Increasing human disturbance and climate change have threatened ecological connectivity and structural stability,especially in semi-arid mountain areas with sparse vegetation and weak hydrological regulation.Large-sca...Increasing human disturbance and climate change have threatened ecological connectivity and structural stability,especially in semi-arid mountain areas with sparse vegetation and weak hydrological regulation.Large-scale ecological restoration,such as adding ecological sources or corridors,is difficult in such environments and often faces poor operability and high implementation costs in practice.Taking the southern slope of the Qilian Mountains in China as the study area and 2020 as the baseline,this study integrated weighted complex network theory into the"ecological source–resistance surface–corridor"framework to construct a heterogeneous ecological network(EN).Circuit theory was integrated with weighted betweenness to identify critical barrier points for locally differentiated restoration,followed by assessment of the network optimization effects.The results revealed that 494 ecological sources and 1308 ecological corridors were identified in the study area.Fifty-one barrier points with restoration potential were identified along key ecological corridors and locally restored.After optimization,the network gained 11 additional ecological corridors,and the total ecological corridor length increased by approximately 1143 km.Under simulated attacks,the decline rates of maximum connected subgraph(MCS)and network efficiency(Ne)slowed compared with pre-restoration conditions,indicating improved robustness.These findings demonstrate that targeted local restoration can enhance network connectivity and stability while minimizing disturbance to the overall landscape pattern,providing a practical pathway for ecological restoration and sustainable management in semi-arid mountain areas.展开更多
Poyang Lake (PYL) and the Yellow River Delta (YRD) are two critical wintering areas for the Siberian Crane (Leucogeranus leucogeranus) along the East Asian–Australasian Flyway in China. Based on nearly two decades of...Poyang Lake (PYL) and the Yellow River Delta (YRD) are two critical wintering areas for the Siberian Crane (Leucogeranus leucogeranus) along the East Asian–Australasian Flyway in China. Based on nearly two decades of remote sensing and environmental data, this study used the MaxEnt model to assess wintering habitat suitability in Poyang Lake (PYL) and the Yellow River Delta (YRD). Landscape pattern and ecological network (EN) analyses were integrated to examine habitat changes and their impact on Siberian Crane distribution. In PYL, land use/land cover (LULC) change was driven primarily by water level fluctuations, leading to transitions among natural habitat types. In contrast, LULC change in YRD was dominated by anthropogenic activities, with widespread conversion of natural habitats into artificial habitats. In both regions, Siberian Cranes favored wetlands that are food-rich, flat, and minimally disturbed. In PYL, ecological sources were mainly found in sub-lakes of nature reserves and nearby moist areas, averaging 87.42 km^(2). In the YRD, sources were distributed across tidal flats, paddy land, and grasslands, with a larger mean area of 198.37 km^(2). Mann–Kendall tests showed significant trends in PYL, including increased patch density and decreased EN cumulative resilience. The maximum habitat suitability in the YRD significantly declined. Comparative analysis revealed that PYL had significantly higher habitat suitability and EN cumulative resilience, whereas the YRD had larger but more fragmented habitats. By introducing key stepping-stone nodes to optimize the ENs, the connectivity and resilience of PYL's EN were notably enhanced. Although improvements in the YRD were less marked, the optimization scheme still improved the security of the crane migration network. Based on the findings, it is recommended to implement refined water level management in PYL to maintain the stability of sub-lakes and adjacent wetlands, and to strengthen the protection of natural wetlands in the YRD by limiting the expansion of artificial land use, in order to mitigate habitat fragmentation.展开更多
Ecological network(EN)identification and optimization is an essential research tool for safeguarding regional ecological security patterns and planning territorial space.Especially for the ecologically fragile inland ...Ecological network(EN)identification and optimization is an essential research tool for safeguarding regional ecological security patterns and planning territorial space.Especially for the ecologically fragile inland river basins,EN optimization is of significance in ensuring regional ecological security and virtuous cycle of ecosystems.In addition,EN is a dynamically changing structural system that is more applicable to the regional development by optimizing it from comprehensive future development perspective.EN of Shiyang River basin was constructed on account of the circuit theory,and land use/cover changes(LUCC)of the basin in 2035 was predicted by PLUS model,so as to explore the ecological conservation priorities and formulate optimization strategies.54 ecological sources(ESs)were identified,covering an area of 12,198 km^(2),mainly in the southern basin.133 ecological corridors(ECs)with an area of 3,176.92 km^(2)were extracted.38 ecological pinchpoints(EPs)and 22 ecological barriers(EBs)were identified respectively,which were mainly distributed in the lower basin.To effectively enhance the connectivity of EN in Minqin County,which has the worst ecological environment,we added five stepping stones based on the Ant Forest project.In addition,the optimal EPS is selected according to the development and limitation needs of inland river basins and the threat degree of warning points(WPs)under different scenarios.Scientific and reasonable optimization of future urban layout to prevent WPs can effectively alleviate the contradiction between ecological protection and economic development.The study is intended to provide basis for ecological sustainable development and rational planning territorial space in Shiyang River basin,as well as opinion for EN optimization in inland river basin.展开更多
Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem stability.The assessment of Ecological Network Resilience(ENR)is crucial for ...Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem stability.The assessment of Ecological Network Resilience(ENR)is crucial for establishing mitigation strategies and sustainable socioeconomic development in arid regions.Shiyang River Basin is an arid watershed in Northwest China with complex characteristics,its ENR and spatial differentiation characteristics in 2020 were investigated in this work based on the Complex Adaptive System(CAS)theory.The results indicated that the mean Ecological Network Resilience Index(ENRI)value for the Shiyang River Basin was 0.390 in 2020,and the mean values in the southern mountainous,middle oasis,and northern desert regions of the basin were 0.598,0.461,and 0.237,respectively,demonstrating evident spatial differences.Additionally,the ENR of the basin exhibited distinct distribution characteristics across different dimension,whereas the trend of the integrated ENR of the basin was consistent with that of elemental,structural,and functional resilience,indicating the constructed three-region ENR model based on the logical relationship of element-structure-function was suitable for evaluation of the ENR in arid inland river watersheds.Furthermore,strategies for enhancing regional ENR were proposed from the perspective of adapting to climate change.展开更多
