Whether climate change or anthropogenic activities play a more pivotal role in regulating vegetation growth on the Tibetan Plateau is still controversial.A better understanding on grassland changes at a fine scale may...Whether climate change or anthropogenic activities play a more pivotal role in regulating vegetation growth on the Tibetan Plateau is still controversial.A better understanding on grassland changes at a fine scale may provide important guidance for local government policy and grassland management.Using two of the most reliable satellite NDVI products(MODIS NDVI and SPOT NDVI),we evaluated the dynamic of grasslands in the Zhegucuo valley on the southern Tibetan Plateau from 2000 to 2020,and analyzed its driving factors and relative influences of climate change and anthropogenic activities.Here,the key indicators of climate change were assumed to be precipitation and temperature.The main results were:(1)the grassland NDVI in Zhegucuo valley did not reflect a significant temporal change during the last 21 years.The variation of precipitation during the early growing season(GSP)resembled that of NDVI,and the GSP was positively correlated with NDVI.At the pixel level,the partial correlation analysis showed that 37.79%of the pixels depicted a positive relationship between GSP and NDVI,while 11.32%of the pixels showed a negative relationship between temperature during the early growing season(GST)and NDVI.(2)In view of the spatial distribution,the areas mainly controlled by GSP were generally distributed in the southern part,while those affected by GST stood in the eastern part,mainly around the Zhegucuo lake where most population in Cuomei County settled down.(3)Decreasing NDVI trends were mainly occurred in alpine steppe at lower elevations rather than alpine meadow at higher elevations.(4)The residual trend(RESTREND)analysis further indicated that the anthropogenic activities played a more pivotal role in regulating the annual changes of NDVI rather than climate factors in this area.Future studies should pay more attention on climate extremes rather than the simple temporal trends.Also,the influence of human activities on alpine grassland needs to be accessed and fully considered in future sustainable management.展开更多
Living fishery resources, although rich and important for human populations, are subject to strong anthropization, thus causing a change in the environmental parameters of aquatic ecosystems. These multiple combined p...Living fishery resources, although rich and important for human populations, are subject to strong anthropization, thus causing a change in the environmental parameters of aquatic ecosystems. These multiple combined pressures: chemical, hydro-morphological, thermal or trophic, affect and disrupt the functioning of aquatic organisms. The objective of this study was to assess the main human pressures influencing the surface water resources of the Kamsar sub-prefecture, in order to propose mitigation measures. The following methodological approach was adopted: 1) Survey of managers and analysis records;2) Survey of stakeholders;3) Assessment of the effect of human activities on surface water resources;4) Data processing;5) Corrective measures. The survey farmers working near aquatic environments, revealed a low use of chemical substances, in particular 3 to 11 kg of fertilizer and 0 to 3 boxes of herbicide on fields of 40 m2 to 2 ha. Some physico-chemical parameters have been determined: Temperature (28.5˚C, 23.7˚C, 22.8˚C, 21.3˚C, 21.6˚C), Salinity (26.9‰, 21.9‰, 21.5‰, 15‰, 15.3‰) and Turbidity (21.3 UTN, 19.3 UTN, 17.8 UTN, 16.7 UTN, 17 UTN). These values show a fluctuation in the environmental parameters of aquatic ecosystems, which constitutes an obstacle to the development and survival of the resources.展开更多
The topography and geomorphology of southwest China are complex,and the intensity of human activities not balanced.The impact of climate change and anthropogenic activities on vegetation shows temporal and spatial dif...The topography and geomorphology of southwest China are complex,and the intensity of human activities not balanced.The impact of climate change and anthropogenic activities on vegetation shows temporal and spatial differences.Therefore,we used normalized difference vegetation index(NDVI)to analyze the impact of climate change and anthropogenic activities on vegetation in four provinces and municipality in the southwest China from 2000 to 2015.The results showed that(1)NDVI increased 0.004–0.005/yr during this period.About 57.74%–69.09%of the area with significant changes was found to be primarily affected by anthropogenic activities during all four seasons and the growing season,while 6.05%–10.74%and 5.09%–9.77%of the area was affected by temperature and precipitation,respectively.(2)The impact of temperature and precipitation changes were spatially heterogeneous.Temperature had a positive impact during spring and summer in the northwestern region.Furthermore,NDVI was positively affected in the southwestern and eastern regions,while the western region was negatively affected by precipitation.Summer temperatures and precipitation had the greatest impact throughout the year.(3)Returning farmland to forests and improving agricultural management demonstrated positive impacts of anthropogenic activities on the vegetation,while areas with significant negative impacts due to anthropogenic activities were located near the provincial capitals of the four provinces and municipality.This study can provide a scientific basis for accurately identifying key ecological protection areas in Southwest China.展开更多
Owing to the intensive human activities, the Modaomen Estuary has been significantly modified since 1950s, which has resulted in considerable changes of hydrodynamics and morphodynamics in the area. In this paper, the...Owing to the intensive human activities, the Modaomen Estuary has been significantly modified since 1950s, which has resulted in considerable changes of hydrodynamics and morphodynamics in the area. In this paper, the effects of the anthropogenic activities on the hydrodynamics and morphological evolution in the estuary at different stages are systematically assessed based on the detailed bathymetric data and field survey. The results show that the human activities have caused the channelization of the enclosed sea area in the Modamen Estuary;fast seaward movement of the mouth bar with high siltation;expansion of the channel volume due to channel deepening. The paper also highlights the main hydrodynamic changes in the estuary, including the rise of the water level;the distinguishing changes of tidal range before and after the 1990s (decrease and increase respectively); as well as the increase of the divided flow ratio. It is found that reclamation is the main factor promoting the transition of nature of the estuary from runoff dominant to runoff and wave dominant, and sand mining activities are mainly to strengthen the tidal dynamic and to low the water level. The results provide useful guidance for better planning of the future developments in the estuary and further research in the area.展开更多
Estuarine ecosystem has greatly changed in the recent decades due to anthropogenic perturbations in the Changjiang Estuary. Change patterns and impact factors were analyzed based on the continuous data in relation to ...Estuarine ecosystem has greatly changed in the recent decades due to anthropogenic perturbations in the Changjiang Estuary. Change patterns and impact factors were analyzed based on the continuous data in relation to the Changjiang estuarine ecosystem from 1998 to 2012. The results showed significant decreases in plankton species and annual output of Coilia nasus, Coilia mystus. Furthermore, species and biomass of benthos showed abrupt change in 2003, downward before that and upward after that. It was noted that, Eriocheir sinensis, a high value commercial fish, had an annual production increase of 97%. Reduction of riverine nutrients, especially dissolved silicate (DSI) loads into the estuary could contribute to the decline in BaciUariophyta species. Dredging and dumping works of the North Passage led to the decreases in regional plankton species. However, the species reproduction and releasing projects could restore the estuarine ecosystem through increasing the output of E. sinensis, as well as species and biomass of benthos.展开更多
