Environmental sociology and the sociology of natural resources are two key subdisciplines of the sociological study on the interactions between nature and human society.Previous discussion on the relationships of thes...Environmental sociology and the sociology of natural resources are two key subdisciplines of the sociological study on the interactions between nature and human society.Previous discussion on the relationships of these two fields has largely focused on their distinctions and synthesis in western(particularly American) academia.Environmental sociology emerged as an important sociological subdiscipline in China in the early 1990s and is under vigorous disciplinary construction at present.By contrast,the sociology of natural resources is still a novel term for most Chinese researchers.This article provides a systematic review of recent literature on the relationships between environmental and natural resource sociologies,which should provide important implications for the further development of environmental sociology in China.展开更多
Hot dry rock(HDR)is a kind of clean energy with significant potential.Since the 1970s,the United States,Japan,France,Australia,and other countries have attempted to conduct several HDR development research projects to...Hot dry rock(HDR)is a kind of clean energy with significant potential.Since the 1970s,the United States,Japan,France,Australia,and other countries have attempted to conduct several HDR development research projects to extract thermal energy by breaking through key technologies.However,up to now,the development of HDR is still in the research,development,and demonstration stage.An HDR exploration borehole(with 236℃ at a depth of 3705 m)was drilled into Triassic granite in the Gonghe Basin in northwest China in 2017.Subsequently,China Geological Survey(CGS)launched the HDR resources exploration and production demonstration project in 2019.After three years of efforts,a sequence of significant technological breakthroughs have been made,including the genetic model of deep heat sources,directional drilling and well completion in high-temperature hard rock,large-scale reservoir stimulation,reservoir characterization,and productivity evaluation,reservoir connectivity and flow circulation,efficient thermoelectric conversion,monitoring,and geological risk assessment,etc.Then the whole-process technological system for HDR exploration and production has been preliminarily established accordingly.The first power generation test was completed in November 2021.The results of this project will provide scientific support for HDR development and utilization in the future.展开更多
Kafr El-Dawar is a major industrial city and a municipality on the Nile Delta in northern Egypt. Kafr El-Dawar area is unfortunately suffering from many factories that let out their waste water into the irrigation can...Kafr El-Dawar is a major industrial city and a municipality on the Nile Delta in northern Egypt. Kafr El-Dawar area is unfortunately suffering from many factories that let out their waste water into the irrigation canal and agricultural drains. Twenty five water samples were collected from five water resources to assess their heavy pollution. The determination of heavy metals (HV) water resources content conducted to compose the following increasing HV concentration sequences;Drain Abu Qir (DA): Min (Cu)_Max (Zn), Canal Dbora Deufsho (CD): Min (Cu)_Max (Zn), Drain Dbora Abu Qir (DD): Min (Cu)_Max (Fe), Drain Kafr Dawar Deufsho (DK) : Min (Cu)_Max (Mn) and Drain Yarn and Fabric (DY) Min (Cu)_Max (Zn). Distribution patterns of HV concentration of water resources were (a) wide spread-distribution (Cr, Co, Mn), (b) moderately spread distribution pattern (Cu, Ni, Pb),and (c) narrow spread distribution pattern (Fe, Cd, Li and Zn) . The association study conducted to classify the HV concentration into three groups;positively highly correlated HV: (Pb_Cd), (Pb_Co), (Pb_Cr), (Cd_Co), (Zn_Fe), (Cr_Co), (Ni_Co) and (Ni_Fe), negatively highly correlated HV: (Pb_Mn), (Cd_Mn), (Mn_Cu) and (Co_Li) and intermediate cases (non-significant positive and negative intercorrelation) that was represented by the other cases. The low values of contamination factor, of short term use (CfiST), showed that the majority of HV concentration, of the studied water resources was at safe use level. This certainly with exception of the cases of cadmium that classified the water resources DA and CD, and DD into polluted and risky levels, respectively. The high values of contamination factor, of long term use (CfiLT), indicated that the studied water resources were mainly contaminated by Cd, Co and Cr heavy metals. Contrary, the low values of (CfiLT) of Zn, Fe, Li, Ni, Pb and Cu, all studied water resources are safe. Contamination degree index (Cd) indicated the safe use at short term of water resources (DA), (CD) and (DD), and (DY) water resources were highly contaminated. According to (Cd) values, moderate risk is expected if we use the water resource (DK), even in the short term. As for the long term use, all studied water resources were highly contaminated that they cannot be absolutely used in the long run.展开更多
The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been tested.Using a comprehensive global dataset including 27,297 m...The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been tested.Using a comprehensive global dataset including 27,297 measurements of wood density from 2621 tree species worldwide,we test the hypothesis that the legacy of evolutionary history plays an important role in driving the variation of wood density among tree species.We assessed phylogenetic signal in different taxonomic(e.g.,angiosperms and gymnosperms)and ecological(e.g.,tropical,temperate,and boreal)groups of tree species,explored the biogeographical and phylogenetic patterns of wood density,and quantified the relative importance of current environmental factors(e.g.,climatic and soil variables)and evolutionary history(i.e.,phylogenetic relatedness among species and lineages)in driving global wood density variation.We found that wood density displayed a significant phylogenetic signal.Wood density differed among different biomes and climatic zones,with higher mean values of wood density in relatively drier regions(highest in subtropical desert).Our study revealed that at a global scale,for angiosperms and gymnosperms combined,phylogeny and species(representing the variance explained by taxonomy and not direct explained by long-term evolution process)explained 84.3%and 7.7%of total wood density variation,respectively,whereas current environment explained 2.7%of total wood density variation when phylogeny and species were taken into account.When angiosperms and gymnosperms were considered separately,the three proportions of explained variation are,respectively,84.2%,7.5%and 6.7%for angiosperms,and 45.7%,21.3%and 18.6%for gymnosperms.Our study shows that evolutionary history outpaced current environmental factors in shaping global variation in wood density.展开更多
Alfalfa (Medicago sativa L.) is an important forage and conservation crop in North America but occurrences of naturalized alfalfa in rangelands are rare. A naturalized population of yellow-flowered alfalfa in mixed-gr...Alfalfa (Medicago sativa L.) is an important forage and conservation crop in North America but occurrences of naturalized alfalfa in rangelands are rare. A naturalized population of yellow-flowered alfalfa in mixed-grass prairie on the Grand River National Grassland in South Dakota has potential agricultural value for the region. Despite this value, the distribution pattern of this alfalfa among and within native plant communities in the northern Great Plains is unknown. Field studies were conducted from 2003 through 2006 along topographic positions at two sites where yellow-flowered alfalfa was naturalized to evaluate the relationships of yellow-flowered alfalfa on biomass production, cover, species diversity, and alfalfa seedbank distribution characteristics. High yellow-flowered alfalfa cover (>50%) was associated with increased total biomass and occurred exclusively in swales and toeslopes that had silty loam soils. However, species diversity and non-alfalfa biomass were reduced when yellow-flowered alfalfa cover was high. Yellow-flowered alfalfa cover was lower and species richness was higher on backslopes and shoulder areas where sandy loam soils were present. A strong positive linear association existed between yellow-flowered alfalfa cover and alfalfa seedbank density (r values ranged from 0.76 to 0.82, P < 0.0001). Greater than 99% of the seeds were viable but germination rate was only 4%, indicating a high percentage of hard seed in this alfalfa population. Naturalized yellow-flowered alfalfa was a dominant component of a stable, low diversity plant community composed of mainly introduced species in rich soils of swales/toeslopes that contributed to forage production and quality in mixed-grass prairie in the northern Great Plains.展开更多
