Healthy soils are essential for sustainableagricultural development and soil health requires carefulassessment with increasing societal concern over envir-onmentally friendly agricultural development. Soil healthis th...Healthy soils are essential for sustainableagricultural development and soil health requires carefulassessment with increasing societal concern over envir-onmentally friendly agricultural development. Soil healthis the capacity of soil to function within ecologicalboundaries to sustain productivity, maintain environmentalquality, and promote plant and animal health. Physical,chemical and biological indicators are used to evaluate soilhealth;the biological indicators include microbes, proto-zoa and metazoa. Nematodes are the most abundantmetazoa and they vary in their sensitivity to pollutants andenvironmental disturbance. Soil nematode communitiesare useful biological indicators of soil health, withcommunity characteristics such as abundance, diversity,community structure and metabolic footprint all closelycorrelated with the soil environment. The community size,complexity and structure reflect the condition of the soil.Both free-living and plant parasitic nematodes are effec-tive ecological indicators, contributing to nutrient cyclingand having important roles as primary, secondary andtertiary consumers in food webs. Tillage inversion,cropping patterns and nutrient management may havestrong effects on soil nematodes, with changes in soilnematode communities reflecting soil disturbance. Somefree-living nematodes serve as biological models to testsoil condition in the laboratory and because of theseadvantages soil nematodes are increasingly being used asbiological indicators of soil health.展开更多
Microwave radiation has been widely used in various fields,such as communication,industry,medical treatment,and military applications.Microwave radiation may cause injuries to both the structures and functions of vari...Microwave radiation has been widely used in various fields,such as communication,industry,medical treatment,and military applications.Microwave radiation may cause injuries to both the structures and functions of various organs,such as the brain,heart,reproductive organs,and endocrine organs,which endanger human health.Therefore,it is both theoretically and clinically important to conduct studies on the biological effects induced by microwave radiation.The successful establishment of injury models is of great importance to the reliability and reproducibility of these studies.In this article,we review the microwave exposure conditions,subjects used to establish injury models,the methods used for the assessment of the injuries,and the indicators implemented to evaluate the success of injury model establishment in studies on biological effects induced by microwave radiation.展开更多
Biological indicator(BI)is the gold standard in verifying the effectiveness of the sterilization processes.The resistance of biological indicators generally means the population of viable organism and D value.The popu...Biological indicator(BI)is the gold standard in verifying the effectiveness of the sterilization processes.The resistance of biological indicators generally means the population of viable organism and D value.The population and the D value are all not intrinsic,which will vary according to the lot,the manufacturer.Spores,carrier,recovery medium and the packaging compose the self-contained biological indicators.And all of the component will affect BI resistance.Different kinds of carrier spore inoculated on exhibit different manners to attach different D-values.Another factor that affects the resistance of BI is spore production methods.The sporulation conditions including temperature,p H,humidity,nutrient and ions content,largely influence the spore resistance to heat.Furthermore,resistometer performance and the different test method are also the major source of the D value variation.All the factors affect the resistance of biological in an comprehensive manner,and when a resistance variation occur,all the factors above should be taken into consideration.展开更多
Developments in soil biology and in methodsto characterize soil organic carbon can potentially delivernovel soil quality indicators that can help identifymanagement practices able to sustain soil productivityand envir...Developments in soil biology and in methodsto characterize soil organic carbon can potentially delivernovel soil quality indicators that can help identifymanagement practices able to sustain soil productivityand environmental resilience. This work aimed atsynthesizing results regarding the suitability of a range ofsoil biological and biochemical properties as novel soilquality indicators for agricultural management. The soilproperties, selected through a published literature review,comprised different labile organic carbon fractions [hydrophilicdissolved organic carbon, dissolved organic