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Javed T, Wang Z, Liu J, Li W, Lin H, Zhang J. Unlocking the ecohydrological dynamics of vegetation growth's impact on Terrestrial Water Storage trends across the China-Pakistan Economic Corridor. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 955:176977. [PMID: 39426533 DOI: 10.1016/j.scitotenv.2024.176977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2024] [Revised: 09/29/2024] [Accepted: 10/14/2024] [Indexed: 10/21/2024]
Abstract
Studying the influence of vegetation dynamics on water storage is fundamental for efficiently managing ecosystems in dryland areas. Therefore, this study was designed to investigate the ecohydrological dynamics of vegetation growth's impact on Terrestrial Water Storage (TWS) trends across the China-Pakistan Economic Corridor (CPEC). Exploring vegetation growth's effect on TWS utilizes remote sensing and statistical methods such as generalized additive model (GAM), random forest, Mann-Kendall test, Sen's slope, and Partial correlation coefficient. Our results revealed a consistent increase in vegetation cover in semi-arid and dry sub-humid regions, especially in croplands, from 1986 to 2020. However, a noticeable finding was that TWS has declined by approximately 39.65 % in the study area. On the other hand, forests have displayed resilience by mitigating the effects of climate change and human activities through hydraulic memory effects. Additionally, soil moisture has decreased in various land cover types, with croplands experiencing the most significant decrease. Similarly, increased vegetation growth in greening drylands significantly negatively impacts terrestrial water storage, with correlations of -0.31 for terrestrial water storage anomaly (TWSA), -0.26 for root zone soil moisture (RZSM), and -0.29 for surface soil moisture (SSM). Meanwhile, evapotranspiration (ET) also had negative correlations with TWSA, RZSM, and SSM, with standardized coefficients of -0.23, -0.16, and -0.11, respectively. These findings exposed the study area's vegetation interaction with land cover and hydrological dynamics. Addressing these hydrological imbalances will help ensure sustainable ecological management in the study area.
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Affiliation(s)
- Tehseen Javed
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi, Xinjiang 832000, China; Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Technology Innovation Center for Agricultural Water and Fertilizer Efficiency Equipment of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Engineering Technology Center for Comprehensive Utilization of Saline and Alkaline Land in the Xinjiang Production & Construction Group, Shihezi, Xinjiang 832000, China
| | - Zhenhua Wang
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi, Xinjiang 832000, China; Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Technology Innovation Center for Agricultural Water and Fertilizer Efficiency Equipment of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Engineering Technology Center for Comprehensive Utilization of Saline and Alkaline Land in the Xinjiang Production & Construction Group, Shihezi, Xinjiang 832000, China.
| | - Jian Liu
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi, Xinjiang 832000, China; Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Technology Innovation Center for Agricultural Water and Fertilizer Efficiency Equipment of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Engineering Technology Center for Comprehensive Utilization of Saline and Alkaline Land in the Xinjiang Production & Construction Group, Shihezi, Xinjiang 832000, China
| | - Wenhao Li
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi, Xinjiang 832000, China; Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Technology Innovation Center for Agricultural Water and Fertilizer Efficiency Equipment of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Engineering Technology Center for Comprehensive Utilization of Saline and Alkaline Land in the Xinjiang Production & Construction Group, Shihezi, Xinjiang 832000, China
| | - Haixia Lin
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi, Xinjiang 832000, China; Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Technology Innovation Center for Agricultural Water and Fertilizer Efficiency Equipment of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Engineering Technology Center for Comprehensive Utilization of Saline and Alkaline Land in the Xinjiang Production & Construction Group, Shihezi, Xinjiang 832000, China
| | - Jihong Zhang
- College of Water Conservancy & Architectural Engineering, Shihezi University, Shihezi, Xinjiang 832000, China; Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Technology Innovation Center for Agricultural Water and Fertilizer Efficiency Equipment of Xinjiang Production & Construction Group, Shihezi University, Shihezi, Xinjiang 832000, China; Engineering Technology Center for Comprehensive Utilization of Saline and Alkaline Land in the Xinjiang Production & Construction Group, Shihezi, Xinjiang 832000, China
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Shao M, Wang J, Ding H, Yang F. Response of Siberian Cranes ( Grus leucogeranus) to Hydrological Changes and the Availability of Foraging Habitat at Various Water Levels in Poyang Lake. Animals (Basel) 2024; 14:234. [PMID: 38254403 PMCID: PMC10812764 DOI: 10.3390/ani14020234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/09/2024] [Accepted: 01/09/2024] [Indexed: 01/24/2024] Open