In this study, the roles of indigenous knowledge and farmers’ perception of natural resources management were analyzed. A total of seventy households were selected by simple random sampling with replacement method fo...In this study, the roles of indigenous knowledge and farmers’ perception of natural resources management were analyzed. A total of seventy households were selected by simple random sampling with replacement method for collection of data. Formal interviews were conducted to the 5% plus of households in the study area in addition to the focus group discussions and qualitative field observations. It was expressed by 98.6% of the total respondents that “Sera” which is the traditional practice has being used to manage natural resources in the study area. In the “Sera” systems, individuals are excluded a punishment from any kind of social interaction in a response to their unlawful action in the community natural resources. It was indicated by 84.3% of respondents that deforestation and related problems are the major challenges including grazing and shortage of farm size for the management of the culturally protected forest in the study area. The majority of the respondents (77.1%) believed that soil fertility decline in the study area. Development of effective participatory forest management and encouragement and supporting the traditional method of natural resources management is required to ensure the preservation and protection of these areas essential to ecosystem service provision, provide high biodiversity value and cultural heritage, and maintain the sustainability of culturally protected forest.展开更多
Water resources face many pressures and stresses around the world.Assessing the vulnerability of water resources is,therefore,increasingly an essential practice in water resources management.Several studies of water r...Water resources face many pressures and stresses around the world.Assessing the vulnerability of water resources is,therefore,increasingly an essential practice in water resources management.Several studies of water resources vulnerability have been carried out around the world during the last three decades.Thus,the main objective of this study was to analyze water resources vulnerability assessment tools and identify the methodological trend of water resources vulnerability assessment at the local level in existing literature.To achieve this objective,the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)method has been applied to include or exclude articles.Articles on water vulnerability numbering 374 were preselected in the ScienceDirect and the Google Scholar databases.Only 32 out of the 374 articles met the inclusion criteria defined for the analysis.The results show that China(21.9%),U.S.A.(9.4%)and Canada(6.3%)are the most active countries publishing water resources vulnerability assessments.Some 191 vulnerability indicators from the 32 articles were classified into five categories of factors:physical factors(33.5%),socio-economic factors(28.3%),environmental or eco-environmental factors(25.1%),institutions and governance factors(7.3%)and infrastructure factors(5.8%).This study shows that almost half of the studies(47%)considered all five categories of factors,9.4%considered four categories of factors,6.3%considered three categories of factors,28%used two types of factors and 9.4%considered only one category.Researchers have used several methods to assess water resources vulnerability:overlay and index methods(59.4%),process-based models(12.5%),statistical methods(9.4%),overlay and index methods plus process-based model(9.4%),overlay and index methods plus statistical methods(6.3%)and statistical methods plus process-based models(3.1%).Geographic information system(GIS)is an important tool in assessing the vulnerability of water resources with almost 60%of the studies using it at some stage of the assessment.In recent years,there is an increasing trend toward conceptualizing the vulnerability of water resources in a holistic way.展开更多
The Upper Mississippi River flows approximately 2000 km from Lake Itasca, Minnesota to Cairo, Illinois where it is confluences with the Ohio River to form the Lower Mississippi River. North of the confluence, numerous...The Upper Mississippi River flows approximately 2000 km from Lake Itasca, Minnesota to Cairo, Illinois where it is confluences with the Ohio River to form the Lower Mississippi River. North of the confluence, numerous snags, sand bars, rapids, and other obstructions made the Upper Mississippi River travel difficult. This paper highlights how the geological and landscape resources of the Upper Mississippi River and tributary watershed were responsible for the successful economic development of this historically rich region of North America. Environmental challenges include an attempt to keep invasive species such as the Asian carp out of the rivers and lakes north of the Twin Cities. In an attempt to protect the Mississippi River resource, Environmental and Conservation groups have opposed continued navigation through Minneapolis and St. Paul and the planned Upper Mississippi River navigation infrastructure restoration by the United States Corps of Engineers including the upper and lower St. Anthony locks and dams. These Environmental, Conservation and Save the River groups are attempting to mitigate the historic highest and best use of the Mississippi River and adjacent watershed, navigation, and economic development, by having the urban river restored to the natural state.展开更多
The economy of Ethiopia has prospered for many years on agricultural products but currently, the country expands to industrialization and service providing for additional incomes. However, the wildlife tourism and con...The economy of Ethiopia has prospered for many years on agricultural products but currently, the country expands to industrialization and service providing for additional incomes. However, the wildlife tourism and conservation practices are still at low attention. Therefore, this review paper identifies potential opportunities and wildlife diversity to promote wildlife tourism practices in Ethiopia. Furthermore, it also identifies the challenges and future directions to put into practice for future wildlife tourism industry. Wildlife tourism is one of the best potential economies to the country due to the presence of magnificent diversity of wildlife with high endemism and expansion of protected areas. The main intentions of tourists are to visit large mammals and birds with their natural habitats. The country earns million dollars per year only from protected areas through nature based tourism. The Montane and Afroalpine, Rift Valley and Transboundary ecosystem, a world class icon for wildlife tourism which attracts various tourists, and potential tourism destination for Ethiopia due to its high mammalian diversity and scenic area. The expansion of protected areas, peaceful and friendly people, and endemism promote tourism industry in Ethiopia. Even though, Ethiopia is the third country next to Tanzania and Uganda in terms of land surface of protected area;human-wildlife conflict, loss of biodiversity, and limited tourism and conservation attention with poor infrastructure are some of the major challenges. To scale up wildlife tourism industry, better promotion with practical conservation practices, community based tourism approaches and infrastructures should be implemented throughout the whole area of tourist destination.展开更多
Balneological use of the Albanian Geothermal springs and waters dates back centuries, but the first modern use started in 1937. Unfortunately they had not been used for its energetic values yet. The temperature of the...Balneological use of the Albanian Geothermal springs and waters dates back centuries, but the first modern use started in 1937. Unfortunately they had not been used for its energetic values yet. The temperature of the water is above 60 °C and the flow above 16 l/s, thus direct utilization is possible, in particular for space heating. Three-dimensional temperature field calculations and engineering calculations on a heating system with heat exchangers are presented here. The results show that the water temperature is expected to be stable and considerably higher temperature is expected through deep well drilling. The University’s Campus of Tirana is composed of 29 buildings, which are partially heated through a coal heater. The installed capacity is 2558kW while the coal consumption is about 920 kg/h. The University’s Campus of Tirana is one of the most important areas and with the highest density of population in Tirana, so it is the best area to show the heat exchanger efficiency. The economic analyses prove that the borehole heat exchangers are more convenient than the coal heating systems.展开更多