carbon,permanganate oxidizable carbon (POXC), hot waterextractable carbon and particulate organic matter carbon],soil disease suppressiveness measured using a Pythium-Lepidium bioassay, nematode communities characterizedby amplicon sequencing and qPCR, and microbialcommunity level physiological profiling measured withMicroResp™. Prior studies tested the sensitivity of each ofthe novel indicators to tillage and organic matter additionin ten European long-term field experiments (LTEs) andassessed their relationships with pre-existing soil qualityindicators of soil functioning. Here, the results of theseprevious studies are brought together and interpretedrelative to each other and to the broader body of literatureon soil quality assessment. Reduced tillage increasedcarbon availability, disease suppressiveness, nematoderichness and diversity, the stability and maturity of thefood web, and microbial activity and functional diversity.Organic matter addition played a weaker role in enhancingsoil quality, possibly due to the range of composition of theorganic matter inputs used in the LTEs. POXC was theindicator that discriminated best between soil managementpractices, followed by nematode indices based on functionalcharacteristics. Structural equation modeling showsthat POXC has a central role in nutrient retention/supply,carbon sequestration, biodiversity conservation, erosion control and disease regulation/suppression. The novelindicators proposed here have great potential to improveexisting soil quality assessment schemes. Their feasibilityof application is discussed and needs for future research are outlined.展开更多
To examine the eukaryotic biodiversity of aquatic ecosystems in the Qiantang River,China,eukaryotic microbes in the river were investigated using 18S rRNA gene sequencing during the breeding season(July to August 2018...To examine the eukaryotic biodiversity of aquatic ecosystems in the Qiantang River,China,eukaryotic microbes in the river were investigated using 18S rRNA gene sequencing during the breeding season(July to August 2018).Four distinct distribution patterns(1.Jiande;2.Tonglu and Fuyang;3.Jiubao;4.Yanguan)of the microbial community and their potential effects on fishery activities were observed.Results show lower abundances of Dinophyta and Fungi and higher abundances of Cryptophyta and Chlorophyta in Tonglu and Fuyang than those in the other three sections.In addition,the reserves(Tonglu and Fuyang)destabilized the original eukaryotic microbial co-occurrence network.Among all the environmental factors measured,nitrogen(nitrite,nitrate,ammonium),water temperature and total chlorophyll a acted as major driving factors that controlled the eukaryotic microbial distribution.Furthermore,the existence of some algae(e.g.,Chrysophyceae,Cryptophytes,and Chlorophyceae)and fungi(e.g.,Rhizophydium)in Tonglu and Fuyang was beneficial to juvenile fish growth and water quality,although some detrimental species(e.g.,Aphanomyces)needed attention.This study provides further insights into the sustainable protection and utilization of rivers.展开更多
Bryophyte communities have been widely used to monitor and assess heavy metal pollution in soil,air and water.However,the unique value of acrocarpous moss in monitoring environmental pollution and the harm of non-meta...Bryophyte communities have been widely used to monitor and assess heavy metal pollution in soil,air and water.However,the unique value of acrocarpous moss in monitoring environmental pollution and the harm of non-metallic sulfur to human health caused by carbonate manganese mining were seldom considered in previous studies.This study investigated the heavy metal and sulfur pollution level by soil and moss sample collection in Changgou manganese ore and its surrounding environment in the Zunyi area,Guizhou Province,China.By means of cluster analysis,diversity analysis,correlation analysis and redundancy analysis,the relationship between dominant moss communities and major pollutants were analyzed.The results showed that there were pollutants such as iron(Fe),manganese(Mn),cadmium(Cd),sulfur(S)and others in the 500 meters buffer zone centered on Changgou manganese ore.The ore sorting area and waste rock accumulation area were considered as the most seriously polluted,followed by the ore outlet area and ore transport line,at last the miners’living area and vegetable planting area were the least polluted.A total of 23 species of moss communities were identified in the Changgou manganese ore area,among which 9 were dominant,including Bryum blindii Bruch&Schimp.(Bry.bli),Weissia planifolia Dix(Wei.pla)-Bry.bli,Bryum caespiticium Hedw.(Bry.cae),Bryum pallescens Schleicher ex Schw?gr.(Bry.pal),Didymodon longicostatus X.J.Li et Iwats(Did.lon),Weissia brachycarpa(Nees&Hornsch.)Jur.(Wei.bra),Trichostomum brachydontium Bruch.(Tri.bra),Bryum argenteum Hedw.(Bry.arg)Wei.bra and Bryum algovicum Sendt.ex M?ll.Hal.(Bry.alg),all of which are from the acrocarp species.Bry.cae showed a strong tolerance to S,Did.lon to Fe,Bry.pal to Cd and Bry.bli to Mn.There was a significant correlation between the main polluting elements and the dominant bryophyte community(P<0.05),indicating a high biological indicator value.Together,our results can provide the scientific basis for soil pollution monitoring and human health risk assessment in carbonate manganese mining areas.展开更多
