Under increasing anthropogenic pressure,species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations.The critically endangered Yangtze finless porpoise(Neopho...Under increasing anthropogenic pressure,species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations.The critically endangered Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis),once commonly observed in the Yangtze River-Poyang Lake junction,is now rarely seen in the river-lake corridor.In this study,static passive acoustic monitoring techniques were used to detect the biosonar activities of the Yangtze finless porpoise in this unique corridor.Generalized linear models were used to examine the correlation between these activities and anthropogenic impacts from the COVID-19 pandemic lockdown and boat navigation,as well as environmental variables,including hydrological conditions and light levels.Over approximately three consecutive years of monitoring(2020–2022),porpoise biosonar was detected during 93%of logged days,indicating the key role of the corridor for finless porpoise conservation.In addition,porpoise clicks were recorded in 3.80%of minutes,while feeding correlated buzzes were detected in 1.23%of minutes,suggesting the potential existence of localized,small-scale migration.Furthermore,both anthropogenic and environmental variables were significantly correlated with the diel,lunar,monthly,seasonal,and annual variations in porpoise biosonar activities.During the pandemic lockdown period,porpoise sonar detection showed a significant increase.Furthermore,a significant negative correlation was identified between the detection of porpoise click trains and buzzes and boat traffic intensity.In addition to water level and flux,daylight and moonlight exhibited significant correlations with porpoise biosonar activities,with markedly higher detections at night and quarter moon periods.Ensuring the spatiotemporal reduction of anthropogenic activities,implementing vessel speed restrictions(e.g.,during porpoise migration and feeding),and maintaining local natural hydrological regimes are critical factors for sustaining porpoise population viability.展开更多
The Poyang Lake is one of the most frequently flooded areas in China. Understanding the changing characteristics of floods as well as the affecting factors is an important prerequisite of flood disaster prevention and...The Poyang Lake is one of the most frequently flooded areas in China. Understanding the changing characteristics of floods as well as the affecting factors is an important prerequisite of flood disaster prevention and mitigation. The present study identified the characteristics variations of historical floods in the Poyang Lake and their tendencies based on the Mann-Kendall(M-K) test, and also investigated the related affecting factors, both from climate and human activities. The results revealed that the highest flood stages, duration as well as hazard coefficient of floods showed a long-term increasing linear trend during the last 60 years with the M-K statistic of 1.49, 1.60 and 1.50, respectively. And, a slightly increasing linear trend in the timing of the highest stages indicated the floods occurred later and later during the last six decades. The rainfall during the flood season and subsequent discharges of the Changjiang(Yangtze) River and runoff from the Poyang Lake Basin were mainly responsible for the severe flood situation in the Poyang Lake in the 1990 s. In addition, the intensive human activities, including land reclamation and levee construction, also played a supplementary role in increasing severity of major floods. While, the fewer floods in the Poyang Lake after 2000 can be attributed to not only the less rainfall over the Poyang Lake Basin and low discharges of the Changjiang River during flood periods, but also the stronger influences of human activity which increased the floodwater storage of the Poyang Lake than before.展开更多
By using emergy analysis theory and methods, we conduct quantitative analysis on the input and output of emergy, and sustainable development of agro-ecological system in Poyang Lake Area. The results show that compare...By using emergy analysis theory and methods, we conduct quantitative analysis on the input and output of emergy, and sustainable development of agro-ecological system in Poyang Lake Area. The results show that compared with the national average, the environmental loading ratio is relatively low in this area; the net emergy yield rate is high; the sustainable development ability is strong. Finally according to the results of emergy analysis, corresponding countermeasures are put forward as follows: develop agriculture based on the existing rich natural resources; increase technological inputs; develop circular agriculture; promote sustainable agricultural development.展开更多
The heavy metal pollution caused by human activities in river system has become a topic of great concern to multidisciplinary research.Recently,as the economic booming and industrial development,more and more waste is...The heavy metal pollution caused by human activities in river system has become a topic of great concern to multidisciplinary research.Recently,as the economic booming and industrial development,more and more waste is charging into the river and lake in different ways,which would induce serious environmental problem.In this research,the Poyang Lake was selected as the research area,the content,展开更多