Abstract
To assess the Siberian crane (Grus leucogeranus)'s response to changing water levels and habitat quality at Poyang Lake, we analyzed the lake's hydrological trends over the past two decades with the Mann-Kendall and Sen slope methods. Additionally, we explored the link between the crane population size and hydrological conditions at the lake from 2011 to 2019. Meanwhile, five environmental factors, including habitat type, distance from shallow lakes, human footprint index, elevation and normalized vegetation index were selected, and the distribution patterns of suitable habitats for the Siberian crane under 10 water level gradients with intervals of about 1 m (5.3-14.2 m) were simulated by using an improved habitat suitability index model that determines the weights of evaluating factors based on the MaxEnt model. The results showed that the overall trend of the inundated area in Poyang Lake was shrinking in the last 20 years, with a significant increase in the area of exposed floodland during the early wintering period (Z = -2.26). The prolonged drought resulting from this will force vegetation succession, thereby diminishing the food resources for cranes in their natural habitat. The mean inundated area in June demonstrated a significant negative correlation with the population of Siberian cranes in natural habitats (r = -0.75, p = 0.02). Shortage of the Siberian crane-preferred Vallisneria tuber due to June flooding was the primary driver of the crane's altered foraging strategy and habitat shift. In years with relatively normal June inundation, indicating abundant Vallisneria resources, the relationship between the inundated area during the dry season and the crane population fit well, with a quadratic curve (R2 = 0.92, p = 0.02). The dry season's inundated area primarily affected the crane population and distribution pattern by influencing the availability of food resources, and both excessive and insufficient inundation areas were unfavorable for crane survival. The modeling results for habitat suitability indicated that as the water level decreased, the trend of the area of good habitat for the Siberian crane showed an inverted bell shape, peaking at a water level of 8.8 m, with optimal conditions occurring between 8 and 10 m. The combined effects of climate and human activities have made the shortage of food resources in Poyang Lake the new normal. The degradation of natural habitats has led to a decline in the quality of Siberian crane habitats, and artificial habitats can only be used as refuges to a certain extent. Thus, formulating strategies to restore natural habitats and enhance the management of artificial habitats is crucial for the conservation efforts of Siberian cranes.
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Affiliation(s)
- Mingqin Shao
- School of Life Sciences, Jiangxi Normal University, Nanchang 330022, China; (J.W.); (F.Y.)
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Jia Y, Zhang Q, Xue C, Tang H. Nonstationary frequency analysis and uncertainty quantification for extreme low lake levels in a large river-lake-catchment system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166329. [PMID: 37633398 DOI: 10.1016/j.scitotenv.2023.166329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/11/2023] [Accepted: 08/14/2023] [Indexed: 08/28/2023]
Abstract
Extreme hydrological events have become increasingly frequent on a global scale. The middle Yangtze River also faces a substantial challenge in dealing with extreme flooding and drought. However, the long-term characteristics of the extreme hydrological regime have not yet been adequately recognized. Moreover, there is uncertainty in the extreme value estimation, and this uncertainty needs to be distinguished and quantified. In this study, we investigated the nonstationary frequency characteristics of extreme low lake levels (ELLLs), taking the Poyang Lake as an example. Daily lake levels from 1960 to 2022 were utilized to estimate the return level using the generalized Pareto distribution (GPD). The uncertainty from three sources, i.e., the parameter estimator, threshold selection, and covariate, was quantified via variance decomposition. The results indicate that (1) the parameter estimator is the predominant source of uncertainty, with a contribution rate of approximately 87 %. The total uncertainty of the covariate, threshold, and interaction term is only 13 %. (2) Two indexes, namely the annual minimum water level (WLmin) and the days with peak over the 90 % threshold per year (DPOT90), decreased (0.01-0.03 m/year) and increased (0.17-1.39 days/year), respectively, indicating a progressively severe drought trend for Poyang Lake. (3) The return level with return period of 5 to 100 years significantly decreased after the early 21st century. A large spatial heterogeneity was identified for the variation in the return level, and the change rate of the return level with a 100-year return period ranged from 5 % to 40 % for the whole lake. (4) The ELLLs had a stronger correlation with the catchment discharge than with the Yangtze River discharge and the large-scale atmospheric circulation indices. This study provides a methodology with reduced uncertainty for nonstationary frequency analysis (NFA) of ELLLs exemplified in large river-lake systems.