This research investigates anthropogenic activities influencing flood vulnerability in Ala riverfront residential areas of Akure,Nigeria with a view to identifying area susceptible to flood hazard in the river basin a...This research investigates anthropogenic activities influencing flood vulnerability in Ala riverfront residential areas of Akure,Nigeria with a view to identifying area susceptible to flood hazard in the river basin and to suggest possible mitigation measures.With respect to data gathering for the study,265 questionnaires which amounted to 1%of the research population were administered using simple random sampling.Findings from the survey revealed erection of buildings on riparian land and indiscriminate dumping of wastes into river bodies as factors responsible for the blockage of river channels and waterways.It also exposed resident’s poor dispositions to flood forecasts and non-adherence to other management measures.The study concludes by recommending public enlightenment campaign to reducing denizen’s vulnerability to flood disaster.There is the need for provision of waste management and drainage facilities as well as regular dredging of the watercourse to stimulate its absorptive capacity in the event of heavy downpour.It further suggests creation of artificial lake as natural basin to collect huge volume of water discharged from all watersheds leading to the river.Ultimately,stringent efforts of environmental and town planning officers are needed to enforce total compliance to all intended management regulations to check the menace.展开更多
This study aims to examine the quality and quantity of the groundwater resources from hand-dug wells, within two of these slums—Anoumabo (Marcory) and Adjouffou (Port-Bouet), both located in the southern part of the ...This study aims to examine the quality and quantity of the groundwater resources from hand-dug wells, within two of these slums—Anoumabo (Marcory) and Adjouffou (Port-Bouet), both located in the southern part of the city. Twenty-eight representative groundwater samples were collected from different domestic wells within the study area. In addition, water samples were collected from the adjoining surface water bodies—the ébrié lagoon and the Atlantic Ocean. The water samples were also tested for microbial indicators of fecal contamination using the conventional membrane filtration method. The groundwater samples are alkaline to acidic with pH ranging between 4.4 and 8.1. They are slightly mineralized with electrical conductivity, EC values ranging between 388 μS/cm and 1494 μS/cm. The dominant hydrochemical facies are Na-Cl, Na-SO4, Ca-Cl and Ca-SO4. Although, majority of the water samples have anions and cations concentrations conforming to the World Health Organization, alerting levels of nitrate contamination was recorded in the area. About 67 percent of the tested samples have nitrate values greater than the recommended WHO limit for drinking water (NO3 > 50 mg/ι). Exceeding high nitrate concentrations in drinking water have been medically proven to be detrimental to infant health. Microbial analyses reveal bacterial contamination at varying degrees in all of the water wells. The presence of these microbial organisms in the samples is also indicative of the presence of some other disease causing pathogens, responsible for sicknesses like cholera, diarrhea, typhoid, etc. The water wells located within Anoumabo have relatively higher levels of groundwater contaminants in comparison to those located within Adjouffou. This is obviously due to the poor well designs and prevalent unhygienic and poor sanitary habits of its inhabitants. These waters though completely unsuitable for drinking and domestic purposes, can be used for irrigation purposes with very little or no sodium problems.展开更多
This study deals with the degradation of the quality of the water environment in the village of Abia Koumassi, due to the pollution that has risen in Abidjan. The method used in this study is based on piezometric meas...This study deals with the degradation of the quality of the water environment in the village of Abia Koumassi, due to the pollution that has risen in Abidjan. The method used in this study is based on piezometric measurements, the physico-chemical and microbiological analysis. The results were processed using statistical and hydrochemical methods. The groundwater in the village is shallow, with a piezometric average level 0.55 m. The groundwater flows from the north of the village to the south. The Water resources have a neutral pH that varies between 6.8 and 7.43. Water temperature varies from 27.7°C to 29.8°C. The Water is highly mineralized, with electrical conductivity ranging from 585 μS/cm to 1310 μS/cm. The groundwater contains high levels of nitrate (116.81 mg·L-1) greater than the WHO standard for drinking water. High levels of Metallic Trace Elements (Ni, Zn, Co, Cr, Pb, Fe, Cu and Cd) are found in the water. Microbiological analysis shows that the water contains important levels of Escherichia coli, faecal streptococci, Clostridium perfringens and thermo tolerant coliform. These microorganisms create microbiological pollution in the water from the area. The Water resources of the village are facing a recent faecal pollution of human origin. This pollution comes from anthropogenic activities taking place in the area.展开更多
Large amounts of sediments originating from the Changjiang(Yangtze)River are deposited in the subaqueous delta and in the adjacent muddy area off the mouth and on the inner shelf of the East China Sea.The terrestrial ...Large amounts of sediments originating from the Changjiang(Yangtze)River are deposited in the subaqueous delta and in the adjacent muddy area off the mouth and on the inner shelf of the East China Sea.The terrestrial sediments deposited in these areas not only contain information about the composition and environment of the source area,but they also record changes in anthropogenic activities.A sediment piston core(CJ0702)was extracted from the Changjiang subaqueous depocenter(31.00°N,122.67°E)in a water depth of 22.0 m.The core was subsampled at 1–2 cm intervals and analyzed for grain size,clay mineralogy,and major element geochemistry.Results indicate a relatively high sediment accumulation rate of approximately 3.11 cm yr−1.These parameters exhibited only minor cyclical fluctuations in the core,which resulted from many factors.During the past 120 years,the Changjiang River-derived sediment is the primary source of sediment in the offshore mud area without evidence for the Yellow River-derived sediment increasing.After the trunk stream shifted from the North Branch to South Branch,the variations of proxies are controlled by the periodic fluctuation possibly linked to El Niño-Southern Oscillation(ENSO)and the Pacific Decadal Oscillation(PDO).In addition,anthropogenic heavy metal concentrations can be divided into three stages,which coincide well with economic development and environmental protection policies.展开更多
The coastal wetlands of the Yellow River Delta(YRD)in China are crucial for their valuable resources,environmental significance,and economic contributions.However,these wetlands are also vulnerable to the dual threats...The coastal wetlands of the Yellow River Delta(YRD)in China are crucial for their valuable resources,environmental significance,and economic contributions.However,these wetlands are also vulnerable to the dual threats of climate change and human disturbances.Despite substantial attention to the historical shifts in YRD's coastal wetlands,uncertainties remain regarding their future trajectory in the face of compound risks from climate change and anthropogenic activities.Based on a range of remote sensing data sources,this study undertakes a comprehensive investigation into the evolution of YRD's coastal wetlands between 2000 and 2020.Subsequently,the potential fate of coastal wetlands is thoroughly analyzed through the Land Use/Cover Change(LUCC)simulation using System Dynamic-Future Land Use Simulation(SD-FLUS)model and the extreme water levels projection integrated future sea-level rise,storm surge,and astronomical high tide in 2030,2050,and 2100 under scenarios of SSP1-2.6,SSP2-4.5,and SSP5-8.5.Results revealed that YRD's coastal wetlands underwent a marked reduction,shrinking by 1688.72 km²from 2000 to 2020.This decline was mostly attributed to the substantial expansion in the areas of artificial wetlands(increasing by 823.78 km2),construction land(increasing by 767.71 km²),and shallow water(increasing by 274.58 km²).Looking ahead to 2030-2100,the fate of coastal wetlands appears to diverge based on different scenarios.Under the SSP1-2.6 scenario,the area of coastal wetland is projected to experience considerable growth.In contrast,the SSP5-8.5 scenario anticipates a notable decrease in coastal wetlands.Relative to the inundated area suffered from the current extreme water levels,the study projects a decrease of 6.8%-10.6%in submerged coastal wetlands by 2030 and 9.4%-18.2%by 2050 across all scenarios.In 2100,these percentages are projected to decrease by 0.4%(SSP2-4.5)and 27.1%(SSP5-8.5),but increase by 35.7%(SSP1-2.6).Results suggest that coastal wetlands in the YRD will face a serious compound risk from climate change and intensified human activities in the future,with climate change being the dominant factor.More effcient and forward-looking measures must be implemented to prioritize the conservation and management of coastal wetland ecosystems to address the challenges,especially those posed by climate change.展开更多