From two aspects,namely the sensitivity of regional economic system to internal and external interference,and its resilience,we establish the evaluation indicator system of fragility of the economic system in Poyang L...From two aspects,namely the sensitivity of regional economic system to internal and external interference,and its resilience,we establish the evaluation indicator system of fragility of the economic system in Poyang Lake Ecological Economic Zone,and evaluate the internal differences in fragility of the regional economic system,using set pair analysis method. The results show that there is a great difference in fragility of the economic system between different administrative units; the difference in resilience is the major factor responsible for difference in fragility of the economic system in various cities and counties within the region; according to the difference in fragility characteristics,we conduct classification as follows: Nanchang City is a low-sensitivity and high-resilience type; Jiujiang City is a high-sensitivity and high-resilience type; Jiujiang County,Xingzi County,Yongxiu County,Hukou County,Duchang County,Ruichang County,De'an Xian,Wuning County,Pengze County,Leping City, Dongxiang County,Fengcheng City and Gao'an City are a high-sensitivity and low-resilience type; other cities and counties are a low-sensitivity and low-resilience type.展开更多
Stable isotopes are increasingly used to investigate seasonal migrations of aquatic organisms. This study employed stable isotopes(δ^(13) and δ15N) for Coilia nasus from the lower Yangtze River and the adjacent East...Stable isotopes are increasingly used to investigate seasonal migrations of aquatic organisms. This study employed stable isotopes(δ^(13) and δ15N) for Coilia nasus from the lower Yangtze River and the adjacent East China Sea to distinguish different ecotypic groups, ascertain trophic nutrition positions, and reflect environmental influences on C. nasus. δ^(13)C signatures of C. nasus sampled from Zhoushan(ZS), Chongming(CM), and Jingjiang(JJ) waters were significantly higher than those from the Poyang Lake(PYL)(P < 0.05). By contrast, δ^(15)Nsignatures of C. nasus in ZS, CM, and JJ groups were significantly lower than those in PYL group(P < 0.05). Basing on δ^(13) and δ^(15)Nsignatures, we could distinguish anadromous(ZS, CM, and JJ) and non-anadromous(PYL) groups. The trophic level(TL) of anadromous C. nasus ranged from 2.90 to 3.04, whereas that of non-anadromous C. nasus was 4.38. C. nasus occupied the middle and top nutrition positions in the marine and Poyang Lake food webs, respectively. C. nasus in Poyang Lake were significantly more enriched in δ^(15)N but depleted in δ^(13), suggesting that anthropogenic nutrient inputs and terrigenous organic carbon are important to the Poyang Lake food web. This study is the first to apply δ^(15)Nand δ^(13) to population assignment studies of C. nasus in the Yangtze River and its affiliated waters. Analysis of stable isotopes(δ^(15)Nand δ^(13)) is shown to be a useful tool for discriminating anadromous and non-anadromous C. nasus.展开更多
基金supported by Science and Technology Service Network Initiative Program of the Chinese Academy of Sciencesthe National Natural Science Foundation of China (41806197)the Exploratory Program of the Natural Science Foundation of Zhejiang Province (ZX2023000154)。
文摘Under increasing anthropogenic pressure,species with a previously contiguous distribution across their ranges have been reduced to small fragmented populations.The critically endangered Yangtze finless porpoise(Neophocaena asiaeorientalis asiaeorientalis),once commonly observed in the Yangtze River-Poyang Lake junction,is now rarely seen in the river-lake corridor.In this study,static passive acoustic monitoring techniques were used to detect the biosonar activities of the Yangtze finless porpoise in this unique corridor.Generalized linear models were used to examine the correlation between these activities and anthropogenic impacts from the COVID-19 pandemic lockdown and boat navigation,as well as environmental variables,including hydrological conditions and light levels.Over approximately three consecutive years of monitoring(2020–2022),porpoise biosonar was detected during 93%of logged days,indicating the key role of the corridor for finless porpoise conservation.In addition,porpoise clicks were recorded in 3.80%of minutes,while feeding correlated buzzes were detected in 1.23%of minutes,suggesting the potential existence of localized,small-scale migration.Furthermore,both anthropogenic and environmental variables were significantly correlated with the diel,lunar,monthly,seasonal,and annual variations in porpoise biosonar activities.During the pandemic lockdown period,porpoise sonar detection showed a significant increase.Furthermore,a significant negative correlation was identified between the detection of porpoise click trains and buzzes and boat traffic intensity.In addition to water level and flux,daylight and moonlight exhibited significant correlations with porpoise biosonar activities,with markedly higher detections at night and quarter moon periods.Ensuring the spatiotemporal reduction of anthropogenic activities,implementing vessel speed restrictions(e.g.,during porpoise migration and feeding),and maintaining local natural hydrological regimes are critical factors for sustaining porpoise population viability.