With the continuous acceleration of urbanization,the resulting habitat fragmentation poses a serious threat to regional ecological security.Constructing an ecological network not only facilitates the positive circulat...With the continuous acceleration of urbanization,the resulting habitat fragmentation poses a serious threat to regional ecological security.Constructing an ecological network not only facilitates the positive circulation of regional materials and energy but also holds significant importance for achieving regional sustainable development.Taking the Guangxi Beibu Gulf Economic Zone as the study area,and supported by GIS and other technologies,this study uses 10-meter high-resolution land use data from 2017 and 2021 to select ecological sources based on MSPA and landscape connectivity.Using the MCR-gravity model,a higher precision ecological network for the Guangxi Beibu Gulf Economic Zone is constructed.This network is then optimized and comparatively analyzed using circuit theory and network analysis methods.The results showed that:① Although the core area of ecological sources accounts for 95.16%of the total ecological source area,a comparison of the two-year analysis results shows an increasing degree of landscape fragmentation and a decline in landscape connectivity.② The optimized ecological network of the Beibu Gulf Economic Zone of Guangxi comprises 11 ecological sources,91 ecological corridors,and 71 ecological nodes.③ The indices of the optimized network structure have all improved,enhancing the degree of ecological network connectivity within the study area.展开更多
As a key carrier supporting urban ecological health and living environment quality,urban ecological network is a key focus of current urban green space research.Jingzhou City of Hubei Province is taken as the research...As a key carrier supporting urban ecological health and living environment quality,urban ecological network is a key focus of current urban green space research.Jingzhou City of Hubei Province is taken as the research object.Relying on GIS technology platform,MSPA method is used to analyze the landscape pattern of Jingzhou City.On this basis,the landscape connectivity evaluation method is used to accurately identify and extract the source areas with important ecological value in Jingzhou City.Then,the normalization method and weighting method are combined to create a resistance factor evaluation system to construct the resistance surface.Based on the MCR model,the ecological network of Jingzhou City is successfully constructed,and targeted spatial optimization strategies and development suggestions are proposed.展开更多
The paper gives an overview of approaches towards ecological networks throughout Europe. It does not intend to present a complete picture, but to highlight common developments within countries and regions and show com...The paper gives an overview of approaches towards ecological networks throughout Europe. It does not intend to present a complete picture, but to highlight common developments within countries and regions and show common principles and differences between countries and regions that have to be taken into account when developing a joint European initiative. Countries or regions that have not been included can be active in the same way, but information was not accessible to the authors for different reasons. This overview shows the comparable trends in decline of landscapes and the diversity in approaches to biodiversity conservation and nature conservation planning. Understanding the differences and common issues are of utmost importance to generalise common principles and to understand the way neighbours and other European partners approach problems.展开更多
Green spaces in Wanzhou District, Chongqing Municipality were not closely linked and failed to form an integrated ecological network, this paper analyzed and assessed current situation of green spaces in the local are...Green spaces in Wanzhou District, Chongqing Municipality were not closely linked and failed to form an integrated ecological network, this paper analyzed and assessed current situation of green spaces in the local area from the perspective of landscape ecology, and then established the landscape ecology-oriented ecological network construction, restructured green paces in Wanzhou District using the landscape composition of "patch–corridor–matrix", and connected the scattered green patches using green corridors, so as to form a reasonable ecological network of green spaces.展开更多
Microbial activity and regrowth in drinking water distribution systems is a major concern for water service companies.However,previous studies have focused on the microbial composition and diversity of the drinkingwat...Microbial activity and regrowth in drinking water distribution systems is a major concern for water service companies.However,previous studies have focused on the microbial composition and diversity of the drinkingwater distribution systems(DWDSs),with little discussion on microbial molecular ecological networks(MENs)in different water supply networks.MEN analysis explores the potentialmicrobial interaction and the impact of environmental stress,to explain the characteristics of microbial community structures.In this study,the random matrix theory-based network analysis was employed to investigate the impact of seasonal variation including water source switching on the networks of three DWDSs that used different disinfection methods.The results showed that microbial interaction varied slightly with the seasons but was significantly influenced by different DWDSs.Proteobacteria,identified as key species,play an important role in the network.Combined UV-chlorine disinfection can effectively reduce the size and complexity of the network compared to chlorine disinfection alone,ignoring seasonal variations,which may affect microbial activity or control microbial regrowth in DWDSs.This study provides new insights for analyzing the dynamics of microbial interactions in DWDSs.展开更多
Next generation grid systems where the emphasis shifts to distributed global collaboration, a service-oriented approach and information layer issues exhibit a strong sense of automation. Requirements for these systems...Next generation grid systems where the emphasis shifts to distributed global collaboration, a service-oriented approach and information layer issues exhibit a strong sense of automation. Requirements for these systems resemble the self-organizing and the healing properties of natural ecosystems. Some key ecological concepts and mechanisms are introduced into the design for the third generation grid computing architectures by inspiration of this resemblance. Also, an Ecological Network-based Computing Environment (ENCE) platform is designed in this paper. Based on the ENCE platform, a grid-computing model of three-layered grid conceptual prototype that embeds the ENCE layers is presented from the viewpoint of implementation. The implementation model should be useful to the design of the third generation grid systems.展开更多
Using the case study methodology, firm＇s competition behavior in strategic network and strategic ecosystems are analyzed. With the ecology view, there is consistency between strategic network and strategic ecosystem....Using the case study methodology, firm＇s competition behavior in strategic network and strategic ecosystems are analyzed. With the ecology view, there is consistency between strategic network and strategic ecosystem. Enterprise should pursue for suitable ecological niche to hold a strategic competitive power.展开更多
Biodiversity plays a crucial role in the global ecosystem and is essential for the sustainable development of human society.Constructing scientifically ecological networks is the foundation of biodiversity conservatio...Biodiversity plays a crucial role in the global ecosystem and is essential for the sustainable development of human society.Constructing scientifically ecological networks is the foundation of biodiversity conservation.While previous studies have focused on constructing urban ecological networks with an emphasis on ecological security and habitat quality,there remains a need for methods that align with biodiversity and conservation objectives at the urban agglomeration scale.In light of future climatic and environmental changes and the rapid pace of urbanization,this study focuses on the Beijing–Tianjin–Hebei urban agglomeration,a leading urban cluster in China.This study explores the development of ecological networks at the scale of urban agglomerations through the forecasting of bird species distributions with different migration habits,a critical indicator of biodiversity.The identification of ecological sources utilized 3 methodologies:morphological spatial pattern analysis,habitat quality assessment,and species distribution forecasting,together pinpointing 134 pivotal ecological sources.Utilizing circuit theory,the research delineates 117 primary ecological corridors,285 secondary corridors,9 potential ecological corridors,and 1,134 ecological nodes.By conducting a comprehensive analysis of the current state and spatial distribution patterns of various ecological network components,the study proposes specific implementation strategies.The findings offer vital spatial guidance for the planning of future urban conglomerates and the formulation of corresponding policies,thereby facilitating national ecological protection and restoration initiatives.展开更多
