Vegetation plays an important role in the environmental transport behavior of organic pollutants,however,the different roles of crops and natural vegetation have been ignored in most previous studies.In this study,we ...Vegetation plays an important role in the environmental transport behavior of organic pollutants,however,the different roles of crops and natural vegetation have been ignored in most previous studies.In this study,we developed the BETR-Urban-Rural-Veg model to quantitatively evaluate the influences of both natural vegetation and crops on the multimedia transport processes of Phenanthrene(PHE)and Benzo(a)pyrene(BaP)in mainland of China.The geographic distribution of polycyclic aromatic hydrocarbon(PAH)emissions and concentrations were consistent,displaying higher levels in northern China while lower levels in southern China.Under seasonal simulations,for both natural vegetation and crops,PAH concentrations in winter and spring were 1.5 to 27-fold higher than in summer and autumn,especially for PHE.Owing to the higher leaf area index(LAI)of natural vegetation and harvesting of crops,the filter and sequestration effect of natural vegetation was stronger than crops,while the seasonal changes of PAH concentrations in crops were more significant than natural vegetation.Temperature,precipitation rates and LAI might have important influences on seasonal concentrations and overall persistence of PAHs.PHE was more sensitive to the impacts of seasonal environmental parameters.Under different landscape scenarios,average annual PAH concentrations in natural vegetation were always a little higher than those in crops,and the overall persistence of BaP was greatly affected increasing by 15.15%-16.47%.This improved model provides a useful tool for environmental management.The results of this study are expected to support land use plans and decision-making in China's mainland.展开更多
Environmental Flow Assessments （EFAs） are becoming the global standard for determining the amount of water required to sustain aquatic ecosystems and sustain socio-economic development. EFAs comprise structured, sci...Environmental Flow Assessments （EFAs） are becoming the global standard for determining the amount of water required to sustain aquatic ecosystems and sustain socio-economic development. EFAs comprise structured, science-based approaches to determine how much water must be left in the river to protect the aquatic ecosystems and achieve the desired ecological state, The building block methodology （BBM） that was used in this study is designed to identify a series of important flows （the building blocks） which will together provide the essential aspects of the natural hydrological regime that ensure the persistence of as much of the biodiversity as possible. The results show that a total inflow into eastern wetland of 5.52-6.81 m^3/s is required in order to sustain an outflow of 1-2 m^3/s past Ng＇iriama and hence meet the ＂minimum＂ recommended flow rates further downstream at BBM1 and BBM2 during the drought low flow conditions. The rationale being that a satisfactory flow during drought low flow conditions will guarantee sufficient flows during low flow periods in normal and wet years. The low flows of 2.5 m^3/s and 19 m^3/s are recommended for the driest and wettest months, respectively.展开更多
Aquatic ecosystem sustainability around the globe is facing crucial challenges because of increasing anthropogenic and natural disturbances. In this study, the Tianchi Lake, a typical cold-water lake and a UNESCO/MAB(...Aquatic ecosystem sustainability around the globe is facing crucial challenges because of increasing anthropogenic and natural disturbances. In this study, the Tianchi Lake, a typical cold-water lake and a UNESCO/MAB(Man and Biosphere) nature reserve located in high latitude and elevation with the relatively low intensity of human activity was chosen as a system to examine the linkages between climate change and eutrophication. As a part of the UNESCO Bogda Man and Biosphere Reserve, Tianchi Lake has been well preserved for prevention from human intervention, but why has it been infected with eutrophication recent years? Our results show that climate change played a significant role in the eutrophication in the Tianchi Lake. Increased temperature, changed precipitation pattern and wind-induced hydrodynamic fluctuations in the summer season were suggested to make a major contribution to the accelerated eutrophication. The results also showed that the local temperature and precipitation changes were closely linked to the large-scale atmospheric circulation, which opens the door for the method to be applied in other regions without local climatic information. This study suggests that there is an urgent need to take into consideration of climate change adaptation into the conservation and management of cold-water lakes globally.展开更多
The leaf muntjac （Muntiacus putaoensis） is an endemic deer species found in the east trans- Himalayan region. In recent years, population numbers have decreased due to heavy hunting and habitat loss, and little gene...The leaf muntjac （Muntiacus putaoensis） is an endemic deer species found in the east trans- Himalayan region. In recent years, population numbers have decreased due to heavy hunting and habitat loss, and little genetic data exists for this species, thus our knowledge of distribution rangs and population sizes likewise remain limited. We obtained mtDNA genes and the complete mitochondrial genome sequence of M. putaoensis using PCR, followed by direct sequencing. The complete mitogenome sequence was determined as a circular 16 349 bp mitochondrial genome, containing 13 protein-coding genes, two rRNA genes 22 tRNA genes, and one control region, the gene composition and order of which were similar to most other vertebrates so far reported. Most mitochondrial genes, except for ND6 and eight tRNAs, were encoded on the heavy strand. The overall base composition of the heavy strand was 33.1% A, 29.3% T, 24.2% C, and 13.4% G, with a strong AT bias of 62.4%. There were seven regions of gene overlap totaling 95 bp and 11 intergenic spacer regions totaling 74 bp. Phylogenetic analyses （ML and BI） among the Muntiacus genus based on the sequenced of mitogenome and ND4L-ND4 supported M. putaoensis as a member of Muntiacus, most closely related to M. vuquangensis. However, when analyses based on cyt b included two more muntjacs, M. truongsonensis was most closely related to M. putaoensis rather than M. vuquangensis, and together with M. rooseveltorum, likely forming a M. rooseveltorum complex of the species. This study will help in the exploration of the evolutionary history and taxonomic status of the leaf muntjac, as well as its protection as a genetic resource.展开更多
Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus（P） nutrient, thus impacting the water quality. Modeling the effect of forest los...Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus（P） nutrient, thus impacting the water quality. Modeling the effect of forest loss on surface water quality provides valuable information for forest management. This study predicts the future impacts of forest loss between 2010 and 2040 on P loading in the Tajan River watershed at the sub-watershed level. To understand drivers of the land cover, we used Land Change Modeler（LCM） combining with the Soil Water Assessment Tool（SWAT） model to simulate the impacts of land use change on P loading. We characterized priority management areas for locating comprehensive and cost-effective management practices at the sub-watershed level. Results show that agricultural expansion has led to an intense deforestation. During the future period 2010–2040, forest area is expected to decrease by 34,739 hm^2. And the areas of pasture and agriculture are expected to increase by 7668 and 27,071 hm^2, respectively. In most sub-watersheds, P pollution will be intensified with the increase in deforestation by the year 2040. And the P concentration is expected to increase from 0.08 to 2.30 mg/L in all of sub-watersheds by the year 2040. It should be noted that the phosphorous concentration exceeds the American Public Health Association′s water quality standard of 0.2 mg/L for P in drinking water in both current and future scenarios in the Tajan River watershed. Only 30% of sub-watersheds will comply with the water quality standards by the year 2040. The finding of the present study highlights the importance of conserving forest area to maintain a stable water quality.展开更多