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Affiliation(s)
- Yuxue Jia
- Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China
| | - Qi Zhang
- Yangtze Institute for Conservation and Development, Hohai University, Nanjing 210024, China.
| | - Chenyang Xue
- Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China
| | - Hongwu Tang
- Yangtze Institute for Conservation and Development, Hohai University, Nanjing 210024, China; College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210024, China
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Teng J, Xia S, Liu Y, Duan H, Yu X, Chen J. An integrated model for prediction of hydrologic anomalies for habitat suitability of overwintering geese in a large floodplain wetland, China. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 331:117239. [PMID: 36638722 DOI: 10.1016/j.jenvman.2023.117239] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/14/2022] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
Climate anomalies and increasing human activities cause a high frequency of extreme hydrological events in wetlands, which has put waterbirds under greater survival pressure than ever. Therefore, it is crucial to predict the impact of this phenomenon on the habitat suitability of waterbirds. This study investigated the response of the goose distribution probability to hydrological variations using the flood duration index (FD), enhanced vegetation index (EVI), and waterbirds GPS tracking data in Poyang Lake. An overwintering geese habitat suitability index (HSI) is built based on the FD, EVI, and threat index and verifies the accuracy of the model simulation. Then, the effects of drought and flood on the goose habitat especially sub-lakes with different connectivity were analyzed. The findings reveal that in dry and flood years, geese will broaden their range of feeding vegetation (more fresh or mature vegetation) in response to environmental deterioration. Both drought and flood can lead to a decline in the HSI, especially flood. Connected sub-lakes are more vulnerable to hydrological anomalies than controlled sub-lakes. This research establishes a scientific foundation for floodplain wetland hydrology management and waterbird conservation.
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Affiliation(s)
- Jiakun Teng
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Shaoxia Xia
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
| | - Yu Liu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Houlang Duan
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiubo Yu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100101, China.
| | - Jiang Chen
- Office of Poyang Lake Water Control Project Construction of Jiangxi Province, Nanchang 330009, China
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Knox RL, Wohl EE, Morrison RR. Levees don't protect, they disconnect: A critical review of how artificial levees impact floodplain functions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 837:155773. [PMID: 35537517 DOI: 10.1016/j.scitotenv.2022.155773] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/26/2022] [Accepted: 05/04/2022] [Indexed: 06/14/2023]
Abstract
Despite the recognition of floodplain importance in the scientific community, floodplains are not afforded the same legal protection as river channels. In the United States alone, flood-related economic losses were much higher in the second half of the 20th century than the first half despite the expenditure of billions of dollars on flood defenses. Partially to blame are the low appraisal and understanding of human impacts to floodplain functions. Here, we explore the impacts of levees on floodplain functions and analyze case studies of floodplain restoration through levee removal. Floodplain functions include (1) fluxes of water, solutes, and particulate materials; (2) enhanced spatial heterogeneity of hydrology and biogeochemistry; (3) enhanced habitat abundance and diversity; (4) enhanced biomass and biodiversity; and (5) hazard mitigation. Case studies of floodplain restoration involving artificial levee adjustment are heavily concentrated in North America, Europe, and Japan, and those case studies assess floodplain functions within 30 years of restoration. In the United States, restoration through levee removal comprises less than 1% of artificial levee length and 1-2% of disconnected floodplains. In Europe, restoration effectiveness was severely limited by upstream flow regulation. Most case studies were impacted by stressors outside the study site and took place in lowland alluvial rivers. Reconfiguration was successful at achieving limited aims while reconnection set floodplains on a trajectory to more fully restore floodplain functions. Case studies illustrated the tension between restoration scale and study resolution in time and space as well as the role of site-specific characteristics in determining restoration outcomes. Numerous knowledge gaps surrounding the integrative relationships between floodplain functions must be addressed in future studies. The ubiquity of flow regulation demands that future floodplain restoration occur in a whole-of-basin manner. Monitoring of restoration must take place for longer periods of time and include multiple functions.