Previous studies have confirmed the time-lagged and cumulative effects of drought and anthropogenic activities on vegetation growth,but these studies focus on the time-lagged effect of drought and are poorly known how...Previous studies have confirmed the time-lagged and cumulative effects of drought and anthropogenic activities on vegetation growth,but these studies focus on the time-lagged effect of drought and are poorly known how vegetation productivity responds to anthropogenic activities.Here,based on the reconstructed Normalized Difference Vegetation Index,the Standardized Precipitation Evapotranspiration Index and land use degree comprehensive index,we diagnosed the spatiotemporal pattern of vegetation and drought,investigated time-lagged and cumulative effects of drought and anthropogenic activities over China through the month where the maximum correlation coefficient occurred.It revealed that the browning trend of 32.21%of vegetated lands was covered by overall greening,especially northwestern China.Drought intensified with a rate of 0.0014/year.in 66.41%and 54.57%of the vegetated lands had time-lagged and cumulative response to drought,with a shorter timescales of 1–4 months,indicating the higher sensitivity of vegetation growth to drought.There was a U-shaped relationship between moisture conditions and vegetation response time.49.9%of China’s vegetation showed time-lagged effects to anthropogenic activities,with a longer timescales of 6–10 years,demonstrating that anthropogenic activities triggered ecological changes but vegetation ecosystems cannot keep pace.The accumulated and time-lagged years declined with increased land use intensity.展开更多
Previous studies on environmental antibiotics resistance genes(ARGs) have focused on the pollution sources such as wastewater treatment plants, aquaculture and livestock farms,etc. Few of them had addressed this iss...Previous studies on environmental antibiotics resistance genes(ARGs) have focused on the pollution sources such as wastewater treatment plants, aquaculture and livestock farms,etc. Few of them had addressed this issue in a regional scale such as river catchment. Hence,the occurrence and abundances of 23 ARGs were investigated in surface water samples collected from 38 sites which located from the river source to estuary of the Beijiang River.Among them, 11 ARGs were frequently detected in this region and 5 ARGs(sul Ⅰ, sul Ⅱ, tet B,tet C, and tet W) were selected for their distribution pattern analysis. The abundances of the selected ARGs were higher in the upstream(8.70 × 10^6 copies/ng DNA) and downstream areas(3.17 × 10^6 copies/ng DNA) than those in the midstream areas(1.23 × 10^6 copies/ng DNA), which was positively correlated to the population density and number of pollution sources. Pollution sources of ARGs along the Beijiang River not only had a great impact on the abundances and diversity, but also on the distribution of specific ARGs in the water samples. Both sul Ⅰ and sul Ⅱ were likely originated from aquaculture farms and animal farms,tet W gene was possibly associated with the mining/metal melting industry and the electric waste disposal and tet C gene was commonly found in the area with multiple pollution sources.However, the abundance of tet B was not particularly related to anthropogenic impacts. These findings highlight the influence of pollution sources and density of population on the distribution and dissemination of ARGs at a regional scale.展开更多
As ecologically fragile areas,coastal zones are affected by both anthropogenic activities and climate change.However,the impacts of these factors on large nearshore mammals,such as Indo-Pacific humpback dolphins(IPHDs...As ecologically fragile areas,coastal zones are affected by both anthropogenic activities and climate change.However,the impacts of these factors on large nearshore mammals,such as Indo-Pacific humpback dolphins(IPHDs,Sousa chinensis),are poorly understood.Here,modeling revealed that the suitable habitats of IPHDs are affected mainly by the sea surface temperature(SST),and the habitat suitability decreases as the distance to the nearest coastline increases.In addition,anthropogenic activities involving demersal fishing,contamination and shipping have narrowed IPHD habitats and reduced the habitat suitability.We found that climate change will further narrow suitable habitats located farther than 7 km from coastlines and trigger habitat losses in the eastern Taiwan Strait by 2090-2100 under the Representative Concentration Pathway(RCP)8.5 scenario.The projected decreases in habitat suitability and area emphasize the urgency of establishing connected marine protected areas(MPAs)while considering climate change,intergovernmental cooperation,and public involvement.展开更多
Marine spatial planning(MSP)is designed to divide the sea area into different types of functional zones,to implement corresponding development activities.However,the long-term impacts of anthropogenic activities assoc...Marine spatial planning(MSP)is designed to divide the sea area into different types of functional zones,to implement corresponding development activities.However,the long-term impacts of anthropogenic activities associated with MSP practice on the marine microbial biosphere are still unclear.Yalu River Estuary,a coastal region in northeast of China,has been divided into fishery&agricultural(F&A)zone,shipping&port(S&P)zone and marine protected area(MPA)zone by a local MSP guideline that has been run for decades.To examine the effects of long-term executed MSP,benthic bacterial communities from different MSP zones were obtained and compared in this study.The results revealed significant differences in the bacterial community structure and predict functions among different zones.Bacterial genera enriched in different zones were identified,including SBR1031 in MPA,Woeseia and Sva0996 in S&P,and Halioglobus in F&A.In addition,correlations between some bacterial genera and sediment pollutants were uncovered.Furthermore,bacteria related to sulphide production were more abundant in the F&A zone,which was according to the accumulation of sulphides in this area.Moreover,bacteria associated with chemoheterotrophy and fermentation were more predominant in the S&P zone,consistent with high levels of organic matter and petroleum caused by shipping.Our findings indicated benthic bacterial communities could bring to light the anthropogenic activity footprints by different activities induced by long-term MSP practice.展开更多
Understanding trends of land use land cover (LULC) changes is important for biodiversity monitoring and conservation planning, and identifying the areas affected by change and designing sustainable solutions to reduce...Understanding trends of land use land cover (LULC) changes is important for biodiversity monitoring and conservation planning, and identifying the areas affected by change and designing sustainable solutions to reduce the changes. The study aims to evaluate and quantify the historical changes in land use and land cover in Mukumbura (Ward 2), Mt Darwin, Zimbabwe, from 2002 to 2022. The objective of the study was to analyse the LULC changes in Ward 2 (Mukumbura), Mt Darwin, Northern Zimbabwe, for a period of 20 years using geospatial techniques. Landsat satellite images were processed using Google Earth Engine (GEE) and the supervised classification with maximum likelihood algorithm was employed to generate LULC maps between 2002 and 2022 with a five (5) year interval, investigating the following variables, forest cover, barren land, water cover and the fields. Findings revealed a substantial reduction in forest cover by 38.8%, water bodies (wetlands, ponds, and rivers) declined by 55.6%, whilst fields (crop/agricultural fields) increased by 93.3% and the barren land cover increased by 26.3% from 2002 to 2022. These findings point to substantial changes in LULC over the observed years. LULC changes have resulted in habitat fragmentation, reduced biodiversity, and the disruption of ecosystem functions. The study concludes that if these deforestation trends, cultivation, and settlement land expansion continue, the ward will have limited indigenous fruit trees. Therefore, the causes for LULC changes must be controlled, sustainable forest resources use practiced, hence the need to domesticate the indigenous fruit trees in arborloo toilets.展开更多