Hybridization presents a unique challenge for conservation biologists and managers. While hybridization is an important evolutionary process, hybridization is also a threat formany native species. The endangered speci...Hybridization presents a unique challenge for conservation biologists and managers. While hybridization is an important evolutionary process, hybridization is also a threat formany native species. The endangered species recovery effort for the red wolf Canis rufus is a classic system for understanding and addressing the challenges of hybridization. From 1987-1993, 63 red wolves were released from captivity in eastern North Carolina, USA, to establish a free-ranging, non-essential experimental population. By 1999, managers recognized hybridization with invasive coyotes Canis latrans was the single greatest threat to successful recovery, and an adaptive management plan was adopted with innovative approaches for managing the threat of hybri- dization. Here we review the application and results of the adaptive management efforts from 1993 to 2013 by comparing： （1） the numbers of wolves, coyotes, and hybrids captured, （2） the numbers of territorial social groups with presumed breeding capabili- ties, （3） the number of red wolf and hybrid litters documented each year and （4） the degree of coyote introgression into the wild red wolf gene pool. We documented substantial increases in the number of known red wolves and red wolf social groups from 1987-2004 followed by a plateau and slight decline by 2013.The number of red wolf litters exceeded hybrid litters each year and the proportion of hybrid litters per year averaged 21%. The genetic composition of the wild red wolf population is estimated to include 〈 4% coyote ancestry from recent introgression since reintroduction. We conclude that the adaptive management plan was effective at reducing the introgression of coyote genes into the red wolf population, but population recovery of red wolves will require continuation of the current management plan, or alternative approaches, for the foreseeable future. More broadly, we discuss the lessons learned from red wolf adaptive management that could assist other endangered species recovery efforts facing the challenge of minimizing hybridization [Current Zoology 61 （1）： 191-205, 2015 ].展开更多
Savanna woodlands in Sudan host great biodiversity, provide a plethora of ecosystem goods and services to local communities, and sustain numerous ecological functions. Although the importance of the Acacia trees in th...Savanna woodlands in Sudan host great biodiversity, provide a plethora of ecosystem goods and services to local communities, and sustain numerous ecological functions. Although the importance of the Acacia trees in these areas is well known, up-to-date information about these woodlands' diversity is limited and changes in their woody vegetation composition, density, diversity and relative frequency are not monitored over time. This study explored tree diversity and stand stage structure in Nuara Reserved Forest, a typical savanna woodland ecosystem in southeastern Sudan. A total of 638 circular sample plots(1000 m^2 for each) were established using a systematic sampling grid method. The distance between plots was 200 m. In each plot, all living trees with diameter at breast height(DBH) ≥5.00 cm were identified and counted, and their DBH values were recorded. From these data, tree composition, diversity, density and stage structure were assessed. There were 12,259 individual trees representing four species(Acacia seyal, Balanites aegyptiaca, Acacia Senegal and Acacia mellifera) that belong to two families. The dominant species was Acacia seyal. Average tree density was 191 trees/hm^2 and the Shannon-Weiner index for trees diversity was 0.204. Overall, young trees comprised 86.30% of the forest. The state of tree richness and density in the study area was low compared to other similar environments in the region and around the world. We recommended adoption of a proper management system that includes monitoring of woody vegetation diversity in this forest, and management actions to enhance tree diversity and sustain ecosystem services to local communities. In addition to care for the dominant Acacia seyal stands, more attention and conservation should be devoted to reestablishing Acacia senegal and Acacia mellifera trees because of their high ecological and economic values for local communities.展开更多
DEAR EDITOR,Muntjac deer(Cervidae: Muntiacus) are often cited as an excellent model for the study of vertebrate evolution due to their fast rate of change in chromosome number among vertebrates. However, the phylogene...DEAR EDITOR,Muntjac deer(Cervidae: Muntiacus) are often cited as an excellent model for the study of vertebrate evolution due to their fast rate of change in chromosome number among vertebrates. However, the phylogenetic relationships within Muntiacus generally, and the taxonomic status of Muntiacus gongshanensis specifically, remain unclear.展开更多
Hester-Dendy (HD) multi-plate samplers have been widely used by state and federal government agencies for bioassessment of water quality through use of macroinvertebrate community data. To help guide remediation and r...Hester-Dendy (HD) multi-plate samplers have been widely used by state and federal government agencies for bioassessment of water quality through use of macroinvertebrate community data. To help guide remediation and restoration efforts at the Niagara River Great Lakes Area of Concern site, a multi-agency study was conducted in 2014 to assess the contribution of seven major urban tributaries on the US side of the river toward the impairment of the Niagara River. As part of this study, macroinvertebrate communities were sampled using two co-located versions of HD samplers: one version used by the New York State Department of Environmental Conservation (NYSDEC) and another by the US Environmental Protection Agency Office of Research and Development. Samplers were deployed in tributaries in highly developed watersheds with high percent impervious surface. The two sampling methods varied in terms of number and size of plates, between-plate spacing, and deployment method. Comparison of the similarity/grouping of communities with multivariate ordination techniques, Nonmetric Multidimensional Scaling and Multi-Response Permutation Procedure, showed that both methods were able to detect differences in communities at stations, despite some grouping by month and method. The indices and metrics derived from the two HD methods were found to give comparable but not identical assessments of water quality. Despite their differences, the methods were robust with respect to water quality categories derived from indices used nationally (HBI) and by NY state (BAP). For the common richness metrics, total taxa and EPT richness, there was no statistical difference between means from 3 samplings. Some metrics, especially percent tolerant collector-gatherer individuals, did show significant differences at certain stations. Indicator Species Analysis showed some taxa associated with each method. The observed community differences were thought mostly due to the difference in sampler deployment position. .展开更多
