Search

Anthropogenic perturbations make negative effects on wetland ecosystems, such as increasing levels of eutrophication. Under variable environmental conditions, studying the processes and mechanisms underlying their spatial distribution is critical to biogeochemical significance of microorganisms. In order to understand the changes in sediment bacterial community and their assembly with long-term eutrophication of the Baiyangdian Lake of China, we explored the microbial communities for 24 surface sediment samples using high throughput sequencing of V3-V4 region of 16S rRNA gene, meanwhile we employed Neutral community model (NCM) to characterize the community assembly processes. Then, the β-nearest taxon index (βNTI) based on a null model was used to provide a quantitative description of the assembly processes of the bacterial community. Dispersal limitation, quantified by βNTI, accounted for ∼64.6% of all assembly processes. As the increasing levels of eutrophication, deterministic processes of bacterial community assembly may be enhanced. Moreover, the significant correlation between the βNTI and change in water NO 3 − or sediment pH might lead to deterministic processes. There was some selection pressure acting within the Baiyangdian lake sediments. The neutral community model properly explained bacterial community assembly. The NO 3 −, NH 4 +, pH and EC were main influencing factors on the composition of the bacterial community. The overlying water NO 3 −, surface water NO 3 − and sediment pH were the three most crucial environmental factors to drive bacterial assembly. The findings revealed that Group 4 with relatively stronger deterministic processes as a more eutrophic area should be monitored as an indicator for eutrophication governance. [ABSTRACT FROM AUTHOR] more...

To reveal the characteristics of climate and environmental changes in the Baiyangdian area during the late Pleistocene and their future evolutionary trends, a comprehensive analysis was conducted on the climate dry and wet changes in Baiyangdian since the late Pleistocene (26.9ka B.P.) by analyzing the grain size characteristics of lake sediment in a borehole in the southern part of Baiyangdian, combined with chronological data.The result showed that in the period of 26.9~10.5 ka B.P., the area was mainly tubidity current deposit under deluvial and alluvial function, and the climate was in the recovery process in the post glacial age, but generally dry; in the period of 10.5~8.3 ka B.P., the depositional environment was mainly fluvial facies deposit, and the climate was warmer and moister than in the previous period; since 8.3ka B.P.~ now, the dipositional environment has gradually transitioned from fluvial facies deposit to lake facies deposit, and the climate has become mainly warm and moist glacial climate, reached the period of the warmest and moistest climate since the end of the Late Pleistocene epoch in the mid-Holocene (about 6.6 ka B.P.), and then gone through two times of remarkable cold-arid fluctuation around 3.2 ka B.P. And 1.8 ka B.P.; Baiyangdian started to shrink and disintegrate under the impact of geological structure and rivers’ vicissitude, and finally formed the modern patterns of Baiyangdian Lake, under the interference of human activities.In summary, due to the influence of monsoon evolution, the environment in North China during the last glacial period was cold and dry. It began to turn wet in the early Holocene, was the wettest in the middle Holocene, and became dry in the late Holocene. This lake evolution model is similar to the evolution model of the East Asian summer monsoon, and has important reference value for understanding the future monsoon evolution model under the influence of human activities. [ABSTRACT FROM AUTHOR] more...

Groundwater plays a vital role in water resources and a key process of watershed water cycle. Baiyangdian basin was taken as the typical area to analyze the major ion sources and influence factors by using Piper diagram, ion ratio coefficient method, and forward succession model. The results show that the major cation in groundwater in the Baiyangdian Basin is Na+, and the major anion is ... . The hydrochemical types of shallow groundwater are mainly Ca · Mg-HCO3 and Ca · Mg-HCO3 · NO3, while deep groundwater types are mainly Na-HCO3 and Na · Mg-HCO3. Rock weathering is the main source of ions in groundwater, with carbonate rock weathering contributing the most (47.83%), followed by silicate rock (29.65%) and evaporite rock (13.52%). The major ions are influenced by rock weathering, dissolution-filtration processes, cation exchange, and human activities. In the piedmont alluvial plain area, agricultural activities have a significant impact on shallow groundwater, while shallow groundwater near Baiyangdian is more influenced by industrial activities. These research findings can provide valuable insights and guidance for the protection and improvement of the water ecological environment in the Baiyangdian Basin and Xiong'an New Area. [ABSTRACT FROM AUTHOR] more...

