Environmental Impact Assessment Studies (EIA) for four developmental projects were chosen for this study viz-a-viz., oil and gas, river diversion, hydropower and gold mining. The EIA studies for these activities have ...Environmental Impact Assessment Studies (EIA) for four developmental projects were chosen for this study viz-a-viz., oil and gas, river diversion, hydropower and gold mining. The EIA studies for these activities have been conducted in three different ecological regions: the flood region in the former southern Sudan, low rainfall Savannah and desert region. Trees, shrubs and herbaceous species were identified and recorded in each region. Species encountered for the first time, endangered, invasive and increasers were also reported. The EIA studies have produced lists of natural flora in areas which were difficult to access without the EIA missions. During the EIA study for Jonglei Canal project the new mono specific genus Suddia sagitifolia was discovered in the flood region as the only endemic aquatic plant in Sudan. Within the same region, the smallest floating plant in Sudan (Wollfia hyaline) was reported. The critically endangered “Argon Palm” (Medemia argun) was encountered in the Nubian Desert of the Red Sea State during a gold mining EIA study. The Seha (Belpharis persica), not reported to exist in desert conditions, has been found in the Great Desert west of the Nile during an EIA study for Kajbar Hydropower project. The paper calls for the publication of the above findings and highlights the need for further detailed studies in order to enhance knowledge of the Sudanese biodiversity status.展开更多
This paper addresses urban sustainability challenges amid global urbanization, emphasizing the need for innova tive approaches aligned with the Sustainable Development Goals. While traditional tools and linear models ...This paper addresses urban sustainability challenges amid global urbanization, emphasizing the need for innova tive approaches aligned with the Sustainable Development Goals. While traditional tools and linear models offer insights, they fall short in presenting a holistic view of complex urban challenges. System dynamics (SD) models that are often utilized to provide holistic, systematic understanding of a research subject, like the urban system, emerge as valuable tools, but data scarcity and theoretical inadequacy pose challenges. The research reviews relevant papers on recent SD model applications in urban sustainability since 2018, categorizing them based on nine key indicators. Among the reviewed papers, data limitations and model assumptions were identified as ma jor challenges in applying SD models to urban sustainability. This led to exploring the transformative potential of big data analytics, a rare approach in this field as identified by this study, to enhance SD models’ empirical foundation. Integrating big data could provide data-driven calibration, potentially improving predictive accuracy and reducing reliance on simplified assumptions. The paper concludes by advocating for new approaches that reduce assumptions and promote real-time applicable models, contributing to a comprehensive understanding of urban sustainability through the synergy of big data and SD models.展开更多
Microorganisms actively participate in biogeochemical cycling processes and play a crucial role in maintaining the dynamic balance of hot spring ecosystems.However,the distribution of microbial functional genes and th...Microorganisms actively participate in biogeochemical cycling processes and play a crucial role in maintaining the dynamic balance of hot spring ecosystems.However,the distribution of microbial functional genes and their influencing factors in hot springs remain largely unclear.Therefore,this study investigated the microbial functional genes and their potential for controlling biogeochemical cycles(C,N,S,and P) in the hot Springs of Tengchong,China,using the Geochip method,a functional gene microarray technology.The examined hot springs have very different microbial functional genes.A total of 22 736 gene probe signals were identified,belonging to 567 functional genes and associated with 15 ecological functions,mainly involving stress response,carbon cycle,nitrogen cycle,sulfur cycle,phosphorus cycle and energy processes.The amyA,narG,dsrA and ppx genes were most abundant in carbon,nitrogen,sulfur and phosphorus cycles,respectively,and were significantly correlated with pH,temperature and SO_(4)^(2-).The diversity and abundance of detected gene probes were negatively correlated with temperature.The α-diversity(i.e.,Shannon index) was high at low temperature and low pH.Molecular functional interactions revealed by the gene connectivity levels were negatively correlated with temperature,pH and SO_(4)^(2-).These results suggested that the abundance,diversity and interactions of microbial functional genes were significantly influenced by geochemical parameters.-In addition,some genera possessed functional genes related to carbon,nitrogen,sulfur,and phosphorus cycles and can synergistically control the biogeochemical cycles of carbon,nitrogen,sulfur and phosphorus.These findings provide new insights into the functional potentials of microorganisms to participate in biogeochemical cycles and their responses to environmental factors in hot springs.展开更多
The sensitivity of phytoplankton growth to chemical stressors influences the composition and function of phytoplankton communities.In this study,we compared the growth,photosynthetic,and metabolic responses of the cya...The sensitivity of phytoplankton growth to chemical stressors influences the composition and function of phytoplankton communities.In this study,we compared the growth,photosynthetic,and metabolic responses of the cyanobacterium Microcystis aeruginosa FACHB-469and the green alga Raphidocelis subcapitata FACHB-271 to herbicide diuron.The 5-day growth inhibition test showed the M.aeruginosa FACHB-469 is more sensitive to diuron.Meanwhile,the photosynthetic performance,quantum yield and efficiencies,and structural indicators of the photosynthetic apparatus were influenced by environmentally relevant levels of diuron differently between the two phytoplankton.These photosynthetic alterations were more significant in the M.aeruginosa FACHB-469 than in the R.subcapitata FACHB-271 under the three levels of diuron(5,10,and 20μg/L).Cellular metabolism of the two phytoplankton was considerably disturbed after diuron exposure.The metabolism of amino acids,such as L-arginine,L-homoserine,and N-Acetyl-L-alanine,was significantly altered in the R.subcapitata FACHB-271,while only L-valine level was significantly altered in the M.aeruginosa FACHB-469.The levels of allantoic acid,epicatechin,and taurine were significantly downregulated in the R.subcapitata FACHB-271,while pyrimidine metabolism andγ-linolenic acid metabolism were altered in the M.aeruginosa FACHB-469.Overall,distinct responses in photosynthetic physiology and cellular metabolism are suggestive of invisible differences under environmentally relevant level of diuron,contributing to the differences in sensitivity of growth between the two phytoplankton under diuron.展开更多
Contaminants in the water environment of different pyritemines have varying characteristics due to different geological origins.Sulfur isotope(δ^(34)S)is an effective tool to reveal the mechanism of water environment...Contaminants in the water environment of different pyritemines have varying characteristics due to different geological origins.Sulfur isotope(δ^(34)S)is an effective tool to reveal the mechanism of water environment contamination,but no investigations have yet analyzed the characteristics and environmental significance of the δ^(34)S in the water environment of different pyritemines.This study involved a field investigation of four typical pyritemines in China(representing volcanic,skarn,sedimentary-metamorphic,and coal-deposited types)and the analysis of the hydrochemistry of aqueous samples and the δ^(34)S of both pyrite and dissolved sulfates.The S isotopes in minerals of different types of mines were associated with the deposit genesis,and S isotopes in the water environment were affected by sulfide minerals and indicative of the contaminant sources,types of contaminants,and contaminant transport processes.The environmental significance of δ^(34)S in the water environment was further explored and a contamination model for pyrite mines established based on S isotope data.The study offers a theoretical foundation for further research on the prevention,control,and management of water pollution at various types of pyrite mines.展开更多