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Affiliation(s)
- Richard L Knox
- Department of Geosciences, Colorado State University, Fort Collins, CO, USA.
| | - Ellen E Wohl
- Department of Geosciences, Colorado State University, Fort Collins, CO, USA
| | - Ryan R Morrison
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO, USA
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Li B, Yang G, Wan R, Xu L. Chlorophyll a variations and responses to environmental stressors along hydrological connectivity gradients: Insights from a large floodplain lake. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 307:119566. [PMID: 35654250 DOI: 10.1016/j.envpol.2022.119566] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/30/2022] [Accepted: 05/29/2022] [Indexed: 06/15/2023]
Abstract
Understanding the key drivers of eutrophication in floodplain lakes has long been a challenge. In this study, the Chlorophyll a (Chla) variations and associated relationships with environmental stressors along the temporal hydrological connectivity gradient were investigated using a 11-year dataset in a large floodplain lake (Poyang Lake). A geostatistical method was firstly used to calculate the hydrological connectivity curves for each sampling campaign that was further classified by K-means technique. Linear mixed effect (LME) models were developed through the inclusion of the site as a random effect to identify the limiting factors of Chla variations. The results identified three clear hydrological connectivity variation patterns with remarkable connecting water area changes in Poyang Lake. Furthermore, hydrological connectivity changes exerted a great influence on environmental variables in Poyang Lake, with a decrease in nutrient concentrations as the hydrological connectivity enhanced. The Chla exhibited contrast variations with nutrient variables along the temporal hydrological connectivity gradient and generally depended on WT, DO, EC and TP, for the entire study period. Nevertheless, the relative roles of nutrient and non-nutrient variables in phytoplankton growth varied with different degrees of hydrological connectivity as confirmed by the LME models. In the low hydrological connectivity phase, the Chla dynamics were controlled only by water temperature with sufficient nutrients available. In the high hydrological connectivity phase, the synergistic influences of both nutrient and physical variables jointly limited the Chla dynamics. In addition, a significant increasing trend was observed for Chla variations from 2008 to 2018 in the HHC phase, which could largely be attributed to the elevated nutrient concentrations. This study confirmed the strong influences of hydrological connectivity on the nutrient and non-nutrient limitation of phytoplankton growth in floodplain lakes. The present study could provide new insights on the driving mechanisms underlying phytoplankton growth in floodplain lakes.
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Affiliation(s)
- Bing Li
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; College of Nanjing, University of Chinese Academy of Sciences, Nanjing, 211135, PR China.
| | - Guishan Yang
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; College of Nanjing, University of Chinese Academy of Sciences, Nanjing, 211135, PR China
| | - Rongrong Wan
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; College of Nanjing, University of Chinese Academy of Sciences, Nanjing, 211135, PR China
| | - Ligang Xu
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, PR China; University of Chinese Academy of Sciences, Beijing, 100049, PR China; College of Nanjing, University of Chinese Academy of Sciences, Nanjing, 211135, PR China
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Review of Effects of Dam Construction on the Ecosystems of River Estuary and Nearby Marine Areas. SUSTAINABILITY 2022. [DOI: 10.3390/su14105974] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Dams have made great contributions to human society, facilitating flood control, power generation, shipping, agriculture, and industry. However, the construction of dams greatly impacts downstream ecological environments and nearby marine areas. The present manuscript presents a comprehensive review of the influence of human activities on the environment, especially the effect of dam construction on the ecosystems of river estuaries and nearby marine areas, so as to provide a scientific basis for ecological environment protection. To summarize these impacts, this review used recent studies to comprehensively analyze how dam construction has affected river hydrology, geomorphology, and downstream ecosystems globally. Effects of dams on ecosystems occur through reduced river flow, reduced sediment flux, altered water temperature, changed estuary delta, altered composition and distribution of nutrients, altered structure and distribution of phytoplankton populations, habitat fragmentation, and blocked migration routes in river sections and adjacent seas. Effects of dam construction (especially the Three Gorges Dam) on the Yangtze River were also reviewed. Performing community and mitigation planning before dam construction, exploring new reservoir management strategies (including targeted control of dam storage and flushing sediment operations), banning fishing activities, and removing unnecessary dams (obsolete or small dams) are becoming crucial tools for ecosystem restoration.