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Copyright of China Rural Water & Hydropower is the property of China Rural Water & Hydropower Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Abstract Background The drastic change in an ecosystem as a threshold phenomenon caused by abrupt changes in environmental conditions is a focus of current ecological research. However, the study of ecological thresholds has generally been limited to estimating the threshold values of single factors. Using eDNA metabarcoding technology, we collected zooplankton data from Baiyangdian Lake, the largest freshwater lake in the North China Plain, to explore the zooplankton community distribution characteristics and the relevant environmental factors. We used Threshold Indicator Taxa Analysis (TITAN) to determine the thresholds of key environmental factors and to identify the factors influencing biological diversity. Results By comparing previous studies, we found that the zooplankton community composition based on eDNA metabarcoding was similar to that based on morphological methods, and that the data could be used to estimate ecological thresholds and assess risk conditions. Temperature (T), electrical conductivity (EC), and turbidity were the major environmental factors affecting the zooplankton community structure. The composition and structure of zooplankton communities in rivers and lakes were significantly different due to the influence of specific environmental factors. The results of TITAN analysis showed that there were different indicator species for T and EC in rivers and lakes. The protection thresholds of zooplankton in rivers were T = 19.0 °C and EC = 795 μS/cm, whereas the protection thresholds of zooplankton in lakes were T = 14.3 °C and EC = 1920 μS/cm. The overall values for the Baiyangdian watershed were T = 15.5 °C and EC = 1073 μS/cm. Compared with the field monitoring results, approximately 50% of the water quality index values at the sampling points in the Baiyangdian watershed exceeded the negative response threshold, indicating that Baiyangdian Lake was disturbed. Conclusions The validity of eDNA technology in biodiversity analysis was confirmed by the zooplankton community data from Baiyangdian Lake. The ecological thresholds derived by combining eDNA technology with Threshold Indicator Taxa Analysis (TITAN) are beneficial to the biological conservation of the region. more...

Quantitative assessments of ecosystem stability are critical to properly understand the internal state of ecosystems and to implement scientific ecosystem management. Historically, ecosystem stability assessments have remained limited in their consideration of ecosystem services. This paper presents a new method for assessing ecosystem stability that combines ecosystem quality and function. We used this method to assess ecosystem stability in the upper Baiyangdian watershed and compared it to a single-indicator approach. Our results showed that the coupled approach was more accurate, especially when assessing ecosystems with low carrying capacity. This new method provides a feasible way to quantify ecosystem stability and inform regional ecosystem management. [ABSTRACT FROM AUTHOR] more...

Background: The drastic change in an ecosystem as a threshold phenomenon caused by abrupt changes in environmental conditions is a focus of current ecological research. However, the study of ecological thresholds has generally been limited to estimating the threshold values of single factors. Using eDNA metabarcoding technology, we collected zooplankton data from Baiyangdian Lake, the largest freshwater lake in the North China Plain, to explore the zooplankton community distribution characteristics and the relevant environmental factors. We used Threshold Indicator Taxa Analysis (TITAN) to determine the thresholds of key environmental factors and to identify the factors influencing biological diversity. Results: By comparing previous studies, we found that the zooplankton community composition based on eDNA metabarcoding was similar to that based on morphological methods, and that the data could be used to estimate ecological thresholds and assess risk conditions. Temperature (T), electrical conductivity (EC), and turbidity were the major environmental factors affecting the zooplankton community structure. The composition and structure of zooplankton communities in rivers and lakes were significantly different due to the influence of specific environmental factors. The results of TITAN analysis showed that there were different indicator species for T and EC in rivers and lakes. The protection thresholds of zooplankton in rivers were T = 19.0 °C and EC = 795 μS/cm, whereas the protection thresholds of zooplankton in lakes were T = 14.3 °C and EC = 1920 μS/cm. The overall values for the Baiyangdian watershed were T = 15.5 °C and EC = 1073 μS/cm. Compared with the field monitoring results, approximately 50% of the water quality index values at the sampling points in the Baiyangdian watershed exceeded the negative response threshold, indicating that Baiyangdian Lake was disturbed. Conclusions: The validity of eDNA technology in biodiversity analysis was confirmed by the zooplankton community data from Baiyangdian Lake. The ecological thresholds derived by combining eDNA technology with Threshold Indicator Taxa Analysis (TITAN) are beneficial to the biological conservation of the region. [ABSTRACT FROM AUTHOR] more...