Groundwater is the major source of fresh water,and it performs a crucial role in maintaining ecosystems and adapting humans to climate variation.Due to excessive reliance on groundwater in some regions,the amount of g...Groundwater is the major source of fresh water,and it performs a crucial role in maintaining ecosystems and adapting humans to climate variation.Due to excessive reliance on groundwater in some regions,the amount of groundwater being consumed is higher than the recharge,which leads to a durative decline of groundwater level.This study analyzed the spatiotemporal variability in groundwater storage(GWS)in China.And the possible drivers of observed GWS changes were also identified.GWS level displayed large regional disparities with higher reserves in the Yangtze River Basin and Songhua River Basin.Temporally,GWS level showed decreasing trends in the North China Plain region,Yellow River Basin,Inner Mongolia Plateau and Junggar Basin.And,GWS showed a significant increase in the Tibetan Plateau and Songhua River Basin.Without considering the impact of human activities,groundwater reserves are also showing a decreasing trend in future climate scenarios in most of the 15 zones.Contribution analysis of driving forces on the basis of the percentages of standardized coefficient(r)suggested that the variations of GWS were largely controlled by anthropogenic activities with the contribution proportions of 35.43%-73.37%.And the contribution proportions of natural drivers accounted for 26.63%-64.62%,with the key factors of precipitation,temperature and vegetation cover.The results would help to formulate sustainable strategies for managing groundwater resource.展开更多
Fecal bacteria contaminate water resources and result in associated waterborne diseases.This study assessed drinking water quality and evaluated their potential health risks in Swat, Pakistan. Ground and surface drink...Fecal bacteria contaminate water resources and result in associated waterborne diseases.This study assessed drinking water quality and evaluated their potential health risks in Swat, Pakistan. Ground and surface drinking water were randomly collected from upstream to downstream in the River Swat watershed and analyzed for fecal contamination using fecal indicator bacteria（Escherichia coli） and physiochemical parameters（potential of hydrogen, turbidity, temperature, electrical conductivity, total dissolved solid, color, odor and taste）. The physiochemical parameters were within their safe limits except in a few locations, whereas, the fecal contaminations in drinking water resources exceeded the drinking water quality standards of Pakistan Environmental Protection Agency（Pak-EPA）,2008 and World Health Organization（WHO）, 2011. Multivariate and univariate analyses revealed that downstream urbanization trend, minimum distance between water sources and pit latrines/sewerage systems, raw sewage deep well injection and amplified urban,pastures and agricultural runoffs having human and animal excreta were the possible sources of contamination. The questionnaire survey revealed that majority of the local people using 10–20 years old drinking water supply schemes at the rate of 73% well supply,13% hand pump supply, 11% spring supply and 3% river/streams supply, which spreads high prevalence of water borne diseases including hepatitis, intestinal infections and diarrhea, dysentery, cholera, typhoid fever, jaundice and skin diseases in children followed by older and younger adults.展开更多
Forests provide multiple ecosystem services that are critical to sustain societies and ecosystems. Protecting the forest systems become imperative as human demand for forest products and services increase. In addition...Forests provide multiple ecosystem services that are critical to sustain societies and ecosystems. Protecting the forest systems become imperative as human demand for forest products and services increase. In addition to current stressors, several emerging threats pose serious implications on the survival and sustainability of forest ecosystems. These include climatic change, invasive species, natural disasters, land use change, and pest/diseases that can severally impact the ability of forest to sustain ecosystem services. There is a need for using a systems-based framework to increase resilience of forest systems to cope with these threats. We review literature on these threats and propose a systems-framework for forest resilience. While strategies for each threat are often easier, comprehensive strategies that can handle multiple threats and specific to forest type is required. There is also a need for further research into forest resilience and landscape-scale response and resilience.展开更多
Zero-valent iron(ZVI)technology has recently gained significant interest in the efficient sequestration of a wide variety of contaminants.However,surface passivation of ZVI because of its intrinsic passive layer would...Zero-valent iron(ZVI)technology has recently gained significant interest in the efficient sequestration of a wide variety of contaminants.However,surface passivation of ZVI because of its intrinsic passive layer would lead to the inferior reactivity of ZVI and its lower efficacy in contaminant removal.Therefore,to activate the ZVI surface cheaply,continuously,and efficiently is an important challenge that ZVI technology must overcome before its wide-scale application.To date,several physical and chemical approaches have been extensively applied to increase the reactivity of the ZVI surface toward the elimination of broad-spectrum pollutants.Nevertheless,these techniques have several limitations such as low efficacy,narrow working pH,eco-toxicity,and high installation cost.The objective of this mini-review paper is to identify the critical role of oxygen in determining the reactivity of ZVI toward contaminant removal.Subsequently,the effect of three typical oxidants(H2O2,KMnO4,and NaClO)on broad-spectrum contaminants removal by ZV1 has been documented and discussed.The reaction mechanism and sequestration efficacies of the ZVI/oxidant system were evaluated and reviewed.The technical basis of the ZVI/oxidant approach is based on the half-reaction of the cathodic reduction of the oxidants.The oxidants commonly used in the water treatment industry,i.e.,NaClO,O3,and H2O2,can be served as an ideal coupling electron receptor.With the combination of these oxidants,the surface corrosion of ZVI can be continuously driven.The ZVI/oxidants technology has been compared with other conventional technologies and conclusions have been drawn.展开更多
Extreme climate events exhibit an increasing spatio-temporal trend globally, and the increasing intensity and frequency may have severe impacts on the human society and natural ecosystems. This study analyzed the extr...Extreme climate events exhibit an increasing spatio-temporal trend globally, and the increasing intensity and frequency may have severe impacts on the human society and natural ecosystems. This study analyzed the extreme temperature and precipitation variability from 1956 to 2016, and evaluated their potential effects on crop yield in Ethiopia. Relative extreme temperature indices exhibited a decreasing trend with low-temperature events, but a significantly upward trend with extreme high temperature events. The frequency of annual warm nights increased to a greater degree than that of cold days. The total annual wet-day precipitation decreased significantly at a rate of-46 mm/decade. Further, the succession of dry days gradually increased by 5.6 day/decade, while an opposite trend of wet days was found with a decline of 1.4 day/decade. The correlation between annual precipitation and crop production was 0.422, indicating that extreme precipitation indices may have higher explanatory power than extreme temperature indices in the crop yield variations. Moreover, the extreme climate changes have induced significant adverse impacts on crops yield particularly in Ethiopia where no proper adaptation measures have been implemented.展开更多
