villages should merge, through spatial integration, with neighboring villages with high development potential to form the scale effect of village merger. The merger will enhance development potential and comprehensive competitiveness. The intention to relocate villagers and the restoration of rural ecology should be important considerations. The study provides method reference and a decision basis for the evaluation and classification of county-level rural potential.
【Objective】The hundred-mile ecological corridor of the Songhua River is a diverse environment with abundant biological resources. Studying the construction and classification of its habitat network is crucial for enhancing regional biodiversity and ecological stability.【Method】Using the Songhua River Ecological Corridor as a case study, we first identified regional habitat types and assessed habitat quality using the InVEST analysis. We then pinpointed habitat sources, habitat corridors, and habitat nodes based on habitat suitability analysis for focal species and circuit theory, forming a comprehensive habitat network. Lastly, we classified the importance levels of sources and corridors based on current density.【Result】(1) The corridor features 23 habitat types; 44.31% of the areas are classified as having high habitat quality. (2) The habitat network consists of 82 sources, 147 corridors and 57 nodes. (3) Analysis of current density revealed seven primary habitat sources covering 484.82 km2, primarily in large nature reserves, and 14 first-class habitat corridors totaling 7 560 meters, mainly along the main stream of the Songhua River, though the corridors are relatively short.【Conclusion】The habitat conditions in the Songhua River ecological corridor are generally favorable. However, attention must be given to ecological threats posed by rapid urban development. Effective strategies include classifying and expanding habitat sources, managing and enhancing corridor connectivity, and restoring and adding habitat nodes. These measures will optimize the habitat network and facilitate biological migration, providing essential “Stepping stones.”
【Objective】 To explore the potential problems and conflicts of habitat quality in the Qilianshan Nature Reserve as per future land use changes; to respond to the regional ecological environmental protection policy per the concept of “Mountain, Water, Forest, Field, Lake, Grass, and Sand”, and to provide a scientific basis for regional ecological management and sustainable development. 【Method】 Based on five phases of land use data from 2000 to 2020, the PLUS model was used to simulate land use under different scenarios in the future through 2030. The InVEST model was coupled to assess and predict the current and future habitat quality of the Qilian Mountain Nature Reserve. 【Results】 Land use in the Qilian Mountain Nature Reserve was dominated by grassland, forest land, and unused land, and an increase in the area of ecological land. The increase in the area of ecological land under the ecological protection scenario was significantly higher than under the natural development scenario for 2030. Habitat quality showed a spatial distribution pattern of “low in the northwest and high in the southeast,” with the mean value of habitat quality from 2000 to 2020 as follows: 0.656 2, 0.656 3, 0.665 8, 0.664 6, and 0.665 7, respectively. This showed a fluctuating trend of increasing, decreasing, and increasing values. The average value of habitat quality in 2030 was 0.667 9 under the ecological protection scenario and 0.665 6 under the natural development scenario. The total habitat contribution under the ecological protection scenario was greater than that under the natural development scenario. The degree of habitat degradation increased and then decreased from 2000 to 2030, showed a spatial distribution from weak to strong circles from the center outwards, with the most degraded areas located at the edges of grassland adjacent to unused land—the areas most affected by human activities. 【Conclusion】 The habitat quality of the Qilian Mountain Nature Reserve is developing in a positive direction; the habitat quality under the future ecological protection scenario is significantly better than that under the natural development scenario; strengthening the protection of ecological land such as woodland and grassland is conducive to the improvement of habitat quality.
【Objective】The establishment of the national carbon market represents a significant institutional innovation for reducing greenhouse gas emissions through market mechanisms and promoting green and low-carbon development. It also serves as a crucial policy instrument for advancing the achievement of the carbon-peak goal and the carbon-neutrality vision. The scientific, fair, and reasonable allocation of carbon emission quotas lies at the core of the carbon trading process. This study analyzed the allocation of carbon emission quotas within the carbon trading system based on the current situation and proposed optimization strategies to offer references for the development of China’s carbon trading market.【Method】Adopting the research path of “status quo-problems-countermeasures”, this study employed methods such as literature review, case summarization, and comparative analysis. It analyzed the quota allocation models of major international carbon markets, summarized the current status and main problems of China’s carbon emission quota allocation mechanism, and puts forward relevant suggestions for future mechanism and strategy optimization.【Result】(1) From an international perspective, the practical experiences of major markets in carbon emission quota allocation were summarized. For instance, setting appropriate emission-reduction targets and flexible adjustment mechanisms in the carbon market, building sufficient confidence in participation and a stable price mechanism, as well as establishing a sound and perfect market mechanism and supporting legal system, provided valuable insights and references for the orderly implementation of a combination of free and paid carbon emission quota allocation methods.(2) From a domestic perspective, the current situation of China’s carbon emission quota allocation was summarized. With the development of China’s carbon trading market, certain achievements have been made in carbon emission quota allocation, including the gradual optimization of the tier-by-tier total quota amount, the progressive expansion of the covered industry scope, the diversification of allocation principles, and the gradual transition of the allocation mode from free to paid. Nevertheless, there are still numerous issues to be addressed, such as the need to improve the top-level design, the relative simplicity of the allocation method, the lack of stimulation of market vitality, and the necessity to enhance supporting measures.【Conclusion】Based on the current situation and future development trends of China’s carbon emission quota allocation, it is essential to strengthen the overall planning and top-level design of allocation, promote the progressive development of allocation, establish a scientific and reasonable trading ecosystem, improve laws, regulations, allocation methods, market mechanisms, and other supporting measures, and promote the market-based empowerment and optimization of the carbon emission quota allocation strategy. This will offer solution paths and model references for the development of China’s carbon trading market and the effective realization of carbon-emission-reduction targets.