Natural rivers often have complex water network structures, and the continuous water inflow from tributaries may have crucial impacts on the water quality of ecological water replenishment in the mainstream. This study selected two main inflow rivers of the largest lake in Hebei Province (Baiyangdian), the Fu River and Baigou River, to explore the influence of tributaries on the quality changes of ecological replenishment water in the mainstreams. In December 2020 and 2021, water samples were collected along the two river routes, and eutrophic parameters and heavy metals were determined. The results showed that the tributaries of the Fu River were all severely polluted. With the inflows of the tributaries, the comprehensive pollution index of eutrophication greatly increased along the replenished water route of the Fu River, and the replenished water in the lower reaches of the Fu River mainstream was mostly considered moderate to heavy pollution. Whereas, because the Baigou River's tributaries were only moderately polluted, the water quality in the Baigou River's replenished water was mostly better than moderate pollution. Due to the slight pollution of heavy metals in the tributaries, the replenished water in both the Fu and Baigou Rivers did not show any impact from heavy metal pollution. Correlation and principal component analysis indicated that the main sources of serious eutrophic pollution in the tributaries of the Fu and Baigou Rivers were related to domestic sewage, industrial wastewater, plant decay, and sediment release. This non-point source pollution then caused the decline in the quality of the replenished water in the mainstreams. This study exposed a long-standing but neglected problem in ecological water replenishment and provided a scientific foundation for conducting better water management to improve the inland water environment. [ABSTRACT FROM AUTHOR] more...

Baiyangdian is located in the core area of xiong’an new area and is the focus of current social attention. Water quality monitoring of Baiyangdian water area is an important basis for water pollution prevention and control, and is of great significance to the lives of surrounding residents and local economic development. ZY-1 02D AHSI hyperspectral image and ZY-1 02D VNIC multispectral image were used as remote sensing data sources to carry out separate inversion based on single image data and joint inversion based on two kinds of images respectively. The research results show that the joint inversion model can effectively improve the inversion accuracy of chlorophyll a concentration compared with the inversion model based on AHSI. Among the three inversion models, the inversion model based on VNIC has the highest accuracy. Compared with the research results of previous scholars, the advantages of hyperspectral data are not fully reflected, which shows that it has a greater impact on the spatial resolution of chlorophyll a concentration inversion in Baiyangdian district. Therefore, the 36 band of ZY-1 02D AHSI is further fused with ZY-1 02D VNIC to increase the spatial resolution to 10 m, and the optimized model AURE (average unbiased relative error, AURE) and RMSE (root mean square error, RMSE) are reduced to 13.62% and 0.52 μg/L respectively, further improving the inversion accuracy of chlorophyll a concentration. The research shows that ZY-1 02D image data has good applicability in inland water quality monitoring. Using model algorithm to improve the spatial resolution of hyperspectral data will be an important way to improve the inversion accuracy of chlorophyll a concentration. The research results are of great significance to the water quality monitoring and application of ZY-1 02D image in Baiyangdian water area. [ABSTRACT FROM AUTHOR] more...

Introduction: As the largest shallow freshwater lake in the North China Plain, Baiyangdian lake is essential for maintaining ecosystem functioning in this highly populated region. Sediments are considered to record the impacts of human activities. Methods: The abundance, diversity and metabolic pathways of microbial communities in sediments were studied by metagenomic approach to reveal patterns and mechanism of C, N, P and S cycling under the threat of lake eutrophication. Results: Many genera, with plural genes encoding key enzymes involved in genes, belonging to Proteobacteria and Actinobacteria which were the most main phylum in bacterial community of Baiyangdian sediment were involved in C, N, S, P cycling processes, such as Nocardioides (Actinobacteria), Thiobacillus, Nitrosomonas, Rhodoplanes and Sulfuricaulis (Proteobacteria). For instance, the abundance of Nocardioides were positively correlated to TN, EC, SOC and N/P ratio in pathways of phytase, regulation of phosphate starvation, dissimilatory sulfate reduction and oxidation, assimilatory sulfate reduction, assimilatory nitrate reduction and reductive tricarboxylic acid (rTCA) cycle. Many key genes in C, N, P, S cycling were closely related to the reductive citrate cycle. A complete while weaker sulfur cycle between SO42- and HS- might occur in Baiyangdian lake sediments compared to C fixation and N cycling. In addition, dissimilatory nitrate reduction to ammonia was determined to co-occur with denitrification. Methanogenesis was the main pathway of methane metabolism and the reductive citrate cycle was accounted for the highest proportion of C fixation processes. The abundance of pathways of assimilatory nitrate reduction, denitrification and dissimilatory nitrate reduction of nitrogen cycling in sediments with higher TN content was higher than those with lower TN content. Besides, Nocardioides with plural genes encoding key enzymes involved in nasAB and nirBD gene were involved in these pathways. Discussion: Nocardioides involved in the processes of assimilatory nitrate reduction, denitrification and dissimilatory nitrate reduction of nitrogen cycling may have important effects on nitrogen transformation. [ABSTRACT FROM AUTHOR] more...