Using multi-source reanalysis data,this study examines the relationship between the tropical Pacific-Atlantic SST Dipole Mode(TPA-DM)and summer precipitation in North China(NCSP)on the interannual timescale during the...Using multi-source reanalysis data,this study examines the relationship between the tropical Pacific-Atlantic SST Dipole Mode(TPA-DM)and summer precipitation in North China(NCSP)on the interannual timescale during the period of 1979-2022.The results show that the TPA-DM,the dominant pattern of interannual variability in the tropical Pacific and Atlantic regions,exhibits a significant negative correlation with NCSP.The positive phase of TPA-DM induces subsidence over the Maritime Continent through a zonal circulation pattern,which initiates a Pacific-Japan-like wave train along the East Asian coast.The circulation anomalies lead to moisture deficits and convergence subsidence over North China,leading to below-normal rainfall.Further analysis reveals that cooler SST in the Southern Tropical Atlantic facilitates the persistence of the TPA-DM by stimulating the anomalous Walker circulation associated with wind-evaporation-SST-convection feedback.展开更多
Northeast India has a good deposit of sub-bituminous tertiary coal. The northeast Indian coals have unusual physico-chemical characteristics such as high sulfur, volatile matter and vitrinite content, and low ash cont...Northeast India has a good deposit of sub-bituminous tertiary coal. The northeast Indian coals have unusual physico-chemical characteristics such as high sulfur, volatile matter and vitrinite content, and low ash content. In addition, many environmental sensitive organic and mineral bound elements such as Fe, Mg, Bi, AI, V, Cu, Cd, Ni, Pb, and Mn etc. remain enriched in these coals. Such characteristics are associated with more severe environmental impacts due to mining and its utilization in coal based industries. Environmental challenges include large scale landscape damage, soil erosion, loss of forest ecosystem and wildlife habitat, air, water and soil pollution. Several physical and chemical methods are reported in literature for the removal of mineral matter, total sulfur and different forms of sulfur from high sulfur coal in northeast India. This paper may help different researchers and stakeholders to understand current state of research in the field. Initiatives may be taken towards sustainable use of coal resources by adopting innovative clean technologies and by implementing effective control measures and regulatory policies.展开更多
Methane(CH4) flux was measured by using the Eddy covariance technique in the Dajiuhu Wetland of Shennongjia Forestry District, Hubei Province, China. The seasonal and daily variation of CH4 emissions was investigated,...Methane(CH4) flux was measured by using the Eddy covariance technique in the Dajiuhu Wetland of Shennongjia Forestry District, Hubei Province, China. The seasonal and daily variation of CH4 emissions was investigated, and the correlation of CH4 fluxes with the environmental impact factors were discussed to understand the activity of CH4 flux and the effects of environmental factors including air temperature, soil temperature, photosynthetic photon flux density(PPFD), and rainfall on a wetland ecosystem. The results indicated that CH4 flux was significantly correlated with air temperature and photosynthetic photon flux density(PPFD), which may be the primary driver of controlling peatland CH4 flux.展开更多
Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health.However,current analysis approaches are not ideal,as ...Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health.However,current analysis approaches are not ideal,as they tend to be laborious,time-consuming,or technically difficult.Disinfection byproducts(DBPs)are a family of well-known secondary pollutants formed by the reactions of chemical disinfectants with DBP precursors during water disinfection treatment.Since DBP precursors have various origins(e.g.,natural,domestic,industrial,and agricultural sources),and since the formation of DBPs from different precursors in the presence of specific disinfectants is distinctive,we argue that DBPs and DBP precursors can serve as alternative indicators to assess the contamination in water sources and identify pollution origins.After providing a retrospective of the origins of DBPs and DBP precursors,as well as the specific formation patterns of DBPs from different precursors,this article presents an overview of the impacts of various natural and anthropogenic factors on DBPs and DBP precursors in drinking water sources.In practice,the DBPs(i.e.,their concentration and speciation)originally present in source water and the DBP precursors determined using DBP formation potential tests—in which water samples are dosed with a stoichiometric excess of specific disinfectants in order to maximize DBP formation under certain reaction conditions—can be considered as alternative metrics.When jointly used with other water quality parameters(e.g.,dissolved organic carbon,dissolved organic nitrogen,fluorescence,and molecular weight distribution)and specific contaminants of emerging concern(e.g.,certain pharmaceuticals and personal care products),DBPs and DBP precursors in drinking water sources can provide a more comprehensive picture of water pollution for better managing water resources and ensuring human health.展开更多
The record of paleo-environment in clayey aquitard pore water is much more effective relative to aquifer groundwater owing to the low permeability of clayey aquitard. Oxygen-18（18O）, deuterium（D）, and chemical pat...The record of paleo-environment in clayey aquitard pore water is much more effective relative to aquifer groundwater owing to the low permeability of clayey aquitard. Oxygen-18（18O）, deuterium（D）, and chemical patterns were determined in pore water samples extracted from two 500 m depth boreholes, G1 and G2, in western Bohai Bay, China. Shallow pore water samples（depth〈102 m） are saline water, with the TDS（total dissolved solids） of 3.69–30.75 g/L, and deeper ones（depth=102–500 m） are fresh water, with the TDS〈1 g/L. Content of major ions（i.e., Cl-, Na＋, K＋, Mg2＋, SO2-4, Ca2＋） is high in marine sediment pore water samples and gradually decrease towards to terrestrial sediment pore water, together with the Cl/Br and Sr/Ba ratios changing significantly in different sedimentary facies along the study profile, indicating that pore water may be paleo-sedimentary water and not replaced by modern water. δ18O profile and positive correlation between δ18O and Cl- of shallow saline pore water indicated diffusion as the main transport mechanism, and distinguished four transgressive layers since Late Quaternary（i.e., Holocene marine unit, two Late Pleistocene marine units and Middle Pleistocene marine unit）, further supporting the finding that pore water retained the feature of paleo-sedimentary water. Climate was identified as the main influence on the isotopic signature of aquitard pore water and four climate periods were determined by δ18O profile.展开更多