Ecological security patterns are paramount to the advancement of an ecological civilization in China,aiming to enhance the stability and service functions of ecosystems to achieve sustainable regional development.Howe...Ecological security patterns are paramount to the advancement of an ecological civilization in China,aiming to enhance the stability and service functions of ecosystems to achieve sustainable regional development.However,current regional ecological protection efforts have not been effectively integrated into the regional development planning of ecological security pattern.This study systematically assessed the effectiveness of ecological protection projects in Yanchi County,Ningxia Hui Autonomous Region,China,through the evaluation of landscape ecological quality.Based on the evaluation results of landscape ecological quality,this study used morphological pattern analysis(MSPA),minimum cumulative resistance(MCR)model,and gravity model together to construct the ecological security pattern of Yanchi County.The findings revealed that from 1990 to 2020,with the implementation of ecological protection projects started from 2000,the landscape stability of Yanchi County first decreased and then increased,and the intensity of landscape disturbance first intensified but then decreased,indicating an improvement in the landscape ecological quality and a significant enhancement of the ecological environment in Yanchi County.The ecological security pattern of Yanchi County consisted of 10 ecological sources,10 ecological source points,23 ecological corridors,and 27 ecological nodes.The ecological security pattern of Yanchi County exhibited distinct spatial variations,with stronger ecological security observed in the southern part than in northern part of the county.The ecological sources were denser in the southern part than in the northern part of the county,and accordingly,the length of ecological corridors was shorter and denser in the southern than that in the northern part of the county.Based on the spatial distribution of landscape ecological quality and the characteristics of ecological security pattern of Yanchi County in 2020,we suggested Yanchi County to build four zones to optimize the ecological security pattern construction:the Haba Lake ecological conservation zone,the urban ecological planning zone,the ecological environment restoration zone,and the ecological security improvement zone.This study can provide essential guidance for the construction of ecological security pattern in farming-pastoral areas both in China and worldwide.展开更多
Continuous cropping can lead to soil environment deterioration,cause plant health problems,and reduce crop productivity.However,the response mechanisms of soil microbial co-occurrence patterns to the duration of conti...Continuous cropping can lead to soil environment deterioration,cause plant health problems,and reduce crop productivity.However,the response mechanisms of soil microbial co-occurrence patterns to the duration of continuous melon cropping remain poorly understood.Here,we employed the metagenomic techniques to comparatively investigate the bulk and rhizosphere soil microbial communities of major melon-producing regions(where the duration of continuous melon cropping ranges from 1 to 30 a)in the eastern and southern parts of Xinjiang Uygur Autonomous Region,China.The results showed that soil pH clearly decreased with increasing melon cropping duration,while soil electrical conductivity(EC)and the other soil nutrient indices increased with increasing melon cropping duration(with the exception of AN and TK in the southern melon-producing region).The most dominant bacterial phyla were Proteobacteria and Actinobacteria,and the most abundant fungal phyla were Ascomycota and Mucoromycota.Redundancy analysis(RDA)indicated that soil pH and EC had no significant effects on the bacterial communities.However,after many years of continuous melon cropping in the southern melon-producing region,fungal communities were significantly negatively correlated with soil pH and significantly positively correlated with soil EC(P<0.050).Co-occurrence network analysis showed that continuous melon cropping increased the complexity but decreased the connectivity of the cross-domain microbial networks.Moreover,the enrichment patterns of microorganisms in the main microbial network modules varied significantly with the duration of continuous melon cropping.Based on the analysis of keystone taxa,we found that continuous melon cropping increased some plant pathogens(e.g.,Fusarium and Stagonospora)but decreased beneficial bacteria(e.g.,Mesorhizobium and Pseudoxanthomonas).In conclusion,this study has greatly enhanced the understanding of the effects of continuous melon cropping on alterations in the microbial community structure and ecological networks in Xinjiang.展开更多
Scientifically constructing an ecological security pattern(ESP)is an important spatial analysis approach to improve ecological functions in arid areas and achieve sustainable development.However,previous research meth...Scientifically constructing an ecological security pattern(ESP)is an important spatial analysis approach to improve ecological functions in arid areas and achieve sustainable development.However,previous research methods ignored the complex trade-offs between ecosystem services in the process of constructing ESP.Taking the mainstream of the Tarim River Basin(MTRB),China as the study area,this study set seven risk scenarios by applying Ordered Weighted Averaging(OWA)model to trade-off the importance of the four ecosystem services adopted by this study(water conservation,carbon storage,habitat quality,and biodiversity conservation),thereby identifying priority protection areas for ecosystem services.And then,this study identified ecological sources by integrating ecosystem service importance with eco-environmental sensitivity.Using circuit theory,the ecological corridors and nodes were extracted to construct the ESP.The results revealed significant spatial heterogeneity in the four ecosystem services across the study area,primarily driven by hydrological gradients and human activity intensity.The ESP of the MTRB included 34 ecological sources with a total area of 1471.38 km^(2),66 ecological corridors with a length of about 1597.45 km,11 ecological pinch points,and 13 ecological barrier points distributed on the ecological corridors.The spatial differentiation of the ESP was obvious,with the upper and middle reaches of the MTRB having a large number of ecological sources and exhibiting higher clustering of ecological corridors compared with the lower reaches.The upper and middle reaches require ecological protection to sustain the existing ecosystem,while the lower reaches need to carry out ecological restoration measures including desertification control.Overall,this study makes up for the shortcomings of constructing ESP simply by spatial superposition of ecosystem service functions and can effectively improve the robustness and stability of ESP construction.展开更多
The objectives of this study were to investigate the influence of chromium nanoparticles(Cr NPs)on the nitrogen and phosphorus removal performance and the bacterial structures of an activated sludge(AS)system.Also,we ...The objectives of this study were to investigate the influence of chromium nanoparticles(Cr NPs)on the nitrogen and phosphorus removal performance and the bacterial structures of an activated sludge(AS)system.Also,we through molecular ecological networks(MENs)discussed the bacterial interactions.At last we researched the change of the functional genes and their expression patterns related to nitrogen and phosphorus removaT in an AS system.The results showed that long-term exposure to 1 mg/L Cr NPs significantly promoted the denitrifying process and phosphorus removal in the AS system.The relative abundance of denitrifying and phosphorus removal microorganisms,such as Denitratisoma,Thauera,Dechloromonas,and Defluviicoccus,increased significantly.Candidatus Accumulibacter,well-known as polyphosphate-accumulating organisms(PAOs),increased significantly;the relative abundance of Candidatus Competibacter,known as glycogen-accumulating organisms(GAOs),decreased significantly.Furthermore,metagenomic and metatranscriptomic analysis revealed that most of the genera related to denitrifying and phosphorus removal had greatly increased,according to the quantities of denitrifying and phosphorus genes,and the corresponding transcription likewise greatly increased.Lastly,MENs analysis showed that although the overall network became smaller and looser in the presence of Cr NPs,the microbial connections among members related to nitrogen and phosphorus removal were enhanced.The abundance increases of denitrifiers and PAOs,and their increased transcription of functional genes,together with the enhanced interactions may be associated with the promotion of the denitrifying process and phosphorus removal.展开更多