Understanding the factors influencing the distribution of plant species is crucial for enhancing the management of endangered ecosystems. This study investigated the response of Hedysarum criniferum Boiss, an endemic ...Understanding the factors influencing the distribution of plant species is crucial for enhancing the management of endangered ecosystems. This study investigated the response of Hedysarum criniferum Boiss, an endemic and endangered species to 25 environmental variables within its habitats with an area of 2.95×10^(5) km^(2) in arid and semi-arid rangelands of Iran. The purpose of this research is to identify the key environmental factors affecting the distribution and habitat preferences of H. criniferum for further conservation and restoration of the species. To predict the occurrence of H. criniferum and explore its relationship with environmental factors, we employed the best subset regression analysis, the hierarchical classification, and the extended Huisman-Olf-Fresco(eHOF) model. The results showed that four environmental variables, i.e., gravel content, pH, annual minimum temperature, and mean annual temperature showed significant correlations with the canopy cover of H. criniferum(P<0.05). The probability of H. criniferum occurrence increased with higher precipitation and elevation, while it decreased with higher mean annual temperature, annual minimum temperature, and gravel content. The species' response curves and their optimal values, as assessed by the eHOF model, indicated that the response to mean annual temperature, ranging from 12℃ to 16℃, was optimal at 13℃. The response to mean annual precipitation, within a range of 150–650 mm, was optimal at 650 mm. Elevation responses, spanning from 1546 to 2450 m, showed an optimum at 2450 m. Regarding soil characteristics, the response to gravel content, ranging from 13.0%–48.0%, demonstrated an optimal value at 20.0%. The pH levels, varying from 7.5 to 8.2, prompted a sine-shaped response with an optimal pH of 8.0. These findings provide valuable insights for predicting species occurrence and identifying suitable locations for restoration programs. Our study underscores the importance of considering multiple environmental variables in habitat suitability assessments. By incorporating these broader considerations, we can further refine predictive models and enhance conservation efforts aimed at restoring habitats conducive to the luxuriance of endangered species like H. criniferum.展开更多
The inflection point is an important feature of sigmoidal height-diameter(H-D)models.It is often cited as one of the properties favoring sigmoidal model forms.However,there are very few studies analyzing the inflectio...The inflection point is an important feature of sigmoidal height-diameter(H-D)models.It is often cited as one of the properties favoring sigmoidal model forms.However,there are very few studies analyzing the inflection points of H-D models.The goals of this study were to theoretically and empirically examine the behaviors of inflection points of six common H-D models with a regional dataset.The six models were the Wykoff(WYK),Schumacher(SCH),Curtis(CUR),HossfeldⅣ(HOS),von Bertalanffy-Richards(VBR),and Gompertz(GPZ)models.The models were first fitted in their base forms with tree species as random effects and were then expanded to include functional traits and spatial distribution.The distributions of the estimated inflection points were similar between the two-parameter models WYK,SCH,and CUR,but were different between the threeparameter models HOS,VBR,and GPZ.GPZ produced some of the largest inflection points.HOS and VBR produced concave H-D curves without inflection points for 12.7%and 39.7%of the tree species.Evergreen species or decreasing shade tolerance resulted in larger inflection points.The trends in the estimated inflection points of HOS and VBR were entirely opposite across the landscape.Furthermore,HOS could produce concave H-D curves for portions of the landscape.Based on the studied behaviors,the choice between two-parameter models may not matter.We recommend comparing seve ral three-parameter model forms for consistency in estimated inflection points before deciding on one.Believing sigmoidal models to have inflection points does not necessarily mean that they will produce fitted curves with one.Our study highlights the need to integrate analysis of inflection points into modeling H-D relationships.展开更多
Mountain biodiversity is of great importance to biogeography and ecology.However,it is unclear what ecological and evolutionary processes best explain the generation and maintenance of its high levels of species diver...Mountain biodiversity is of great importance to biogeography and ecology.However,it is unclear what ecological and evolutionary processes best explain the generation and maintenance of its high levels of species diversity.In this study,we determined which of six common hypotheses(e.g.,climate hypotheses,habitat heterogeneity hypothesis and island biogeography theory)best explain global patterns of species diversity in Rhododendron.We found that Rhododendron diversity patterns were most strongly explained by proxies of island biogeography theory(i.e.,mountain area)and habitat heterogeneity(i.e.,elevation range).When we examined other relationships important to island biogeography theory,we found that the planimetric area and the volume of mountains were positively correlated with the Rhododendron diversity,whereas the‘mountains-to-mainland’distance was negatively correlated with Rhododendron diversity and shared species.Our findings demonstrate that Rhododendron diversity can be explained by island biogeography theory and habitat heterogeneity,and mountains can be regarded as islands which supported island biogeography theory.展开更多
The use of the Albanian geothermal springs and waters, for their curative effects (Natural SPA) dates back centuries, since the time of the Roman Empire, while their first modern use started only in 1937. Unfortunat...The use of the Albanian geothermal springs and waters, for their curative effects (Natural SPA) dates back centuries, since the time of the Roman Empire, while their first modern use started only in 1937. Unfortunately they had not been used for its energetic values yet. The temperature of the water is above 60 ~C and the flow above 16 L/s, thus direct utilization is possible, in particular for space heating. Three-dimensional temperature field calculations and engineering calculations on a heating system with heat exchangers are presented here. The results show that the water temperature is expected to be stable and considerably higher temperature is expected through deep well drilling. The University's Campus of Tirana is composed of 29 buildings, which are partially heated through a coal heater. The installed capacity is 2,558 kW while the coal consumption is about 920 kg/h. The University's Campus of Tirana is one of the most important areas and with the highest density of population in Tirana, so it is the best area to show the heat exchanger efficiency. The economic analyses prove that the borehole heat exchangers are more convenient than the coal heating systems.展开更多
Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic conditions.The A...Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic conditions.The African birch(Anogeissus leiocarpa(DC.)Guill.&Perr.)and pink jacaranda(Stereospermum kunthianum Cham.)trees are the dominant species in the agroforestry parkland system in the drylands of Tigray,Ethiopia.Smallholder farmers highly value these trees for their multifunctional uses including timber,firewood,charcoal,medicine,etc.These trees also could improve soil fertility.However,the amount of soil physical and chemical properties enhanced by the two species must be determined to maintain the sustainable conservation of the species in the parklands and to scale up to similar agroecological systems.Hence,we selected twelve isolated trees,six from each species that had similar dendrometric characteristics and were growing in similar environmental conditions.We divided the canopy cover of each tree into three radial distances:mid-canopy,canopy edge,and canopy gap(control).At each distance,we took soil samples from three different depths.We collected 216 soil samples(half disturbed and the other half undisturbed)from each canopy position and soil depth.Bulk density(BD),soil moisture content(SMC),soil organic carbon(SOC),total nitrogen(TN),available phosphorus(AP),available potassium(AK),p H,electrical conductivity(EC),and cation exchange capacity(CEC)were analysed.Results revealed that soil physical and chemical properties significantly improved except for soil texture and EC under both species,CEC under A.leiocarpus,and soil p H under S.kunthianum,all the studied soils were improved under both species canopy as compared with canopy gap.SMC,TN,AP,and AK under canopy of these trees were respectively 24.1%,11.1%,55.0%,and 9.3% higher than those soils under control.The two parkland agroforestry species significantly enhanced soil fertility near the canopy of topsoil through improving soil physical and chemical properties.These two species were recommended in the drylands with similar agro-ecological systems.展开更多