基金Under the auspices of National Basic Research Program of China(No.2012CB417003)National Natural Science Foundation of China(No.41101024)
文摘The Poyang Lake is one of the most frequently flooded areas in China. Understanding the changing characteristics of floods as well as the affecting factors is an important prerequisite of flood disaster prevention and mitigation. The present study identified the characteristics variations of historical floods in the Poyang Lake and their tendencies based on the Mann-Kendall(M-K) test, and also investigated the related affecting factors, both from climate and human activities. The results revealed that the highest flood stages, duration as well as hazard coefficient of floods showed a long-term increasing linear trend during the last 60 years with the M-K statistic of 1.49, 1.60 and 1.50, respectively. And, a slightly increasing linear trend in the timing of the highest stages indicated the floods occurred later and later during the last six decades. The rainfall during the flood season and subsequent discharges of the Changjiang(Yangtze) River and runoff from the Poyang Lake Basin were mainly responsible for the severe flood situation in the Poyang Lake in the 1990 s. In addition, the intensive human activities, including land reclamation and levee construction, also played a supplementary role in increasing severity of major floods. While, the fewer floods in the Poyang Lake after 2000 can be attributed to not only the less rainfall over the Poyang Lake Basin and low discharges of the Changjiang River during flood periods, but also the stronger influences of human activity which increased the floodwater storage of the Poyang Lake than before.
基金Supported by the National Natural Science Foundation of China(71063015)the Eleventh Five-Year Plan Social Sciences Project in Jiangxi Province(10YJ61)the Science and Technology Project of the Education Department of Jiangxi Province(GJJ11271)
文摘By using emergy analysis theory and methods, we conduct quantitative analysis on the input and output of emergy, and sustainable development of agro-ecological system in Poyang Lake Area. The results show that compared with the national average, the environmental loading ratio is relatively low in this area; the net emergy yield rate is high; the sustainable development ability is strong. Finally according to the results of emergy analysis, corresponding countermeasures are put forward as follows: develop agriculture based on the existing rich natural resources; increase technological inputs; develop circular agriculture; promote sustainable agricultural development.
文摘The heavy metal pollution caused by human activities in river system has become a topic of great concern to multidisciplinary research.Recently,as the economic booming and industrial development,more and more waste is charging into the river and lake in different ways,which would induce serious environmental problem.In this research,the Poyang Lake was selected as the research area,the content,
基金Supported by Water Special Project of Ministry of Water Resources (201001054)
文摘From two aspects,namely the sensitivity of regional economic system to internal and external interference,and its resilience,we establish the evaluation indicator system of fragility of the economic system in Poyang Lake Ecological Economic Zone,and evaluate the internal differences in fragility of the regional economic system,using set pair analysis method. The results show that there is a great difference in fragility of the economic system between different administrative units; the difference in resilience is the major factor responsible for difference in fragility of the economic system in various cities and counties within the region; according to the difference in fragility characteristics,we conduct classification as follows: Nanchang City is a low-sensitivity and high-resilience type; Jiujiang City is a high-sensitivity and high-resilience type; Jiujiang County,Xingzi County,Yongxiu County,Hukou County,Duchang County,Ruichang County,De'an Xian,Wuning County,Pengze County,Leping City, Dongxiang County,Fengcheng City and Gao'an City are a high-sensitivity and low-resilience type; other cities and counties are a low-sensitivity and low-resilience type.
基金financially supported by the Special Fund for Agro-scientific Research in the Public-Interest(Grant No.201203065)the National Natural Science Foundation of China(Nos.31172407+1 种基金1472280)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20123104110006)
文摘Stable isotopes are increasingly used to investigate seasonal migrations of aquatic organisms. This study employed stable isotopes(δ^(13) and δ15N) for Coilia nasus from the lower Yangtze River and the adjacent East China Sea to distinguish different ecotypic groups, ascertain trophic nutrition positions, and reflect environmental influences on C. nasus. δ^(13)C signatures of C. nasus sampled from Zhoushan(ZS), Chongming(CM), and Jingjiang(JJ) waters were significantly higher than those from the Poyang Lake(PYL)(P < 0.05). By contrast, δ^(15)Nsignatures of C. nasus in ZS, CM, and JJ groups were significantly lower than those in PYL group(P < 0.05). Basing on δ^(13) and δ^(15)Nsignatures, we could distinguish anadromous(ZS, CM, and JJ) and non-anadromous(PYL) groups. The trophic level(TL) of anadromous C. nasus ranged from 2.90 to 3.04, whereas that of non-anadromous C. nasus was 4.38. C. nasus occupied the middle and top nutrition positions in the marine and Poyang Lake food webs, respectively. C. nasus in Poyang Lake were significantly more enriched in δ^(15)N but depleted in δ^(13), suggesting that anthropogenic nutrient inputs and terrigenous organic carbon are important to the Poyang Lake food web. This study is the first to apply δ^(15)Nand δ^(13) to population assignment studies of C. nasus in the Yangtze River and its affiliated waters. Analysis of stable isotopes(δ^(15)Nand δ^(13)) is shown to be a useful tool for discriminating anadromous and non-anadromous C. nasus.