Copyright of Acta Petrologica et Mineralogica / Yanshi Kuangwuxue Zazhi is the property of Acta Petrologica et Mineralogica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Pollution in inflow rivers seriously endangers the water environment in downstream lakes. In this study, an inflow river system of the Baiyangdian-Fuhe river system (FRS) was investigated to display timely pollution patterns of eutrophication and heavy metals after the establishment of Xiongan New Area, aiming to reveal the weak parts in current pollution treatments and guide the further water quality management. The results showed that the pollution of eutrophication was worse than the heavy metals in FRS, with serious eutrophic parameters of ammonia nitrogen (NH4+-N) and chemical oxygen demand (COD). There were greatly spatiotemporal variations of the pollution in FRS. (1) Concentrations of NH4+-N and total phosphorus were all higher in summer and autumn, whereas, COD contents were higher in spring; the water quality index (WQI) of eutrophication linearly increased along FRS in summer and autumn, with pollution hotspots around the estuary area. (2) The pollution levels of plumbum exceeded cadmium (Cd) and chromium (Cr) but without strongly spatiotemporal changes; however, Cd and Cr in the town area and Cd in spring showed higher concentrations; the WQI of heavy metals showed single peak curves along FRS, with significantly higher values around the town area. Additionally, the four potential pollution sources: domestic sewage, traffic pollution, agricultural wastewater and polluted sediments were identified based on the pollution patterns and pollutant associations. These findings demonstrated current treatments failed to eliminate the pollution in some hotspots and periods, and the in-depth understanding of the pollution spatiotemporal patterns in this study, especially the pollution hotspots, serious periods and potential sources, are crucial to furtherly develop spatiotemporally flexible pollution treatment strategies. [ABSTRACT FROM AUTHOR] more...

Aims: To evaluate the effects of periodic application of effective microorganism (EM) bacteria and calcium peroxide on water environment restoration of a trench wetland ecosystem and its impact on microbiota in water and sediment. Methods and Results: The EM bacteria and calcium peroxide were alternately sprayed into the trench water, and changes in the physicochemical indices of water and sediment, and in microbiota structure were subsequently investigated. Alternately spraying of calcium peroxide and EM bacteria improved the water quality, especially in terms of the dissolved oxygen and transparency of water body, and could further reduce the levels of total nitrogen, total phosphorus and ammonia nitrogen. At the same time, the microbiota structure of the water body was significantly changed by spraying with calcium peroxide and EM bacteria, and the relative abundances of Pseudanabaena, Legionellaceae, Planktothrix, Planctomyces, Phenylobacterium, Rhodobacter, Rhodoferax and Aquirestis were significantly increased. However, there was no significant effect on the physicochemical indexes and microbiota composition of the sediment. Conclusions: The water quality of the Baiyangdian trench could be significantly restored by regular sprinkling of calcium peroxide and EM bacteria. Significance and Impact of Study: The results provide an effective technical method for the restoration of trench wetland water. [ABSTRACT FROM AUTHOR] more...

Water diversion is crucial for maintaining sustainable development in populated lake areas. However, there has been no clear evaluation of how water diversion affects lake health in these areas, which are often limited by scarce in situ observations. To address this issue, we selected Baiyangdian, a fragmented freshwater shallow lake in Xiongan New Area, as our study area. We conducted a time series analysis of Baiyangdian’s water level and area changes, and identified the impact of water diversion on Baiyangdian. We used laser altimetry data (ICESat, ICESat-2), remotely-sensed lake extent, water diversion data, precipitation data, and in situ lake level data. Our results show that water diversion, rather than natural precipitation, has maintained healthy water levels in Baiyangdian in recent years. Baiyangdian’s water level has risen significantly and stabilized, moving from a drying-up level to a healthy level. The intensity of water diversion has increased from 0.91 million m ^3 in the 2000s to 7.17 million m ^3 in the 2020 s, with a corresponding water level rise from 4.93 m to 7.14 m, respectively. Moreover, a positive feedback loop between economic development, policy-making, and the lake’s ecological health can promote the sustainable development of both people and nature. more...

A novel actinomycete, strain HBU206404T, belonging to the genus Actinokineospora, was isolated from the lakeside soil of Baiyangdian, in China. Cells grew at 9–37 °C (optimum temperature, 28 °C) and pH 6–9 (optimum, pH 7). Meso-diaminopimelic acid was the diagnostic diamino acid of the cell-wall peptidoglycan, and sugars present in whole-cell hydrolysates were arabinose, mannose, glucose and galactose. The predominant menaquinone was MK-9(H4). The predominant cellular fatty acids (> 5%) of the strain HBU206404T were iso-C16:0 (21.5%), iso-C15:0 (20.3%), C16:1ω7c/C16:1ω6c and/or C16:1ω6c/C16:1ω7c (15.0%), iso-C17:0 (8.6%), C16:0 (7.0%) and C17:1ω8c (6.9%). The major polar lipids of the strain HBU206404T were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, six unknown aminolipids, two unknown aminolipids and an unidentified lipid. The 16S rRNA gene sequence analysis indicated that the strain HBU206404T was most closely related to Actinokineospora alba KCTC 19294T (99.58%), but whole-genome comparisons, using average nucleotide identity (ANI) value (91.77%) and digital DNA-DNA hybridization (dDDH) value (60%), confirmed low genome relatedness. Nitrogen metabolism pathway was found in the genome of strain HBU206404T which haboured nitrate reductase and nitrite reductase. Other phenotypic characteristics, such as ability to hydrolyze substances, enzyme activity, acid production from carbon source, etc., could also distinguish strain HBU206404T from Actinokineospora alba KCTC 19294T. On the basis of genetic and phenotypic evidence, strain HBU206404T represents a novel species of the genus Actinokineospora, for which the name Actinokineospora xionganensis sp. nov. is proposed. The type strain is HBU206404T (= MCCC 1K04412T = KCTC 49404T). [ABSTRACT FROM AUTHOR] more...