The sustainability of environmental management initiatives,such as watershed management programs,relies on the presence of effective institutions at the watershed level.However,there needs to be more empirical evidenc...The sustainability of environmental management initiatives,such as watershed management programs,relies on the presence of effective institutions at the watershed level.However,there needs to be more empirical evidence from evaluating the effectiveness of watershed-level institutions.Therefore,this study presents a pioneering effort to evaluate the effectiveness of Nepal’s first watershed conservation committee at the watershed scale,focusing on the case of the Khageri Khola watershed in Central Nepal.The study involved conducting a household survey,key informant interviews,focus group discussions,and field observations to collect and analyze the data.Descriptive analysis,index value calculation,and chi-square statistics were then employed to summarize the results regarding local respondents’perceptions of twelve institutional characteristics,their rationalities,and their association with socio-demographic variables.The results reveal that the watershed conservation committee was perceived as performing well in managing the watershed.Specifically,good interaction,appropriate scale,technical,environmental,social,organizational,and government rationality were perceived as highly effective,with an average index value of less than 0.36.In contrast,clarity of objectives and economic rationality showed moderate effectiveness,with an average index value ranging from 0.36 to 0.65.However,the results suggested that adaptiveness,compliance capacity,and financial rationality merit increased attention,intending to improve their performance.Further,the results showed the association of socio-demographics with respondents’perceptions of various indicators of institutional characteristics and their rationalities.Therefore,the study provides valuable insights for policymakers,researchers,and development practitioners charged with designing sustainable and effective programs and institutions.To enhance the effectiveness and sustainability of watershed management programs,we recommend establishing a policy-guided institutional mechanism at the watershed scale.This mechanism should be based on various institutional characteristics and rationalities and should consider the extant variability in the socio-demographic and topographic characteristics of the watershed.展开更多
Barshore is a small village in the Pishin District,Balochistan,Pakistan,with dry summers and cold rainy winters.This is an agrarian region,mostly with orchards of various fruit trees.This study investigated the physic...Barshore is a small village in the Pishin District,Balochistan,Pakistan,with dry summers and cold rainy winters.This is an agrarian region,mostly with orchards of various fruit trees.This study investigated the physico-chemical properties and macrofauna of soils under various agricultural management practices of this region.The concentrations of soil organic matter(SOM),soil organic carbon(SOC),nutrients,pH,electrical conductivity,soil texture,and the abundance and number of species of soil macrofauna of the agricultural fields were measured.Fifteen agricultural fields were sampled.Fourteen fields were orchards of apple,apricot or the mixture of apple and apricot trees and one field was a cropland,cultivated with wheat as a monocrop.The orchards were under conservation agricultural practices;whereas,the cropland was under conventional management.These agricultural lands were 2-26 years old.The concentration of soil organic matter(SOM)in the upper 0-10 cm depth of these field sites ranged from 11.6 g kg^(-1)to 32.8 g kg^(-1)soil.As compared to cropland,orchards had significantly higher concentration of SOM and SOC.A total of 18 soil macrofauna species were found and the most common and abundant were ants(Monomorium minimum,Camponotus pennsylvanicus,Solenopsis invicta,and Lasius niger)followed by Arion ssp.(Brown Slug)and earthworm Lumbricus terrestris.Regression analysis revealed non-significant relationship of the age and the concentration of SOM with the number of macrofauna species and with the concentrations of total mineral nitrogen,bioavailable phosphorus and clay.The existence of ants had no relationship with the concentration of SOM;whereas,existence of Lumbricus terrestris tended to had a positive relationship with the concentration of SOM.The field of tree-based intercropping system was 2 years of age since the land was converted from rangeland to a cropland,had two ant species coexisting.This indicates the positive influence of crop diversification on soil macrofauna.展开更多
Volume is an important attribute used in many forest management decisions.Data from 83 fixed-area plots located in central New Brunswick,Canada,are used to examine how different measures of stand-level diameter and he...Volume is an important attribute used in many forest management decisions.Data from 83 fixed-area plots located in central New Brunswick,Canada,are used to examine how different measures of stand-level diameter and height influence volume prediction using a stand-level variant of Honer's(1967)volume equation.When density was included in the models(Volume=f(Diameter,Height,Density))choice of diameter measure was more important than choice of height measure.When density was not included(Volume=f(Diameter,Height)),the opposite was true.For models with density included,moment-based estimators of stand diameter and height performed better than all other measures.For models without density,largest tree estimators of stand diameter and height performed better than other measures.The overall best equation used quadratic mean diameter,Lorey's height,and density(root mean square error=5.26 m^3·ha^(-1);1.9%relative error).The best equation without density used mean diameter of the largest trees needed to calculate a stand density index of 400 and the mean height of the tallest 400 trees per ha(root mean square error=32.08 m^(3)·ha^(-1);11.8%relative error).The results of this study have some important implications for height subsampling and LiDAR-derived forest inventory analyses.展开更多
Objective:To explore the potential therapeutic impact of an alcoholic extract derived from the sea cucumber(Holothuria parva)on letrozole-induced polycystic ovary syndrome(PCOS)in adult female Sprague-Dawley rats.Meth...Objective:To explore the potential therapeutic impact of an alcoholic extract derived from the sea cucumber(Holothuria parva)on letrozole-induced polycystic ovary syndrome(PCOS)in adult female Sprague-Dawley rats.Methods:Sixteen female rats,aged 8 to 10 weeks,with a mean weight of(200±20)g,were randomly assigned to four groups:the control,PCOS,and two treatment groups receiving sea cucumber extract and metformin,respectively.PCOS was induced by administering letrozole at a dose of 1 mg/kg to initiate the treatment period at 60 days of age.The study spanned four weeks,during which ovarian and uterine tissues were collected for histological examination,and blood samples were collected for hormonal levels.Results:Significant decreases in luteinizing hormone/follicle stimulating hormone(LH/FSH)and testosterone and increases progesterone levels among groups treated with sea cucumber extract were observed.While no significant differences were observed in follicle-stimulating hormone(FSH)and testosterone levels,the distinctive variations in key hormones suggested a potential role for sea cucumber alcoholic extract in ameliorating PCOS symptoms.Conclusions:This research highlights the moderate efficacy of sea cucumber extract as a therapeutic intervention for PCOS,providing a novel perspective in the search for effective remedies.The observed hormonal alterations,particularly in LH,estradiol,and progesterone,underscore the need for further exploration into the underlying mechanisms and for optimizing the application of sea cucumber extract in PCOS management.展开更多
Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility ...Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMN). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary.展开更多
文摘Environmental sociology and the sociology of natural resources are two key subdisciplines of the sociological study on the interactions between nature and human society.Previous discussion on the relationships of these two fields has largely focused on their distinctions and synthesis in western(particularly American) academia.Environmental sociology emerged as an important sociological subdiscipline in China in the early 1990s and is under vigorous disciplinary construction at present.By contrast,the sociology of natural resources is still a novel term for most Chinese researchers.This article provides a systematic review of recent literature on the relationships between environmental and natural resource sociologies,which should provide important implications for the further development of environmental sociology in China.