【Objective】Springtail(Collembolan species), as a kind of microarthropods widely distributed in soils, plays an important role in regulating the functions of soil ecosystems. However, the effects of nitrogen deposition on springtail communities in soils are poorly understood. This study aimed to elucidate the effects of nitrogen addition on springtail communities in soils by simulating nitrogen deposition for 10 years in a poplar plantation in Dongtai Forest Farm, Jiangsu Province.【Method】Four experimental treatments with different concentrations of nitrogen addition, i.e., the control (N0,No nitrogen addition), N5[5 g/(m2·a)], N15[15 g/(m2·a)], and N30[30 g/(m2·a)], were established in May 2012, respectively. A total of four replicate plots were prepared for each treatment, thus accounting for a total of 16 sample plots. The springtail communities in the litter and soil layers were analyzed in July 2021, October 2021, January 2022, and April 2022. The springtails in the litter layer were collected using a collection frame. Springtail samples were collected using soil drills with different diameters from the three soil layer at depths of 0 (floormas), 10 and 25 cm, respectively. Following transportation to the laboratory, the springtails were collected according to the Tullgren method, and the physical and chemical properties of the soil were analyzed. Statistical analysis was performed using SPSS 26 and Canoco 5.0.【Result】A total of 1 446 springtails, belonging to 4 Orders, 7 Families, and 18 Genera, were collected in this study. Of these, the Isoma, Toocerus, Entomobrya and Folsomia genera were the most abundant and accounted for 66.87% of the total number of individuals. The number of springtails in the soil increased significantly at a nitrogen concentration of 15 g/(m2·a), but decreased at a concentration of 30 g/(m2·a). The number of springtails in litter layer was significantly higher than that in the soil layer. The number of individuals varied across the seasons, in the following order: October (autumn) > July (summer) > April (spring) > January (winter). The Shannon-Wiener diversity index and Simpson dominance index were highest in the 15 g/(m2·a) treatment group, whereas the Pielou evenness index was highest for the 30 g/(m2·a) treatment group. The results of RDA analysis demonstrated that the pH, nitrate nitrogen content, and the C/N were the primary environmental factors that affected the distribution of springtails in the soil, and that different springtail populations responded differently to the environmental factors.【Conclusion】The results demonstrated that nitrogen deposition affected the composition of the springtail community in the soil. The findings further revealed that the application of nitrogen within a moderate concentration might increase the number and diversity of springtails; however, the excessive addition of nitrogen may reduce the number of springtails, thus indicating a threshold effect.
【Objective】 The construction of natural resources classification systems for protected areas is important for the conservation, supervision, and identification of rights and value-added assets in protected areas, witch can help modernizate their governance system and capacity. 【Method】 The key problems of natural resources classification in protected areas were analyzed and identified the concept of natural resources using a systematic process. Taking the investigation of protected areas as the starting point, attempts were made to establish a natural resources classification system. 【Result】 The problems of natural resources classification in various protected area stem types from the inadequacy of the classification systems, as such lack of key resources, unclear levels, overlapping resources, and unclear scope. The natural resources classification systems under the new protected areas systems involved a single natural resource classification system with four categories, eight subcategories, and twenty-one subdivisions. On this basis, the system of an organic complex of natural resources was proposed, including natural ecosystems, natural landscapes, and natural monuments. Finally, a new natural resources classification system of “Single natural resource classification system + Classification system of natural resource organic complexes” was established under the concept of new protected areas system. 【Conclusion】 Based on the results of special resource surveys on animals, wetlands, and the results of scientific research on protected areas, it is necessary to continue to deepen and refine the classification systems. Relevant documents should be issued as soon as possible to accurately define the boundaries of various natural resources. Concerning the main protection objects of protected areas, focus on the classification management of natural resources. Under the general pattern of unified management of natural resources, the classification systems of natural resources in protected areas should be integrated into the unified management systems to build a foundation for the effective management of natural resources in protected areas.
【Objective】This study aims to explore the structural composition and spatial distribution patterns of bird communities in Chengdu, Sichuan, China, analyze the differences in bird diversity across various habitats and seasons, and identify bird hotspots to provide a basis for bird diversity protection in Chengdu and similar areas.【Method】In 2020, a survey of bird diversity was conducted across different seasons in 20 administrative districts of Chengdu using the line transect method and the sampling point methods. Species richness, Shannon-Wiener diversity index, Simpson index, Pielou evenness index, and community similarity coefficient were calculated to analyze bird diversity in Chengdu. Additionally, 41 key bird species were selected and categorized into raptorial birds, terrestrial birds, natatorial birds, and wading birds based on their ecological habits. The MaxEnt model was used to predict the potential habitats of key birds and identify bird biodiversity hotspots in Chengdu.【Result】A total of 261 bird species across 17 Orders and 62 Families were identified, including one species under national first-class key protection and 29 species under national second-class key protection. Among these, there are 99 species of resident birds, 61 species of summer migratory birds, 60 species of winter migratory birds, and 41 species of transient birds. The number of bird species and individuals, the Shannon-Wiener diversity index, the Simpson index, and the Pielou evenness index were highest in winter, followed by spring, autumn, and summer. Among the six habitats studied, forests (200 species) and wetlands (169 species) had the highest bird species counts. Urban land and wetlands had the highest number of individual birds and population sizes. Forest habitats exhibited the highest Shannon-Wiener diversity index and Simpson index, while urban land had the highest evenness index. The MaxEnt model predictions showed that the distribution of raptorial birds was significantly influenced by land cover type, distance from lakes, and distance from forests. Terrestrial birds distribution was largely affected by distance from forests, altitude, and settlement density. The distribution of waterbirds, including natatorial birds and wading birds, was heavily influenced by land cover type and distance from lakes. Chengdu’s bird diversity hotspots are primarily located in nature reserves, the Longmen Mountain Range, Chaoyang Lake, Longquan Mountain Forest Park, Sancha Lake, Xinglong Lake, Qinglonghu Wetland Park, and along the Minjiang and Tuojiang Rivers.【Conclusion】The rich bird diversity in Chengdu is closely linked to its natural environment, characterized by extensive forest areas, high spatial heterogeneity, and abundant food sources, making it a crucial habitat for birds. Although wetlands comprise only about 2% of the city’s land area, they rank second to forests in bird richness and should be a focal point in future bird biodiversity conservation efforts.