The coupling of zero-valent iron(ZVI)with common oxidants has recently achieved very rapid and highly efficient removal of Heavy metals from wastewater.However,the uniform activation of ZVI throughout the column and t...The coupling of zero-valent iron(ZVI)with common oxidants has recently achieved very rapid and highly efficient removal of Heavy metals from wastewater.However,the uniform activation of ZVI throughout the column and the proportional removal of target contaminants are urgently required for the prevention of premature filter clogging and the extension of the effective column operational time.In this study,we successfully achieved this objective by simply doping granular sand with ZVI at appropriate weight ratios.When pure ZVI packed column was spiked with oxidants,the majority of As trapping occurred between the column inlet and the first sampling point.In a packed column with a 1:20 mixture of ZVI and sand,the average As removal efficiency was 36(1st),13.1(2nd),18.5(3rd),19.2(4th)and 5.9%(5th outlet).The overall arsenic removal performance of the composite filling system of ZVI/sand was equally as efficient as that of the previous pure ZVI-packed system.Moreover,the leaching of Fe was significantly reduced with an increased sand ratio,resulting in clearer water with less turbidity.The results of X-ray photoelectron spectroscopy(XPS)demonstrated that more than 54%of the arsenic was reduced to As(III).X-ray diffraction(XRD)and scanning electron microscopy(SEM)confirmed the extensive corrosion of the ZVI surface,which resulted in various species of iron oxyhydroxides responsible for the highly efficient sequester of arsenic through reduction,adsorption,and coprecipitation.展开更多
The purpose of this research was to conduct a pilot study of LEED certified homes in New England one to five years after occupancy to determine whether they continue to perform at the level predicted during the certif...The purpose of this research was to conduct a pilot study of LEED certified homes in New England one to five years after occupancy to determine whether they continue to perform at the level predicted during the certification process.Four criteria were defined to assess the performance of each home:(1)energy consumption for heating,cooling,lighting,electronics and appliances;(2)building envelope and air infiltration;(3)operations and maintenance;and(4)occupant satisfaction and indoor air quality.Both qualitative and quantitative methods including blower door and duct blaster tests,utility bill analysis,and an occupant satisfaction survey were used to measure the post-occupancy performance of seven LEED certified homes in New England.Discrepancies were found between the original building performance as determined at the time of certification and the current level of building performance.While this is limited,initial research,these findings indicate a need for further post-occupancy research that can provide feedback to green certification programs,allowing them to be modified as necessary to better reflect the actual environmental impacts of certified buildings.展开更多
In 2007,Mayor Menino and the Boston Redevelopment Authority implemented Article 37,an amendment to the Boston Zoning Code requiring new construction approved under Large Project Review be designed and built to meet th...In 2007,Mayor Menino and the Boston Redevelopment Authority implemented Article 37,an amendment to the Boston Zoning Code requiring new construction approved under Large Project Review be designed and built to meet the U.S.Green Building Council’s LEED certification.The amendment was intended to promote green building practices in the city and reduce the environmental impacts of buildings larger than 50,000 square feet.Article 37 dictates that buildings be LEED“certifiable,”but does not require that they actually achieve LEED certification.This study examines how this policy has affected building practice in the city.This research relied on several data sources including public records,communication with public officials,and qualitative research interviews with building industry professionals working in Boston.Interviews were conducted with 9 individuals at 7 firms.Both architecture and engineering firms were included and all have worked under Article 37.The experiences of each firm were treated as a case study,and cases were considered in relation to each other.A cross-case analysis was completed using the qualitative research methods of interpretation,synthesis,meaning condensation,and meaning categorization.It was concluded that Article 37 has advanced sustainability goals in Boston and has provided an educational benefit to building practitioners and clients.However,Article 37 has not had a substantial impact on building practice in the city.The LEED certifiable standard is not actually equivalent to LEED certification and does not set an aggressive goal.This research fills a gap in the literature and is an important step in critically examining the outcomes of green building policy.This understanding of how Article 37 has influenced building practice in Boston is valuable not only to the city,but also to the numerous municipalities that have adopted LEED-based requirements for private construction.展开更多
Linear regression analysis is one the most common methods for weather-normalizing energy data,where energy versus degree-days is plotted,quantifying the impacts of outside temperature on buildings’energy use.However,...Linear regression analysis is one the most common methods for weather-normalizing energy data,where energy versus degree-days is plotted,quantifying the impacts of outside temperature on buildings’energy use.However,this approach solely con-siders dry-bulb temperature,while other climate variables are ignored.In addition,depending on buildings’internal loads,weather impact can be less influential,making the linear regression method not applicable for energy data normalization in inter-nally driven buildings(such as research laboratory buildings,healthcare facilities,etc.).In this study,several existing buildings from different categories,all located on the University of Massachusetts Amherst campus and exposed to the same weather conditions in a heating-dominated climate,were analyzed.For all cases,regression of monthly steam use on heating degree-days and floor-area normalized steam data were used,investigating applicability of the former when the latter changes.It was found that internal loads can skew steam consumption,depending on the build-ing functionality,making the effect of degree-days negligible.For laboratory-type buildings,besides heating and domestic hot water production,steam is also used for scientific experiments.Here,daily occupancy percentage,even during weekends and holidays,was higher than that of other buildings,indicating the intensity of scientific experiments performed.This significantly impacted steam consumption,resulting in higher floor-area-normalized steam usage.In these cases,steam use did not provide an outstanding correlation to heating degree-days.Whereas,for cases with other func-tionality-types and lower floor-area normalized steam,coefficients of determination in regressions were high.This study concludes that even for buildings located in the same climate,depending on how building functionality and occupancy schedule influ-ence floor-area normalized steam use,multivariate linear regression can provide more accurate analysis,rather than simple linear regression of steam on heating degree-days.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42107420,U23A20157,and U1910207)Shanxi Province Science Foundation for Young Scholars(No.20210302124363).