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Wang H, Yuan W, Zeng Y, Liang D, Deng Y, Zhang X, Li Y. How does Three Gorges Dam regulate heavy metal footprints in the largest freshwater lake of China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 292:118313. [PMID: 34634400 DOI: 10.1016/j.envpol.2021.118313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 09/12/2021] [Accepted: 10/06/2021] [Indexed: 06/13/2023]
Abstract
Herein, a two-dimensional (2-D) vertically-averaged hydrodynamic model was applied to study the heavy metal particle footprints pre- and post-Three Gorges Dam (TGD) in Poyang Lake. Two defined indexes-Reserve Impact Index (σRII) and Species Impact Index (ηSII) were applied to assess the potential impact of the copper footprint on nature reserves and sensitive species quantitatively. The results demonstrated that the movement speed, distribution, and trajectory of copper particle footprints differed enormously pre- and post-TGD. By contrast, the post-TGD footprints were more complex because of the dam-induced variations in hydrology and meteorology. TGD had both pros and cons for the copper footprint on the reserves based on the results of σRII. It had changed the way for the transport of heavy metals and altered the patterns of exposure risk in the reserves. Sustainable management of Poyang Lake could be achieved by optimizing daily monitoring works. The ηSII for Finless Porpoises do not differ significantly between scenarios, but the ηSII for Siberian White Cranes increased by 0.92 and 0.83 for the two periods pre- and post-TGD, respectively. Heavy metals in food sources and the excreta of Siberian White Cranes could be of great concern in future studies. This study provides a theoretical basis for the in-depth study of the TGD-induced impact on Poyang Lake and provides a reference for the long-term treatment of Poyang Lake and the protection of key species.
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Affiliation(s)
- Hua Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; College of Environment, Hohai University, Nanjing, 210098, China.
| | - Weihao Yuan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; College of Environment, Hohai University, Nanjing, 210098, China
| | - Yichuan Zeng
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; College of Environment, Hohai University, Nanjing, 210098, China
| | - Dongfang Liang
- Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK
| | - Yanqing Deng
- Water Quality Department, Jiangxi Hydrological Bureau, Nanchang, 330000, China
| | - Xinyue Zhang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; College of Environment, Hohai University, Nanjing, 210098, China
| | - Yuanyuan Li
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake of Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China; College of Environment, Hohai University, Nanjing, 210098, China
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Mu S, Li B, Yao J, Yang G, Wan R, Xu X. Monitoring the spatio-temporal dynamics of the wetland vegetation in Poyang Lake by Landsat and MODIS observations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 725:138096. [PMID: 32302824 DOI: 10.1016/j.scitotenv.2020.138096] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/12/2020] [Accepted: 03/19/2020] [Indexed: 06/11/2023]
Abstract
Poyang Lake, the largest freshwater lake of China, provides critical ecological functions for water circulation and biodiversity conservation as a dynamic wetland system. However, recent climate change and human activities exerted strong pressures on this ecosystem. In this paper, we applied object-based image analysis (OBIA) and Radom Forests (RF) classifier to ten Landsat images to examine the land cover composition and its change during 1987-2017 low water season at Poyang Lake. NDVI time series (2000-2017) derived from MODIS imagery was used to document the changes of vegetation growth status. To investigate the potential driving mechanism of the inundation patterns, we differentiated the spatial-temporal changes of vegetation coverage and NDVI accumulation on eight elevation bands. Major result indicates that the vegetation area increased by 15.5% of the lake area during 1987-2017. A much faster-increasing rate (58.0 km2 year-1) can be observed during 2001-2009 as compared to that of the overall study period (18.4 km2 year-1). Analysis of NDVI accumulation showed that 42.1% of the lake's area displayed a significant increasing trend during 2000-2017. Spatially, the increase of vegetation area and NDVI accumulation mainly took place in the 11-12 m elevation band in the lower lake center. Early dry season and prolonged exposure period after the operation of Three Gorges Dam (TGD) was the major reason for the spatio-temporal evolution of the wetland vegetation in Poyang Lake. The Lake's water level started to fall below 12 m before 9th November might cause a boost of vegetation growth in the low lake center, and in turn, triggering xerophilization for the vegetation in the highlands and a shift in foraging patterns of waterbirds due to phenology variations. The findings of this study provide a clear reference for sustaining the inter-annual stability of the ecosystem by controlling the depth of water in the lake.