Taking the lower Yellow River basin as the study area,this study aims to construct ecological networks to mitigate the negative impacts of rapid urbanization on the ecosystem.Ecological sources were identified based o...Taking the lower Yellow River basin as the study area,this study aims to construct ecological networks to mitigate the negative impacts of rapid urbanization on the ecosystem.Ecological sources were identified based on morphological spatial pattern analysis(MSPA),habitat quality and landscape connectivity.The ecological resistance surface was constructed and corrected by integrating natural and anthropogenic factors.The spatial range of ecological corridors and some of their key nodes were identified based on circuit theory.The ecological network(EN)was finally optimized using a similarity search and cost connectivity modules.The results show that the optimized ecological network structure is more stable than before.The EN includes 23 ecological sources with a total area of 5464.8 km^(2)and 30 ecological corridor clusters with a total area of 2205.92 km^(2).Through the internal landscape heterogeneity of the corridor,28 ecological node areas and 75 barrier areas were identified as key protection and restoration areas,with a total area of 78.44 km^(2)and 372.79 km^(2),respectively.Through the construction and optimization of EN,this study identifies key areas for promoting ecological sustainability and provides a useful framework for coordinating regional ecological conservation and economic development.展开更多
As a complex social ecosystem network,the area along the Grand Canal has a prominent contradiction between the demand for economic development and the protection of natural resources,which means that there is an urgen...As a complex social ecosystem network,the area along the Grand Canal has a prominent contradiction between the demand for economic development and the protection of natural resources,which means that there is an urgent need for ecological restoration and environmental protection.Using ArcGIS,Conefor,Linkage Mapper and other software platforms,this paper developed an integrated analysis framework,through loose coupling of the attribute-function-structure index system and a series of methods such as the least cost path,circuit theory and moving window search.Based on the framework,we resolve a series of scientific issues in developing regional ecological networks,such as the selection of ecological sources,the simulation of potential ecological corridors,the assessment of the importance of ecological sources and corridors,and the identification of key ecological nodes.Moreover,an overall conservation pattern of the regional ecological network is constructed.The results show that:1)A total of 88 important ecological sources are identified in the study area.The patches with high centrality values are mainly concentrated in the southern mountainous area and the areas with abundant rivers and lakes.2)A total of 138 important ecological corridors are identified,and they are not evenly distributed.Extremely important corridors mostly appear between important patches,and very important corridors are mainly distributed in the central area.3)Fifteen ecological pinch points are extracted,and they are mainly concentrated in the northern part of the study area and eastern Zhejiang Province.The barriers are mostly concentrated in the southern and northern parts of the study area.4)Combining the demands of ecological protection and socioeconomic development,we propose an overall ecological conservation pattern of"one axis,five sections,multiple cores and multiple nodes"to effectively guide future ecological restoration work.These results can provide a useful reference and spatial guidance for decision makers in terms of ecological restoration and cooperation on cross-regional ecological protection along the Grand Canal.展开更多
Soil nitrogen(N)cycling is one of the most critical biogeochemical cycles,and N cycling-related microorganisms are the primary driving force behind N cycling in natural environments.The large karst sinkholes in China,...Soil nitrogen(N)cycling is one of the most critical biogeochemical cycles,and N cycling-related microorganisms are the primary driving force behind N cycling in natural environments.The large karst sinkholes in China,known as Tiankengs,harbor abundant unique biological resources due to their particular environmental conditions.However,N cycling-related microorganisms in Tiankeng soils and their connection to ecosystem processes remain poorly studied.In this study,we investigated the distribution patterns and genomic diversity of N cycling-related microorganisms both inside and outside the Luohun cave Tiankeng in Guizhou,China,utilizing high-throughput sequencing and other techniques.The results indicated that the diversities and abundances of denitrifying bacteria,ammonia-oxidizing bacteria,and ammonia-oxidizing archaea communities inside the Tiankeng were higher than those outside the Tiankeng;however,the microbial network relationships were more fragile inside the Tiankeng.The most abundant species of denitrifying bacteria,ammonia-oxidizing bacteria,and ammonia-oxidizing archaea inside the Tiankeng were unclassified_p_Proteobacteria(47.8%),unclassified_k_norank(AOB,OTU121,37.3%),and unclassified_g_norank_f_norank_o_norank_c_environmental_samples(55.7%),respectively;outside the Tiankeng,they were unclassified_k_norank_d_bacteria(54.5%),unclassified_k_norank(AOB,OTU121,48.1%),and unclassified_k_norank(AOA,OTU70,49.6%),respectively.Additionally,the N content inside the Tiankeng was significantly lower(P<0.05)under the influence of these N cycling-related microorganisms,whereas the nutrient contents were higher than that outside the Tiankeng.To the best of our knowledge,this is the first report on the crucial microbial distribution patterns driving N cycling in karst Tiankengs and provides new insights into the structure and potential functions of N cycling-related microorganisms in the unique ecological environment of fragile Tiankeng ecosystems.展开更多
Hancang River is a river on the eastern border of Jinan City. In recent years, with the development of cities, river flow has dropped sharply, river water has been polluted, and the ecological environment of the basin...Hancang River is a river on the eastern border of Jinan City. In recent years, with the development of cities, river flow has dropped sharply, river water has been polluted, and the ecological environment of the basin has declined. Improving the water ecological environment and enhancing the resilience of the water ecology of the river basin were set as the research goals, especially coupling of hydrological and ecological processes and the recycling of sewage resources. The “patch-corridor-matrix” theory of landscape ecology, the Least-cost distance model and the Arc Hydro Tools module of the ArcGIS platform were used to describe the river system and basin boundaries, optimize the current water network and the path network of the ecosystem. A novel ecological network and water network were proposed to form the final aquatic ecosystem, which combines the hydrological process with the ecosystem, and three decentralized wastewater treatment systems were designed to reduce the wastewater directly flowing into the river. The ecosystem resilience of the basin will be enhanced.展开更多
基金supported by the Sichuan Science and Technology Program(2022JDJQ0015)the Major Research and Development and Achievement Transformation Projects of Qinghai Province,China(2022-QY-224)the National Natural Science Foundation of China(42471225).