文摘Vegetation plays an important role in the environmental transport behavior of organic pollutants,however,the different roles of crops and natural vegetation have been ignored in most previous studies.In this study,we developed the BETR-Urban-Rural-Veg model to quantitatively evaluate the influences of both natural vegetation and crops on the multimedia transport processes of Phenanthrene(PHE)and Benzo(a)pyrene(BaP)in mainland of China.The geographic distribution of polycyclic aromatic hydrocarbon(PAH)emissions and concentrations were consistent,displaying higher levels in northern China while lower levels in southern China.Under seasonal simulations,for both natural vegetation and crops,PAH concentrations in winter and spring were 1.5 to 27-fold higher than in summer and autumn,especially for PHE.Owing to the higher leaf area index(LAI)of natural vegetation and harvesting of crops,the filter and sequestration effect of natural vegetation was stronger than crops,while the seasonal changes of PAH concentrations in crops were more significant than natural vegetation.Temperature,precipitation rates and LAI might have important influences on seasonal concentrations and overall persistence of PAHs.PHE was more sensitive to the impacts of seasonal environmental parameters.Under different landscape scenarios,average annual PAH concentrations in natural vegetation were always a little higher than those in crops,and the overall persistence of BaP was greatly affected increasing by 15.15%-16.47%.This improved model provides a useful tool for environmental management.The results of this study are expected to support land use plans and decision-making in China's mainland.
文摘Environmental Flow Assessments （EFAs） are becoming the global standard for determining the amount of water required to sustain aquatic ecosystems and sustain socio-economic development. EFAs comprise structured, science-based approaches to determine how much water must be left in the river to protect the aquatic ecosystems and achieve the desired ecological state, The building block methodology （BBM） that was used in this study is designed to identify a series of important flows （the building blocks） which will together provide the essential aspects of the natural hydrological regime that ensure the persistence of as much of the biodiversity as possible. The results show that a total inflow into eastern wetland of 5.52-6.81 m^3/s is required in order to sustain an outflow of 1-2 m^3/s past Ng＇iriama and hence meet the ＂minimum＂ recommended flow rates further downstream at BBM1 and BBM2 during the drought low flow conditions. The rationale being that a satisfactory flow during drought low flow conditions will guarantee sufficient flows during low flow periods in normal and wet years. The low flows of 2.5 m^3/s and 19 m^3/s are recommended for the driest and wettest months, respectively.
基金supported by the National Key R&D Program of China (No.2017YFC0505704)the Key technology R&D Program of Tianjin (No.16YFXTSF00380)+1 种基金the National Natural Science Foundation of China (Nos.41420104004 and 71761147001)the Key Project of the Chinese Academy of Sciences (No.KFZDSW-322)
文摘Aquatic ecosystem sustainability around the globe is facing crucial challenges because of increasing anthropogenic and natural disturbances. In this study, the Tianchi Lake, a typical cold-water lake and a UNESCO/MAB(Man and Biosphere) nature reserve located in high latitude and elevation with the relatively low intensity of human activity was chosen as a system to examine the linkages between climate change and eutrophication. As a part of the UNESCO Bogda Man and Biosphere Reserve, Tianchi Lake has been well preserved for prevention from human intervention, but why has it been infected with eutrophication recent years? Our results show that climate change played a significant role in the eutrophication in the Tianchi Lake. Increased temperature, changed precipitation pattern and wind-induced hydrodynamic fluctuations in the summer season were suggested to make a major contribution to the accelerated eutrophication. The results also showed that the local temperature and precipitation changes were closely linked to the large-scale atmospheric circulation, which opens the door for the method to be applied in other regions without local climatic information. This study suggests that there is an urgent need to take into consideration of climate change adaptation into the conservation and management of cold-water lakes globally.
基金supported by a grant from the Southeast Asia Biodiversity Research Institute,Chinese Academy of Sciences(Y4ZK111B01)
文摘The leaf muntjac （Muntiacus putaoensis） is an endemic deer species found in the east trans- Himalayan region. In recent years, population numbers have decreased due to heavy hunting and habitat loss, and little genetic data exists for this species, thus our knowledge of distribution rangs and population sizes likewise remain limited. We obtained mtDNA genes and the complete mitochondrial genome sequence of M. putaoensis using PCR, followed by direct sequencing. The complete mitogenome sequence was determined as a circular 16 349 bp mitochondrial genome, containing 13 protein-coding genes, two rRNA genes 22 tRNA genes, and one control region, the gene composition and order of which were similar to most other vertebrates so far reported. Most mitochondrial genes, except for ND6 and eight tRNAs, were encoded on the heavy strand. The overall base composition of the heavy strand was 33.1% A, 29.3% T, 24.2% C, and 13.4% G, with a strong AT bias of 62.4%. There were seven regions of gene overlap totaling 95 bp and 11 intergenic spacer regions totaling 74 bp. Phylogenetic analyses （ML and BI） among the Muntiacus genus based on the sequenced of mitogenome and ND4L-ND4 supported M. putaoensis as a member of Muntiacus, most closely related to M. vuquangensis. However, when analyses based on cyt b included two more muntjacs, M. truongsonensis was most closely related to M. putaoensis rather than M. vuquangensis, and together with M. rooseveltorum, likely forming a M. rooseveltorum complex of the species. This study will help in the exploration of the evolutionary history and taxonomic status of the leaf muntjac, as well as its protection as a genetic resource.