Soil enzyme activities have been suggested as suitable indicators for the evaluation of metal contamination because they are susceptible to microbial changes caused by heavy metal stress and are strictly related to so...Soil enzyme activities have been suggested as suitable indicators for the evaluation of metal contamination because they are susceptible to microbial changes caused by heavy metal stress and are strictly related to soil nutrient cycles.However,there is a growing lack of recognition and summary of the historic advancements that use soil enzymology as the proposal of evaluation methods.Here,we review the most common methods of heavy metal pollution evaluation based on enzyme activities,which include single enzyme index,combined enzyme index,enzyme-based functional diversity index,microbiological stress index,and ecoenzymatic stoichiometry models.This review critically examines the advantages and disadvantages of these methods based on their execution complexity,performance,and ecological implications and gets a glimpse of avenues to come to improved future evaluation systems.Indices based on a single enzyme are variable and have no consistent response to soil heavy metals,and the following three composite indices are characterized by the loss of many critical microbial processes,which thus not conducive to reflect the effects of heavy metals on soil ecosystems.Considering the dexterity of ecoenzymatic stoichiometry methods in reflecting changes in soil functions under heavy metal stress,we propose that microbial metabolic limitations quantified by ecoenzymatic stoichiometry models could be promising indicators for enhancing the reality and acceptance of results and further improving the potential for actual utility in environmental decision-making.展开更多
The labile organic carbon(C)and C-related enzymes are sensitive indicators capturing alterations of soil organic matter(SOM),even in a short-time scale.Although the effects of crop husbandry and land use change on the...The labile organic carbon(C)and C-related enzymes are sensitive indicators capturing alterations of soil organic matter(SOM),even in a short-time scale.Although the effects of crop husbandry and land use change on these attributes have been well studied,there is no consensus about how plant phenology may impact them.This study aimed to determine the short-term effect o f six distinct phenological stages(PS-1:full bloom;PS-2:fruit set;PS-3:pit hardening;PS-4:physiological maturity;PS-5:60 d after physiological maturity;and PS-6:fall)o f peach on the changes in soil organic carbon(SOC)fractions of different oxidizability,labile C pools,and C-cycle enzyme activities in soils,for two consecutive years(2015 and 2016)in the North-Western Himalayas(NWH).Peach rhizosphere soils were sampled at the topsoil(0-15 cm)and subsoil(16-30 cm)layers,along with rhizosphere soils from adjacent perennial grasses,which served as a control.Values for most of the assessed parameters,including very labile C,labile C,microbial biomass C,permanganate oxidizable C,dissolved organic C,mineralizable C,amylase activity,and carboxymethyl-cellulase activity,were significantly(P<0.05)higher at PS-3 than at other phenological stages of peach.Conversely,a sudden decline in these soil variables was recorded at PS-5,followed by a slight buildup at PS-6,particularly in the topsoil of the peach orchard.Short-term changes in organic C fractions of different oxidizability,influenced by peach phenological stage,significantly(P<0.05)affected C management index,C pool index,and lability index.Both the C management index and lability index showed their highest values at PS-3 and their lowest values at PS-5,clearly indicating short-term accretion and depletion of SOC,in tandem with the peach phenological events.Principal component analysis suggested that a composite of soil indicators,including microbial biomass C,dissolved organic C,amylase,and invertase,could help detect short-term changes in SOC content.It is concluded that peach phenological events had a major impact on the short-term variations of the studied soil variables,which could be attributed to changes in the above-and belowground plant residues,as well as the extent of nutrients and water acquisition.展开更多