【Objective】 This study explored the rules governing the spatial relationships among mountains, water and the locations of traditional villages to shed light on their reasonable protection and construction. 【Method】 Jinting Town, a scenic location near Taihu Lake with well-protected traditional villages and towns, was selected as the research subject. Based on extracted digital topography, satellite maps and the general planning CAD base map data for Jinting Town, we analyzed the spatial relationships among the mountains, water and villages using ArcGIS (ver. 10.0). We also analyzed the correlations between the distributions of mountains and water with the distribution of villages. We used spatial logistic regression modeling to analyze the factors affecting the distribution of traditional villages. 【Result】 The spatial distribution of traditional villages in Jinting Town exhibited a cluster mode, with circular spatial density characteristics. The impacts of mountain elevation and distance from a river were negatively correlated with the spatial distribution of traditional villages. Owing to the terrain, which is surrounded by lakes on all sides, the circular distribution of traditional villages in Jinting Town has a special research value. The elevation of the mountains affected the direction of the water system and roads in Jinting Town and was the main driving force for constructing villages in the region. The proximity to the water also affected the distribution of villages. 【Conclusion】 Using ArcGIS and logistic regression modeling, the spatial relationships among villages, mountains, and water can be analyzed and widely used in the pre-planning stages of protecting and constructing traditional villages and towns.
【Objective】 The aim of this study was to determine the influence of varying phosphorus concentrations and mycorrhizal fungi on Pinus massoniana container seedlings.【Method】A split-plot experimental design was adopted. The main plot was the mycorrhizal fungi treatment with two treatment levels: inoculation and non-inoculation. The inoculation treatment involved placing 0.3 g of solid preparation made of vermiculite and Lactarius deliciosus mycelium suspension under the planting hole during sowing. The sub-plot was the phosphorus addition treatment, which set a P-based water-soluble fertilizerof seven treatment levels. The amount of phosphorus added ranged between 50 and 600 g/m3. From July to October, water-soluble fertilizers of different gradients were dissolved in water for 15 times at equal intervals, and then evenly sprayed on the seedlings. Once this was done, growth was analyzed in relation to N and P uptake, the use of phosphorus and mycorrhizal fungi. 【Result】 After inoculation with mycorrhizal fungi, compared with the non-inoculation treatment, the average seedling height, caliper, total biomass and root diameter of 1-year-old P. massoniana container seedlings increased by 9.87%, 3.35%, 41.50% and 12.41%, respectively, whereas nutrient indices such as N and P uptake and utilization index increased by 5.05%, 25.03%, 100.36% and 70.53%, respectively. The height-to-diameter ratio, total root length, and N and P contents decreased by 5.98%, 22.47%, 24.97%, and 11.26%, respectively. There were significant differences in growth and nutrient traits, except for seedling height and N uptake, before and after inoculation. Along with the increase in P content, the caliper and P uptake of the whole plant increased before and after inoculation, the height-diameter ratio decreased, and the N and P content of the whole plant initially increased and then decreased. For the caliper, total biomass, root diameter, P uptake of the whole plant, and N and P utilization index of different P addition gradients, the values of the inoculated treatment were greater than those of the non-inoculated treatment. As for the height-diameter ratio, total root length, and P content of the whole plant, the non-inoculated values were greater than the inoculated values. Inoculation with mycorrhizal fungi and P addition had no significant interaction effect on the growth and nutrient traits of P. massoniana container seedlings. After inoculation, the growth traits of P. massoniana container seedlings were more sensitive to changes in N content in the whole plant, and the response to N and P uptake and utilization indices was further enhanced. 【Conclusion】 Inoculation of mycorrhizal fungi (L. deliciosus) can establish a good synergistic symbiotic relationship with container seedlings of P. massoniana, which not only promoted the growth of P. massoniana container seedlings but also improved the nutrient utilization efficiency of N and P. After inoculation, the height-diameter ratio of seedlings decreased, their utilization index of N and P increased, and the seedlings could experience normal growth and metabolism under low nutrient concentrations, which is vital for cultivating high-quality seedlings while reducing seedling cost.
【Objective】With the continuous promotion of park city construction, many urban development goals require synergistic planning of blue-green spaces to achieve, and it is particularly important to scientifically develop criteria for measuring blue-green spaces in order to promote synergistic planning of blue-green spaces. 【Method】This study adopts a dual-performance measurement approach, based on a GIS platform, and takes Putuo District in Shanghai City as an example. It selects four performance measurement factors, namely spatial accessibility, spatial use level, waterlogging diversion, and cold island effect, from two aspects: recreation services and environmental ecology, to scientifically analyze the rationality of the layout of urban blue-green spaces, and to derive typical areas of low performance in Putuo District in Shanghai and analyze their causes. The layout optimization strategies of urban blue-green spaces are proposed from three aspects. 【Result】The performance rating of blue-green spaces in the whole Putuo District is not high, and there are several obvious characteristics of the blue-green spaces in Putuo District based on the double performance assessment: (1) the number and distribution of community blue-green spaces are small; (2) the performance of recreation services differs greatly from north to south and is unevenly distributed; (3) the environmental and ecological performance shows a better characteristic in the north and south but less in the middle district; (4) the performance rating of the whole blue-green spaces is not high, and the lowest performance areas are roughly. The lowest-performing areas are located in the central and southern regions. 【Conclusion】Based on the above characteristics, optimization strategies are proposed from three aspects: the layout of urban water bodies, the layout of urban green spaces, and the coordinated layout of blue-green spaces. The research results show that the current spatial layout of the city's water bodies and the coordinated layout of blue-green spaces can be improved. The research results will provide practical criteria and solutions for improving the current spatial layout and planning future blue-green spaces.