基金The Modares Tarbiat University of Iran funded this work
文摘Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus（P） nutrient, thus impacting the water quality. Modeling the effect of forest loss on surface water quality provides valuable information for forest management. This study predicts the future impacts of forest loss between 2010 and 2040 on P loading in the Tajan River watershed at the sub-watershed level. To understand drivers of the land cover, we used Land Change Modeler（LCM） combining with the Soil Water Assessment Tool（SWAT） model to simulate the impacts of land use change on P loading. We characterized priority management areas for locating comprehensive and cost-effective management practices at the sub-watershed level. Results show that agricultural expansion has led to an intense deforestation. During the future period 2010–2040, forest area is expected to decrease by 34,739 hm^2. And the areas of pasture and agriculture are expected to increase by 7668 and 27,071 hm^2, respectively. In most sub-watersheds, P pollution will be intensified with the increase in deforestation by the year 2040. And the P concentration is expected to increase from 0.08 to 2.30 mg/L in all of sub-watersheds by the year 2040. It should be noted that the phosphorous concentration exceeds the American Public Health Association′s water quality standard of 0.2 mg/L for P in drinking water in both current and future scenarios in the Tajan River watershed. Only 30% of sub-watersheds will comply with the water quality standards by the year 2040. The finding of the present study highlights the importance of conserving forest area to maintain a stable water quality.
文摘Hybridization presents a unique challenge for conservation biologists and managers. While hybridization is an important evolutionary process, hybridization is also a threat formany native species. The endangered species recovery effort for the red wolf Canis rufus is a classic system for understanding and addressing the challenges of hybridization. From 1987-1993, 63 red wolves were released from captivity in eastern North Carolina, USA, to establish a free-ranging, non-essential experimental population. By 1999, managers recognized hybridization with invasive coyotes Canis latrans was the single greatest threat to successful recovery, and an adaptive management plan was adopted with innovative approaches for managing the threat of hybri- dization. Here we review the application and results of the adaptive management efforts from 1993 to 2013 by comparing： （1） the numbers of wolves, coyotes, and hybrids captured, （2） the numbers of territorial social groups with presumed breeding capabili- ties, （3） the number of red wolf and hybrid litters documented each year and （4） the degree of coyote introgression into the wild red wolf gene pool. We documented substantial increases in the number of known red wolves and red wolf social groups from 1987-2004 followed by a plateau and slight decline by 2013.The number of red wolf litters exceeded hybrid litters each year and the proportion of hybrid litters per year averaged 21%. The genetic composition of the wild red wolf population is estimated to include 〈 4% coyote ancestry from recent introgression since reintroduction. We conclude that the adaptive management plan was effective at reducing the introgression of coyote genes into the red wolf population, but population recovery of red wolves will require continuation of the current management plan, or alternative approaches, for the foreseeable future. More broadly, we discuss the lessons learned from red wolf adaptive management that could assist other endangered species recovery efforts facing the challenge of minimizing hybridization [Current Zoology 61 （1）： 191-205, 2015 ].
文摘Savanna woodlands in Sudan host great biodiversity, provide a plethora of ecosystem goods and services to local communities, and sustain numerous ecological functions. Although the importance of the Acacia trees in these areas is well known, up-to-date information about these woodlands' diversity is limited and changes in their woody vegetation composition, density, diversity and relative frequency are not monitored over time. This study explored tree diversity and stand stage structure in Nuara Reserved Forest, a typical savanna woodland ecosystem in southeastern Sudan. A total of 638 circular sample plots(1000 m^2 for each) were established using a systematic sampling grid method. The distance between plots was 200 m. In each plot, all living trees with diameter at breast height(DBH) ≥5.00 cm were identified and counted, and their DBH values were recorded. From these data, tree composition, diversity, density and stage structure were assessed. There were 12,259 individual trees representing four species(Acacia seyal, Balanites aegyptiaca, Acacia Senegal and Acacia mellifera) that belong to two families. The dominant species was Acacia seyal. Average tree density was 191 trees/hm^2 and the Shannon-Weiner index for trees diversity was 0.204. Overall, young trees comprised 86.30% of the forest. The state of tree richness and density in the study area was low compared to other similar environments in the region and around the world. We recommended adoption of a proper management system that includes monitoring of woody vegetation diversity in this forest, and management actions to enhance tree diversity and sustain ecosystem services to local communities. In addition to care for the dominant Acacia seyal stands, more attention and conservation should be devoted to reestablishing Acacia senegal and Acacia mellifera trees because of their high ecological and economic values for local communities.
基金supported by the Lancang-Mekong Cooperation Special Fund (Biodiversity Monitoring and Network Construction along Lancang-Mekong River Basin Project,Y8GK041B01)CAS-SEABRI (Y4ZK111B01)+1 种基金CAS 135 Program(2017 XTBG-F03)National Natural Science Foundation of China(31901080)。
文摘DEAR EDITOR,Muntjac deer(Cervidae: Muntiacus) are often cited as an excellent model for the study of vertebrate evolution due to their fast rate of change in chromosome number among vertebrates. However, the phylogenetic relationships within Muntiacus generally, and the taxonomic status of Muntiacus gongshanensis specifically, remain unclear.
文摘Hester-Dendy (HD) multi-plate samplers have been widely used by state and federal government agencies for bioassessment of water quality through use of macroinvertebrate community data. To help guide remediation and restoration efforts at the Niagara River Great Lakes Area of Concern site, a multi-agency study was conducted in 2014 to assess the contribution of seven major urban tributaries on the US side of the river toward the impairment of the Niagara River. As part of this study, macroinvertebrate communities were sampled using two co-located versions of HD samplers: one version used by the New York State Department of Environmental Conservation (NYSDEC) and another by the US Environmental Protection Agency Office of Research and Development. Samplers were deployed in tributaries in highly developed watersheds with high percent impervious surface. The two sampling methods varied in terms of number and size of plates, between-plate spacing, and deployment method. Comparison of the similarity/grouping of communities with multivariate ordination techniques, Nonmetric Multidimensional Scaling and Multi-Response Permutation Procedure, showed that both methods were able to detect differences in communities at stations, despite some grouping by month and method. The indices and metrics derived from the two HD methods were found to give comparable but not identical assessments of water quality. Despite their differences, the methods were robust with respect to water quality categories derived from indices used nationally (HBI) and by NY state (BAP). For the common richness metrics, total taxa and EPT richness, there was no statistical difference between means from 3 samplings. Some metrics, especially percent tolerant collector-gatherer individuals, did show significant differences at certain stations. Indicator Species Analysis showed some taxa associated with each method. The observed community differences were thought mostly due to the difference in sampler deployment position. .