Surface water bodies are progressively subjected to stress as a result of anthropogenic activities. This study assessed and examined the impact of human activities on spatial variation in the water quality of 19 river...Surface water bodies are progressively subjected to stress as a result of anthropogenic activities. This study assessed and examined the impact of human activities on spatial variation in the water quality of 19 rivers in the Taihu watershed. Concentrations of physicochemical parameters of surface water quality were determined at the mouth of each river during the period of 2000-2004. Multivariate statistical techniques were applied to identify characteristics of the water quality in the studied rivers. The results showed that rivers strongly influenced by household wastewater have the highest concentrations of nutrients (TN and TP). Moreover, rivers in the vicinity of a metropolis presented low dissolved oxygen (DO) levels. However, organic-chemical pollution (petroleum and volatile phenolics) was identified with high localization. Two rivers influenced by sewage from industry and ships were distinguished from other rivers with high values of petroleum. The Taige channel, a river located in Changzhou City that is strongly influenced by wastewater from industry, was characterized with an extraordinarily high value of volatile phenolics. Rivers passing through countries, especially through hilly countries were characterized with high DO contents and low nutrient and organic-chemical pollution, suggesting that agriculture puts less pressure on water quality in adjacent rivers. Therefore, more effort should be made in controlling point pollution to restore water quality in rivers adjacent to cities.展开更多
A thorough understanding of the vegetation succession in relation to both climatic changes and anthropogenic activities is vital for the formulation of adaptation strategies that address potential ecosystem challenges...A thorough understanding of the vegetation succession in relation to both climatic changes and anthropogenic activities is vital for the formulation of adaptation strategies that address potential ecosystem challenges.Various climatic factors such as temperature,precipitation,and solar radiation,as well as anthropogenic factors such as ecological engineering and population migration,will affect the conditions for vegetation.However,the relationships among various factors remain unclear and the response of vegetation to climate change and anthropogenic activities in the Loess Plateau of China has not been well established.This study investigated the spatio-temporal characteristics and relationships between vegetation coverage and climatic factors in the Loess Plateau for the period of 1985–2015.Further analysis separated the anthropogenic and climatic factors on vegetation succession based on residual analysis.The results showed that the normalized difference vegetation index(NDVI)followed a significant upward trend with annual change rates of 0.15%during 1985–2015.The trend of human-induced NDVI increase was consistent with the spatial distribution of increasing forest areas in the eastern part of the Loess Plateau.Eco-restoration projects were the main driving factors that promoted vegetation coverage on the Loess Plateau.Furthermore,these results demonstrated that migrants to cities in the Loess Plateau could relieve ecological pressures and promote vegetation restoration.Therefore,the government should strive to increase population mobility and restore vegetation to sustain this particularly fragile ecological environment.展开更多
A wide range of anthropogenic activities impacts estuarine and coastal marine environments including interactive climate and non-climatic drivers of change that can significantly degrade biotic communities and habitat...A wide range of anthropogenic activities impacts estuarine and coastal marine environments including interactive climate and non-climatic drivers of change that can significantly degrade biotic communities and habitats. Many of these environments are in decline due to changes in ecosystem structure and function resulting from multiple stressor effects. In addition, inadequate governance has supported a patchwork of single issues or sectoral approaches rather than integrated management of multiple human uses and activities to maintain healthy, productive, resilient, and sustainable ecosystems and the provision of goods and services. Ecosystem-based marine spatial planning is a viable framework for a more effective governance structure and management of these vital coastal environments. An important component of this approach is a holistic effort to assess the environmental, economic, and societal impacts of anthropogenic activities. Thus, a multidisciplinary integrated approach is preferred that links ecological, physical, and socio-economic systems, increasing the protection of resources and societal benefits. For degraded estuarine and coastal marine ecosystems, restoration and rehabilitation initiatives are important intervention strategies used to reverse the loss of habitats and biotic resources and to support management programs. Marine Protected Areas (MPAs) are an integral element of marine management plans to conserve and sustain estuarine and coastal marine environments by protecting threatened ecosystems and their resources from anthropogenic activities. National and international regulatory frameworks and directives are also in place to protect and conserve these environments.展开更多
A survey on the hyperbenthic communities was carried out in the coastal waters of Sishili Bay in the Yellow Sea in July 2009,to investigate the impact of putative anthropogenic activities related to the presence of a ...A survey on the hyperbenthic communities was carried out in the coastal waters of Sishili Bay in the Yellow Sea in July 2009,to investigate the impact of putative anthropogenic activities related to the presence of a sewage outfall,a harbor and an aquaculture site on the benthic ecosystem.An Agassiz net trawl was used to collect hyperbenthos at 10 sampling stations.Species,diversity,abundance,and biomass were analyzed against water sample data and historical data obtained from records from nearby Yantai City.Fifty-two species were identified in the region,of which Crustacea were the most abundant taxon,followed by Echinodermata.Dominant species included five crustaceans,two echinoderms,one mollusk and one fish species.The results of a BIOENV analysis show that the concentrations of NO3-N and Chl-a were slightly positively correlated with hyperbenthic community structure,while other factors were negatively correlated,including sediment grain size and the percentage of TN and TOC in sediment.Abundance- Biomass Comparison(ABC method) curves indicate that the hyperbenthos in Sishili Bay had been disturbed by putative sources of human activities.Eight out of 10 stations were classified as "moderately perturbed" to "perturbed".展开更多
Climate change in the Arctic region is more rapid than that in other areas owing to Arctic amplification. To better understand climate change and the driving mechanisms, long-term historical reconstructions throughout...Climate change in the Arctic region is more rapid than that in other areas owing to Arctic amplification. To better understand climate change and the driving mechanisms, long-term historical reconstructions throughout the Holocene and high-resolution records of the past few hundred years are required. Intense anthropogenic activities in the Arctic have had a great impact on the local environment. Here, we review the Holocene climate change record, responses of the ecosystems to climate change, and the anthropogenic impacts on the environment based mainly on Chinese research from Ny-Alesund. Climate reconstruction studies from Svalbard have revealed several cold episodes during the Holocene, which are consistent with ice rafting events in the North Atlantic region and glacier activity from Greenland, Iceland, and Svalbard. The ecosystem also showed corresponding responses to climate change, especially during the late Holocene. Over recent decades, anthropogenic activities have caused serious pollution and deterioration to the local environment in Svalbard in areas frequented by people. Greater environmental protection is therefore needed to reduce the anthropogenic impacts on the local environment.展开更多
基金funded by the Second Tibetan Plateau Scientific Expedition and Research program(2019QZKK0301)the Natural Science Foundation of Xizang Autonomous Region(XZ202301ZR0027G).