The ability to manage and restore plant communities in the face of human-induced landscape change may rely on our ability to predict how species respond to environmental variables.Understanding this response requires ...The ability to manage and restore plant communities in the face of human-induced landscape change may rely on our ability to predict how species respond to environmental variables.Understanding this response requires examining factors or their interactions that have influence on plant and resource availability.Our objective was to analyze the relationships between changes in plant abundance and the interaction among environmental habitat factors including soil, geological(rock type), and other environmental variables in the Longhushan karst mountains ecosystem.Species density and dominance were examined using ANOVA, ANCOVA,and Generalized Linear Models to establish the single or combined effects of these groups of factors.The results showed that trends in abundance were mainly affected by rock type(related to the percentage content of dolomite and calcite), soil characteristics in association with topography.Both plant indices were higher in dolomite dominated areas and varied positively with moisture, and elevation, but negatively with organic matter, while density also increased with slope degree.The results demonstrate that significant variations in species abundance was produced with the combination of variables from soil, geological, andenvironmental factors, suggesting their interaction influence on plants.We postulate that spatial variations in plant abundance in karst ecosystem depends on the carbonate rock type in addition to water and nutrient availability which are mainly controlled by topography and other factors such as soil texture and temperature.The study suggests that in karst areas carbonate rock type, in addition to local environmental variables, should be taken into account when analyzing the factors that have impact on plant communities.展开更多
The Hindu Kush Himalayan (HKH hereafter) region is characterized by mountainous environments and a variety of regional climatic conditions. High-altitude regions in the HKH have the recent warming amplifications, espe...The Hindu Kush Himalayan (HKH hereafter) region is characterized by mountainous environments and a variety of regional climatic conditions. High-altitude regions in the HKH have the recent warming amplifications, especially during the global warming hiatus period. The rapid warming cause solid state water (snow, ice, glacier, and permafrost) to shrink, leading to increase in meltwater and there have been found more frequent incidences of flash floods, landslides, livestock diseases, and other disasters in the HKH region. Increasing awareness of climate change over the HKH region is reached a consensus. Meanwhile, the HKH region is often referred to as the water towers of Asia as many highaltitude regions store its water in the form of snow and/or glacier, feeding ten major large rivers in Asia. Therefore, the impacts of climate change on water availability in these river basins have huge influences on the livelihood of large number of population, especially in downstream regions. However, the scarcity of basic hydro-meteorological observations particularly in high-altitude regions of HKH limits rigorous analysis of climate change. Most studies used reanalysis data and/or model-reconstructed products to explore the spatial and temporal characteristics of hydro-meteorological processes, especially for extreme events. In this study, we review recent climate change in the HKH region, and the scientific challenges and research recommendations are suggested for this high-altitude area.展开更多
Degradation processes affect a vast area of arid and semi-arid lands around the world and damage the environment and people′s health. Degradation processes are driven by human productive activities that cause direct ...Degradation processes affect a vast area of arid and semi-arid lands around the world and damage the environment and people′s health. Degradation processes are driven by human productive activities that cause direct and indirect effects on natural resources, such as species extinction at regional scale, reduction and elimination of vegetation cover, soil erosion, etc. In this context, ecological rehabilitation is an important tool to recover key aspects of the degraded ecosystem. Rehabilitation trials rely on the use of native plant species with characteristics that allow them to obtain high survival and growth rates. The aim of this work was to assess the survival and growth of native woody species in degraded areas of northeastern Patagonia and relate them to plant functional traits and environmental variables. We observed high early and late survival rates, and growth rates in Prosopis flexuosa DC. var. depressa F.A. Roig and Schinus johnstonii F.A. Barkley, and low values in Condalia microphylla Cav. and Geoffroea decorticans(Gillies ex Hook. & Arn.) Burkart. Early survival rates were positively associated with specific leaf area(SLA) and precipitation, but negatively associated with wood density, the maximum mean temperature of the warmest month and the minimum mean temperature of the coldest month. Late survival rates were positively associated with SLA and soil organic matter, but negatively associated with plant height and precipitation. The temperature had a positive effect on late survival rates once the plants overcame the critical period of the first summer after they were transplanted to the field. Prosopis flexuosa and S. johnstonii were the most successful species in our study. This could be due to their functional traits that allow these species to acclimatize to the local environment. Further research should focus on C. microphylla and G. decorticans to determine how they relate to productive conditions, acclimation to environmental stress, auto-ecology and potential use in ecological rehabilitation trials.展开更多
In this study, we compared and analysed vegetation communities in the estuarine tidal flats of the four major rivers of Ise Bay (Suzuka River, Tanaka River, Kushida River and Miya River) in Mie Prefecture, Japan. Alon...In this study, we compared and analysed vegetation communities in the estuarine tidal flats of the four major rivers of Ise Bay (Suzuka River, Tanaka River, Kushida River and Miya River) in Mie Prefecture, Japan. Along the Suzuka River, Eragrostis curvula of the exotic plant accounted for 60.0% or more of the entire surface area, and the plant volume was high. Along the Tanaka River, Suaeda maritima community occupied the sand-mud zone in the vicinity of the shoreline on gravel bars, while Phragmites australis community was distributed along a shallow lake upstream. In the Kushida River, a salt marsh plant community (a community type found in areas flooded at high tide) of Suaeda maritima, Phragmites australis and Artemisia fukudo was distributed on the sand-mud surface along the main river. A salt marsh plant community (a community type found in areas that do not flood at high tide) of Phacelurus latifolius accounted for least 50.0% of the entire surface area. Along the Miya River, the area covered by the annual salt marsh plant community type was larger than the area occupied by this community type along the other rivers. The flow volume of the Miya River was high in April, June and August-October of 2006, July and September of 2007 and April-June of 2008. The flow volume was especially high in July 2007, when it reached levels above 1500.0 m3/s;change in flow volume was also large. We suggest that a large-scale disturbance occurred in the estuary, resulting in the formation of a gravelly sandy surface where an annual salt marsh plant community of Suaeda maritime and Artemisia fukudo has been established and grown as the annual precipitation and catchment volume of the basin have increased.展开更多
Ecological restoration is one of the hot technologies for the reconstruction of eutrophic lake ecosystems in which the restoration and propagation of submerged plants is the key and difficult step. In this paper, the ...Ecological restoration is one of the hot technologies for the reconstruction of eutrophic lake ecosystems in which the restoration and propagation of submerged plants is the key and difficult step. In this paper, the effect of vermiculite on the growth process of Vallisneria spiralis and sediment microenvironment were investigated, aiming to provide a theoretical basis for the application of vermiculite in aquatic ecological restoration. Results of growth indexes demonstrated that 5% and 10% vermiculite treatment groups statistically promote the growth of Vallisneria spiralis compared to the control. Meanwhile, the results of ecophysiological indexes showed that photosynthetic pigment, soluble sugar content, superoxide dismutase(SOD), and catalase(CAT) activity of 5% and 10% group were increased compared with the control while the malondialdehyde(MDA) content exhibited the opposite result(p < 0.05), which illustrated that vermiculite can improve the resistance of plants and delay the aging process of Vallisneria spiralis. In addition, result of PCA(Principal Component Analysis) demonstrated 5% and 10% group has improved the sediment physical conditions and create more ecological niche for microorganisms directly, and then promoted the growth of plants. The dissolution results showed that vermiculite can dissolve the constant and trace elements needed for plant growth. Furthermore, the addition of vermiculite increased the diversity of microorganisms in the sediments, and promoted the increase of plant growth-promoting bacteria and phosphorus-degrading bacteria. This study could provide a technique reference for the further application of vermiculite in the field of ecological restoration.展开更多