基金funded by the China Geological Survey Program(No.DD20230075)the key project supported by the National Natural Science Foundation of China(No.U21A20155)。
文摘Groundwater is the major source of fresh water,and it performs a crucial role in maintaining ecosystems and adapting humans to climate variation.Due to excessive reliance on groundwater in some regions,the amount of groundwater being consumed is higher than the recharge,which leads to a durative decline of groundwater level.This study analyzed the spatiotemporal variability in groundwater storage(GWS)in China.And the possible drivers of observed GWS changes were also identified.GWS level displayed large regional disparities with higher reserves in the Yangtze River Basin and Songhua River Basin.Temporally,GWS level showed decreasing trends in the North China Plain region,Yellow River Basin,Inner Mongolia Plateau and Junggar Basin.And,GWS showed a significant increase in the Tibetan Plateau and Songhua River Basin.Without considering the impact of human activities,groundwater reserves are also showing a decreasing trend in future climate scenarios in most of the 15 zones.Contribution analysis of driving forces on the basis of the percentages of standardized coefficient(r)suggested that the variations of GWS were largely controlled by anthropogenic activities with the contribution proportions of 35.43%-73.37%.And the contribution proportions of natural drivers accounted for 26.63%-64.62%,with the key factors of precipitation,temperature and vegetation cover.The results would help to formulate sustainable strategies for managing groundwater resource.
基金supported by the National Key R&D Program of China(No.2017YFC0505704)the National Natural Science Foundation of China(Nos.41420104004 and 71761147001)+3 种基金the Key Project of the Chinese Academy of Sciences(No.KFZDSW-322)the Key Technology R&D Program of Tianjin(No.16YFXTSF00380)the Chinese Academy of Sciences(CAS)President's International Fellowship Initiative(PIFI)
文摘Fecal bacteria contaminate water resources and result in associated waterborne diseases.This study assessed drinking water quality and evaluated their potential health risks in Swat, Pakistan. Ground and surface drinking water were randomly collected from upstream to downstream in the River Swat watershed and analyzed for fecal contamination using fecal indicator bacteria（Escherichia coli） and physiochemical parameters（potential of hydrogen, turbidity, temperature, electrical conductivity, total dissolved solid, color, odor and taste）. The physiochemical parameters were within their safe limits except in a few locations, whereas, the fecal contaminations in drinking water resources exceeded the drinking water quality standards of Pakistan Environmental Protection Agency（Pak-EPA）,2008 and World Health Organization（WHO）, 2011. Multivariate and univariate analyses revealed that downstream urbanization trend, minimum distance between water sources and pit latrines/sewerage systems, raw sewage deep well injection and amplified urban,pastures and agricultural runoffs having human and animal excreta were the possible sources of contamination. The questionnaire survey revealed that majority of the local people using 10–20 years old drinking water supply schemes at the rate of 73% well supply,13% hand pump supply, 11% spring supply and 3% river/streams supply, which spreads high prevalence of water borne diseases including hepatitis, intestinal infections and diarrhea, dysentery, cholera, typhoid fever, jaundice and skin diseases in children followed by older and younger adults.
文摘Forests provide multiple ecosystem services that are critical to sustain societies and ecosystems. Protecting the forest systems become imperative as human demand for forest products and services increase. In addition to current stressors, several emerging threats pose serious implications on the survival and sustainability of forest ecosystems. These include climatic change, invasive species, natural disasters, land use change, and pest/diseases that can severally impact the ability of forest to sustain ecosystem services. There is a need for using a systems-based framework to increase resilience of forest systems to cope with these threats. We review literature on these threats and propose a systems-framework for forest resilience. While strategies for each threat are often easier, comprehensive strategies that can handle multiple threats and specific to forest type is required. There is also a need for further research into forest resilience and landscape-scale response and resilience.
基金Authors greatly acknowledge the support from the National Natural Science Foundation of China(Grant No.21876011)the National Key Research and Development Program of China(No.2017YFA0605001)the Fund for Innovative Research Group of the National Natural Science Foundation of China(No.51721093).
文摘Zero-valent iron(ZVI)technology has recently gained significant interest in the efficient sequestration of a wide variety of contaminants.However,surface passivation of ZVI because of its intrinsic passive layer would lead to the inferior reactivity of ZVI and its lower efficacy in contaminant removal.Therefore,to activate the ZVI surface cheaply,continuously,and efficiently is an important challenge that ZVI technology must overcome before its wide-scale application.To date,several physical and chemical approaches have been extensively applied to increase the reactivity of the ZVI surface toward the elimination of broad-spectrum pollutants.Nevertheless,these techniques have several limitations such as low efficacy,narrow working pH,eco-toxicity,and high installation cost.The objective of this mini-review paper is to identify the critical role of oxygen in determining the reactivity of ZVI toward contaminant removal.Subsequently,the effect of three typical oxidants(H2O2,KMnO4,and NaClO)on broad-spectrum contaminants removal by ZV1 has been documented and discussed.The reaction mechanism and sequestration efficacies of the ZVI/oxidant system were evaluated and reviewed.The technical basis of the ZVI/oxidant approach is based on the half-reaction of the cathodic reduction of the oxidants.The oxidants commonly used in the water treatment industry,i.e.,NaClO,O3,and H2O2,can be served as an ideal coupling electron receptor.With the combination of these oxidants,the surface corrosion of ZVI can be continuously driven.The ZVI/oxidants technology has been compared with other conventional technologies and conclusions have been drawn.
基金National Natural Science Foundation of China(4176114405341501539+5 种基金41420104004)National Key R&D Program of China(2017YFC0505706)International Partnership Program of Chinese Academy of Sciences(121311KYSB20170004)Key Technologies R&D program of Tianjin(16YFXTSF00380)Natural Science Foundation of Inner Mongolia Autonomous(2015KF0120131510)
文摘Extreme climate events exhibit an increasing spatio-temporal trend globally, and the increasing intensity and frequency may have severe impacts on the human society and natural ecosystems. This study analyzed the extreme temperature and precipitation variability from 1956 to 2016, and evaluated their potential effects on crop yield in Ethiopia. Relative extreme temperature indices exhibited a decreasing trend with low-temperature events, but a significantly upward trend with extreme high temperature events. The frequency of annual warm nights increased to a greater degree than that of cold days. The total annual wet-day precipitation decreased significantly at a rate of-46 mm/decade. Further, the succession of dry days gradually increased by 5.6 day/decade, while an opposite trend of wet days was found with a decline of 1.4 day/decade. The correlation between annual precipitation and crop production was 0.422, indicating that extreme precipitation indices may have higher explanatory power than extreme temperature indices in the crop yield variations. Moreover, the extreme climate changes have induced significant adverse impacts on crops yield particularly in Ethiopia where no proper adaptation measures have been implemented.