文摘Increasing human disturbance and climate change have threatened ecological connectivity and structural stability,especially in semi-arid mountain areas with sparse vegetation and weak hydrological regulation.Large-scale ecological restoration,such as adding ecological sources or corridors,is difficult in such environments and often faces poor operability and high implementation costs in practice.Taking the southern slope of the Qilian Mountains in China as the study area and 2020 as the baseline,this study integrated weighted complex network theory into the"ecological source–resistance surface–corridor"framework to construct a heterogeneous ecological network(EN).Circuit theory was integrated with weighted betweenness to identify critical barrier points for locally differentiated restoration,followed by assessment of the network optimization effects.The results revealed that 494 ecological sources and 1308 ecological corridors were identified in the study area.Fifty-one barrier points with restoration potential were identified along key ecological corridors and locally restored.After optimization,the network gained 11 additional ecological corridors,and the total ecological corridor length increased by approximately 1143 km.Under simulated attacks,the decline rates of maximum connected subgraph(MCS)and network efficiency(Ne)slowed compared with pre-restoration conditions,indicating improved robustness.These findings demonstrate that targeted local restoration can enhance network connectivity and stability while minimizing disturbance to the overall landscape pattern,providing a practical pathway for ecological restoration and sustainable management in semi-arid mountain areas.
基金supported by the National Natural Science Foundation of China(Grant No.32360142).
文摘Poyang Lake (PYL) and the Yellow River Delta (YRD) are two critical wintering areas for the Siberian Crane (Leucogeranus leucogeranus) along the East Asian–Australasian Flyway in China. Based on nearly two decades of remote sensing and environmental data, this study used the MaxEnt model to assess wintering habitat suitability in Poyang Lake (PYL) and the Yellow River Delta (YRD). Landscape pattern and ecological network (EN) analyses were integrated to examine habitat changes and their impact on Siberian Crane distribution. In PYL, land use/land cover (LULC) change was driven primarily by water level fluctuations, leading to transitions among natural habitat types. In contrast, LULC change in YRD was dominated by anthropogenic activities, with widespread conversion of natural habitats into artificial habitats. In both regions, Siberian Cranes favored wetlands that are food-rich, flat, and minimally disturbed. In PYL, ecological sources were mainly found in sub-lakes of nature reserves and nearby moist areas, averaging 87.42 km^(2). In the YRD, sources were distributed across tidal flats, paddy land, and grasslands, with a larger mean area of 198.37 km^(2). Mann–Kendall tests showed significant trends in PYL, including increased patch density and decreased EN cumulative resilience. The maximum habitat suitability in the YRD significantly declined. Comparative analysis revealed that PYL had significantly higher habitat suitability and EN cumulative resilience, whereas the YRD had larger but more fragmented habitats. By introducing key stepping-stone nodes to optimize the ENs, the connectivity and resilience of PYL's EN were notably enhanced. Although improvements in the YRD were less marked, the optimization scheme still improved the security of the crane migration network. Based on the findings, it is recommended to implement refined water level management in PYL to maintain the stability of sub-lakes and adjacent wetlands, and to strengthen the protection of natural wetlands in the YRD by limiting the expansion of artificial land use, in order to mitigate habitat fragmentation.
基金funded by the National Natural Science Foundation of China(Grant No.42101276)。
文摘Ecological network(EN)identification and optimization is an essential research tool for safeguarding regional ecological security patterns and planning territorial space.Especially for the ecologically fragile inland river basins,EN optimization is of significance in ensuring regional ecological security and virtuous cycle of ecosystems.In addition,EN is a dynamically changing structural system that is more applicable to the regional development by optimizing it from comprehensive future development perspective.EN of Shiyang River basin was constructed on account of the circuit theory,and land use/cover changes(LUCC)of the basin in 2035 was predicted by PLUS model,so as to explore the ecological conservation priorities and formulate optimization strategies.54 ecological sources(ESs)were identified,covering an area of 12,198 km^(2),mainly in the southern basin.133 ecological corridors(ECs)with an area of 3,176.92 km^(2)were extracted.38 ecological pinchpoints(EPs)and 22 ecological barriers(EBs)were identified respectively,which were mainly distributed in the lower basin.To effectively enhance the connectivity of EN in Minqin County,which has the worst ecological environment,we added five stepping stones based on the Ant Forest project.In addition,the optimal EPS is selected according to the development and limitation needs of inland river basins and the threat degree of warning points(WPs)under different scenarios.Scientific and reasonable optimization of future urban layout to prevent WPs can effectively alleviate the contradiction between ecological protection and economic development.The study is intended to provide basis for ecological sustainable development and rational planning territorial space in Shiyang River basin,as well as opinion for EN optimization in inland river basin.
基金Under the Major Special Science and Technology Project of Gansu Province(No.23ZDKA0004)。
文摘Due to the uncertainties posed by climate change,resilience has become an increasingly important variable for evaluating regional ecosystem stability.The assessment of Ecological Network Resilience(ENR)is crucial for establishing mitigation strategies and sustainable socioeconomic development in arid regions.Shiyang River Basin is an arid watershed in Northwest China with complex characteristics,its ENR and spatial differentiation characteristics in 2020 were investigated in this work based on the Complex Adaptive System(CAS)theory.The results indicated that the mean Ecological Network Resilience Index(ENRI)value for the Shiyang River Basin was 0.390 in 2020,and the mean values in the southern mountainous,middle oasis,and northern desert regions of the basin were 0.598,0.461,and 0.237,respectively,demonstrating evident spatial differences.Additionally,the ENR of the basin exhibited distinct distribution characteristics across different dimension,whereas the trend of the integrated ENR of the basin was consistent with that of elemental,structural,and functional resilience,indicating the constructed three-region ENR model based on the logical relationship of element-structure-function was suitable for evaluation of the ENR in arid inland river watersheds.Furthermore,strategies for enhancing regional ENR were proposed from the perspective of adapting to climate change.
基金National Natural Science Foundation of China(Nos.42101369U21A2022)Natural Science Foundation of Guangxi(No.2023GXNSFBA026278).