• Acute toxicity of surface water was determined by luminescent bacteria. • 17 typical indexes were selected for surface water assessment. • The correlation between various indexes and toxicity was analyzed. The biological toxicity of aquatic ecosystems should be considered when assessing the effects of toxicity on the water environment. The aim of this study was to identify the main pollutants in the Baiyangdian (BYD) and the factors that contribute to biological toxicity. We determined various physical and chemical indicators in the surface water of the BYD, including nutrients and heavy metals, and the biological toxicity. We also explored the sources of the main pollutants and how the pollutants contributed to toxicity in the lake, using correlation analysis and an index of the biological toxicity. The results showed that total nitrogen (TN), ammoniacal nitrogen (NH 4 +-N), chromium (Cr), and zinc (Zn) were the main pollutants in the BYD surface water. The average concentration of Cr was 2.3 times greater than the Class V threshold, and the concentrations at about 65% of the sampling points, mainly those in the southern part of the BYD, exceeded the threshold standard. The average concentration of Zn was 1.25 times higher than the Class V threshold, with the concentrations of about 35% of the samples greater than the threshold concentration. The integrated toxicity of the surface water to luminescent bacteria ranged from 0.51% to 58%, and averaged 24.07%, which was within the range of moderate toxicity. The inhibition rates were high near Diantou (59%) and Duan (51.6%). The pollutant levels in the BYD tend to be related to the population density, with pollution mainly caused by sewage and domestic garbage, with little influence from local industries. Cr and TN were strongly correlated, but the biological toxicity was not correlated with any of the individual environmental indicators, which suggests that the toxicity in the surface water of the BYD reflected the combined effects of the environmental factors, rather than a single factor. The information from this study, about the main pollutants and the relationships between the physical and chemical properties of the surface water in the BYD, can be used to support plans for restoring the BYD. Image, graphical abstract [ABSTRACT FROM AUTHOR] more...

An aerobic, gram-negative-staining, motile and rod-shaped bacterium, designated strain 3-BNT, was isolated from sewage sediment collected from Baiyangdian, located in Xiongan New Area of China. This heterotrophic bacterium grows on glucose, yeast extract and a limited range of defined organic acids including lactic and propionic acids. The major isoprenoid quinone is ubiquinone Q-8. Major polar lipids are phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidyl glycerol (DPG) and three unidentified glycolipids. The major fatty acids are C16:0 (30.9%), C18:1ω7c (18.3%), C17:0 cyclo (16.1%) and C14:0 (7.9%). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 3-BNT belongs to the family Burkholderiaceae, and its closest phylogenetic neighbors are members of the genera Burkholderia and Caballeronia. However, strain 3-BNT did not make a coherent clade with members of the currently recognized genera. Based on phylogenetic and chemotaxonomic characteristics of this bacterium, a novel genus and species, Caenibaculum baiyandianus gen. nov., sp. nov., is proposed. The type strain is 3-BNT (=ACCC 60082T=KCTC 62431T). [ABSTRACT FROM AUTHOR] more...

Copyright of Tourism Tribune / Lvyou Xuekan is the property of Tourism Institute of Beijing Union University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

The Fuhe River in Baoding City is one of the rivers entering Baiyangdian Lake, but its pollution is serious, so improving the water quality of the Fuhe River can not be ignored. In this paper, the horizontal subsurface flow constructed wetland was used to purify the water of Fuhe River, and the pollutant removal effect of ceramsite, crushed stone filler, cyperus alternifolius, Reed and yellow iris plants was analyzed. The results showed that the cyperus alternifolius ceramsite constructed wetland has the best removal effect on COD and TP, its average removal rates are 56.18% and 61.97%, respectively, and its average effluent concentrations are 18.64 mg/L and 0.27 mg/L; the reed ceramsite constructed wetland has the best removal effect on NH4+-N, with a rate of 64.00%, respectively, and its average effluent concentration is 0.82 mg/L. The results can provide theoretical reference for improving the water quality of Fuhe River. [ABSTRACT FROM AUTHOR] more...