As a sensitive biological indicator,earthworms are widely used to monitor various pollutants of soil and provide an early warning for soil pollution.However,because many indices are involved in the exposure-induced ox...As a sensitive biological indicator,earthworms are widely used to monitor various pollutants of soil and provide an early warning for soil pollution.However,because many indices are involved in the exposure-induced oxidative stress response,practical applications of these indices are quite inconvenient.Therefore,it is appropriate to investigate the key monitoring index for use in early warning and pollution monitoring.Using Eisenia fetida as an experimental model in an indoor simulation experiment,the mathematical modelling of the effect on oxidative stress in earthworms under cadmium(Cd)stress was studied.The test lasted 40 d,with the removal of one earthworm every 10 d.The Cd2+concentration gradient was set as 0,1,10,20,100,200,400,and 800 mg kg^(-1) dry weight.The earthworms were divided into two sections from the clitellum for the determination of total protein(TP)and peroxidase(POD),superoxide dismutase(SOD),glutathione-S-transferase(GST),glutathione peroxidase(GPX),catalase(CAT),malondialdehyde(MDA),and acetylcholinesterase(AChE)activities.Results showed that POD was the key index of oxidative stress in head tissues after 10 d of exposure,TP was the key index at 20 d,and POD became the key index again at 30 and 40 d.By contrast,in tail tissues,MDA and SOD were the key indices at an exposure time of 10 d,GPX at 20 d,CAT and TP at 30 d,and POD and MDA at 40 d.These results contribute to establishing a scientific method for ecotoxicological diagnosis and revealing the mechanism of soil Cd toxicity.展开更多
Background:Indoor air quality(IAQ)is a concern in kindergartens as children spend much of their time there.Yet,there is a shortage of biological indicators needed for assessing IAQ.Thus,this study evaluated IAQ using ...Background:Indoor air quality(IAQ)is a concern in kindergartens as children spend much of their time there.Yet,there is a shortage of biological indicators needed for assessing IAQ.Thus,this study evaluated IAQ using transplanted lichen Usnea misaminensis as a biological indicator.Methods:Lichen samples,collected from Bukit Larut,Perak,Malaysia,were exposed to indoor and outdoor environments in an urban area(Ummi Aiman Kindergarten)and a rural area(Ummi Qaseh Pelangi Kindergarten)for 2 months during August 15 to October 14,2019.The concentrations of 12 selected elements and the vitality of the lichens were then evaluated.Results:Increased concentrations of eleven of the twelve elements deposited in the lichen samples in both urban and rural areas were observed.For both areas,the element concentrations in the samples from the indoor environment was lower than those from the outdoor environment,and those in the rural area were lower than those from in the urban area,suggesting the impacts of traffic emissions.The vitality of the lichens showed no significant change in indoor environment,compared to that in outdoor environment,indicating that even exposed to indoor environment,the lichens remained effective biological indicators as same as they were in the outdoor environment.Conclusions:Lichens are effective biological indicators for both outdoor and indoor environments.Furthermore,outdoor emissions could influence IAQ,which could be problematic in densely populated areas such as kindergartens.Mitigation measures should be taken.展开更多
Ice core provides a valuable vertical timeline of past climates and anthropogenic activities.Environmental proxies have been widely used in these studies,but there are few biological indicators available.To address th...Ice core provides a valuable vertical timeline of past climates and anthropogenic activities.Environmental proxies have been widely used in these studies,but there are few biological indicators available.To address this gap,we investigated the bacterial community from a 74 m ice core of Muztag ata glacier on the Tibetan Plateau to link biological indicators with past climate and anthropogenic activities.By analyzing the portion of the ice core with environmental proxies available(corresponding to 1907 to 1991),we observed an increase in bacterial richness throughout the ice core,which was associated with higher NH_(4)^(+),an indicator of agricultural development.The bacterial community was jointly determined by human activity,natural input,and air temperature,with a strong human influence after the 1950s.Furthermore,the relative abundance of animal gut-associated bacteria,including Aerococcaceae,Nocardiaceae,Muribaculaceae,and Lachnospiraceae,was associated with livestock number changes in the Central Asian region.Together with other bacterial lineages,they jointly explained 59.8%of the livestock number changes.This study provides quantitative evidence of the associations between bacterial indicators and past climate and human activities,highlighting the potential of using bacterial proxies for ice core studies.展开更多
基金the National KeyResearch and Development Program of China (2017YFD0202102,2016YFD0200405, and 2016YFE0101100).