There are currently two commonly used approaches to assessing economic impacts of health damage resulting from environmental pollution： human capital approach （HCA） and willingness-to-pay （WTP）. WTP can be furthe...There are currently two commonly used approaches to assessing economic impacts of health damage resulting from environmental pollution： human capital approach （HCA） and willingness-to-pay （WTP）. WTP can be further divided into averted expenditure approach （AEA）, hedonlc wage approach （HWA）, contingent valuation approach （CVA） and hedonlc price approach （HPA）. A general review of the principles behind these approaches by the authors indicates that these methods are incapable of unveiling the mechanism of health impact from the point of view of national economy. On a basis of economic system, the shocks brought about by health effects of environmental pollution change the labor supply and medical expenditure, which in turn affects the level of production activity in each sector and the total final consumption pattern of the society. The general equilibrium approach within the framework of macroeconomic theory is able to estimate the health impact on national economy comprehensively and objectively. Its mechanism and applicability are discussed in detail by the authors.展开更多
Land use changes such as deforestation,increase in cropping or grazing areas and built-up land, likely modify the water balance and land surface behavior in the Himalayan watersheds.An integrated approach of hydrologi...Land use changes such as deforestation,increase in cropping or grazing areas and built-up land, likely modify the water balance and land surface behavior in the Himalayan watersheds.An integrated approach of hydrological and hydraulic modeling was adopted for comparative analysis of hydrological pattern in three Himalayan watersheds i.e.Khanpur,Rawal and Simly situated in the Northern territory of Pakistan.The rainfall-runoff model SWAT- Soil and water assessment tool and Hydro CAD were calibrated for the selected watersheds.The correlation analysis of the precipitation data of two climate stations i.e.Murree and Islamabad, with the discharge data of three rivers was utilized to select best suitable input precipitation data for Hydro CAD rainfall-runoff modeling.The peak flood hydrograph were generated using Hydro CAD runoff to optimize the basin parameters like CN, runoff volume, peak flows of the three watersheds.The hydrological response of the Rawal watershed was studied as a case study to different scenarios of land use change using SWAT model.The scenario of high deforestation indicated a decline of about 6.3% in the groundwater recharge tostream while increase of 7.1% in the surface runoff has been observed under the scenario of growth in urbanization in the recent decades.The integrated modeling approach proved helpful in investigating the hydrological behavior under changing environment at watershed level in the Himalayan region.展开更多
Many investigations suggest that dissimilatory arsenate-respiring prokaryotes(DARPs)play a key role in stimulating reductive mobilization of As from solid phase into groundwater,but it is not clear how environmental ...Many investigations suggest that dissimilatory arsenate-respiring prokaryotes(DARPs)play a key role in stimulating reductive mobilization of As from solid phase into groundwater,but it is not clear how environmental Mn(Ⅱ)affects the DARPs-mediated reductive mobilization of arsenic.To resolve this issue,we collected soil samples from a realgar tailingsaffected area.We found that there were diverse arsenate-respiratory reductase(arr)genes in the soils.The microbial communities had high arsenate-respiring activity,and were able to efficiently stimulate the reductive mobilization of As.Compared to the microcosms without Mn(Ⅱ),addition of 10 mmol/L Mn(Ⅱ)to the microcosms led to 23.99%-251.79%increases in the microbial mobilization of As,and led to 133.3%-239.2%increases in the abundances of arr genes.We further isolated a new cultivable DARP,Bacillus sp.F11,from the arseniccontaminated soils.It completely reduced 1 mmol/L As(V)in 5 days under the optimal reaction conditions.We further found that it was able to efficiently catalyze the reductive mobilization and release of As from the solid phase;the addition of 2 mmol/L Mn(Ⅱ)led to 98.49%-248.78%increases in the F11 cells-mediated reductive mobilization of As,and70.6%-104.4%increases in the arr gene abundances.These data suggest that environmental Mn(Ⅱ)markedly increased the DARPs-mediated reductive mobilization of As in arseniccontaminated soils.This work provided a new insight into the close association between the biogeochemical cycles of arsenic and manganese.展开更多
The present paper deals with the behavior of the Attached Microbial Community (AMC) for water self-purification at different riverbeds in a typical local river. The study quantitatively investigated the problem starti...The present paper deals with the behavior of the Attached Microbial Community (AMC) for water self-purification at different riverbeds in a typical local river. The study quantitatively investigated the problem starting with in-situ sampling. It was found that more biomass of AMC was at riffles with wider distribution than in pools. High current velocity (HCV) plays a negative role at the initial stage of attachment on the riverbed, but HCV aids the community proliferation after stable attachment. External disturbances such as rainfalls and discharges from dams or reservoirs would detach the periphyton depending on the intensity of turbulence in water. However, it was discovered that the flock of periphyton could be restored very quickly because it was not completely removed. Thus, in order to enhance self-purification by periphyton, a suitable configuration of the riverbed must be constructed, and occasional appropriate repair along the channels would improve the decontamination of the river.展开更多
文摘Environmental Impact Assessment Studies (EIA) for four developmental projects were chosen for this study viz-a-viz., oil and gas, river diversion, hydropower and gold mining. The EIA studies for these activities have been conducted in three different ecological regions: the flood region in the former southern Sudan, low rainfall Savannah and desert region. Trees, shrubs and herbaceous species were identified and recorded in each region. Species encountered for the first time, endangered, invasive and increasers were also reported. The EIA studies have produced lists of natural flora in areas which were difficult to access without the EIA missions. During the EIA study for Jonglei Canal project the new mono specific genus Suddia sagitifolia was discovered in the flood region as the only endemic aquatic plant in Sudan. Within the same region, the smallest floating plant in Sudan (Wollfia hyaline) was reported. The critically endangered “Argon Palm” (Medemia argun) was encountered in the Nubian Desert of the Red Sea State during a gold mining EIA study. The Seha (Belpharis persica), not reported to exist in desert conditions, has been found in the Great Desert west of the Nile during an EIA study for Kajbar Hydropower project. The paper calls for the publication of the above findings and highlights the need for further detailed studies in order to enhance knowledge of the Sudanese biodiversity status.