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Affiliation(s)
- Shaojie Mu
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, PR China
| | - Bing Li
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, PR China
| | - Jing Yao
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, PR China
| | - Guishan Yang
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, PR China.
| | - Rongrong Wan
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, PR China
| | - Xibao Xu
- Key Laboratory of Watershed Geographic Sciences, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, PR China
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Zhao M, Ma YT, He SY, Mou X, Wu L. Dynamics of bacterioplankton community structure in response to seasonal hydrological disturbances in Poyang Lake, the largest wetland in China. FEMS Microbiol Ecol 2020; 96:5863183. [DOI: 10.1093/femsec/fiaa064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 06/25/2020] [Indexed: 11/14/2022] Open
Abstract
ABSTRACT
Bacterioplankton communities play a critical role in biogeochemical cycling in freshwater environments, but how the hydrological regime impacts the assembly of bacterioplankton communities remains unclear. This study examined differences in bacterioplankton community structures between wet (July and September) and dry (October and November) seasons in two consecutive years (2016 and 2017) in Poyang Lake, the largest seasonal freshwater lake in China. Our results revealed no overall difference in bacterioplankton compositions and their predicted functions among spatially separated sites. However, bacterioplankton communities did show significant temporal shifts, mainly between samples in November and other months. Transitions from the dry to the wet season were observed in October in both sampling years. Meanwhile, insignificant spatial but significant temporal differences were also found for physicochemical variables. Moreover, redundancy analysis indicates that compared with water depth, water temperature was found to better explain changes in the bacterioplankton community. These findings consistently indicate that the bacterioplankton community in Poyang Lake is relatively less sensitive to annual hydrology shifts than water temperature and nutrient conditions.
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Affiliation(s)
- Man Zhao
- School of Life Science, Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang 330022, China
| | - Yan-tian Ma
- School of Life Science, Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang 330022, China
| | - Shi-yao He
- School of Life Science, Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang 330022, China
| | - Xiaozhen Mou
- Department of Biological Sciences, Kent State University, OH 44242, USA
| | - Lan Wu
- School of Life Science, Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang 330022, China
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Annual Green Water Resources and Vegetation Resilience Indicators: Definitions, Mutual Relationships, and Future Climate Projections. REMOTE SENSING 2019. [DOI: 10.3390/rs11222708] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Satellites offer a privileged view on terrestrial ecosystems and a unique possibility to evaluate their status, their resilience and the reliability of the services they provide. In this study, we introduce two indicators for estimating the resilience of terrestrial ecosystems from the local to the global levels. We use the Normalized Differential Vegetation Index (NDVI) time series to estimate annual vegetation primary production resilience. We use annual precipitation time series to estimate annual green water resource resilience. Resilience estimation is achieved through the annual production resilience indicator, originally developed in agricultural science, which is formally derived from the original ecological definition of resilience i.e., the largest stress that the system can absorb without losing its function. Interestingly, we find coherent relationships between annual green water resource resilience and vegetation primary production resilience over a wide range of world biomes, suggesting that green water resource resilience contributes to determining vegetation primary production resilience. Finally, we estimate the changes of green water resource resilience due to climate change using results from the sixth phase of the Coupled Model Inter-comparison Project (CMIP6) and discuss the potential consequences of global warming for ecosystem service reliability.
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