文摘Healthy soils are essential for sustainableagricultural development and soil health requires carefulassessment with increasing societal concern over envir-onmentally friendly agricultural development. Soil healthis the capacity of soil to function within ecologicalboundaries to sustain productivity, maintain environmentalquality, and promote plant and animal health. Physical,chemical and biological indicators are used to evaluate soilhealth;the biological indicators include microbes, proto-zoa and metazoa. Nematodes are the most abundantmetazoa and they vary in their sensitivity to pollutants andenvironmental disturbance. Soil nematode communitiesare useful biological indicators of soil health, withcommunity characteristics such as abundance, diversity,community structure and metabolic footprint all closelycorrelated with the soil environment. The community size,complexity and structure reflect the condition of the soil.Both free-living and plant parasitic nematodes are effec-tive ecological indicators, contributing to nutrient cyclingand having important roles as primary, secondary andtertiary consumers in food webs. Tillage inversion,cropping patterns and nutrient management may havestrong effects on soil nematodes, with changes in soilnematode communities reflecting soil disturbance. Somefree-living nematodes serve as biological models to testsoil condition in the laboratory and because of theseadvantages soil nematodes are increasingly being used asbiological indicators of soil health.
基金supported by the National Natural Science Foundation of China(61801506)。
文摘Microwave radiation has been widely used in various fields,such as communication,industry,medical treatment,and military applications.Microwave radiation may cause injuries to both the structures and functions of various organs,such as the brain,heart,reproductive organs,and endocrine organs,which endanger human health.Therefore,it is both theoretically and clinically important to conduct studies on the biological effects induced by microwave radiation.The successful establishment of injury models is of great importance to the reliability and reproducibility of these studies.In this article,we review the microwave exposure conditions,subjects used to establish injury models,the methods used for the assessment of the injuries,and the indicators implemented to evaluate the success of injury model establishment in studies on biological effects induced by microwave radiation.
文摘Biological indicator(BI)is the gold standard in verifying the effectiveness of the sterilization processes.The resistance of biological indicators generally means the population of viable organism and D value.The population and the D value are all not intrinsic,which will vary according to the lot,the manufacturer.Spores,carrier,recovery medium and the packaging compose the self-contained biological indicators.And all of the component will affect BI resistance.Different kinds of carrier spore inoculated on exhibit different manners to attach different D-values.Another factor that affects the resistance of BI is spore production methods.The sporulation conditions including temperature,p H,humidity,nutrient and ions content,largely influence the spore resistance to heat.Furthermore,resistometer performance and the different test method are also the major source of the D value variation.All the factors affect the resistance of biological in an comprehensive manner,and when a resistance variation occur,all the factors above should be taken into consideration.
基金the EU Horizon 2020 projectInteractive Soil Quality Assessment in Europe and China for agriculturalproductivity and environmental resilience (iSQAPER), grant number 635750(mediated through the Swiss State Secretariat for Education, Research andInnovation). The University of Ljubljana, University of Trier, UniversityMiguel Hernandez, and the long-term field experiment owners providedsamples and data, and Lijbert Brussaard, Ron de Goede, Else Biinemann-Konig and Paul Mader provided constructive feedback on earlier versions ofthe manuscript.