文摘Whether climate change or anthropogenic activities play a more pivotal role in regulating vegetation growth on the Tibetan Plateau is still controversial.A better understanding on grassland changes at a fine scale may provide important guidance for local government policy and grassland management.Using two of the most reliable satellite NDVI products(MODIS NDVI and SPOT NDVI),we evaluated the dynamic of grasslands in the Zhegucuo valley on the southern Tibetan Plateau from 2000 to 2020,and analyzed its driving factors and relative influences of climate change and anthropogenic activities.Here,the key indicators of climate change were assumed to be precipitation and temperature.The main results were:(1)the grassland NDVI in Zhegucuo valley did not reflect a significant temporal change during the last 21 years.The variation of precipitation during the early growing season(GSP)resembled that of NDVI,and the GSP was positively correlated with NDVI.At the pixel level,the partial correlation analysis showed that 37.79%of the pixels depicted a positive relationship between GSP and NDVI,while 11.32%of the pixels showed a negative relationship between temperature during the early growing season(GST)and NDVI.(2)In view of the spatial distribution,the areas mainly controlled by GSP were generally distributed in the southern part,while those affected by GST stood in the eastern part,mainly around the Zhegucuo lake where most population in Cuomei County settled down.(3)Decreasing NDVI trends were mainly occurred in alpine steppe at lower elevations rather than alpine meadow at higher elevations.(4)The residual trend(RESTREND)analysis further indicated that the anthropogenic activities played a more pivotal role in regulating the annual changes of NDVI rather than climate factors in this area.Future studies should pay more attention on climate extremes rather than the simple temporal trends.Also,the influence of human activities on alpine grassland needs to be accessed and fully considered in future sustainable management.
文摘Living fishery resources, although rich and important for human populations, are subject to strong anthropization, thus causing a change in the environmental parameters of aquatic ecosystems. These multiple combined pressures: chemical, hydro-morphological, thermal or trophic, affect and disrupt the functioning of aquatic organisms. The objective of this study was to assess the main human pressures influencing the surface water resources of the Kamsar sub-prefecture, in order to propose mitigation measures. The following methodological approach was adopted: 1) Survey of managers and analysis records;2) Survey of stakeholders;3) Assessment of the effect of human activities on surface water resources;4) Data processing;5) Corrective measures. The survey farmers working near aquatic environments, revealed a low use of chemical substances, in particular 3 to 11 kg of fertilizer and 0 to 3 boxes of herbicide on fields of 40 m2 to 2 ha. Some physico-chemical parameters have been determined: Temperature (28.5˚C, 23.7˚C, 22.8˚C, 21.3˚C, 21.6˚C), Salinity (26.9‰, 21.9‰, 21.5‰, 15‰, 15.3‰) and Turbidity (21.3 UTN, 19.3 UTN, 17.8 UTN, 16.7 UTN, 17 UTN). These values show a fluctuation in the environmental parameters of aquatic ecosystems, which constitutes an obstacle to the development and survival of the resources.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA23090501)The Second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0307)。
文摘The topography and geomorphology of southwest China are complex,and the intensity of human activities not balanced.The impact of climate change and anthropogenic activities on vegetation shows temporal and spatial differences.Therefore,we used normalized difference vegetation index(NDVI)to analyze the impact of climate change and anthropogenic activities on vegetation in four provinces and municipality in the southwest China from 2000 to 2015.The results showed that(1)NDVI increased 0.004–0.005/yr during this period.About 57.74%–69.09%of the area with significant changes was found to be primarily affected by anthropogenic activities during all four seasons and the growing season,while 6.05%–10.74%and 5.09%–9.77%of the area was affected by temperature and precipitation,respectively.(2)The impact of temperature and precipitation changes were spatially heterogeneous.Temperature had a positive impact during spring and summer in the northwestern region.Furthermore,NDVI was positively affected in the southwestern and eastern regions,while the western region was negatively affected by precipitation.Summer temperatures and precipitation had the greatest impact throughout the year.(3)Returning farmland to forests and improving agricultural management demonstrated positive impacts of anthropogenic activities on the vegetation,while areas with significant negative impacts due to anthropogenic activities were located near the provincial capitals of the four provinces and municipality.This study can provide a scientific basis for accurately identifying key ecological protection areas in Southwest China.
基金funded by the Program of International S&T Cooperation(Grant No.2010DFA24470)the Non-profitable Special Scientific Research Project from the Ministry of Water Resources,China(Grant No.200901034–01)
文摘Owing to the intensive human activities, the Modaomen Estuary has been significantly modified since 1950s, which has resulted in considerable changes of hydrodynamics and morphodynamics in the area. In this paper, the effects of the anthropogenic activities on the hydrodynamics and morphological evolution in the estuary at different stages are systematically assessed based on the detailed bathymetric data and field survey. The results show that the human activities have caused the channelization of the enclosed sea area in the Modamen Estuary;fast seaward movement of the mouth bar with high siltation;expansion of the channel volume due to channel deepening. The paper also highlights the main hydrodynamic changes in the estuary, including the rise of the water level;the distinguishing changes of tidal range before and after the 1990s (decrease and increase respectively); as well as the increase of the divided flow ratio. It is found that reclamation is the main factor promoting the transition of nature of the estuary from runoff dominant to runoff and wave dominant, and sand mining activities are mainly to strengthen the tidal dynamic and to low the water level. The results provide useful guidance for better planning of the future developments in the estuary and further research in the area.
基金The Funds for Ministry of Science and Technology of China(SKLEC)the National Natural Science Foundation of China under contact Nos 41076050 and 48505350New Century Excellent Talents in University of China under contract No.NCET-12-0182
文摘Estuarine ecosystem has greatly changed in the recent decades due to anthropogenic perturbations in the Changjiang Estuary. Change patterns and impact factors were analyzed based on the continuous data in relation to the Changjiang estuarine ecosystem from 1998 to 2012. The results showed significant decreases in plankton species and annual output of Coilia nasus, Coilia mystus. Furthermore, species and biomass of benthos showed abrupt change in 2003, downward before that and upward after that. It was noted that, Eriocheir sinensis, a high value commercial fish, had an annual production increase of 97%. Reduction of riverine nutrients, especially dissolved silicate (DSI) loads into the estuary could contribute to the decline in BaciUariophyta species. Dredging and dumping works of the North Passage led to the decreases in regional plankton species. However, the species reproduction and releasing projects could restore the estuarine ecosystem through increasing the output of E. sinensis, as well as species and biomass of benthos.