【Objective】The relationship between odorous substances in flowers and the visiting behavior of insects has attracted increasing attention from biologists. However, previous studies on specific plants and pollinators are scare. The present study investigated the species differences and dynamic changes in the volatile organic components of male and female flowers of Ilex rotunda during flowering, and recorded the species and behaviors of pollinators. The study aimed to elucidate the characteristics of the pollinating system, explore the potential effects of volatile compounds on the behaviors of pollinating insects, and provide a reference for improving the pollination and fruiting of I. rotunda.【Method】The changes in the volatile components during the four flowering stages, the big bud stage, first blooming stage, full blooming stage, and final flowering stage, were determined by head space solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The species, visiting behavior, and visiting frequency of the pollinators were recorded by observation.【Result】The results demonstrated that the flowering of I. rotunda began in late April and ended in early May in Nanjing, with a flowering period of nearly half a month. A total of 30 volatile substances were detected from the flowers, of which 19 and 21 were detected from female and male flowers, respectively. There was a moderate difference in the overall number of male and female plants. The results revealed that the levels of β-caryophyllene and other major components increased initially, reached a peak at the full-opening stage, and decreased thereafter. The proportion of the main components generally decreased at the final flowering stage. However, there was an increase in the proportion of alcohols and alkanes during final flowering, which was accompanied by the production of several new compounds. The sole insect pollinator of I. rotunda is Apis cerana. There was a considerable overlap between male and female plants during the peak visiting period. The findings revealed that A. cerana preferred visiting male flowers, and that there was a positive correlation between the changes in the visiting frequency pattern and β-caryophyllene content.【Conclusion】The results indicated that β-caryophyllene could be used as an information substance to attract A. cerana for pollinating I. rotunda. Additionally, male and female I. rotunda plants can be planted in a centralized and reasonable manner according to the “centralized” flower visiting behavior of A. cerana. The success rate of I. rotunda pollination can be effectively improved by complying with the consistent flowering period, the concentrated flowering period, and planting large numbers of male plants.
【Objective】This study aims to investigate the carbon dynamics of subtropical mixed coniferous and broadleaved forests in Fengyang Mountain, Zhejiang Province and their response to climate change. 【Method】The Biome-BGC model was used to simulate the net primary productivity (NPP), gross primary productivity (GPP), and net ecosystem productivity (NEP) in Fengyang Mountain from 1979 to 2018, to investigate the relationships between climate factors and NPP at different time scales. Pearson correlation analysis and quadratic function fitting were performed between climate factors and NPP at different temporal scales to explore the relationship and response patterns between NPP and major climate factors, and finally, different climate scenarios were applied to predict the carbon cycling trends in Fengyang Mountain in the next 100 years. 【Result】The average values of GPP, NPP and NEP of mixed coniferous and broadleaved forests in Fengyang Mountain for 40 years were 1 392.94, 451.25 and 16.21 g/(m2·a), respectively. Except for 1984, 2002, 2005, 2008 and 2010, which were carbon sinks and showed that the sensitivity of NPP to temperature change was the highest, and the increase of temperature in summer had a positive effect on the increase of NPP, while the increase of temperature in winter had a negative effect on NPP. To a certain extent, winter rainfall showed a positive effect on NPP, while summer precipitation showed a negative effect on NPP. The gross primary productivity of Fengyang Mountain forests in RCP2.6, RCP4.5 and RCP6.0 scenarios will keep increasing in the 21st century, and by 2100, the GPP of the studied forests in Fengyang Mountain under RCP2.6, RCP4.5 and RCP6.0 scenarios will reach 1 552.73, 1 660.30 and 1 960.41 g/(m2·a), respectively, and get increased 1.38%, 8.41% and 28.00% relative to the GPP in 2018. 【Conclusion】Overall, the forest ecosystem of Fengyang Mountain exhibited carbon sinks under normal conditions, but the cloudy and rainy summer weather in the mountainous area inhibited the increasing effect of temperature on carbon sinks to some extent. The future warming, increased rainfall and higher CO2 concentration simultaneously will favor the vegetation growth of mixed coniferous forests in Fengyang Mountain.