基金sponsored by the U.S.Department of Housing and Urban Development(Grant No.NJLTS0027-22)The opinions expressed in this study are the authors alone,and do not represent the U.S.Depart-ment of HUD’s opinions.
文摘This paper addresses urban sustainability challenges amid global urbanization, emphasizing the need for innova tive approaches aligned with the Sustainable Development Goals. While traditional tools and linear models offer insights, they fall short in presenting a holistic view of complex urban challenges. System dynamics (SD) models that are often utilized to provide holistic, systematic understanding of a research subject, like the urban system, emerge as valuable tools, but data scarcity and theoretical inadequacy pose challenges. The research reviews relevant papers on recent SD model applications in urban sustainability since 2018, categorizing them based on nine key indicators. Among the reviewed papers, data limitations and model assumptions were identified as ma jor challenges in applying SD models to urban sustainability. This led to exploring the transformative potential of big data analytics, a rare approach in this field as identified by this study, to enhance SD models’ empirical foundation. Integrating big data could provide data-driven calibration, potentially improving predictive accuracy and reducing reliance on simplified assumptions. The paper concludes by advocating for new approaches that reduce assumptions and promote real-time applicable models, contributing to a comprehensive understanding of urban sustainability through the synergy of big data and SD models.
基金supported by grants from the National Natural Science Foundation of China(Nos.42172339,91951205)。
文摘Microorganisms actively participate in biogeochemical cycling processes and play a crucial role in maintaining the dynamic balance of hot spring ecosystems.However,the distribution of microbial functional genes and their influencing factors in hot springs remain largely unclear.Therefore,this study investigated the microbial functional genes and their potential for controlling biogeochemical cycles(C,N,S,and P) in the hot Springs of Tengchong,China,using the Geochip method,a functional gene microarray technology.The examined hot springs have very different microbial functional genes.A total of 22 736 gene probe signals were identified,belonging to 567 functional genes and associated with 15 ecological functions,mainly involving stress response,carbon cycle,nitrogen cycle,sulfur cycle,phosphorus cycle and energy processes.The amyA,narG,dsrA and ppx genes were most abundant in carbon,nitrogen,sulfur and phosphorus cycles,respectively,and were significantly correlated with pH,temperature and SO_(4)^(2-).The diversity and abundance of detected gene probes were negatively correlated with temperature.The α-diversity(i.e.,Shannon index) was high at low temperature and low pH.Molecular functional interactions revealed by the gene connectivity levels were negatively correlated with temperature,pH and SO_(4)^(2-).These results suggested that the abundance,diversity and interactions of microbial functional genes were significantly influenced by geochemical parameters.-In addition,some genera possessed functional genes related to carbon,nitrogen,sulfur,and phosphorus cycles and can synergistically control the biogeochemical cycles of carbon,nitrogen,sulfur and phosphorus.These findings provide new insights into the functional potentials of microorganisms to participate in biogeochemical cycles and their responses to environmental factors in hot springs.
基金supported by the Technology Innovation Guidance Program of Jiangxi Province“Science and Technology&Water Conservancy”Joint Plan(No.2022KSG01004)the National Natural Science Foundation of China(No.42107150)+1 种基金China Postdoctoral Science Foundation(No.2022M713317)the National Key R&D Program of China(No.2020YFA0907400)。
文摘The sensitivity of phytoplankton growth to chemical stressors influences the composition and function of phytoplankton communities.In this study,we compared the growth,photosynthetic,and metabolic responses of the cyanobacterium Microcystis aeruginosa FACHB-469and the green alga Raphidocelis subcapitata FACHB-271 to herbicide diuron.The 5-day growth inhibition test showed the M.aeruginosa FACHB-469 is more sensitive to diuron.Meanwhile,the photosynthetic performance,quantum yield and efficiencies,and structural indicators of the photosynthetic apparatus were influenced by environmentally relevant levels of diuron differently between the two phytoplankton.These photosynthetic alterations were more significant in the M.aeruginosa FACHB-469 than in the R.subcapitata FACHB-271 under the three levels of diuron(5,10,and 20μg/L).Cellular metabolism of the two phytoplankton was considerably disturbed after diuron exposure.The metabolism of amino acids,such as L-arginine,L-homoserine,and N-Acetyl-L-alanine,was significantly altered in the R.subcapitata FACHB-271,while only L-valine level was significantly altered in the M.aeruginosa FACHB-469.The levels of allantoic acid,epicatechin,and taurine were significantly downregulated in the R.subcapitata FACHB-271,while pyrimidine metabolism andγ-linolenic acid metabolism were altered in the M.aeruginosa FACHB-469.Overall,distinct responses in photosynthetic physiology and cellular metabolism are suggestive of invisible differences under environmentally relevant level of diuron,contributing to the differences in sensitivity of growth between the two phytoplankton under diuron.