基金funded by the“Hot Dry Rock Resources Exploration and Production Demonstration Project”of the China Geological Survey(DD20190131,DD20190135,DD20211336).
文摘Hot dry rock(HDR)is a kind of clean energy with significant potential.Since the 1970s,the United States,Japan,France,Australia,and other countries have attempted to conduct several HDR development research projects to extract thermal energy by breaking through key technologies.However,up to now,the development of HDR is still in the research,development,and demonstration stage.An HDR exploration borehole(with 236℃ at a depth of 3705 m)was drilled into Triassic granite in the Gonghe Basin in northwest China in 2017.Subsequently,China Geological Survey(CGS)launched the HDR resources exploration and production demonstration project in 2019.After three years of efforts,a sequence of significant technological breakthroughs have been made,including the genetic model of deep heat sources,directional drilling and well completion in high-temperature hard rock,large-scale reservoir stimulation,reservoir characterization,and productivity evaluation,reservoir connectivity and flow circulation,efficient thermoelectric conversion,monitoring,and geological risk assessment,etc.Then the whole-process technological system for HDR exploration and production has been preliminarily established accordingly.The first power generation test was completed in November 2021.The results of this project will provide scientific support for HDR development and utilization in the future.
文摘Kafr El-Dawar is a major industrial city and a municipality on the Nile Delta in northern Egypt. Kafr El-Dawar area is unfortunately suffering from many factories that let out their waste water into the irrigation canal and agricultural drains. Twenty five water samples were collected from five water resources to assess their heavy pollution. The determination of heavy metals (HV) water resources content conducted to compose the following increasing HV concentration sequences;Drain Abu Qir (DA): Min (Cu)_Max (Zn), Canal Dbora Deufsho (CD): Min (Cu)_Max (Zn), Drain Dbora Abu Qir (DD): Min (Cu)_Max (Fe), Drain Kafr Dawar Deufsho (DK) : Min (Cu)_Max (Mn) and Drain Yarn and Fabric (DY) Min (Cu)_Max (Zn). Distribution patterns of HV concentration of water resources were (a) wide spread-distribution (Cr, Co, Mn), (b) moderately spread distribution pattern (Cu, Ni, Pb),and (c) narrow spread distribution pattern (Fe, Cd, Li and Zn) . The association study conducted to classify the HV concentration into three groups;positively highly correlated HV: (Pb_Cd), (Pb_Co), (Pb_Cr), (Cd_Co), (Zn_Fe), (Cr_Co), (Ni_Co) and (Ni_Fe), negatively highly correlated HV: (Pb_Mn), (Cd_Mn), (Mn_Cu) and (Co_Li) and intermediate cases (non-significant positive and negative intercorrelation) that was represented by the other cases. The low values of contamination factor, of short term use (CfiST), showed that the majority of HV concentration, of the studied water resources was at safe use level. This certainly with exception of the cases of cadmium that classified the water resources DA and CD, and DD into polluted and risky levels, respectively. The high values of contamination factor, of long term use (CfiLT), indicated that the studied water resources were mainly contaminated by Cd, Co and Cr heavy metals. Contrary, the low values of (CfiLT) of Zn, Fe, Li, Ni, Pb and Cu, all studied water resources are safe. Contamination degree index (Cd) indicated the safe use at short term of water resources (DA), (CD) and (DD), and (DY) water resources were highly contaminated. According to (Cd) values, moderate risk is expected if we use the water resource (DK), even in the short term. As for the long term use, all studied water resources were highly contaminated that they cannot be absolutely used in the long run.
基金supported by the Scientific Research Project of Anhui Province(2022AH050873)the State Key Laboratory of Subtropical Silviculture(SKLSS-KF2023-08)+1 种基金the Provincial Natural Resources Fund(1908085QC140)the National Key R&D Program of China(2018YFD1000600).
文摘The effect of evolutionary history on wood density variation may play an important role in shaping variation in wood density,but this has largely not been tested.Using a comprehensive global dataset including 27,297 measurements of wood density from 2621 tree species worldwide,we test the hypothesis that the legacy of evolutionary history plays an important role in driving the variation of wood density among tree species.We assessed phylogenetic signal in different taxonomic(e.g.,angiosperms and gymnosperms)and ecological(e.g.,tropical,temperate,and boreal)groups of tree species,explored the biogeographical and phylogenetic patterns of wood density,and quantified the relative importance of current environmental factors(e.g.,climatic and soil variables)and evolutionary history(i.e.,phylogenetic relatedness among species and lineages)in driving global wood density variation.We found that wood density displayed a significant phylogenetic signal.Wood density differed among different biomes and climatic zones,with higher mean values of wood density in relatively drier regions(highest in subtropical desert).Our study revealed that at a global scale,for angiosperms and gymnosperms combined,phylogeny and species(representing the variance explained by taxonomy and not direct explained by long-term evolution process)explained 84.3%and 7.7%of total wood density variation,respectively,whereas current environment explained 2.7%of total wood density variation when phylogeny and species were taken into account.When angiosperms and gymnosperms were considered separately,the three proportions of explained variation are,respectively,84.2%,7.5%and 6.7%for angiosperms,and 45.7%,21.3%and 18.6%for gymnosperms.Our study shows that evolutionary history outpaced current environmental factors in shaping global variation in wood density.
文摘Alfalfa (Medicago sativa L.) is an important forage and conservation crop in North America but occurrences of naturalized alfalfa in rangelands are rare. A naturalized population of yellow-flowered alfalfa in mixed-grass prairie on the Grand River National Grassland in South Dakota has potential agricultural value for the region. Despite this value, the distribution pattern of this alfalfa among and within native plant communities in the northern Great Plains is unknown. Field studies were conducted from 2003 through 2006 along topographic positions at two sites where yellow-flowered alfalfa was naturalized to evaluate the relationships of yellow-flowered alfalfa on biomass production, cover, species diversity, and alfalfa seedbank distribution characteristics. High yellow-flowered alfalfa cover (>50%) was associated with increased total biomass and occurred exclusively in swales and toeslopes that had silty loam soils. However, species diversity and non-alfalfa biomass were reduced when yellow-flowered alfalfa cover was high. Yellow-flowered alfalfa cover was lower and species richness was higher on backslopes and shoulder areas where sandy loam soils were present. A strong positive linear association existed between yellow-flowered alfalfa cover and alfalfa seedbank density (r values ranged from 0.76 to 0.82, P < 0.0001). Greater than 99% of the seeds were viable but germination rate was only 4%, indicating a high percentage of hard seed in this alfalfa population. Naturalized yellow-flowered alfalfa was a dominant component of a stable, low diversity plant community composed of mainly introduced species in rich soils of swales/toeslopes that contributed to forage production and quality in mixed-grass prairie in the northern Great Plains.