文摘With the continuous acceleration of urbanization,the resulting habitat fragmentation poses a serious threat to regional ecological security.Constructing an ecological network not only facilitates the positive circulation of regional materials and energy but also holds significant importance for achieving regional sustainable development.Taking the Guangxi Beibu Gulf Economic Zone as the study area,and supported by GIS and other technologies,this study uses 10-meter high-resolution land use data from 2017 and 2021 to select ecological sources based on MSPA and landscape connectivity.Using the MCR-gravity model,a higher precision ecological network for the Guangxi Beibu Gulf Economic Zone is constructed.This network is then optimized and comparatively analyzed using circuit theory and network analysis methods.The results showed that:① Although the core area of ecological sources accounts for 95.16%of the total ecological source area,a comparison of the two-year analysis results shows an increasing degree of landscape fragmentation and a decline in landscape connectivity.② The optimized ecological network of the Beibu Gulf Economic Zone of Guangxi comprises 11 ecological sources,91 ecological corridors,and 71 ecological nodes.③ The indices of the optimized network structure have all improved,enhancing the degree of ecological network connectivity within the study area.
基金by Jingzhou Science and Technology Program(2023EC45).
文摘As a key carrier supporting urban ecological health and living environment quality,urban ecological network is a key focus of current urban green space research.Jingzhou City of Hubei Province is taken as the research object.Relying on GIS technology platform,MSPA method is used to analyze the landscape pattern of Jingzhou City.On this basis,the landscape connectivity evaluation method is used to accurately identify and extract the source areas with important ecological value in Jingzhou City.Then,the normalization method and weighting method are combined to create a resistance factor evaluation system to construct the resistance surface.Based on the MCR model,the ecological network of Jingzhou City is successfully constructed,and targeted spatial optimization strategies and development suggestions are proposed.
文摘The paper gives an overview of approaches towards ecological networks throughout Europe. It does not intend to present a complete picture, but to highlight common developments within countries and regions and show common principles and differences between countries and regions that have to be taken into account when developing a joint European initiative. Countries or regions that have not been included can be active in the same way, but information was not accessible to the authors for different reasons. This overview shows the comparable trends in decline of landscapes and the diversity in approaches to biodiversity conservation and nature conservation planning. Understanding the differences and common issues are of utmost importance to generalise common principles and to understand the way neighbours and other European partners approach problems.
文摘Green spaces in Wanzhou District, Chongqing Municipality were not closely linked and failed to form an integrated ecological network, this paper analyzed and assessed current situation of green spaces in the local area from the perspective of landscape ecology, and then established the landscape ecology-oriented ecological network construction, restructured green paces in Wanzhou District using the landscape composition of "patch–corridor–matrix", and connected the scattered green patches using green corridors, so as to form a reasonable ecological network of green spaces.
基金supported by the National Key R&D Program of China (No. 2019YFC0408700)the National Science and Technology Major Projects of China (Nos. 2017ZX07108-002 and 2017ZX07502003)the funds from the National Natural Science Foundation of China (No. 51778323)
文摘Microbial activity and regrowth in drinking water distribution systems is a major concern for water service companies.However,previous studies have focused on the microbial composition and diversity of the drinkingwater distribution systems(DWDSs),with little discussion on microbial molecular ecological networks(MENs)in different water supply networks.MEN analysis explores the potentialmicrobial interaction and the impact of environmental stress,to explain the characteristics of microbial community structures.In this study,the random matrix theory-based network analysis was employed to investigate the impact of seasonal variation including water source switching on the networks of three DWDSs that used different disinfection methods.The results showed that microbial interaction varied slightly with the seasons but was significantly influenced by different DWDSs.Proteobacteria,identified as key species,play an important role in the network.Combined UV-chlorine disinfection can effectively reduce the size and complexity of the network compared to chlorine disinfection alone,ignoring seasonal variations,which may affect microbial activity or control microbial regrowth in DWDSs.This study provides new insights for analyzing the dynamics of microbial interactions in DWDSs.
基金Supported in part by the National Nature Science Foundation of China (No. 60474037 and 60004006) and Specialized Research Fund for the Doctoral Program of Higher Education from Educational Committee of China (No. 20030255009)
文摘Next generation grid systems where the emphasis shifts to distributed global collaboration, a service-oriented approach and information layer issues exhibit a strong sense of automation. Requirements for these systems resemble the self-organizing and the healing properties of natural ecosystems. Some key ecological concepts and mechanisms are introduced into the design for the third generation grid computing architectures by inspiration of this resemblance. Also, an Ecological Network-based Computing Environment (ENCE) platform is designed in this paper. Based on the ENCE platform, a grid-computing model of three-layered grid conceptual prototype that embeds the ENCE layers is presented from the viewpoint of implementation. The implementation model should be useful to the design of the third generation grid systems.
文摘Using the case study methodology, firm＇s competition behavior in strategic network and strategic ecosystems are analyzed. With the ecology view, there is consistency between strategic network and strategic ecosystem. Enterprise should pursue for suitable ecological niche to hold a strategic competitive power.
基金supported by the National Natural Science Foundation of China(grant number 52308047)the National Key R&D Program of China(grant number 2022YFC3802603)
文摘Biodiversity plays a crucial role in the global ecosystem and is essential for the sustainable development of human society.Constructing scientifically ecological networks is the foundation of biodiversity conservation.While previous studies have focused on constructing urban ecological networks with an emphasis on ecological security and habitat quality,there remains a need for methods that align with biodiversity and conservation objectives at the urban agglomeration scale.In light of future climatic and environmental changes and the rapid pace of urbanization,this study focuses on the Beijing–Tianjin–Hebei urban agglomeration,a leading urban cluster in China.This study explores the development of ecological networks at the scale of urban agglomerations through the forecasting of bird species distributions with different migration habits,a critical indicator of biodiversity.The identification of ecological sources utilized 3 methodologies:morphological spatial pattern analysis,habitat quality assessment,and species distribution forecasting,together pinpointing 134 pivotal ecological sources.Utilizing circuit theory,the research delineates 117 primary ecological corridors,285 secondary corridors,9 potential ecological corridors,and 1,134 ecological nodes.By conducting a comprehensive analysis of the current state and spatial distribution patterns of various ecological network components,the study proposes specific implementation strategies.The findings offer vital spatial guidance for the planning of future urban conglomerates and the formulation of corresponding policies,thereby facilitating national ecological protection and restoration initiatives.
基金funded by the National Natural Science Foundation of China(41807519)the Open Fund Project of Key Laboratory of Deserts and Desertification,Chinese Academy of Sciences(KLDD-2018-002).
