[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in t...[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.展开更多
The authors discussed the metallogenic conditions of goldbearing skarn deposits along the middlelower Yangtze River reaches. Gold was enriched in mantleoriginated magmas while copper was enriched in crustoriginated ma...The authors discussed the metallogenic conditions of goldbearing skarn deposits along the middlelower Yangtze River reaches. Gold was enriched in mantleoriginated magmas while copper was enriched in crustoriginated magmas. So the enrichment of gold in skarn deposits was decided by the M/C ratios of the intrusive rocks. The distribution of these deposits was controlled not only by the localization of the intrusive rocks which were decided by Mesozoic Eradeveloped largescaled and deepseated faults, but also by the favorable stratigraphic horizons.展开更多
The evaluation method, model and process for the flood and waterlogging disaster condition by GIS,RS and GPS technology and the method for setting up disaster condition database, dyke database and historical disaster ...The evaluation method, model and process for the flood and waterlogging disaster condition by GIS,RS and GPS technology and the method for setting up disaster condition database, dyke database and historical disaster damage database are presented. An index of flood damage degree(FDD) used to evaluate the relative degree of disaster loss and divide flood and waterlogging area is suggested. The value of flood damage degree can be calculated as follows :taking the various disaster losses of sample area in a base year as standard value and computing the ratios of various disaster loss values in different areas and years to the standard flood disaster loss values, then summing up the weighted ratios. The computed results are the value of flood damage degree in the every year. The macroscopic flood disaster distribution can be evaluated by the values of flood loss degree.展开更多
Based on geographical and hydrological characteristics of lakes in the middle and lower reaches of Yangtze River, this paper analyzes the factors restricting the sustainable utilization of lake resources, including th...Based on geographical and hydrological characteristics of lakes in the middle and lower reaches of Yangtze River, this paper analyzes the factors restricting the sustainable utilization of lake resources, including the conflict among agriculture water conservancy, and fishery, lake water pollution and eutrophication, lake siltation and swamping. The countermeasures and suggestions, such as improving the strategic status of lake harnessing, strengthening integrated management of lakes and their watershed, strengthening researches on lake environment and lake resources, are proposed to practice the sustainable utilization of lake resources.展开更多
科学测度水生态韧性对长江流域韧性城市的建设至关重要。基于“抵抗-适应-恢复-转型”框架构建城市水生态韧性指标体系,以2011—2022年长江中游城市群26个地级市为例,运用熵权-逼近理想解排序法(Technique for Order Preference by Simi...科学测度水生态韧性对长江流域韧性城市的建设至关重要。基于“抵抗-适应-恢复-转型”框架构建城市水生态韧性指标体系,以2011—2022年长江中游城市群26个地级市为例,运用熵权-逼近理想解排序法(Technique for Order Preference by Similarity to Ideal Solution,TOPSIS)、核密度估计等定量测算水生态韧性水平,分析时空演进特征。之后,利用空间杜宾模型(Spatial Durbin Model,SDM)深入探索不同因素的影响差异。研究得到的主要结果为:(1)在研究期内,长江中游城市群水生态韧性水平有所提升,环长株潭城市群优势显著,武汉城市圈次之,环鄱阳湖城市群最低。(2)研究区水生态韧性形成了以长沙、武汉、南昌省会城市为核心并逐渐向外递减的“中心—外围”格局,多数城市于后期实现了层级跃迁,且空间差异呈收敛趋势,各城市水生态韧性趋于均衡化。(3)人口密度、经济发展水平、金融发展水平对水生态韧性的提升表现为抑制作用,科技创新投入水平对水生态韧性为正向促进作用。研究可为长江中游水生态保护提供参考,同时对其他区域的水生态韧性评价具有借鉴意义。展开更多
文摘[Objective]Implementation of the Ten-Year Fishing Ban policy may alter fish diversity and niche characteristics of dominant species in spawning grounds within the National Nature Reserve for Rare and Endemic Fish in the Upper Yangtze River.This study initiated continuous monitoring of natural spawning habitats from February 2022 to assess these ecological changes.[Methods]Environmental DNA(eDNA)metabarcoding was employed to analyze fish species composition,biodiversity patterns,and niche parameters of dominant species.Water sampling followed the CEN/TS 19461 standard across five monitoring transects(ZT1-ZT5).