文摘In this study, the roles of indigenous knowledge and farmers’ perception of natural resources management were analyzed. A total of seventy households were selected by simple random sampling with replacement method for collection of data. Formal interviews were conducted to the 5% plus of households in the study area in addition to the focus group discussions and qualitative field observations. It was expressed by 98.6% of the total respondents that “Sera” which is the traditional practice has being used to manage natural resources in the study area. In the “Sera” systems, individuals are excluded a punishment from any kind of social interaction in a response to their unlawful action in the community natural resources. It was indicated by 84.3% of respondents that deforestation and related problems are the major challenges including grazing and shortage of farm size for the management of the culturally protected forest in the study area. The majority of the respondents (77.1%) believed that soil fertility decline in the study area. Development of effective participatory forest management and encouragement and supporting the traditional method of natural resources management is required to ensure the preservation and protection of these areas essential to ecosystem service provision, provide high biodiversity value and cultural heritage, and maintain the sustainability of culturally protected forest.
文摘Water resources face many pressures and stresses around the world.Assessing the vulnerability of water resources is,therefore,increasingly an essential practice in water resources management.Several studies of water resources vulnerability have been carried out around the world during the last three decades.Thus,the main objective of this study was to analyze water resources vulnerability assessment tools and identify the methodological trend of water resources vulnerability assessment at the local level in existing literature.To achieve this objective,the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)method has been applied to include or exclude articles.Articles on water vulnerability numbering 374 were preselected in the ScienceDirect and the Google Scholar databases.Only 32 out of the 374 articles met the inclusion criteria defined for the analysis.The results show that China(21.9%),U.S.A.(9.4%)and Canada(6.3%)are the most active countries publishing water resources vulnerability assessments.Some 191 vulnerability indicators from the 32 articles were classified into five categories of factors:physical factors(33.5%),socio-economic factors(28.3%),environmental or eco-environmental factors(25.1%),institutions and governance factors(7.3%)and infrastructure factors(5.8%).This study shows that almost half of the studies(47%)considered all five categories of factors,9.4%considered four categories of factors,6.3%considered three categories of factors,28%used two types of factors and 9.4%considered only one category.Researchers have used several methods to assess water resources vulnerability:overlay and index methods(59.4%),process-based models(12.5%),statistical methods(9.4%),overlay and index methods plus process-based model(9.4%),overlay and index methods plus statistical methods(6.3%)and statistical methods plus process-based models(3.1%).Geographic information system(GIS)is an important tool in assessing the vulnerability of water resources with almost 60%of the studies using it at some stage of the assessment.In recent years,there is an increasing trend toward conceptualizing the vulnerability of water resources in a holistic way.
文摘The Upper Mississippi River flows approximately 2000 km from Lake Itasca, Minnesota to Cairo, Illinois where it is confluences with the Ohio River to form the Lower Mississippi River. North of the confluence, numerous snags, sand bars, rapids, and other obstructions made the Upper Mississippi River travel difficult. This paper highlights how the geological and landscape resources of the Upper Mississippi River and tributary watershed were responsible for the successful economic development of this historically rich region of North America. Environmental challenges include an attempt to keep invasive species such as the Asian carp out of the rivers and lakes north of the Twin Cities. In an attempt to protect the Mississippi River resource, Environmental and Conservation groups have opposed continued navigation through Minneapolis and St. Paul and the planned Upper Mississippi River navigation infrastructure restoration by the United States Corps of Engineers including the upper and lower St. Anthony locks and dams. These Environmental, Conservation and Save the River groups are attempting to mitigate the historic highest and best use of the Mississippi River and adjacent watershed, navigation, and economic development, by having the urban river restored to the natural state.
文摘The economy of Ethiopia has prospered for many years on agricultural products but currently, the country expands to industrialization and service providing for additional incomes. However, the wildlife tourism and conservation practices are still at low attention. Therefore, this review paper identifies potential opportunities and wildlife diversity to promote wildlife tourism practices in Ethiopia. Furthermore, it also identifies the challenges and future directions to put into practice for future wildlife tourism industry. Wildlife tourism is one of the best potential economies to the country due to the presence of magnificent diversity of wildlife with high endemism and expansion of protected areas. The main intentions of tourists are to visit large mammals and birds with their natural habitats. The country earns million dollars per year only from protected areas through nature based tourism. The Montane and Afroalpine, Rift Valley and Transboundary ecosystem, a world class icon for wildlife tourism which attracts various tourists, and potential tourism destination for Ethiopia due to its high mammalian diversity and scenic area. The expansion of protected areas, peaceful and friendly people, and endemism promote tourism industry in Ethiopia. Even though, Ethiopia is the third country next to Tanzania and Uganda in terms of land surface of protected area;human-wildlife conflict, loss of biodiversity, and limited tourism and conservation attention with poor infrastructure are some of the major challenges. To scale up wildlife tourism industry, better promotion with practical conservation practices, community based tourism approaches and infrastructures should be implemented throughout the whole area of tourist destination.
文摘Balneological use of the Albanian Geothermal springs and waters dates back centuries, but the first modern use started in 1937. Unfortunately they had not been used for its energetic values yet. The temperature of the water is above 60 °C and the flow above 16 l/s, thus direct utilization is possible, in particular for space heating. Three-dimensional temperature field calculations and engineering calculations on a heating system with heat exchangers are presented here. The results show that the water temperature is expected to be stable and considerably higher temperature is expected through deep well drilling. The University’s Campus of Tirana is composed of 29 buildings, which are partially heated through a coal heater. The installed capacity is 2558kW while the coal consumption is about 920 kg/h. The University’s Campus of Tirana is one of the most important areas and with the highest density of population in Tirana, so it is the best area to show the heat exchanger efficiency. The economic analyses prove that the borehole heat exchangers are more convenient than the coal heating systems.
基金funded by the Isfahan University of Technology,Iran.
文摘Understanding the factors influencing the distribution of plant species is crucial for enhancing the management of endangered ecosystems. This study investigated the response of Hedysarum criniferum Boiss, an endemic and endangered species to 25 environmental variables within its habitats with an area of 2.95×10^(5) km^(2) in arid and semi-arid rangelands of Iran. The purpose of this research is to identify the key environmental factors affecting the distribution and habitat preferences of H. criniferum for further conservation and restoration of the species. To predict the occurrence of H. criniferum and explore its relationship with environmental factors, we employed the best subset regression analysis, the hierarchical classification, and the extended Huisman-Olf-Fresco(eHOF) model. The results showed that four environmental variables, i.e., gravel content, pH, annual minimum temperature, and mean annual temperature showed significant correlations with the canopy cover of H. criniferum(P<0.05). The probability of H. criniferum occurrence increased with higher precipitation and elevation, while it decreased with higher mean annual temperature, annual minimum temperature, and gravel content. The species' response curves and their optimal values, as assessed by the eHOF model, indicated that the response to mean annual temperature, ranging from 12℃ to 16℃, was optimal at 13℃. The response to mean annual precipitation, within a range of 150–650 mm, was optimal at 650 mm. Elevation responses, spanning from 1546 to 2450 m, showed an optimum at 2450 m. Regarding soil characteristics, the response to gravel content, ranging from 13.0%–48.0%, demonstrated an optimal value at 20.0%. The pH levels, varying from 7.5 to 8.2, prompted a sine-shaped response with an optimal pH of 8.0. These findings provide valuable insights for predicting species occurrence and identifying suitable locations for restoration programs. Our study underscores the importance of considering multiple environmental variables in habitat suitability assessments. By incorporating these broader considerations, we can further refine predictive models and enhance conservation efforts aimed at restoring habitats conducive to the luxuriance of endangered species like H. criniferum.