文摘This research investigates anthropogenic activities influencing flood vulnerability in Ala riverfront residential areas of Akure,Nigeria with a view to identifying area susceptible to flood hazard in the river basin and to suggest possible mitigation measures.With respect to data gathering for the study,265 questionnaires which amounted to 1%of the research population were administered using simple random sampling.Findings from the survey revealed erection of buildings on riparian land and indiscriminate dumping of wastes into river bodies as factors responsible for the blockage of river channels and waterways.It also exposed resident’s poor dispositions to flood forecasts and non-adherence to other management measures.The study concludes by recommending public enlightenment campaign to reducing denizen’s vulnerability to flood disaster.There is the need for provision of waste management and drainage facilities as well as regular dredging of the watercourse to stimulate its absorptive capacity in the event of heavy downpour.It further suggests creation of artificial lake as natural basin to collect huge volume of water discharged from all watersheds leading to the river.Ultimately,stringent efforts of environmental and town planning officers are needed to enforce total compliance to all intended management regulations to check the menace.
文摘This study aims to examine the quality and quantity of the groundwater resources from hand-dug wells, within two of these slums—Anoumabo (Marcory) and Adjouffou (Port-Bouet), both located in the southern part of the city. Twenty-eight representative groundwater samples were collected from different domestic wells within the study area. In addition, water samples were collected from the adjoining surface water bodies—the ébrié lagoon and the Atlantic Ocean. The water samples were also tested for microbial indicators of fecal contamination using the conventional membrane filtration method. The groundwater samples are alkaline to acidic with pH ranging between 4.4 and 8.1. They are slightly mineralized with electrical conductivity, EC values ranging between 388 μS/cm and 1494 μS/cm. The dominant hydrochemical facies are Na-Cl, Na-SO4, Ca-Cl and Ca-SO4. Although, majority of the water samples have anions and cations concentrations conforming to the World Health Organization, alerting levels of nitrate contamination was recorded in the area. About 67 percent of the tested samples have nitrate values greater than the recommended WHO limit for drinking water (NO3 > 50 mg/ι). Exceeding high nitrate concentrations in drinking water have been medically proven to be detrimental to infant health. Microbial analyses reveal bacterial contamination at varying degrees in all of the water wells. The presence of these microbial organisms in the samples is also indicative of the presence of some other disease causing pathogens, responsible for sicknesses like cholera, diarrhea, typhoid, etc. The water wells located within Anoumabo have relatively higher levels of groundwater contaminants in comparison to those located within Adjouffou. This is obviously due to the poor well designs and prevalent unhygienic and poor sanitary habits of its inhabitants. These waters though completely unsuitable for drinking and domestic purposes, can be used for irrigation purposes with very little or no sodium problems.
文摘This study deals with the degradation of the quality of the water environment in the village of Abia Koumassi, due to the pollution that has risen in Abidjan. The method used in this study is based on piezometric measurements, the physico-chemical and microbiological analysis. The results were processed using statistical and hydrochemical methods. The groundwater in the village is shallow, with a piezometric average level 0.55 m. The groundwater flows from the north of the village to the south. The Water resources have a neutral pH that varies between 6.8 and 7.43. Water temperature varies from 27.7°C to 29.8°C. The Water is highly mineralized, with electrical conductivity ranging from 585 μS/cm to 1310 μS/cm. The groundwater contains high levels of nitrate (116.81 mg·L-1) greater than the WHO standard for drinking water. High levels of Metallic Trace Elements (Ni, Zn, Co, Cr, Pb, Fe, Cu and Cd) are found in the water. Microbiological analysis shows that the water contains important levels of Escherichia coli, faecal streptococci, Clostridium perfringens and thermo tolerant coliform. These microorganisms create microbiological pollution in the water from the area. The Water resources of the village are facing a recent faecal pollution of human origin. This pollution comes from anthropogenic activities taking place in the area.
基金the National Natural Science Foundation of China(Nos.41676052 and 41206073)the State Scholarship Fund sponsored by China Scholarship Council(No.201609370007)the China Geological Survey(Nos.DD20190236,DD20160137,and DD20190205).
文摘Large amounts of sediments originating from the Changjiang(Yangtze)River are deposited in the subaqueous delta and in the adjacent muddy area off the mouth and on the inner shelf of the East China Sea.The terrestrial sediments deposited in these areas not only contain information about the composition and environment of the source area,but they also record changes in anthropogenic activities.A sediment piston core(CJ0702)was extracted from the Changjiang subaqueous depocenter(31.00°N,122.67°E)in a water depth of 22.0 m.The core was subsampled at 1–2 cm intervals and analyzed for grain size,clay mineralogy,and major element geochemistry.Results indicate a relatively high sediment accumulation rate of approximately 3.11 cm yr−1.These parameters exhibited only minor cyclical fluctuations in the core,which resulted from many factors.During the past 120 years,the Changjiang River-derived sediment is the primary source of sediment in the offshore mud area without evidence for the Yellow River-derived sediment increasing.After the trunk stream shifted from the North Branch to South Branch,the variations of proxies are controlled by the periodic fluctuation possibly linked to El Niño-Southern Oscillation(ENSO)and the Pacific Decadal Oscillation(PDO).In addition,anthropogenic heavy metal concentrations can be divided into three stages,which coincide well with economic development and environmental protection policies.
基金support from the National Natural Science Foundation of China (41901133,41901016,41975100)Seed project of Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences (YICE351030601)+1 种基金Special Project for Compilation of the Fourth National Assessment Report on Climate Change of the Ministry of Science and Technology (210YBXM201810-8002)Youth Open Project of China Meteorological Administration Key Laboratory for Climate Prediction Studies (CMA-LCPS-23-04).
文摘The coastal wetlands of the Yellow River Delta(YRD)in China are crucial for their valuable resources,environmental significance,and economic contributions.However,these wetlands are also vulnerable to the dual threats of climate change and human disturbances.Despite substantial attention to the historical shifts in YRD's coastal wetlands,uncertainties remain regarding their future trajectory in the face of compound risks from climate change and anthropogenic activities.Based on a range of remote sensing data sources,this study undertakes a comprehensive investigation into the evolution of YRD's coastal wetlands between 2000 and 2020.Subsequently,the potential fate of coastal wetlands is thoroughly analyzed through the Land Use/Cover Change(LUCC)simulation using System Dynamic-Future Land Use Simulation(SD-FLUS)model and the extreme water levels projection integrated future sea-level rise,storm surge,and astronomical high tide in 2030,2050,and 2100 under scenarios of SSP1-2.6,SSP2-4.5,and SSP5-8.5.Results revealed that YRD's coastal wetlands underwent a marked reduction,shrinking by 1688.72 km²from 2000 to 2020.This decline was mostly attributed to the substantial expansion in the areas of artificial wetlands(increasing by 823.78 km2),construction land(increasing by 767.71 km²),and shallow water(increasing by 274.58 km²).Looking ahead to 2030-2100,the fate of coastal wetlands appears to diverge based on different scenarios.Under the SSP1-2.6 scenario,the area of coastal wetland is projected to experience considerable growth.In contrast,the SSP5-8.5 scenario anticipates a notable decrease in coastal wetlands.Relative to the inundated area suffered from the current extreme water levels,the study projects a decrease of 6.8%-10.6%in submerged coastal wetlands by 2030 and 9.4%-18.2%by 2050 across all scenarios.In 2100,these percentages are projected to decrease by 0.4%(SSP2-4.5)and 27.1%(SSP5-8.5),but increase by 35.7%(SSP1-2.6).Results suggest that coastal wetlands in the YRD will face a serious compound risk from climate change and intensified human activities in the future,with climate change being the dominant factor.More effcient and forward-looking measures must be implemented to prioritize the conservation and management of coastal wetland ecosystems to address the challenges,especially those posed by climate change.