【Objective】The Luoshan Mountains in the Ningxia Hui Auto nomons Region are unique ecological security barriers in the arid zone of central China. Therefore, the stoichiometric characteristics of this area’s forest ecosystems were studied to describe the limiting nutrients during vegetation development, to provide a theoretical basis for community selection and forest management in this area.【Method】Spruce (Picea crassifolia) forests, Chinese pine (Pinus tabuliformis) forests, aspen (Populus davidiana) forests, and Picea crassifolia × Pinus tabuliformis mixed forests were examined for carbon (C), nitrogen (N) and phosphorus (P) contents of plant, litter, and soil, and plant-litter-soil ecological stoichiometry correlations were analyzed.【Result】(1) C content of leaves and branches were significantly higher compared with roots, the N and P contents of leaves were significantly higher compared with branches and roots, and leaf C/N was significantly lower compared with branches and roots. Furthermore, leaf and branch N content in Populus davidiana forests were significantly higher, and root N content in Pinus tabuliformis forests were significantly lower, compared with other forests. (2) Litter N, P content, and N/P in Populus davidiana forests were significantly higher, and C/N and C/P were significantly lower, compared with other forests. (3) Soil C, N, P content, C/N, and C/P did not differ significantly among forests, while soil N/P in Picea crassifolia forests was significantly higher than in other forests. (4) Plant N content was significantly positively correlated with litter N content and N/P, and significantly negatively correlated with litter C/N. Plant C/N was significantly positively correlated with litter C content, and strongly negatively correlated with litter N/P. Soil C/N and N/P were significantly positively correlated with plant P content and litter C/P, and significantly negatively correlated with plant C/P. The plant P content was significantly positively correlated with soil pH. Altitude was significantly positively correlated with litter C/N and C/P, and significantly negatively correlated with N content and N/P. Soil N/P was significantly negatively correlated with pH, and significantly positively correlated with altitude and N content. Soil C, N, P content, C/N, and C/P were significantly positively correlated with organic C content.【Conclusion】The plant growth and litter decomposition were both limited by N in the four main forest communities of the Luo Mountains, especially within the coniferous forests. Hence, the protection and use of N elements should be strengthened in these areas. The growth rate is the fastest and litter decomposes more easily in Populus davidiana forests, which are thus candidates for protection and vegetation restoration across the Luoshan Mountains.
【Objective】 Functional diversity is crucial for forest biodiversity protection and maintenance of ecosystem stability. Exploring the characteristics and causes of functional diversity variation at different stratum levels will assist in understanding the maintenance mechanisms of biodiversity and plant community assembly processes. 【Method】 Leaf traits and environmental factors were collected from forest plot data from an 1.6 hm2 evergreen broadleaved forest in Guangxi Yachang Orchidaceae National Natural Reserve. K-means partitioning and Gaussian kernel density estimation were used for stratification. The direct and indirect effects of species diversity and environmental factors (light, topography, and soil) on functional diversity were explored in different forest strata using structural equation models. 【Result】 The diversity indices of the understory were greater than those of the canopy (P<0.05). Species diversity had a significant direct impact on all four functional diversity indices in the understory layer, whereas only the functional richness index (FRic) and quadratic entropy (RAOQ) indices were affected directly by species diversity in the canopy layer (P<0.05). A significant indirect effect (β = 0.278, P<0.01) of canopy openness on FRic index and a direct effect (β = -0.593, P<0.01) of canopy openness on functional evenness index (FEve) were found for understory trees. Topographic factors affected canopy functional diversity. Specifically, there was a relatively significant direct effect of aspect on FEve (β = -0.420, P<0.01) and RAOQ (β = -0.300, P<0.05) indices for canopy trees. Soil factors mainly affected the functional diversity of different forest layers through species diversity. Soil total phosphorus, available phosphorus, alkaline hydrolysis nitrogen, and available potassium content had a greater effect on the functional diversity of the understory, whereas soil total potassium content affected the FRic and RAOQ indices of the canopy. 【Conclusion】 There were marked differences in the characteristics of functional diversity at different forest stratum in the study area. Functional diversity was mainly affected by species diversity, canopy openness, and soil nutrients of understory plants, whereas topographic factors determined the functional diversity of the canopy layer. This study reveals the effects of biological and abiotic environmental factors on functional diversity across different forest layers and expands the understanding of the diversity of vertical stratification. The findings provide a further reference for biodiversity protection in natural forests.
【Objective】Taking the Castanopsis spp. and Schima superba forests in subtropical typical evergreen broad-leaved forests in east China as the research subjects, the effects of environmental factors on aboveground biomass of the tree layer were studied.【Method】The aboveground biomass of the community was calculated based on the allometric growth equation of various plant species, and the Pearson correlation test was used to analyze the relationship between aboveground biomass and environmental factors in different types of evergreen broad-leaved forests. The mechanism of action between environmental factors and aboveground biomass was constructed by the partial least squares structural equation model (PLS-SEM), which was employed to analyze the relationship between multiple sets of variables.【Result】(1) The aboveground biomass of subtropical typical evergreen broad-leaved forests in east China showed a extremely significant increasing trend with forest age. (2) The aboveground biomass of Castanopsis and S. superba natural forests positively correlated with soil pH in the study area, and for the S. superba natural forest, air temperature and total solar radiation intensity factors significantly affected the aboveground biomass. (3) In the structural equation model constructed using environmental factors and the aboveground biomass of Castanopsis natural forests, the direct effect coefficient of climate factors on aboveground biomass was significantly greater than that of soil factors.【Conclusion】The total solar radiation intensity, soil pH, and soil bulk density significantly affected the aboveground biomass of subtropical typical evergreen broad-leaved forests in east China. Among them, in the Castanopsis natural forest, aboveground biomass positively correlated with air the soil pH factor. In the S. superba natural forest, aboveground biomass negatively correlated with air temperature factor and total solar radiation intensity factor and positively correlated with soil pH factor.
【Objective】An investigation on the effects of arbuscular mycorrhizal (AM) fungi inoculation on the growth, physiological metabolism, and salt tolerance of Xanthoceras sorbifolium under salt stress was conducted.【Method】In this study, Funneliformis mosseae was used to infect seedlings and the pot experiment was carried out using one-year-old X. sorbifolium seedlings. We applied different concentrations of NaCl stress (0, 80, 160, 240, and 320 mmol/L). After the stress period, the biomass, colonization characteristics, and physiological indicators of the X. sorbifolium seedlings were measured.【Result】(1)The aboveground and underground biomasses of X. sorbifolium seedlings were enhanced significantly by AM symbiosis upon exposure to salinity. Increasing salinity significantly caused a decrease in the mycorrhizal colonization rate.(2)AM fungi inoculation significantly improved the contents of soluble protein, proline, glutathione(GSH), and ascorbic acid (AsA), and resulted in an increasement in the activities of superoxide dismutase (SOD) and peroxidase (POD), yet a reduction in the relative conductivity and accumulation of malondialdehyde (MDA).(3)Furthermore, two-way analysis of variance(Two-way ANOVA)demonstrated that the duration and concentration were interactively and significantly affecting correlated with the content of MDA, proline, soluble protein, and AsA (P<0.01). Based on principal component analysis(PCA), it was found that the inoculation group had the most profound impact on the physiological characteristics of X. sorbifolium at 320 mmol/L NaCl treatment.【Conclusion】This study found that inoculation with AM fungi may advance osmotic mediation ability, significantly improve the activities of antioxidant enzymes and the contents of antioxidants, and enhance the salt tolerance of plants and eventually promote the growth of X. sorbifolium seedlings under different salt concentrations.