文摘The inflection point is an important feature of sigmoidal height-diameter(H-D)models.It is often cited as one of the properties favoring sigmoidal model forms.However,there are very few studies analyzing the inflection points of H-D models.The goals of this study were to theoretically and empirically examine the behaviors of inflection points of six common H-D models with a regional dataset.The six models were the Wykoff(WYK),Schumacher(SCH),Curtis(CUR),HossfeldⅣ(HOS),von Bertalanffy-Richards(VBR),and Gompertz(GPZ)models.The models were first fitted in their base forms with tree species as random effects and were then expanded to include functional traits and spatial distribution.The distributions of the estimated inflection points were similar between the two-parameter models WYK,SCH,and CUR,but were different between the threeparameter models HOS,VBR,and GPZ.GPZ produced some of the largest inflection points.HOS and VBR produced concave H-D curves without inflection points for 12.7%and 39.7%of the tree species.Evergreen species or decreasing shade tolerance resulted in larger inflection points.The trends in the estimated inflection points of HOS and VBR were entirely opposite across the landscape.Furthermore,HOS could produce concave H-D curves for portions of the landscape.Based on the studied behaviors,the choice between two-parameter models may not matter.We recommend comparing seve ral three-parameter model forms for consistency in estimated inflection points before deciding on one.Believing sigmoidal models to have inflection points does not necessarily mean that they will produce fitted curves with one.Our study highlights the need to integrate analysis of inflection points into modeling H-D relationships.
基金supported by the National Natural Science Foundation of China(NO.41901060).
文摘Mountain biodiversity is of great importance to biogeography and ecology.However,it is unclear what ecological and evolutionary processes best explain the generation and maintenance of its high levels of species diversity.In this study,we determined which of six common hypotheses(e.g.,climate hypotheses,habitat heterogeneity hypothesis and island biogeography theory)best explain global patterns of species diversity in Rhododendron.We found that Rhododendron diversity patterns were most strongly explained by proxies of island biogeography theory(i.e.,mountain area)and habitat heterogeneity(i.e.,elevation range).When we examined other relationships important to island biogeography theory,we found that the planimetric area and the volume of mountains were positively correlated with the Rhododendron diversity,whereas the‘mountains-to-mainland’distance was negatively correlated with Rhododendron diversity and shared species.Our findings demonstrate that Rhododendron diversity can be explained by island biogeography theory and habitat heterogeneity,and mountains can be regarded as islands which supported island biogeography theory.
文摘The use of the Albanian geothermal springs and waters, for their curative effects (Natural SPA) dates back centuries, since the time of the Roman Empire, while their first modern use started only in 1937. Unfortunately they had not been used for its energetic values yet. The temperature of the water is above 60 ~C and the flow above 16 L/s, thus direct utilization is possible, in particular for space heating. Three-dimensional temperature field calculations and engineering calculations on a heating system with heat exchangers are presented here. The results show that the water temperature is expected to be stable and considerably higher temperature is expected through deep well drilling. The University's Campus of Tirana is composed of 29 buildings, which are partially heated through a coal heater. The installed capacity is 2,558 kW while the coal consumption is about 920 kg/h. The University's Campus of Tirana is one of the most important areas and with the highest density of population in Tirana, so it is the best area to show the heat exchanger efficiency. The economic analyses prove that the borehole heat exchangers are more convenient than the coal heating systems.
基金supported by the Sustainable Forest Management Project with the Local Communities in Tigray,northern Ethiopia,which was funded by the Norwegian Agency for Development Cooperation(NORAD)under the Norwegian Programme for Capacity Development in Higher EducationResearch for Development(NORHED)Programme(ETH 13/0018)+4 种基金the Ecological Organic Agriculture Project,Mekelle University,Ethiopiathe Institute of International Education-Scholars Rescue Fund(IIE-SRF)Norwegian University of Life Sciences(NMBU)Faculty of Environmental Sciences and Natural Resource Management(MINA)NORGLOBAL 2 Project in Ethiopia(303600)for supporting the research。
文摘Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic conditions.The African birch(Anogeissus leiocarpa(DC.)Guill.&Perr.)and pink jacaranda(Stereospermum kunthianum Cham.)trees are the dominant species in the agroforestry parkland system in the drylands of Tigray,Ethiopia.Smallholder farmers highly value these trees for their multifunctional uses including timber,firewood,charcoal,medicine,etc.These trees also could improve soil fertility.However,the amount of soil physical and chemical properties enhanced by the two species must be determined to maintain the sustainable conservation of the species in the parklands and to scale up to similar agroecological systems.Hence,we selected twelve isolated trees,six from each species that had similar dendrometric characteristics and were growing in similar environmental conditions.We divided the canopy cover of each tree into three radial distances:mid-canopy,canopy edge,and canopy gap(control).At each distance,we took soil samples from three different depths.We collected 216 soil samples(half disturbed and the other half undisturbed)from each canopy position and soil depth.Bulk density(BD),soil moisture content(SMC),soil organic carbon(SOC),total nitrogen(TN),available phosphorus(AP),available potassium(AK),p H,electrical conductivity(EC),and cation exchange capacity(CEC)were analysed.Results revealed that soil physical and chemical properties significantly improved except for soil texture and EC under both species,CEC under A.leiocarpus,and soil p H under S.kunthianum,all the studied soils were improved under both species canopy as compared with canopy gap.SMC,TN,AP,and AK under canopy of these trees were respectively 24.1%,11.1%,55.0%,and 9.3% higher than those soils under control.The two parkland agroforestry species significantly enhanced soil fertility near the canopy of topsoil through improving soil physical and chemical properties.These two species were recommended in the drylands with similar agro-ecological systems.