文摘Developments in soil biology and in methodsto characterize soil organic carbon can potentially delivernovel soil quality indicators that can help identifymanagement practices able to sustain soil productivityand environmental resilience. This work aimed atsynthesizing results regarding the suitability of a range ofsoil biological and biochemical properties as novel soilquality indicators for agricultural management. The soilproperties, selected through a published literature review,comprised different labile organic carbon fractions [hydrophilicdissolved organic carbon, dissolved organic carbon,permanganate oxidizable carbon (POXC), hot waterextractable carbon and particulate organic matter carbon],soil disease suppressiveness measured using a Pythium-Lepidium bioassay, nematode communities characterizedby amplicon sequencing and qPCR, and microbialcommunity level physiological profiling measured withMicroResp™. Prior studies tested the sensitivity of each ofthe novel indicators to tillage and organic matter additionin ten European long-term field experiments (LTEs) andassessed their relationships with pre-existing soil qualityindicators of soil functioning. Here, the results of theseprevious studies are brought together and interpretedrelative to each other and to the broader body of literatureon soil quality assessment. Reduced tillage increasedcarbon availability, disease suppressiveness, nematoderichness and diversity, the stability and maturity of thefood web, and microbial activity and functional diversity.Organic matter addition played a weaker role in enhancingsoil quality, possibly due to the range of composition of theorganic matter inputs used in the LTEs. POXC was theindicator that discriminated best between soil managementpractices, followed by nematode indices based on functionalcharacteristics. Structural equation modeling showsthat POXC has a central role in nutrient retention/supply,carbon sequestration, biodiversity conservation, erosion control and disease regulation/suppression. The novelindicators proposed here have great potential to improveexisting soil quality assessment schemes. Their feasibilityof application is discussed and needs for future research are outlined.
基金Supported by the Fisheries Species Conservation Program of the Agricultural Department of China(Nos.171821303154051044,17190236)the Natural Science Foundation of Zhejiang Province(No.LQ20C190003)+1 种基金the Natural Science Foundation of Ningbo Municipality(Nos.2019A610421,2019A610443)the K.C.Wong Magna Fund of Ningbo University。
文摘To examine the eukaryotic biodiversity of aquatic ecosystems in the Qiantang River,China,eukaryotic microbes in the river were investigated using 18S rRNA gene sequencing during the breeding season(July to August 2018).Four distinct distribution patterns(1.Jiande;2.Tonglu and Fuyang;3.Jiubao;4.Yanguan)of the microbial community and their potential effects on fishery activities were observed.Results show lower abundances of Dinophyta and Fungi and higher abundances of Cryptophyta and Chlorophyta in Tonglu and Fuyang than those in the other three sections.In addition,the reserves(Tonglu and Fuyang)destabilized the original eukaryotic microbial co-occurrence network.Among all the environmental factors measured,nitrogen(nitrite,nitrate,ammonium),water temperature and total chlorophyll a acted as major driving factors that controlled the eukaryotic microbial distribution.Furthermore,the existence of some algae(e.g.,Chrysophyceae,Cryptophytes,and Chlorophyceae)and fungi(e.g.,Rhizophydium)in Tonglu and Fuyang was beneficial to juvenile fish growth and water quality,although some detrimental species(e.g.,Aphanomyces)needed attention.This study provides further insights into the sustainable protection and utilization of rivers.
基金supported by the National Nature Science Foundation of China(No.31960044)the Department of Science and Technology Foundation of Guizhou Province,China[DSTFGC,(2019)]。
文摘Bryophyte communities have been widely used to monitor and assess heavy metal pollution in soil,air and water.However,the unique value of acrocarpous moss in monitoring environmental pollution and the harm of non-metallic sulfur to human health caused by carbonate manganese mining were seldom considered in previous studies.This study investigated the heavy metal and sulfur pollution level by soil and moss sample collection in Changgou manganese ore and its surrounding environment in the Zunyi area,Guizhou Province,China.By means of cluster analysis,diversity analysis,correlation analysis and redundancy analysis,the relationship between dominant moss communities and major pollutants were analyzed.The results showed that there were pollutants such as iron(Fe),manganese(Mn),cadmium(Cd),sulfur(S)and others in the 500 meters buffer zone centered on Changgou manganese ore.The ore sorting area and waste rock accumulation area were considered as the most seriously polluted,followed by the ore outlet area and ore transport line,at last the miners’living area and vegetable planting area were the least polluted.A total of 23 species of moss communities were identified in the Changgou manganese ore area,among which 9 were dominant,including Bryum blindii Bruch&Schimp.(Bry.bli),Weissia planifolia Dix(Wei.pla)-Bry.bli,Bryum caespiticium Hedw.(Bry.cae),Bryum pallescens Schleicher ex Schw?gr.(Bry.pal),Didymodon longicostatus X.J.Li et Iwats(Did.lon),Weissia brachycarpa(Nees&Hornsch.)Jur.(Wei.bra),Trichostomum brachydontium Bruch.(Tri.bra),Bryum argenteum Hedw.(Bry.arg)Wei.bra and Bryum algovicum Sendt.ex M?ll.Hal.(Bry.alg),all of which are from the acrocarp species.Bry.cae showed a strong tolerance to S,Did.lon to Fe,Bry.pal to Cd and Bry.bli to Mn.There was a significant correlation between the main polluting elements and the dominant bryophyte community(P<0.05),indicating a high biological indicator value.Together,our results can provide the scientific basis for soil pollution monitoring and human health risk assessment in carbonate manganese mining areas.