基金supported by the National Natural Science Foundation of China program(No.42001090)the Special Fund Projects of Central Government Guiding Local Science and Technology Development(No.Guike ZY20198012).
文摘Previous studies have confirmed the time-lagged and cumulative effects of drought and anthropogenic activities on vegetation growth,but these studies focus on the time-lagged effect of drought and are poorly known how vegetation productivity responds to anthropogenic activities.Here,based on the reconstructed Normalized Difference Vegetation Index,the Standardized Precipitation Evapotranspiration Index and land use degree comprehensive index,we diagnosed the spatiotemporal pattern of vegetation and drought,investigated time-lagged and cumulative effects of drought and anthropogenic activities over China through the month where the maximum correlation coefficient occurred.It revealed that the browning trend of 32.21%of vegetated lands was covered by overall greening,especially northwestern China.Drought intensified with a rate of 0.0014/year.in 66.41%and 54.57%of the vegetated lands had time-lagged and cumulative response to drought,with a shorter timescales of 1–4 months,indicating the higher sensitivity of vegetation growth to drought.There was a U-shaped relationship between moisture conditions and vegetation response time.49.9%of China’s vegetation showed time-lagged effects to anthropogenic activities,with a longer timescales of 6–10 years,demonstrating that anthropogenic activities triggered ecological changes but vegetation ecosystems cannot keep pace.The accumulated and time-lagged years declined with increased land use intensity.
基金supported by the National Natural Science Foundation of China(Nos.21177162 and 51579253)the Commodity Inspection and Quarantine in Nanhai,Foshan,for their assistance in the determinations of antibiotics in this project
文摘Previous studies on environmental antibiotics resistance genes(ARGs) have focused on the pollution sources such as wastewater treatment plants, aquaculture and livestock farms,etc. Few of them had addressed this issue in a regional scale such as river catchment. Hence,the occurrence and abundances of 23 ARGs were investigated in surface water samples collected from 38 sites which located from the river source to estuary of the Beijiang River.Among them, 11 ARGs were frequently detected in this region and 5 ARGs(sul Ⅰ, sul Ⅱ, tet B,tet C, and tet W) were selected for their distribution pattern analysis. The abundances of the selected ARGs were higher in the upstream(8.70 × 10^6 copies/ng DNA) and downstream areas(3.17 × 10^6 copies/ng DNA) than those in the midstream areas(1.23 × 10^6 copies/ng DNA), which was positively correlated to the population density and number of pollution sources. Pollution sources of ARGs along the Beijiang River not only had a great impact on the abundances and diversity, but also on the distribution of specific ARGs in the water samples. Both sul Ⅰ and sul Ⅱ were likely originated from aquaculture farms and animal farms,tet W gene was possibly associated with the mining/metal melting industry and the electric waste disposal and tet C gene was commonly found in the area with multiple pollution sources.However, the abundance of tet B was not particularly related to anthropogenic impacts. These findings highlight the influence of pollution sources and density of population on the distribution and dissemination of ARGs at a regional scale.
基金This work was supported by the National Natural Science Founda-tion of China(NSFC)(Grant No.41901349)Marine Economy Develop-ment Foundation of Guangdong Province(Grant No.GDNRC[2022]21)+1 种基金Basic Scientific Research Program of National Nonprofit Research Insti-tutes(Grant No.ZX2022QT025)the Startup Foundation for Tal-ented Scholars in South China Normal University(Grant No.8S0472).
文摘As ecologically fragile areas,coastal zones are affected by both anthropogenic activities and climate change.However,the impacts of these factors on large nearshore mammals,such as Indo-Pacific humpback dolphins(IPHDs,Sousa chinensis),are poorly understood.Here,modeling revealed that the suitable habitats of IPHDs are affected mainly by the sea surface temperature(SST),and the habitat suitability decreases as the distance to the nearest coastline increases.In addition,anthropogenic activities involving demersal fishing,contamination and shipping have narrowed IPHD habitats and reduced the habitat suitability.We found that climate change will further narrow suitable habitats located farther than 7 km from coastlines and trigger habitat losses in the eastern Taiwan Strait by 2090-2100 under the Representative Concentration Pathway(RCP)8.5 scenario.The projected decreases in habitat suitability and area emphasize the urgency of establishing connected marine protected areas(MPAs)while considering climate change,intergovernmental cooperation,and public involvement.
基金The National Key Research and Development Program of China under contract No.2020 YFA0607600。
文摘Marine spatial planning(MSP)is designed to divide the sea area into different types of functional zones,to implement corresponding development activities.However,the long-term impacts of anthropogenic activities associated with MSP practice on the marine microbial biosphere are still unclear.Yalu River Estuary,a coastal region in northeast of China,has been divided into fishery&agricultural(F&A)zone,shipping&port(S&P)zone and marine protected area(MPA)zone by a local MSP guideline that has been run for decades.To examine the effects of long-term executed MSP,benthic bacterial communities from different MSP zones were obtained and compared in this study.The results revealed significant differences in the bacterial community structure and predict functions among different zones.Bacterial genera enriched in different zones were identified,including SBR1031 in MPA,Woeseia and Sva0996 in S&P,and Halioglobus in F&A.In addition,correlations between some bacterial genera and sediment pollutants were uncovered.Furthermore,bacteria related to sulphide production were more abundant in the F&A zone,which was according to the accumulation of sulphides in this area.Moreover,bacteria associated with chemoheterotrophy and fermentation were more predominant in the S&P zone,consistent with high levels of organic matter and petroleum caused by shipping.Our findings indicated benthic bacterial communities could bring to light the anthropogenic activity footprints by different activities induced by long-term MSP practice.
文摘Understanding trends of land use land cover (LULC) changes is important for biodiversity monitoring and conservation planning, and identifying the areas affected by change and designing sustainable solutions to reduce the changes. The study aims to evaluate and quantify the historical changes in land use and land cover in Mukumbura (Ward 2), Mt Darwin, Zimbabwe, from 2002 to 2022. The objective of the study was to analyse the LULC changes in Ward 2 (Mukumbura), Mt Darwin, Northern Zimbabwe, for a period of 20 years using geospatial techniques. Landsat satellite images were processed using Google Earth Engine (GEE) and the supervised classification with maximum likelihood algorithm was employed to generate LULC maps between 2002 and 2022 with a five (5) year interval, investigating the following variables, forest cover, barren land, water cover and the fields. Findings revealed a substantial reduction in forest cover by 38.8%, water bodies (wetlands, ponds, and rivers) declined by 55.6%, whilst fields (crop/agricultural fields) increased by 93.3% and the barren land cover increased by 26.3% from 2002 to 2022. These findings point to substantial changes in LULC over the observed years. LULC changes have resulted in habitat fragmentation, reduced biodiversity, and the disruption of ecosystem functions. The study concludes that if these deforestation trends, cultivation, and settlement land expansion continue, the ward will have limited indigenous fruit trees. Therefore, the causes for LULC changes must be controlled, sustainable forest resources use practiced, hence the need to domesticate the indigenous fruit trees in arborloo toilets.