基金Authors greatly acknowledge the support from the National Natural Science Foundation of China(Grant No.21876011)National Key Research and Development Program of China(Grant No.2017YFA0605001)Fund for Innovative Research Group of the National Natural Science Foundation of China(Grant No.51721093).
文摘The coupling of zero-valent iron(ZVI)with common oxidants has recently achieved very rapid and highly efficient removal of Heavy metals from wastewater.However,the uniform activation of ZVI throughout the column and the proportional removal of target contaminants are urgently required for the prevention of premature filter clogging and the extension of the effective column operational time.In this study,we successfully achieved this objective by simply doping granular sand with ZVI at appropriate weight ratios.When pure ZVI packed column was spiked with oxidants,the majority of As trapping occurred between the column inlet and the first sampling point.In a packed column with a 1:20 mixture of ZVI and sand,the average As removal efficiency was 36(1st),13.1(2nd),18.5(3rd),19.2(4th)and 5.9%(5th outlet).The overall arsenic removal performance of the composite filling system of ZVI/sand was equally as efficient as that of the previous pure ZVI-packed system.Moreover,the leaching of Fe was significantly reduced with an increased sand ratio,resulting in clearer water with less turbidity.The results of X-ray photoelectron spectroscopy(XPS)demonstrated that more than 54%of the arsenic was reduced to As(III).X-ray diffraction(XRD)and scanning electron microscopy(SEM)confirmed the extensive corrosion of the ZVI surface,which resulted in various species of iron oxyhydroxides responsible for the highly efficient sequester of arsenic through reduction,adsorption,and coprecipitation.
基金supported by the National Institute of Food and Agriculture,U.S.Department of Agriculture,the Massachusetts Agricultural Experiment Station and the Department of Environmental Conservation under Project No.MAS00012.Publication no.3473Support was also provided by the University of Massachusetts Healey Endowment Grant.
文摘The purpose of this research was to conduct a pilot study of LEED certified homes in New England one to five years after occupancy to determine whether they continue to perform at the level predicted during the certification process.Four criteria were defined to assess the performance of each home:(1)energy consumption for heating,cooling,lighting,electronics and appliances;(2)building envelope and air infiltration;(3)operations and maintenance;and(4)occupant satisfaction and indoor air quality.Both qualitative and quantitative methods including blower door and duct blaster tests,utility bill analysis,and an occupant satisfaction survey were used to measure the post-occupancy performance of seven LEED certified homes in New England.Discrepancies were found between the original building performance as determined at the time of certification and the current level of building performance.While this is limited,initial research,these findings indicate a need for further post-occupancy research that can provide feedback to green certification programs,allowing them to be modified as necessary to better reflect the actual environmental impacts of certified buildings.
文摘In 2007,Mayor Menino and the Boston Redevelopment Authority implemented Article 37,an amendment to the Boston Zoning Code requiring new construction approved under Large Project Review be designed and built to meet the U.S.Green Building Council’s LEED certification.The amendment was intended to promote green building practices in the city and reduce the environmental impacts of buildings larger than 50,000 square feet.Article 37 dictates that buildings be LEED“certifiable,”but does not require that they actually achieve LEED certification.This study examines how this policy has affected building practice in the city.This research relied on several data sources including public records,communication with public officials,and qualitative research interviews with building industry professionals working in Boston.Interviews were conducted with 9 individuals at 7 firms.Both architecture and engineering firms were included and all have worked under Article 37.The experiences of each firm were treated as a case study,and cases were considered in relation to each other.A cross-case analysis was completed using the qualitative research methods of interpretation,synthesis,meaning condensation,and meaning categorization.It was concluded that Article 37 has advanced sustainability goals in Boston and has provided an educational benefit to building practitioners and clients.However,Article 37 has not had a substantial impact on building practice in the city.The LEED certifiable standard is not actually equivalent to LEED certification and does not set an aggressive goal.This research fills a gap in the literature and is an important step in critically examining the outcomes of green building policy.This understanding of how Article 37 has influenced building practice in Boston is valuable not only to the city,but also to the numerous municipalities that have adopted LEED-based requirements for private construction.
文摘Linear regression analysis is one the most common methods for weather-normalizing energy data,where energy versus degree-days is plotted,quantifying the impacts of outside temperature on buildings’energy use.However,this approach solely con-siders dry-bulb temperature,while other climate variables are ignored.In addition,depending on buildings’internal loads,weather impact can be less influential,making the linear regression method not applicable for energy data normalization in inter-nally driven buildings(such as research laboratory buildings,healthcare facilities,etc.).In this study,several existing buildings from different categories,all located on the University of Massachusetts Amherst campus and exposed to the same weather conditions in a heating-dominated climate,were analyzed.For all cases,regression of monthly steam use on heating degree-days and floor-area normalized steam data were used,investigating applicability of the former when the latter changes.It was found that internal loads can skew steam consumption,depending on the build-ing functionality,making the effect of degree-days negligible.For laboratory-type buildings,besides heating and domestic hot water production,steam is also used for scientific experiments.Here,daily occupancy percentage,even during weekends and holidays,was higher than that of other buildings,indicating the intensity of scientific experiments performed.This significantly impacted steam consumption,resulting in higher floor-area-normalized steam usage.In these cases,steam use did not provide an outstanding correlation to heating degree-days.Whereas,for cases with other func-tionality-types and lower floor-area normalized steam,coefficients of determination in regressions were high.This study concludes that even for buildings located in the same climate,depending on how building functionality and occupancy schedule influ-ence floor-area normalized steam use,multivariate linear regression can provide more accurate analysis,rather than simple linear regression of steam on heating degree-days.