基金supported by the National Key R&D Program of China(No.2022YFC3702203)the National Natural Science Foundation of China(Nos.42030706,and 42277405).
文摘Contaminants in the water environment of different pyritemines have varying characteristics due to different geological origins.Sulfur isotope(δ^(34)S)is an effective tool to reveal the mechanism of water environment contamination,but no investigations have yet analyzed the characteristics and environmental significance of the δ^(34)S in the water environment of different pyritemines.This study involved a field investigation of four typical pyritemines in China(representing volcanic,skarn,sedimentary-metamorphic,and coal-deposited types)and the analysis of the hydrochemistry of aqueous samples and the δ^(34)S of both pyrite and dissolved sulfates.The S isotopes in minerals of different types of mines were associated with the deposit genesis,and S isotopes in the water environment were affected by sulfide minerals and indicative of the contaminant sources,types of contaminants,and contaminant transport processes.The environmental significance of δ^(34)S in the water environment was further explored and a contamination model for pyrite mines established based on S isotope data.The study offers a theoretical foundation for further research on the prevention,control,and management of water pollution at various types of pyrite mines.
基金jointly supported by the Second Tibetan Plateau Scientific Expedition and Research Program[grant number-ber 2019QZKK0103]the National Natural Science Foundation of China[grant number 42293294]the China Meteorological Admin-istration Climate Change Special Program[grant number QBZ202303]。
文摘Using multi-source reanalysis data,this study examines the relationship between the tropical Pacific-Atlantic SST Dipole Mode(TPA-DM)and summer precipitation in North China(NCSP)on the interannual timescale during the period of 1979-2022.The results show that the TPA-DM,the dominant pattern of interannual variability in the tropical Pacific and Atlantic regions,exhibits a significant negative correlation with NCSP.The positive phase of TPA-DM induces subsidence over the Maritime Continent through a zonal circulation pattern,which initiates a Pacific-Japan-like wave train along the East Asian coast.The circulation anomalies lead to moisture deficits and convergence subsidence over North China,leading to below-normal rainfall.Further analysis reveals that cooler SST in the Southern Tropical Atlantic facilitates the persistence of the TPA-DM by stimulating the anomalous Walker circulation associated with wind-evaporation-SST-convection feedback.
文摘Northeast India has a good deposit of sub-bituminous tertiary coal. The northeast Indian coals have unusual physico-chemical characteristics such as high sulfur, volatile matter and vitrinite content, and low ash content. In addition, many environmental sensitive organic and mineral bound elements such as Fe, Mg, Bi, AI, V, Cu, Cd, Ni, Pb, and Mn etc. remain enriched in these coals. Such characteristics are associated with more severe environmental impacts due to mining and its utilization in coal based industries. Environmental challenges include large scale landscape damage, soil erosion, loss of forest ecosystem and wildlife habitat, air, water and soil pollution. Several physical and chemical methods are reported in literature for the removal of mineral matter, total sulfur and different forms of sulfur from high sulfur coal in northeast India. This paper may help different researchers and stakeholders to understand current state of research in the field. Initiatives may be taken towards sustainable use of coal resources by adopting innovative clean technologies and by implementing effective control measures and regulatory policies.
基金Supported by the National Natural Science Foundation of China(31971490)
文摘Methane(CH4) flux was measured by using the Eddy covariance technique in the Dajiuhu Wetland of Shennongjia Forestry District, Hubei Province, China. The seasonal and daily variation of CH4 emissions was investigated, and the correlation of CH4 fluxes with the environmental impact factors were discussed to understand the activity of CH4 flux and the effects of environmental factors including air temperature, soil temperature, photosynthetic photon flux density(PPFD), and rainfall on a wetland ecosystem. The results indicated that CH4 flux was significantly correlated with air temperature and photosynthetic photon flux density(PPFD), which may be the primary driver of controlling peatland CH4 flux.
基金supported by the National Natural Science Foundation of China(52325001,52170009,and 52091542)the National Key Research and Development Program of China(2021YFC3200700)+3 种基金the Program of Shanghai Academic Research Leader,China(21XD1424000)the International Cooperation Project of Shanghai Science and Technology Commission(20230714100)the Key-Area Research and Development Program of Guangdong Province(2020B1111350001)Tongji University Youth 100 Program.
文摘Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health.However,current analysis approaches are not ideal,as they tend to be laborious,time-consuming,or technically difficult.Disinfection byproducts(DBPs)are a family of well-known secondary pollutants formed by the reactions of chemical disinfectants with DBP precursors during water disinfection treatment.Since DBP precursors have various origins(e.g.,natural,domestic,industrial,and agricultural sources),and since the formation of DBPs from different precursors in the presence of specific disinfectants is distinctive,we argue that DBPs and DBP precursors can serve as alternative indicators to assess the contamination in water sources and identify pollution origins.After providing a retrospective of the origins of DBPs and DBP precursors,as well as the specific formation patterns of DBPs from different precursors,this article presents an overview of the impacts of various natural and anthropogenic factors on DBPs and DBP precursors in drinking water sources.In practice,the DBPs(i.e.,their concentration and speciation)originally present in source water and the DBP precursors determined using DBP formation potential tests—in which water samples are dosed with a stoichiometric excess of specific disinfectants in order to maximize DBP formation under certain reaction conditions—can be considered as alternative metrics.When jointly used with other water quality parameters(e.g.,dissolved organic carbon,dissolved organic nitrogen,fluorescence,and molecular weight distribution)and specific contaminants of emerging concern(e.g.,certain pharmaceuticals and personal care products),DBPs and DBP precursors in drinking water sources can provide a more comprehensive picture of water pollution for better managing water resources and ensuring human health.