• Significant differences in the responses of hydrodynamics, water quality and aquatic habitats to connectivity changes. • The connectivity threshold under multi-targets determined based on the water environment response is more accurate. • The optimal connectivity threshold is of great significance for solving wetland environment ecological degradation. The quality of the water environment of wetlands is closely related to the changes in hydrologic connectivity, so wetland responses to changing connectivity exhibit a range of optimal connectivity values. Identifying these ranges of values is of great significance for wetland ecological restoration. Current studies mostly determine the hydrologic connectivity ranges based on a single target, even though connectivity simultaneously affects multiple water environment targets. Hence, the optimal hydrologic connectivity should be determined by accounting for multiple targets. With the Baiyangdian Wetland as the study area, we developed a method to model how the water environment responded to changes in hydrologic connectivity from three perspectives: hydrodynamics, water quality, and aquatic habitat. To do so, we used the BP neural network model and a non-dominated sorting genetic algorithm to calculate the hydrologic connectivity values in a context with multiple targets. We found that under the optimal hydrodynamic target, the integral index of connectivity (IIC) threshold was [0.23, 0.61] and the probability connectivity (PC) threshold was [0.32, 0.68]; under the optimal water quality target, the IIC threshold was [0.42, 0.70] and the PC threshold was [0.48, 0.82]; under the optimal aquatic habitat target, the IIC threshold was [0.38, 0.69] and the PC threshold was [0.35, 0.71]; and under the comprehensive optimization target, the IIC threshold was [0.48, 0.64] and the PC threshold was [0.51, 0.73]. These ranges of values will help wetland managers determine the optimal ecological water releases to meet the ecosystem quality targets. [ABSTRACT FROM AUTHOR] more...

Novel 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) and legacy PFASs, such as perfluorohexane sulfonate (PFHxS), have been used to replace perfluorooctane sulfonate (PFOS), a known persistent organic pollutant. Thus, it is critical to understand these PFOS alternatives regarding their sources and concentrations in the natural environment. In this study, 41 surface water samples as well as edible aquatic organisms were collected from Baiyangdian Lake, the largest freshwater lake in Hebei Province, China. Perfluorooctanoate acid (PFOA) and PFHxS were the predominant PFASs detected in the surface water, reaching concentrations of 8 397.23 ng/L and 1 478.03 ng/L, respectively, with PFHxS accounting for the greatest proportion (∼80.00%) in most water samples. PFHxS (mean: 87.53 ng/g) and PFOS (mean: 35.94 ng/g) were also the most prevalent compounds detected in aquatic organisms. Estimated daily intake (EDI) values of PFOS (16.56 ng/kg bw/d) and PFHxS (16.11 ng/kg bw/d) via aquatic food and drinking water were the highest among PFASs, indicating potential exposure risks to residents. In addition, fish product consumption was the important exposure pathway for residents to PFOA, PFHxS, PFOS, and 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA). This study reports on the highest PFHxS levels ever recorded in surface water, suggesting that further quantification of PFHxS in human serum and assessment of its health risks to local residents are warranted and critical. [ABSTRACT FROM AUTHOR] more...

The Baiyangdian Wetland Natural Reserve is an important breeding habitat for oriental great reed warbler ( OGRWs) , Acrocephalus orientalis, in North China Plain. We investigated the nesting sites of OGRWs by line transect method during June-July, 2011, and 112 nests were found out in total. The ecological-niche factor analysis (ENFA) was applied in nesting habitat suitability assessment for OGRWs in Baiyangdian. The results showed that OGRWs in this reserve preferred nesting in dry land reed landscapes, which located at relatively high altitudes and away from anthropocentric disturbance. In 2011, the suitable and the most suitable nesting habitats of OGRWs in this reserve were 2474. 69 hm2 and 1131. 19 hm2 , accounting 7. 6% and 3. 5% of the total reserve area, respectively. The most suitable nesting habitats shaped a circle-like structure, and they all clustered together around Damai and Shaoche core area, which located in the east part of the reserve. In order to protect the nesting habitats for OGRWs within Baiyangdian wetland reserve, it was suggested that the functional zone should be reorganized, and that the Damai and Shaoche core area should be integrated into one. This new core area would be bigger and more concentrated, at the same time the buffer zone should also be established appropriately, so as to protect the natural landscapes in this reserve as much as possible. [ABSTRACT FROM AUTHOR] more...