[Results]The eDNA analysis detected 45 species of fish belonging to 38 genera,13 families,and 3 orders were detected through environmental DNA(eDNA)in this survey,including 10 species endemic to the upper reaches of the Yangtze River,such as Procypris rabaudi and Myxocyprinus asiaticus.The fish community was mainly composed of bottom-dwelling,settling ovum-producing,omnivorous fish.The variation ranges of the Chao1 index,ACE index,Shannon index,and Simpson index are 736~996,719~965,1.58~3.23,and 0.83~0.99,respectively,indicating that fish species in spawning sites are abundant and community distribution uniformity is high.All indexes are highest at ZT1 monitoring points.Cluster analysis showed that,at a certain similarity level,fish community types in spawning sites could be basically divided into two groups:ZT1,ZT3,and ZT5 clustered together,and ZT2 and ZT4 clustered together,indicating similar fish community habitats.There are 9 dominant fish species in typical deep pool habitats in the reserve,with niche widths(Bi)ranging from 1.13 to 3.87.The dominant fish species are broad and medium niche fish,such as Cyprinus carpio and Hemiculter tchangi,with the niche overlap index(Oik)of some dominant fish species reaching more than 0.95.This indicates fierce competition for resources among the fish in this spawning ground.[Conclusion]The Zhutuo spawning ground demonstrates high species richness with homogeneous community structure and intense resource competition.This study establishes an eDNA-based monitoring framework that enhances conventional survey method,providing critical baseline data for adaptive management under the fishing moratorium regime.
文摘The authors discussed the metallogenic conditions of goldbearing skarn deposits along the middlelower Yangtze River reaches. Gold was enriched in mantleoriginated magmas while copper was enriched in crustoriginated magmas. So the enrichment of gold in skarn deposits was decided by the M/C ratios of the intrusive rocks. The distribution of these deposits was controlled not only by the localization of the intrusive rocks which were decided by Mesozoic Eradeveloped largescaled and deepseated faults, but also by the favorable stratigraphic horizons.
文摘The evaluation method, model and process for the flood and waterlogging disaster condition by GIS,RS and GPS technology and the method for setting up disaster condition database, dyke database and historical disaster damage database are presented. An index of flood damage degree(FDD) used to evaluate the relative degree of disaster loss and divide flood and waterlogging area is suggested. The value of flood damage degree can be calculated as follows :taking the various disaster losses of sample area in a base year as standard value and computing the ratios of various disaster loss values in different areas and years to the standard flood disaster loss values, then summing up the weighted ratios. The computed results are the value of flood damage degree in the every year. The macroscopic flood disaster distribution can be evaluated by the values of flood loss degree.
文摘Based on geographical and hydrological characteristics of lakes in the middle and lower reaches of Yangtze River, this paper analyzes the factors restricting the sustainable utilization of lake resources, including the conflict among agriculture water conservancy, and fishery, lake water pollution and eutrophication, lake siltation and swamping. The countermeasures and suggestions, such as improving the strategic status of lake harnessing, strengthening integrated management of lakes and their watershed, strengthening researches on lake environment and lake resources, are proposed to practice the sustainable utilization of lake resources.
文摘科学测度水生态韧性对长江流域韧性城市的建设至关重要。基于“抵抗-适应-恢复-转型”框架构建城市水生态韧性指标体系,以2011—2022年长江中游城市群26个地级市为例,运用熵权-逼近理想解排序法(Technique for Order Preference by Similarity to Ideal Solution,TOPSIS)、核密度估计等定量测算水生态韧性水平,分析时空演进特征。之后,利用空间杜宾模型(Spatial Durbin Model,SDM)深入探索不同因素的影响差异。研究得到的主要结果为:(1)在研究期内,长江中游城市群水生态韧性水平有所提升,环长株潭城市群优势显著,武汉城市圈次之,环鄱阳湖城市群最低。(2)研究区水生态韧性形成了以长沙、武汉、南昌省会城市为核心并逐渐向外递减的“中心—外围”格局,多数城市于后期实现了层级跃迁,且空间差异呈收敛趋势,各城市水生态韧性趋于均衡化。(3)人口密度、经济发展水平、金融发展水平对水生态韧性的提升表现为抑制作用,科技创新投入水平对水生态韧性为正向促进作用。研究可为长江中游水生态保护提供参考,同时对其他区域的水生态韧性评价具有借鉴意义。