文摘Ecological security patterns are paramount to the advancement of an ecological civilization in China,aiming to enhance the stability and service functions of ecosystems to achieve sustainable regional development.However,current regional ecological protection efforts have not been effectively integrated into the regional development planning of ecological security pattern.This study systematically assessed the effectiveness of ecological protection projects in Yanchi County,Ningxia Hui Autonomous Region,China,through the evaluation of landscape ecological quality.Based on the evaluation results of landscape ecological quality,this study used morphological pattern analysis(MSPA),minimum cumulative resistance(MCR)model,and gravity model together to construct the ecological security pattern of Yanchi County.The findings revealed that from 1990 to 2020,with the implementation of ecological protection projects started from 2000,the landscape stability of Yanchi County first decreased and then increased,and the intensity of landscape disturbance first intensified but then decreased,indicating an improvement in the landscape ecological quality and a significant enhancement of the ecological environment in Yanchi County.The ecological security pattern of Yanchi County consisted of 10 ecological sources,10 ecological source points,23 ecological corridors,and 27 ecological nodes.The ecological security pattern of Yanchi County exhibited distinct spatial variations,with stronger ecological security observed in the southern part than in northern part of the county.The ecological sources were denser in the southern part than in the northern part of the county,and accordingly,the length of ecological corridors was shorter and denser in the southern than that in the northern part of the county.Based on the spatial distribution of landscape ecological quality and the characteristics of ecological security pattern of Yanchi County in 2020,we suggested Yanchi County to build four zones to optimize the ecological security pattern construction:the Haba Lake ecological conservation zone,the urban ecological planning zone,the ecological environment restoration zone,and the ecological security improvement zone.This study can provide essential guidance for the construction of ecological security pattern in farming-pastoral areas both in China and worldwide.
基金funded by the Major Science and Technology Projects of Xinjiang Uygur Autonomous Region(2022A02007-4)the Xinjiang Uygur Autonomous Region Natural Science Foundation Youth Project(2024D01B31)the Graduate Student Research Innovation Project of Xinjiang Agricultural University(XJAUGRI2024033).
文摘Continuous cropping can lead to soil environment deterioration,cause plant health problems,and reduce crop productivity.However,the response mechanisms of soil microbial co-occurrence patterns to the duration of continuous melon cropping remain poorly understood.Here,we employed the metagenomic techniques to comparatively investigate the bulk and rhizosphere soil microbial communities of major melon-producing regions(where the duration of continuous melon cropping ranges from 1 to 30 a)in the eastern and southern parts of Xinjiang Uygur Autonomous Region,China.The results showed that soil pH clearly decreased with increasing melon cropping duration,while soil electrical conductivity(EC)and the other soil nutrient indices increased with increasing melon cropping duration(with the exception of AN and TK in the southern melon-producing region).The most dominant bacterial phyla were Proteobacteria and Actinobacteria,and the most abundant fungal phyla were Ascomycota and Mucoromycota.Redundancy analysis(RDA)indicated that soil pH and EC had no significant effects on the bacterial communities.However,after many years of continuous melon cropping in the southern melon-producing region,fungal communities were significantly negatively correlated with soil pH and significantly positively correlated with soil EC(P<0.050).Co-occurrence network analysis showed that continuous melon cropping increased the complexity but decreased the connectivity of the cross-domain microbial networks.Moreover,the enrichment patterns of microorganisms in the main microbial network modules varied significantly with the duration of continuous melon cropping.Based on the analysis of keystone taxa,we found that continuous melon cropping increased some plant pathogens(e.g.,Fusarium and Stagonospora)but decreased beneficial bacteria(e.g.,Mesorhizobium and Pseudoxanthomonas).In conclusion,this study has greatly enhanced the understanding of the effects of continuous melon cropping on alterations in the microbial community structure and ecological networks in Xinjiang.
基金funded by the Xinjiang Uygur Autonomous Region Tianshan Talent Training Program(2023TSYCLJ0047)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2023D01D18)+1 种基金the Key Research and Development Project of Xinjiang(2022B03024-1)the Science and Technology Planning Project of Xinjiang Production and Construction Corps(2022DB023)。
文摘Scientifically constructing an ecological security pattern(ESP)is an important spatial analysis approach to improve ecological functions in arid areas and achieve sustainable development.However,previous research methods ignored the complex trade-offs between ecosystem services in the process of constructing ESP.Taking the mainstream of the Tarim River Basin(MTRB),China as the study area,this study set seven risk scenarios by applying Ordered Weighted Averaging(OWA)model to trade-off the importance of the four ecosystem services adopted by this study(water conservation,carbon storage,habitat quality,and biodiversity conservation),thereby identifying priority protection areas for ecosystem services.And then,this study identified ecological sources by integrating ecosystem service importance with eco-environmental sensitivity.Using circuit theory,the ecological corridors and nodes were extracted to construct the ESP.The results revealed significant spatial heterogeneity in the four ecosystem services across the study area,primarily driven by hydrological gradients and human activity intensity.The ESP of the MTRB included 34 ecological sources with a total area of 1471.38 km^(2),66 ecological corridors with a length of about 1597.45 km,11 ecological pinch points,and 13 ecological barrier points distributed on the ecological corridors.The spatial differentiation of the ESP was obvious,with the upper and middle reaches of the MTRB having a large number of ecological sources and exhibiting higher clustering of ecological corridors compared with the lower reaches.The upper and middle reaches require ecological protection to sustain the existing ecosystem,while the lower reaches need to carry out ecological restoration measures including desertification control.Overall,this study makes up for the shortcomings of constructing ESP simply by spatial superposition of ecosystem service functions and can effectively improve the robustness and stability of ESP construction.
基金This work has received funding from the Major Science and Technology Project of Water Pollution Control and Treatment(No.2018ZX07111003)the Open Research Fund Program of Key Laboratory of Cleaner Production and Integrated Resource Utilization of China National Light Industry(No.CP-2019-YB8)+1 种基金Beijing Municipal Science and Technology Project(No.Z181100002418017)the Fundamental Research Funds for the Central Universities(No.JD1901).