基金Project supported by the International Project between The Netherlands Royal Academy of Arts and Sciences and Chinese Academy of Sciences (No. 04CDP014) the National Natural Science Foundation of China (No. 40471130).
文摘Surface water bodies are progressively subjected to stress as a result of anthropogenic activities. This study assessed and examined the impact of human activities on spatial variation in the water quality of 19 rivers in the Taihu watershed. Concentrations of physicochemical parameters of surface water quality were determined at the mouth of each river during the period of 2000-2004. Multivariate statistical techniques were applied to identify characteristics of the water quality in the studied rivers. The results showed that rivers strongly influenced by household wastewater have the highest concentrations of nutrients (TN and TP). Moreover, rivers in the vicinity of a metropolis presented low dissolved oxygen (DO) levels. However, organic-chemical pollution (petroleum and volatile phenolics) was identified with high localization. Two rivers influenced by sewage from industry and ships were distinguished from other rivers with high values of petroleum. The Taige channel, a river located in Changzhou City that is strongly influenced by wastewater from industry, was characterized with an extraordinarily high value of volatile phenolics. Rivers passing through countries, especially through hilly countries were characterized with high DO contents and low nutrient and organic-chemical pollution, suggesting that agriculture puts less pressure on water quality in adjacent rivers. Therefore, more effort should be made in controlling point pollution to restore water quality in rivers adjacent to cities.
基金Under the auspices of the National Key Research and Development Program of China(No.2017YFC0504701)National Natural Science Foundation of China(No.41971220,41701119,41471143)National Social Science Foundation of China(No.15ZDA021)
文摘A thorough understanding of the vegetation succession in relation to both climatic changes and anthropogenic activities is vital for the formulation of adaptation strategies that address potential ecosystem challenges.Various climatic factors such as temperature,precipitation,and solar radiation,as well as anthropogenic factors such as ecological engineering and population migration,will affect the conditions for vegetation.However,the relationships among various factors remain unclear and the response of vegetation to climate change and anthropogenic activities in the Loess Plateau of China has not been well established.This study investigated the spatio-temporal characteristics and relationships between vegetation coverage and climatic factors in the Loess Plateau for the period of 1985–2015.Further analysis separated the anthropogenic and climatic factors on vegetation succession based on residual analysis.The results showed that the normalized difference vegetation index(NDVI)followed a significant upward trend with annual change rates of 0.15%during 1985–2015.The trend of human-induced NDVI increase was consistent with the spatial distribution of increasing forest areas in the eastern part of the Loess Plateau.Eco-restoration projects were the main driving factors that promoted vegetation coverage on the Loess Plateau.Furthermore,these results demonstrated that migrants to cities in the Loess Plateau could relieve ecological pressures and promote vegetation restoration.Therefore,the government should strive to increase population mobility and restore vegetation to sustain this particularly fragile ecological environment.
文摘A wide range of anthropogenic activities impacts estuarine and coastal marine environments including interactive climate and non-climatic drivers of change that can significantly degrade biotic communities and habitats. Many of these environments are in decline due to changes in ecosystem structure and function resulting from multiple stressor effects. In addition, inadequate governance has supported a patchwork of single issues or sectoral approaches rather than integrated management of multiple human uses and activities to maintain healthy, productive, resilient, and sustainable ecosystems and the provision of goods and services. Ecosystem-based marine spatial planning is a viable framework for a more effective governance structure and management of these vital coastal environments. An important component of this approach is a holistic effort to assess the environmental, economic, and societal impacts of anthropogenic activities. Thus, a multidisciplinary integrated approach is preferred that links ecological, physical, and socio-economic systems, increasing the protection of resources and societal benefits. For degraded estuarine and coastal marine ecosystems, restoration and rehabilitation initiatives are important intervention strategies used to reverse the loss of habitats and biotic resources and to support management programs. Marine Protected Areas (MPAs) are an integral element of marine management plans to conserve and sustain estuarine and coastal marine environments by protecting threatened ecosystems and their resources from anthropogenic activities. National and international regulatory frameworks and directives are also in place to protect and conserve these environments.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-YW-Q07-04)the National Natural Science Foundation of China(No.NSFC41061130543)the Science and Technology Planning Project of Shandong Province(No.2011GGF01003)
文摘A survey on the hyperbenthic communities was carried out in the coastal waters of Sishili Bay in the Yellow Sea in July 2009,to investigate the impact of putative anthropogenic activities related to the presence of a sewage outfall,a harbor and an aquaculture site on the benthic ecosystem.An Agassiz net trawl was used to collect hyperbenthos at 10 sampling stations.Species,diversity,abundance,and biomass were analyzed against water sample data and historical data obtained from records from nearby Yantai City.Fifty-two species were identified in the region,of which Crustacea were the most abundant taxon,followed by Echinodermata.Dominant species included five crustaceans,two echinoderms,one mollusk and one fish species.The results of a BIOENV analysis show that the concentrations of NO3-N and Chl-a were slightly positively correlated with hyperbenthic community structure,while other factors were negatively correlated,including sediment grain size and the percentage of TN and TOC in sediment.Abundance- Biomass Comparison(ABC method) curves indicate that the hyperbenthos in Sishili Bay had been disturbed by putative sources of human activities.Eight out of 10 stations were classified as "moderately perturbed" to "perturbed".
基金supported by the Chinese Polar Environment Comprehensive Investigation and Assessment Program (Grant nos. CHINARE2017-02-01, CHINARE2017-04-04, and CHINARE 2017-04-03)
文摘Climate change in the Arctic region is more rapid than that in other areas owing to Arctic amplification. To better understand climate change and the driving mechanisms, long-term historical reconstructions throughout the Holocene and high-resolution records of the past few hundred years are required. Intense anthropogenic activities in the Arctic have had a great impact on the local environment. Here, we review the Holocene climate change record, responses of the ecosystems to climate change, and the anthropogenic impacts on the environment based mainly on Chinese research from Ny-Alesund. Climate reconstruction studies from Svalbard have revealed several cold episodes during the Holocene, which are consistent with ice rafting events in the North Atlantic region and glacier activity from Greenland, Iceland, and Svalbard. The ecosystem also showed corresponding responses to climate change, especially during the late Holocene. Over recent decades, anthropogenic activities have caused serious pollution and deterioration to the local environment in Svalbard in areas frequented by people. Greater environmental protection is therefore needed to reduce the anthropogenic impacts on the local environment.