【Objective】The study aims to establish a sound ecological compensation standard, which will provide a sustainable and stable financial guarantee for the construction of national parks. 【Method】 Taking the Qianjiangyuan-Baishanzu National Park as an example, this study calculated the upper and lower range of the national park compensation standard by comparing the difference values of provincial public welfare forests inside and outside the national park with regulating services and opportunity cost losses. 【Result】 Considering the value of forest ecosystem regulation services and opportunity cost losses comprehensively, the value of provincial public welfare forests within the national park reached 47 237.01 yuan/(hm2·a).Among them, the value of provincial public welfare forests regulating service function was 45 672.53 yuan/(hm2·a), which was 13 306.25 yuan/(hm2·a) higher than outside the scope, and the value of each regulating service was higher than that outside the implementation area. The opportunity cost loss of public welfare forests within the national park was 1 564.48 yuan/(hm2·a), which still showed a gap of 841.48 yuan/(hm2·a) compared with the current highest compensation standard of 723 yuan/(hm2·a) of the provincial public welfare forests. 【Conclusion】 At present, there was still a large gap between the ecological compensation standard implemented in Qianjiangyuan-Baisanzu National Park and that calculated based on the regulating service unit area and opportunity cost. In the future, we suggest that the compensation standard be gradually increased year by year, taking into account the actual development needs of the National Park.
【Objective】This study aims to explore a new idea of building ecological network to restore broken landscape and improve landscape connectivity, and to provide scientific basis for landscape pattern optimization and ecological red line protection in Xinfeng County. 【Method】 Taking Xinfeng County, Jiangxi Provinceas as the object, an ecological risk index was constructed based on landscape pattern to assess the ecological risk level, combined with the minimum cumulative resistance model (MCR) and landscape connectivity analysis, the ecological sources were identified and the general,important corridors were distinguished, and the county potential ecological network was constructed with Xinfeng County as the case. 【Result】 The ecological risk of urban construction and cultivated concentration area was relatively high, while the forest cover area was relatively low; the potential ecological network was consisted by 30 ecological sources, 67 ecological corridors and 25 ecological nodes. Important ecological corridors play a key role in the communication and connection of ecological patches in the east-west and north-south directions, and general ecological corridors connect multiple adjacent and scattered ecological sources together in Xinfeng County. 【Conclusion】 Landscape connectivity analysis can be used to determine not only patch importance but also corridor importance. The combination of ecological risk assessments and ecological network construction strengthens the integrity and reliability of county ecological network.
【Objective】 This study aims to comprehensively protect, rationally develop as well as effectively utilize natural scenic resources and alleviate the fragmentation, islanding and uneven distribution of natural resource landscapes in Jiangsu Province.【Method】 Using ArcGIS spatial analysis technology, the spatial distribution characteristics of natural landscape resources in Jiangsu Province were obtained from the Nearest Neighbor Index (NNI) and results of the kernel density analysis and accessibility analysis. Also, based on the double evaluation' of the land and space planning and the natural environment of Jiangsu Province, an ecological protection evaluation, including evaluations of the ecosystem services and ecological sensitivity, was conducted. Based on the evaluation results, the ecological space of Jiangsu Province was delineated. The above results are superimposed with the corresponding physical and human geographical characterizations of Jiangsu Province. 【Result】 The distribution and regional differences of protected areas of natural landscape resources in Jiangsu Province were revealed, which provided a realistic basis for the selection of natural landscape patches, corridors and advantageous regions. Nine natural landscape patches, seven natural landscape corridors and two natural landscape dominant areas in Jiangsu Province were delineated. Also, a natural landscape system in Jiangsu Province was formed based on natural landscape resources dominated by patches, corridors and substrates. 【Conclusion】 The landscape system applied the spatial concept to the study of landscape resources. This approach helps to strengthen the connection between protected areas of natural landscape resources, improve the integration and optimization of resources, create a landscape pattern more suitable for the protection and development of natural landscape resources in Jiangsu Province, and provide effective guidance for the protection and construction of natural landscape resources in Jiangsu Province and a scientific basis for reasonable development and utilization.