基金financially supported by the National Natural Sciences Foundation of China (No. 41272258)the National Basic Research Program of China (No. 2010CB428802)
文摘The record of paleo-environment in clayey aquitard pore water is much more effective relative to aquifer groundwater owing to the low permeability of clayey aquitard. Oxygen-18（18O）, deuterium（D）, and chemical patterns were determined in pore water samples extracted from two 500 m depth boreholes, G1 and G2, in western Bohai Bay, China. Shallow pore water samples（depth〈102 m） are saline water, with the TDS（total dissolved solids） of 3.69–30.75 g/L, and deeper ones（depth=102–500 m） are fresh water, with the TDS〈1 g/L. Content of major ions（i.e., Cl-, Na＋, K＋, Mg2＋, SO2-4, Ca2＋） is high in marine sediment pore water samples and gradually decrease towards to terrestrial sediment pore water, together with the Cl/Br and Sr/Ba ratios changing significantly in different sedimentary facies along the study profile, indicating that pore water may be paleo-sedimentary water and not replaced by modern water. δ18O profile and positive correlation between δ18O and Cl- of shallow saline pore water indicated diffusion as the main transport mechanism, and distinguished four transgressive layers since Late Quaternary（i.e., Holocene marine unit, two Late Pleistocene marine units and Middle Pleistocene marine unit）, further supporting the finding that pore water retained the feature of paleo-sedimentary water. Climate was identified as the main influence on the isotopic signature of aquitard pore water and four climate periods were determined by δ18O profile.
基金founded by the National Natural Scientific Foundation of China(Grant No.40972218)the Fundamental Research Founds for National University,China University of Geosciences(Wuhan)(Grant Nos.G1323521125,G1323521225,G1323521325)
文摘The ability to manage and restore plant communities in the face of human-induced landscape change may rely on our ability to predict how species respond to environmental variables.Understanding this response requires examining factors or their interactions that have influence on plant and resource availability.Our objective was to analyze the relationships between changes in plant abundance and the interaction among environmental habitat factors including soil, geological(rock type), and other environmental variables in the Longhushan karst mountains ecosystem.Species density and dominance were examined using ANOVA, ANCOVA,and Generalized Linear Models to establish the single or combined effects of these groups of factors.The results showed that trends in abundance were mainly affected by rock type(related to the percentage content of dolomite and calcite), soil characteristics in association with topography.Both plant indices were higher in dolomite dominated areas and varied positively with moisture, and elevation, but negatively with organic matter, while density also increased with slope degree.The results demonstrate that significant variations in species abundance was produced with the combination of variables from soil, geological, andenvironmental factors, suggesting their interaction influence on plants.We postulate that spatial variations in plant abundance in karst ecosystem depends on the carbonate rock type in addition to water and nutrient availability which are mainly controlled by topography and other factors such as soil texture and temperature.The study suggests that in karst areas carbonate rock type, in addition to local environmental variables, should be taken into account when analyzing the factors that have impact on plant communities.
文摘The Hindu Kush Himalayan (HKH hereafter) region is characterized by mountainous environments and a variety of regional climatic conditions. High-altitude regions in the HKH have the recent warming amplifications, especially during the global warming hiatus period. The rapid warming cause solid state water (snow, ice, glacier, and permafrost) to shrink, leading to increase in meltwater and there have been found more frequent incidences of flash floods, landslides, livestock diseases, and other disasters in the HKH region. Increasing awareness of climate change over the HKH region is reached a consensus. Meanwhile, the HKH region is often referred to as the water towers of Asia as many highaltitude regions store its water in the form of snow and/or glacier, feeding ten major large rivers in Asia. Therefore, the impacts of climate change on water availability in these river basins have huge influences on the livelihood of large number of population, especially in downstream regions. However, the scarcity of basic hydro-meteorological observations particularly in high-altitude regions of HKH limits rigorous analysis of climate change. Most studies used reanalysis data and/or model-reconstructed products to explore the spatial and temporal characteristics of hydro-meteorological processes, especially for extreme events. In this study, we review recent climate change in the HKH region, and the scientific challenges and research recommendations are suggested for this high-altitude area.
基金funded by the National University of Río Negro, Argentina (PI40c658, PI40c654)。
文摘Degradation processes affect a vast area of arid and semi-arid lands around the world and damage the environment and people′s health. Degradation processes are driven by human productive activities that cause direct and indirect effects on natural resources, such as species extinction at regional scale, reduction and elimination of vegetation cover, soil erosion, etc. In this context, ecological rehabilitation is an important tool to recover key aspects of the degraded ecosystem. Rehabilitation trials rely on the use of native plant species with characteristics that allow them to obtain high survival and growth rates. The aim of this work was to assess the survival and growth of native woody species in degraded areas of northeastern Patagonia and relate them to plant functional traits and environmental variables. We observed high early and late survival rates, and growth rates in Prosopis flexuosa DC. var. depressa F.A. Roig and Schinus johnstonii F.A. Barkley, and low values in Condalia microphylla Cav. and Geoffroea decorticans(Gillies ex Hook. & Arn.) Burkart. Early survival rates were positively associated with specific leaf area(SLA) and precipitation, but negatively associated with wood density, the maximum mean temperature of the warmest month and the minimum mean temperature of the coldest month. Late survival rates were positively associated with SLA and soil organic matter, but negatively associated with plant height and precipitation. The temperature had a positive effect on late survival rates once the plants overcame the critical period of the first summer after they were transplanted to the field. Prosopis flexuosa and S. johnstonii were the most successful species in our study. This could be due to their functional traits that allow these species to acclimatize to the local environment. Further research should focus on C. microphylla and G. decorticans to determine how they relate to productive conditions, acclimation to environmental stress, auto-ecology and potential use in ecological rehabilitation trials.
文摘In this study, we compared and analysed vegetation communities in the estuarine tidal flats of the four major rivers of Ise Bay (Suzuka River, Tanaka River, Kushida River and Miya River) in Mie Prefecture, Japan. Along the Suzuka River, Eragrostis curvula of the exotic plant accounted for 60.0% or more of the entire surface area, and the plant volume was high. Along the Tanaka River, Suaeda maritima community occupied the sand-mud zone in the vicinity of the shoreline on gravel bars, while Phragmites australis community was distributed along a shallow lake upstream. In the Kushida River, a salt marsh plant community (a community type found in areas flooded at high tide) of Suaeda maritima, Phragmites australis and Artemisia fukudo was distributed on the sand-mud surface along the main river. A salt marsh plant community (a community type found in areas that do not flood at high tide) of Phacelurus latifolius accounted for least 50.0% of the entire surface area. Along the Miya River, the area covered by the annual salt marsh plant community type was larger than the area occupied by this community type along the other rivers. The flow volume of the Miya River was high in April, June and August-October of 2006, July and September of 2007 and April-June of 2008. The flow volume was especially high in July 2007, when it reached levels above 1500.0 m3/s;change in flow volume was also large. We suggest that a large-scale disturbance occurred in the estuary, resulting in the formation of a gravelly sandy surface where an annual salt marsh plant community of Suaeda maritime and Artemisia fukudo has been established and grown as the annual precipitation and catchment volume of the basin have increased.