文摘The objectives of this study were to investigate the influence of chromium nanoparticles(Cr NPs)on the nitrogen and phosphorus removal performance and the bacterial structures of an activated sludge(AS)system.Also,we through molecular ecological networks(MENs)discussed the bacterial interactions.At last we researched the change of the functional genes and their expression patterns related to nitrogen and phosphorus removaT in an AS system.The results showed that long-term exposure to 1 mg/L Cr NPs significantly promoted the denitrifying process and phosphorus removal in the AS system.The relative abundance of denitrifying and phosphorus removal microorganisms,such as Denitratisoma,Thauera,Dechloromonas,and Defluviicoccus,increased significantly.Candidatus Accumulibacter,well-known as polyphosphate-accumulating organisms(PAOs),increased significantly;the relative abundance of Candidatus Competibacter,known as glycogen-accumulating organisms(GAOs),decreased significantly.Furthermore,metagenomic and metatranscriptomic analysis revealed that most of the genera related to denitrifying and phosphorus removal had greatly increased,according to the quantities of denitrifying and phosphorus genes,and the corresponding transcription likewise greatly increased.Lastly,MENs analysis showed that although the overall network became smaller and looser in the presence of Cr NPs,the microbial connections among members related to nitrogen and phosphorus removal were enhanced.The abundance increases of denitrifiers and PAOs,and their increased transcription of functional genes,together with the enhanced interactions may be associated with the promotion of the denitrifying process and phosphorus removal.
基金The authors acknowledge financial support from the National Social Science Foundation of China(No.18BJY086)the National Natural Science Foundation of China(No.41871192),。
文摘Taking the lower Yellow River basin as the study area,this study aims to construct ecological networks to mitigate the negative impacts of rapid urbanization on the ecosystem.Ecological sources were identified based on morphological spatial pattern analysis(MSPA),habitat quality and landscape connectivity.The ecological resistance surface was constructed and corrected by integrating natural and anthropogenic factors.The spatial range of ecological corridors and some of their key nodes were identified based on circuit theory.The ecological network(EN)was finally optimized using a similarity search and cost connectivity modules.The results show that the optimized ecological network structure is more stable than before.The EN includes 23 ecological sources with a total area of 5464.8 km^(2)and 30 ecological corridor clusters with a total area of 2205.92 km^(2).Through the internal landscape heterogeneity of the corridor,28 ecological node areas and 75 barrier areas were identified as key protection and restoration areas,with a total area of 78.44 km^(2)and 372.79 km^(2),respectively.Through the construction and optimization of EN,this study identifies key areas for promoting ecological sustainability and provides a useful framework for coordinating regional ecological conservation and economic development.
基金The National Natural Science Foundation of China(51478217)。
文摘As a complex social ecosystem network,the area along the Grand Canal has a prominent contradiction between the demand for economic development and the protection of natural resources,which means that there is an urgent need for ecological restoration and environmental protection.Using ArcGIS,Conefor,Linkage Mapper and other software platforms,this paper developed an integrated analysis framework,through loose coupling of the attribute-function-structure index system and a series of methods such as the least cost path,circuit theory and moving window search.Based on the framework,we resolve a series of scientific issues in developing regional ecological networks,such as the selection of ecological sources,the simulation of potential ecological corridors,the assessment of the importance of ecological sources and corridors,and the identification of key ecological nodes.Moreover,an overall conservation pattern of the regional ecological network is constructed.The results show that:1)A total of 88 important ecological sources are identified in the study area.The patches with high centrality values are mainly concentrated in the southern mountainous area and the areas with abundant rivers and lakes.2)A total of 138 important ecological corridors are identified,and they are not evenly distributed.Extremely important corridors mostly appear between important patches,and very important corridors are mainly distributed in the central area.3)Fifteen ecological pinch points are extracted,and they are mainly concentrated in the northern part of the study area and eastern Zhejiang Province.The barriers are mostly concentrated in the southern and northern parts of the study area.4)Combining the demands of ecological protection and socioeconomic development,we propose an overall ecological conservation pattern of"one axis,five sections,multiple cores and multiple nodes"to effectively guide future ecological restoration work.These results can provide a useful reference and spatial guidance for decision makers in terms of ecological restoration and cooperation on cross-regional ecological protection along the Grand Canal.
基金supported by the National Natural Science Foundation of China(No.31860023)the Light of West China Program of Chinese Academic of Sciences(No.[2019]90)+1 种基金the Basic Research Fund of Guangxi Academy of Sciences,China(No.CQZ-D-1904)the Fundamental Research Fund of the Guangxi Institute of Botany,China(Guizhiye Nos.24010 and 24012).
文摘Soil nitrogen(N)cycling is one of the most critical biogeochemical cycles,and N cycling-related microorganisms are the primary driving force behind N cycling in natural environments.The large karst sinkholes in China,known as Tiankengs,harbor abundant unique biological resources due to their particular environmental conditions.However,N cycling-related microorganisms in Tiankeng soils and their connection to ecosystem processes remain poorly studied.In this study,we investigated the distribution patterns and genomic diversity of N cycling-related microorganisms both inside and outside the Luohun cave Tiankeng in Guizhou,China,utilizing high-throughput sequencing and other techniques.The results indicated that the diversities and abundances of denitrifying bacteria,ammonia-oxidizing bacteria,and ammonia-oxidizing archaea communities inside the Tiankeng were higher than those outside the Tiankeng;however,the microbial network relationships were more fragile inside the Tiankeng.The most abundant species of denitrifying bacteria,ammonia-oxidizing bacteria,and ammonia-oxidizing archaea inside the Tiankeng were unclassified_p_Proteobacteria(47.8%),unclassified_k_norank(AOB,OTU121,37.3%),and unclassified_g_norank_f_norank_o_norank_c_environmental_samples(55.7%),respectively;outside the Tiankeng,they were unclassified_k_norank_d_bacteria(54.5%),unclassified_k_norank(AOB,OTU121,48.1%),and unclassified_k_norank(AOA,OTU70,49.6%),respectively.Additionally,the N content inside the Tiankeng was significantly lower(P<0.05)under the influence of these N cycling-related microorganisms,whereas the nutrient contents were higher than that outside the Tiankeng.To the best of our knowledge,this is the first report on the crucial microbial distribution patterns driving N cycling in karst Tiankengs and provides new insights into the structure and potential functions of N cycling-related microorganisms in the unique ecological environment of fragile Tiankeng ecosystems.
文摘Hancang River is a river on the eastern border of Jinan City. In recent years, with the development of cities, river flow has dropped sharply, river water has been polluted, and the ecological environment of the basin has declined. Improving the water ecological environment and enhancing the resilience of the water ecology of the river basin were set as the research goals, especially coupling of hydrological and ecological processes and the recycling of sewage resources. The “patch-corridor-matrix” theory of landscape ecology, the Least-cost distance model and the Arc Hydro Tools module of the ArcGIS platform were used to describe the river system and basin boundaries, optimize the current water network and the path network of the ecosystem. A novel ecological network and water network were proposed to form the final aquatic ecosystem, which combines the hydrological process with the ecosystem, and three decentralized wastewater treatment systems were designed to reduce the wastewater directly flowing into the river. The ecosystem resilience of the basin will be enhanced.