Vegetation effectively removes airborne particulate matter through “direct” and “indirect” pathways, each with distinct mechanisms and processes. Osmanthus fragrans, one of the top ten traditional flowers in China, is widely distributed in south of the Qinling Mountains across the subtropical regions. Research results indicate that this species plays a significant role in mitigating atmospheric particulate pollution and improving air quality by retaining particulate matter. We analyzed and summarized advancements in understanding the dust retention capacity of O. fragrans, emphasizing key quantitative indicators such as dust retention per unit leaf area, per single leaf, and the ability to retain particulates of various sizes. This study also explored spatiotemporal variations in dust retention and its impact on spectral characteristics, morphological structure, and physiological ecology. Differences in dust retention among O. fragrans varieties and habitats were attributed to genetic traits and environmental factors, including air pollution levels, leaf morphology, leaf area, phyllotaxy, inclination angle and crown shape. Key findings include the following:(1) Correlation with environmental pollution. Dust retention per unit leaf area was positively correlated with the background level of air pollution. (2) Influence of morphological traits: dust retention per single leaf was determined by leaf morphology and environmental conditions, though no significant correlation was found between single-leaf area and particulate retention capacity. (3) Plant-level variation. Total dust retention varied significantly among plants due to differences in leaf area across growth stages, health conditions, and locations. (4) Particulate size specificity. Leaves retained coarse particulates more effectively than fine ones, and dust retention showed predictable spatiotemporal variation. Diurnal and seasonal trends aligned with fluctuations in airborne particulate matter, with species- and region-specific saturation times. (5) Impact on leaf traits. Particulate retention altered leaf spectral characteristics, affecting morphology, functional traits, and adsorption capacity. These changes influenced physiological ecology, growth, floral fragrance, and ornamental value.
【Objective】Rhynchium quinquecinctum was collected by the nest trap method, and Pseudoxenos iwatai samples were reared in the laboratory. The parasitism rate, extrusion time and position, eclosion time, and other behaviors of P. iwatai in the abdomen of R. quinquecinctum were observed by visual observation, photography and videography. 【Result】The parasitism rate of P. iwatai on R. quinquecinctum was 5.85% and the sex ratio of P. iwatai was 1∶6.24. In R. quinquecinctum, 48.98% of females and 51.02% of males were parasitized. The number of P. iwatai parasites in the abdomen of R. quinquecinctum ranged from one to nine, of which one to three were the majority, accounting for 91.54% of the total. The extrusion positions from the abdomens of R. quinquecinctum differed between females and males, and the number of females was the highest in the 3rd-4th segments of the host abdomen, accounting for 40.91%, while it was the highest in the 4th-5th segments of the host abdomen in males, accounting for 65.83%. Males were found on the 1st to 9th day after the R. quinquecinctum eclosion, and the number on the 1st day was the largest, accounting for 66.67%. The number of females observed on the 5th day after eclosion was the highest, accounting for 67.44%. There was a clear attraction to the male after the cephalothorax of the female was extruded from the host’s abdomen, and the attraction peak was at 5:30-6:30 and 13:00-14:30 of the day. Male eclosion occurred on the 5th to 10th day after R. quinquecinctum closion, and the peaks of eclosion were between 5:00-6:30, 9:00-11:00, and 14:00-15:30 in the day.【Conclusion】Different extruding positions from the abdomen of R. quinquecinctum for different sexes of P. iwatai were observed. An important behavior in the reproductive mating strategy of P. iwatai may be the overlap of the time of attracting males by females extruding from R. quinquecinctum and the peak time of male eclosion.
【Objective】Based on the forest resources inventory of Shicheng County, Jiangxi Province, the carbon stored in broad-leaved forests of different origins was estimated to quantify the contribution of driving factors to vegetation carbon storage, then evaluate the direct and indirect effects of such factors, providing a theoretical basis for the scientific management of forest resources.【Method】The biomass of the broad-leaved forest in Shicheng County was calculated based on statistical data from the 2016 forest resource inventory for Shicheng County, Jiangxi Province. Carbon stocks were calculated using the biomass conversion factor continuous function method, and random forest (RF) analysis and structural equation modeling (SEM) were combined to quantify and evaluate the contribution and impact of different drivers on the vegetation carbon stock.【Result】 The results of the random forest and structural equation models indicate that changes in the natural broad-leaved forest vegetation carbon storage are mainly determined by forest age, with a standardized total effect value of 0.54, followed by canopy closure at 0.36. No significant changes were observed in the amount of carbon stored in the forests, which is determined by canopy closure and stand density with total effect values of 0.49 and 0.19, respectively.【Conclusion】Canopy density, forest age and stand density are the main factors driving the carbon storage of subtropical broad-leaved forest ecosystems, providing new insights for understanding the carbon cycle and carbon accumulation in mid-subtropical forest ecosystems in response to climate change. The results of this study provide a theoretical basis for the managements of planted forests and assessment of the carbon sink potential of such forests.
【Objective】 Based on 30 m of high-resolution land use data of Wuxi City in 2000, 2010 and 2018, the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model was used to reveal the changing features of habitat quality in Wuxi. Such information could provide a basis for ecological environment protection and restoration in Wuxi. 【Method】 Using the InVEST model, the habitat quality and habitat degradation degree of Wuxi during recent 20 years were simulated, and the relationship between the changes of land use, habitat quality and habitat degradation degree was analyzed by using the land use transfer matrix. 【Result】 In 2018, high-grade habitats in Wuxi accounted for approximately 31.11% of the city’s area, whereas the proportion of general grades was relatively higher, accounting for approximately 40.60% of the city’s area. The spatial distribution of habitat quality in Wuxi was various, with the high-grade habitats mainly distributed in Yixing City, Binhu District and other areas, while the low-grade habitats are predominantly located in the main urban area of Wuxi City and Jiangyin City. In the past 20 years, habitat quality in Wuxi has shown a significant degradation trend, of which the main urban areas of Wuxi such as Liangxi District and Jiangyin City have the most obvious degradation, whereas the degradation degree of Yixing City has not changed much. The changes of habitat quality and land use in Wuxi are inseparable, and among them, the construction land of Wuxi increased by approximately 12% from 717.40 km2 in 2000 to 1 291.40 km2 in 2018, and the area with increased construction land and the area where the quality of habitat decline is more obvious have good spatial consistency. 【Conclusion】 Degradation of habitat quality in Wuxi is closely related to the reduction of cultivated land area and the increase of urban construction land. Therefore, it is necessary to rationally use land, strictly control the scale of construction land, maintain the scale of ecological land use, and continuously improve the protection and restoration of wetlands.