文摘The sustainability of environmental management initiatives,such as watershed management programs,relies on the presence of effective institutions at the watershed level.However,there needs to be more empirical evidence from evaluating the effectiveness of watershed-level institutions.Therefore,this study presents a pioneering effort to evaluate the effectiveness of Nepal’s first watershed conservation committee at the watershed scale,focusing on the case of the Khageri Khola watershed in Central Nepal.The study involved conducting a household survey,key informant interviews,focus group discussions,and field observations to collect and analyze the data.Descriptive analysis,index value calculation,and chi-square statistics were then employed to summarize the results regarding local respondents’perceptions of twelve institutional characteristics,their rationalities,and their association with socio-demographic variables.The results reveal that the watershed conservation committee was perceived as performing well in managing the watershed.Specifically,good interaction,appropriate scale,technical,environmental,social,organizational,and government rationality were perceived as highly effective,with an average index value of less than 0.36.In contrast,clarity of objectives and economic rationality showed moderate effectiveness,with an average index value ranging from 0.36 to 0.65.However,the results suggested that adaptiveness,compliance capacity,and financial rationality merit increased attention,intending to improve their performance.Further,the results showed the association of socio-demographics with respondents’perceptions of various indicators of institutional characteristics and their rationalities.Therefore,the study provides valuable insights for policymakers,researchers,and development practitioners charged with designing sustainable and effective programs and institutions.To enhance the effectiveness and sustainability of watershed management programs,we recommend establishing a policy-guided institutional mechanism at the watershed scale.This mechanism should be based on various institutional characteristics and rationalities and should consider the extant variability in the socio-demographic and topographic characteristics of the watershed.
基金We are grateful to the Department of Soil Science,Agricultural,Research Institute,Quetta,Pakistan for provision of laboratory facilities for chemical analysis of soil samples.We extend our gratitude to the Department of Zoology,University of Balochistan,Pakistan for the identification of soil fauna。
文摘Barshore is a small village in the Pishin District,Balochistan,Pakistan,with dry summers and cold rainy winters.This is an agrarian region,mostly with orchards of various fruit trees.This study investigated the physico-chemical properties and macrofauna of soils under various agricultural management practices of this region.The concentrations of soil organic matter(SOM),soil organic carbon(SOC),nutrients,pH,electrical conductivity,soil texture,and the abundance and number of species of soil macrofauna of the agricultural fields were measured.Fifteen agricultural fields were sampled.Fourteen fields were orchards of apple,apricot or the mixture of apple and apricot trees and one field was a cropland,cultivated with wheat as a monocrop.The orchards were under conservation agricultural practices;whereas,the cropland was under conventional management.These agricultural lands were 2-26 years old.The concentration of soil organic matter(SOM)in the upper 0-10 cm depth of these field sites ranged from 11.6 g kg^(-1)to 32.8 g kg^(-1)soil.As compared to cropland,orchards had significantly higher concentration of SOM and SOC.A total of 18 soil macrofauna species were found and the most common and abundant were ants(Monomorium minimum,Camponotus pennsylvanicus,Solenopsis invicta,and Lasius niger)followed by Arion ssp.(Brown Slug)and earthworm Lumbricus terrestris.Regression analysis revealed non-significant relationship of the age and the concentration of SOM with the number of macrofauna species and with the concentrations of total mineral nitrogen,bioavailable phosphorus and clay.The existence of ants had no relationship with the concentration of SOM;whereas,existence of Lumbricus terrestris tended to had a positive relationship with the concentration of SOM.The field of tree-based intercropping system was 2 years of age since the land was converted from rangeland to a cropland,had two ant species coexisting.This indicates the positive influence of crop diversification on soil macrofauna.
基金the Natural Sciences and Engineering Research Council of Canada(Discovery Grant RGPIN-2023-05879)the New Brunswick Innovation Foundation(Emerging Projects Grant EP-0000000033)。
文摘Volume is an important attribute used in many forest management decisions.Data from 83 fixed-area plots located in central New Brunswick,Canada,are used to examine how different measures of stand-level diameter and height influence volume prediction using a stand-level variant of Honer's(1967)volume equation.When density was included in the models(Volume=f(Diameter,Height,Density))choice of diameter measure was more important than choice of height measure.When density was not included(Volume=f(Diameter,Height)),the opposite was true.For models with density included,moment-based estimators of stand diameter and height performed better than all other measures.For models without density,largest tree estimators of stand diameter and height performed better than other measures.The overall best equation used quadratic mean diameter,Lorey's height,and density(root mean square error=5.26 m^3·ha^(-1);1.9%relative error).The best equation without density used mean diameter of the largest trees needed to calculate a stand density index of 400 and the mean height of the tallest 400 trees per ha(root mean square error=32.08 m^(3)·ha^(-1);11.8%relative error).The results of this study have some important implications for height subsampling and LiDAR-derived forest inventory analyses.
基金supported by Shiraz University,Vice-Chancellor of Research as a master thesis.
文摘Objective:To explore the potential therapeutic impact of an alcoholic extract derived from the sea cucumber(Holothuria parva)on letrozole-induced polycystic ovary syndrome(PCOS)in adult female Sprague-Dawley rats.Methods:Sixteen female rats,aged 8 to 10 weeks,with a mean weight of(200±20)g,were randomly assigned to four groups:the control,PCOS,and two treatment groups receiving sea cucumber extract and metformin,respectively.PCOS was induced by administering letrozole at a dose of 1 mg/kg to initiate the treatment period at 60 days of age.The study spanned four weeks,during which ovarian and uterine tissues were collected for histological examination,and blood samples were collected for hormonal levels.Results:Significant decreases in luteinizing hormone/follicle stimulating hormone(LH/FSH)and testosterone and increases progesterone levels among groups treated with sea cucumber extract were observed.While no significant differences were observed in follicle-stimulating hormone(FSH)and testosterone levels,the distinctive variations in key hormones suggested a potential role for sea cucumber alcoholic extract in ameliorating PCOS symptoms.Conclusions:This research highlights the moderate efficacy of sea cucumber extract as a therapeutic intervention for PCOS,providing a novel perspective in the search for effective remedies.The observed hormonal alterations,particularly in LH,estradiol,and progesterone,underscore the need for further exploration into the underlying mechanisms and for optimizing the application of sea cucumber extract in PCOS management.
文摘Rhizobium tropici-derived extracellular polymeric substances (EPS) have been used in soils to enhance soil structures and mitigate soil erosions. However, information on their use to improve soil health and fertility indicators, and plant growth is limited. In a greenhouse study, we investigated their effects on some soil health, soil fertility indices, and the growth of black-eyed peas (Vigna unguiculate). Results showed that soils incubated with EPS significantly increased basal soil respiration, soil microbial biomass, permanganate oxidizable carbon (POC), and potentially mineralizable nitrogen (PMN). The EPS shifted microbial populations from bacteria to fungi and Gram (−ve) to Gram ( ve) bacteria. However, it had little or no effects on soil pH, soil organic matter (SOM), and cation exchange capacity (CEC). The EPS decreased soil moisture loss, increased soil aggregate stability, but delayed blacked-eyed peas germinations in the soils. At 0.1% (w/w) concentrations in soils, there was increase in plant root nodulations and vegetative growth. This study was carried out within 40 days of incubating soils with EPS or growing the black-eyed peas in a greenhouse study. The plant growth parameters were taken before flowering and fruiting. Further studies of the effects of incubating soils with the extracellular polymeric substances on plant growth. Soil microbial biomass, microbial diversities, and other soil fertility indices are deemed necessary.