Objective: To establish an ultra-performance liquid chromatography (UPLC) fingerprinting method for quality control of Phragmitis rhizoma from Baiyangdian. Materials and Methods: Ultrasonic extraction with 70% methanol was performed on 10 samples of P. rhizoma collected from 10 different villages in Baiyangdian. The sample solutions were analyzed by Waters UPLC equipped with the ACQUITY UPLC BEH C18 column and photodiode array (PDA) detector, and gradient eluted with acetonitrile/water as the mobile phase. The flow rate was set to 0.1 mL/min; the column temperature was set to 25°C; and the detection wavelength was set to 285 nm. Results: The chromatograms of the 10 samples showed 27 common peaks, of which one was identified as the ferulic acid standard. The similarity indexes were all above 0.82. Hierarchical cluster analysis showed that the constituents and their quantities differed according to the diameter of the original plant, which is related to its age. Conclusion: The UPLC fingerprinting method had the advantages of being fast, accurate, and highly efficient; this indicated that it can be used for quality control of P. rhizoma produced in Baiyangdian. Also, the relation between the quality and diameter/age of the plant needs to be further investigated. [ABSTRACT FROM AUTHOR] more...

Abstract: Water quality is sensitive to changes in landscape patterns in a watershed, particularly during urbanization. Using GIS tools, the landscape pattern index method was proposed to compare the landscape patterns of Baiyangdian Watershed in 2002 and 2007, determine the transformation rules of landscape essential factors, and analyze the correlation between the changes of landscape patterns and water quality in Baiyangdian Watershed. The study shows that 1) the degree of fragmentation of man-made landscape is decreasing and that of the natural landscape is increasing in the watershed during its urbanization; 2) Construction land and farmland are the dominant factors leading to river pollution in most cases, while a higher percentage of forest cover contributes to improved water quality. Furthermore, other physical and social factors were analyzed that may influence the relationship between water quality patterns of land use in the study area. [Copyright &y& Elsevier] more...

Abstract: Wetland ecosystem occupies an important position in the global carbon cycle with a strong ability of carbon storage and fixation. On the basis of field investigation and laboratory measurement, in the paper, the standing biomass and primary production of wetland Phragmites australis in Baiyangdian were study, and its ability of carbon storage and fixation in accordance with the principle of photosynthesis was measured, and then the potential ability of carbon storage from the perspective of efficiency for solar energy utilization was discussed. The results show that carbon storage of wetland Phragmites australis is large in Baiyangdian with 5.81kg • m-2, 7.14kg • m-2 and 8.72kg • m-2 respectively; carbon fixation is also very large with 2.54kg • m-2, 3.12kg • m-2 and 3.81kg • m-2 respectively. In addition, the underground biomass is larger than the aboveground biomass, and the ratio of the two is 2.38-3.30 with the average of 2.90. The underground carbon storage is nearly 3 times as much as the aboveground carbon storage. Wetland Phragmites australis in Baiyangdian has a strong ability of carbon fixation with 1.17kg • m-2 • a-1, 1.49kg • m-2 • a-1 and 1.76kg • m-2 • a-1 respectively, which is 1.7-3.4 times as much as the average ability of carbon fixation of the national terrestrial plants and 2.0- 4.0 times of that of the global plants. [Copyright &y& Elsevier] more...

lthough there are many studies of heavy metal contaminations of sediments, attention has seldom been paid to the problem in developing countries. The purpose of this article is to find the distribution and ecological risk of As, Hg, Cr, Cd, Pb, Cu, and Zn in surface sediment of Baiyangdian which is the biggest wetland in Northeast China. We apply three methodologies. The first is literature analysis comparing total concentrations of heavy metals with other water bodies around world. The second is Chinese Environmental Quality Standard for Soils (EQSS), National Environmental Protection Agency of China 1995, and the third is Soil and Aquatic Sediment Guidelines and Standards issued by New York Department of Environmental Conservation (NYSDEC). The results show that compared to other water bodies around the world, the seven heavy metals are low. However, Cd was found in the most polluting level of EQSS near a village and was second grade some distance from it. The village was also the most polluted site of Zn, which was in the second grade. When assessed by NYSDEC, Cu, Cr, and As contaminated the sediment and with moderate impacts on benthic life while Pb, Hg, and Zn were found at tolerable levels throughout Baiyangdian. The centre of Cu and Cr contamination was also near the village. As is the most polluting heavy metals with a major occurrence in the middle of the wetland. There were no heavy metals creating severe disturbance to the benthic communities. Based on the assessment, this article proposes different options for more sustainable management. [ABSTRACT FROM AUTHOR] more...