【Objective】This study aimed to identify the types, distribution, quantity, and sexual dimorphism of antennal sensilla in Xanthogaleruca aenescens through ultrastructural observation. The findings provide a basis for understanding the genetic evolution, morphological classification, and the role of olfactory sensilla in host volatile detection in leaf beetles.【Method】The antennae of adult female and male X. aenescens were cleaned, air-dried, and gold-coated for scanning electron microscopy (SEM). SEM was used to observe and photograph the morphological characteristics of the antennae and sensilla of both sexes, as well as to identify the types of sensilla present. Independent sample t-tests were conducted to compare differences in antennal length, sensilla length, base diameter, and the number of sensilla between the sexes, and the distribution of sensilla across the antennae was also examined.【Result】The antennae of X. aenescens were linear and consist of the scape, pedicel, and nine flagellar subsegments. The average length of male antennae was (4 558.01 ± 104.15) μm, while that of females was (4 488.75 ± 224.33) μm. Males have slightly longer antennae than females, although this difference was not statistically significant. Both males and females possessed eight types of antennal sensilla: sensilla trichodea (St), sensilla chaetica (Sc), sensilla basiconica (Sb), sensilla styloconica (Sst), Böhm bristles (Bb), sensilla gemmiformium (Sg), sensilla coeloconica (Sco), and sensilla auricillica (Sau). St and Sb each have four subtypes, Sc has two subtypes, and Sst has three subtypes. The female antennal flagellum has Sst 2, while the male flagellum contains Sst 3. The most abundant sensilla are St, followed by Sb, while Sco is the least common. St 4, Sb 1, Sb 3, and Sau exhibit micropores on their surfaces, indicating their role as olfactory sensilla. The total number of antennal sensilla in females was significantly greater than in males (P < 0.01). Specifically, the numbers of St 2, Sb 2, and Sst 1 were significantly higher in females (P < 0.05). St 4 and Sb 3 is significantly higher in females than in males (P < 0.01), while Sau was significantly fewer in females compared to males (P < 0.01). No significant differences were observed in the number of other sensilla. In both sexes, the tips of antennal subsegments F2 to F8 had inwardly concave areas with a high density of sensilla, and a similar concave area was present at the middle of the terminal segment F9. The density and number of sensilla increased from the base to the tip of the antenna. Additionally, the ventral surface of the male antennal flagellum (F1 to F8) exhibited a more densely packed area of epidermal depressions, a feature absent in females.【Conclusion】Both female and male X. aenescens have the same types of antennal sensilla, but there are clear sexual dimorphisms in sensilla subtypes, quantity, and distribution. Different subtypes of Sst were observed in males and females, with variations in the size of sensilla between the sexes. The total number of sensilla in males was significantly lower than in females. The specific roles of these sensilla in environmental perception, host detection, and mating behaviors should be further explored using transmission electron microscopy, electrophysiology, and other advanced techniques.
【Objective】Accurately and efficiently monitoring the spatio-temporal distribution characteristics of the ecological environment quality and its evolving trends in the source area of the Yangtze River is of great significance for maintaining the high-standard protection of the ecological environment. It also serves as a fundamental basis for formulating long-term and effective ecological protection and restoration strategies in the Sanjiangyuan region. The remote sensing ecological index (RSEI) has distinct advantages over traditional evaluation methods relying on single monitoring indices. It boasts rapid assessment capabilities, objectivity, high efficiency, strong visual interpretability, and reliable predictability. Nevertheless, the spatial resolution constraints and the complexity of data acquisition and processing in remote sensing images still present challenges to the large-scale and accurate evaluation of the RSEI.【Method】In this study, the Google Earth Engine (GEE) platform was utilized, with Landsat series images as the data source. Remote sensing images of the Yangtze River source area during the vegetation-growing season (from June to September) from 1990 to 2020 were obtained. Subsequently, long-time-series RSEI data were calculated. To comprehensively analyze the RSEI in the Yangtze River source area from 1990 to 2020, the coefficient of variation was applied to measure its stability, the Sen + Mann-Kendall (Sen + MK) trend analysis was used to explore the spatio-temporal change trends, the Hurst index was employed to predict future evolution, and the trend analysis method was adopted to identify the driving forces behind these changes.【Result】(1) From 1990 to 2020, the RSEI values in the Yangtze River source region were predominantly distributed within the range of 0.4-0.6. Geographically, the region exhibited a clear pattern where the RSEI values were higher in the eastern and southern parts and lower in the western and northern parts.(2) The average coefficient of variation of the RSEI in the source region was 6.52%. This indicates that the ecological environment in the eastern and western regions underwent relatively more pronounced fluctuations, while the central region remained relatively stable. Overall, the RSEI showed a slow oscillating trend, with an average annual growth rate of 0.004 7. Spatially, the RSEI presented an overall upward trend, and the area with improved ecological conditions accounted for 83.63% of the total study area.(3) The average Hurst index value of the RSEI in the source region was 0.53, implying that the future changes of the RSEI were more likely to be continuous rather than show anti-sustainability. The future ecological environment quality in the Yangtze River source region was expected to experience continuous improvement, yet the overall trend was relatively mild, and there still existed an underlying risk of degradation.(4) In the Yangtze River source region, the RSEI was positively correlated with air temperature, night-light index, and potential evapotranspiration. This reveals that both natural factors and human activities had a certain degree of influence on the enhancement of the ecological environment quality.【Conclusion】The integration of using GEE for remote sensing data acquisition and time-series data analysis has significant potential for rapidly and comprehensively monitoring the ecological environment quality on a large scale. This approach can offer valuable references and technical support for ecological monitoring and protection efforts in the Sanjiangyuan area, thereby contributing to the sustainable development of the regional ecological environment.