基金financially supported by the National Natural Science Foundation of China (Nos. 5170925431830013)+1 种基金the Youth Innovation Promotion Association, Chinese Academy of Sciences (No. 2020335)the Natural Science Foundation of Hubei Province (No. 2020CFB555)。
文摘Ecological restoration is one of the hot technologies for the reconstruction of eutrophic lake ecosystems in which the restoration and propagation of submerged plants is the key and difficult step. In this paper, the effect of vermiculite on the growth process of Vallisneria spiralis and sediment microenvironment were investigated, aiming to provide a theoretical basis for the application of vermiculite in aquatic ecological restoration. Results of growth indexes demonstrated that 5% and 10% vermiculite treatment groups statistically promote the growth of Vallisneria spiralis compared to the control. Meanwhile, the results of ecophysiological indexes showed that photosynthetic pigment, soluble sugar content, superoxide dismutase(SOD), and catalase(CAT) activity of 5% and 10% group were increased compared with the control while the malondialdehyde(MDA) content exhibited the opposite result(p < 0.05), which illustrated that vermiculite can improve the resistance of plants and delay the aging process of Vallisneria spiralis. In addition, result of PCA(Principal Component Analysis) demonstrated 5% and 10% group has improved the sediment physical conditions and create more ecological niche for microorganisms directly, and then promoted the growth of plants. The dissolution results showed that vermiculite can dissolve the constant and trace elements needed for plant growth. Furthermore, the addition of vermiculite increased the diversity of microorganisms in the sediments, and promoted the increase of plant growth-promoting bacteria and phosphorus-degrading bacteria. This study could provide a technique reference for the further application of vermiculite in the field of ecological restoration.
基金This study is an international collaboration project between Energy Research Institute, China and National Institute for EnvironmentalStudies, Japan.
文摘There are currently two commonly used approaches to assessing economic impacts of health damage resulting from environmental pollution： human capital approach （HCA） and willingness-to-pay （WTP）. WTP can be further divided into averted expenditure approach （AEA）, hedonlc wage approach （HWA）, contingent valuation approach （CVA） and hedonlc price approach （HPA）. A general review of the principles behind these approaches by the authors indicates that these methods are incapable of unveiling the mechanism of health impact from the point of view of national economy. On a basis of economic system, the shocks brought about by health effects of environmental pollution change the labor supply and medical expenditure, which in turn affects the level of production activity in each sector and the total final consumption pattern of the society. The general equilibrium approach within the framework of macroeconomic theory is able to estimate the health impact on national economy comprehensively and objectively. Its mechanism and applicability are discussed in detail by the authors.
文摘Land use changes such as deforestation,increase in cropping or grazing areas and built-up land, likely modify the water balance and land surface behavior in the Himalayan watersheds.An integrated approach of hydrological and hydraulic modeling was adopted for comparative analysis of hydrological pattern in three Himalayan watersheds i.e.Khanpur,Rawal and Simly situated in the Northern territory of Pakistan.The rainfall-runoff model SWAT- Soil and water assessment tool and Hydro CAD were calibrated for the selected watersheds.The correlation analysis of the precipitation data of two climate stations i.e.Murree and Islamabad, with the discharge data of three rivers was utilized to select best suitable input precipitation data for Hydro CAD rainfall-runoff modeling.The peak flood hydrograph were generated using Hydro CAD runoff to optimize the basin parameters like CN, runoff volume, peak flows of the three watersheds.The hydrological response of the Rawal watershed was studied as a case study to different scenarios of land use change using SWAT model.The scenario of high deforestation indicated a decline of about 6.3% in the groundwater recharge tostream while increase of 7.1% in the surface runoff has been observed under the scenario of growth in urbanization in the recent decades.The integrated modeling approach proved helpful in investigating the hydrological behavior under changing environment at watershed level in the Himalayan region.
基金supported by the General Programs(No.41472219)the Foundations for Innovative Research Groups(No.41521001)from the National Natural Science Foundation of China。
文摘Many investigations suggest that dissimilatory arsenate-respiring prokaryotes(DARPs)play a key role in stimulating reductive mobilization of As from solid phase into groundwater,but it is not clear how environmental Mn(Ⅱ)affects the DARPs-mediated reductive mobilization of arsenic.To resolve this issue,we collected soil samples from a realgar tailingsaffected area.We found that there were diverse arsenate-respiratory reductase(arr)genes in the soils.The microbial communities had high arsenate-respiring activity,and were able to efficiently stimulate the reductive mobilization of As.Compared to the microcosms without Mn(Ⅱ),addition of 10 mmol/L Mn(Ⅱ)to the microcosms led to 23.99%-251.79%increases in the microbial mobilization of As,and led to 133.3%-239.2%increases in the abundances of arr genes.We further isolated a new cultivable DARP,Bacillus sp.F11,from the arseniccontaminated soils.It completely reduced 1 mmol/L As(V)in 5 days under the optimal reaction conditions.We further found that it was able to efficiently catalyze the reductive mobilization and release of As from the solid phase;the addition of 2 mmol/L Mn(Ⅱ)led to 98.49%-248.78%increases in the F11 cells-mediated reductive mobilization of As,and70.6%-104.4%increases in the arr gene abundances.These data suggest that environmental Mn(Ⅱ)markedly increased the DARPs-mediated reductive mobilization of As in arseniccontaminated soils.This work provided a new insight into the close association between the biogeochemical cycles of arsenic and manganese.
文摘The present paper deals with the behavior of the Attached Microbial Community (AMC) for water self-purification at different riverbeds in a typical local river. The study quantitatively investigated the problem starting with in-situ sampling. It was found that more biomass of AMC was at riffles with wider distribution than in pools. High current velocity (HCV) plays a negative role at the initial stage of attachment on the riverbed, but HCV aids the community proliferation after stable attachment. External disturbances such as rainfalls and discharges from dams or reservoirs would detach the periphyton depending on the intensity of turbulence in water. However, it was discovered that the flock of periphyton could be restored very quickly because it was not completely removed. Thus, in order to enhance self-purification by periphyton, a suitable configuration of the riverbed must be constructed, and occasional appropriate repair along the channels would improve the decontamination of the river.