Abstract: In order to study the seasonal variations in the structure and dynamics of phytoplankton community of the Lake Baiyangdian in China, quantitative samples were collected in each season during 2005. A total of 152 taxa were identified by microscope, phytoplankton had an abundance ranging from 131.25×104 ind. L-1 to 745.88×104 ind. L-1. The highest phytoplankton abundance were observed in spring and the lowest in autumn. Cyanophyta, Euglenophyta and Cryptophyta were the most important groups in terms of abundance and biomass. The preponderant and sub-preponderant species changed in accordance with the seasons. Canonical Correspondence Analysis (CCA) was used to investigate the relationship between environmental factors and phytoplankton community. The results indicated that nutrient gradient had a positive correlation with axis 1 in spring, summer and autumn. But in winter, the nutrient gradient had a positive correlation with axis 2. The varieties of environmental factors affected the structure of phytoplankton community in each season. CCA shows a slight, but significant method to understand the spatial distribution of phytoplankton community in lake systems. [ABSTRACT FROM AUTHOR] more...

To clarify the impact of water quality and social activity in the Baiyangdian wetland on the biological community, the change characteristics of bacterial, fungal, and archaeal communities in different areas of the Dian District were studied. Samples were collected at the entrance of Fuhe District (NBB), tourist areas with frequent human social activities (NBD), residential breeding areas (NBX), and village sparse areas (NBN). The physical and chemical characteristics and biological communities of the samples were evaluated. The results of the study show that the COD concentration of organic pollutants in the NBB was 12.35 mg·L -1 , and the total nitrogen concentration was 10.12 mg·L -1 , that the concentration was highest. Moreover, the water quality in NBD and NBX was better than that of NBB. The NBN area exhibited the best water quality, with COD and total nitrogen concentration values of 6.9 mg·L -1 and 1.82 mg·L -1 , respectively. Many types of NBB bacteria were recorded, with a diversity index of 5.86, and NBN diversity index exceeding 4.78. The dominant bacterial flora in all samples was the Proteobacteria, which accounts for 68.8% of the total bacterial communities in NBN samples. The diversity index of fungi in NBB was only 2.14. There were many types of fungi in NBN, with a diversity index of 3.23. Chytridiomycota was found in the NBD and NBN, accounting for 5.4% and 9.8% of the total number of fungi, respectively. The Chytridiomycota was main decomposer of hard to degrade organic carbon. The diversity of archaea of NBN was the lowest among all the samples. Crenarchaeota was the dominant phylum, which accounts for 39.0%, 51.9%, 47.3%, and 30.1% of NBB, NBD, NBX, and NBN samples, respectively. The number of Halobacterota was lower than Crenarchaeota. The main factor of eutrophication and microbial community changes in Baiyangdian wetland was the results of the combined action of external and internal pollution. Both external and internal pollution increased the organic matter, nitrogen and phosphorus content in the water, and the microbial community structure has changed significantly. The contents of organic matter, nitrogen, and phosphorus in water were increased and the microbial community structures were changed significantly by the increase of both external and internal pollution. more...

• The NANI/NAPI methods and ECM model are integrated to quantitatively assess nutrient budgets. • Nutrient budgets were mainly from fertilizer application and livestock breeding. • The hotspots with low area ratio contributed about 50% of total nutrient budgets. • Around 2% of nutrient inputs was exported into rivers. Excessive nitrogen (N) and phosphorus (P) runoff from human activities results in degraded water quality. It is, therefore, crucial to quantitatively assess nutrient inputs over time and their impact on riverine nutrient exports. In this study, we estimated the long-term (1995–2015) nutrient inputs at the county scale by integrating Net Anthropogenic Nitrogen Input (NANI) and Net Anthropogenic Phosphorus Input (NAPI) methods, and nutrient exports into rivers by the Export Coefficient Model (ECM) for a semiarid plain basin, the Baiyangdian (BYD) Basin, China. The results showed that N and P input intensities in the year 2015 reached 18852 kg N km2 yr−1 and 2073 kg P km−2 yr−1, showing a 35% and 11% increase in comparison with 1995, respectively. About 60% of these nutrients were derived from fertilizer application. The multi-year averaged N and P exported to rivers was 548 kg N km−2 yr−1 and 79 kg P km−2 yr−1, respectively. Hotspots for nutrient budgets were found in the southeastern counties. Hotspots covered about 12% of the total land, but contributed by 38–52% of total nutrient budgets. The nutrient export ratios showed no significantly temporal variations, and only about 2.15–2.89% of NANI and NAPI were exported into rivers. The low nutrient export ratio was due to the low water discharge that limited the nutrient transportation in the semi-arid plain basin. As most of anthropogenic nutrient inputs were retained in the basin, their impacts on the pollution of soils and aquifers need to be considered and adequately addressed in the future. This study constructs the spatial quantitative nutrient budgets, which can provide effective information for region policy formulation. [ABSTRACT FROM AUTHOR] more...