基金the National Natural Science Foundation of China(41977031)the Science Foundation for Distinguished Youth of Shaanxi Province(2020JC-31).
文摘Soil enzyme activities have been suggested as suitable indicators for the evaluation of metal contamination because they are susceptible to microbial changes caused by heavy metal stress and are strictly related to soil nutrient cycles.However,there is a growing lack of recognition and summary of the historic advancements that use soil enzymology as the proposal of evaluation methods.Here,we review the most common methods of heavy metal pollution evaluation based on enzyme activities,which include single enzyme index,combined enzyme index,enzyme-based functional diversity index,microbiological stress index,and ecoenzymatic stoichiometry models.This review critically examines the advantages and disadvantages of these methods based on their execution complexity,performance,and ecological implications and gets a glimpse of avenues to come to improved future evaluation systems.Indices based on a single enzyme are variable and have no consistent response to soil heavy metals,and the following three composite indices are characterized by the loss of many critical microbial processes,which thus not conducive to reflect the effects of heavy metals on soil ecosystems.Considering the dexterity of ecoenzymatic stoichiometry methods in reflecting changes in soil functions under heavy metal stress,we propose that microbial metabolic limitations quantified by ecoenzymatic stoichiometry models could be promising indicators for enhancing the reality and acceptance of results and further improving the potential for actual utility in environmental decision-making.
文摘The labile organic carbon(C)and C-related enzymes are sensitive indicators capturing alterations of soil organic matter(SOM),even in a short-time scale.Although the effects of crop husbandry and land use change on these attributes have been well studied,there is no consensus about how plant phenology may impact them.This study aimed to determine the short-term effect o f six distinct phenological stages(PS-1:full bloom;PS-2:fruit set;PS-3:pit hardening;PS-4:physiological maturity;PS-5:60 d after physiological maturity;and PS-6:fall)o f peach on the changes in soil organic carbon(SOC)fractions of different oxidizability,labile C pools,and C-cycle enzyme activities in soils,for two consecutive years(2015 and 2016)in the North-Western Himalayas(NWH).Peach rhizosphere soils were sampled at the topsoil(0-15 cm)and subsoil(16-30 cm)layers,along with rhizosphere soils from adjacent perennial grasses,which served as a control.Values for most of the assessed parameters,including very labile C,labile C,microbial biomass C,permanganate oxidizable C,dissolved organic C,mineralizable C,amylase activity,and carboxymethyl-cellulase activity,were significantly(P<0.05)higher at PS-3 than at other phenological stages of peach.Conversely,a sudden decline in these soil variables was recorded at PS-5,followed by a slight buildup at PS-6,particularly in the topsoil of the peach orchard.Short-term changes in organic C fractions of different oxidizability,influenced by peach phenological stage,significantly(P<0.05)affected C management index,C pool index,and lability index.Both the C management index and lability index showed their highest values at PS-3 and their lowest values at PS-5,clearly indicating short-term accretion and depletion of SOC,in tandem with the peach phenological events.Principal component analysis suggested that a composite of soil indicators,including microbial biomass C,dissolved organic C,amylase,and invertase,could help detect short-term changes in SOC content.It is concluded that peach phenological events had a major impact on the short-term variations of the studied soil variables,which could be attributed to changes in the above-and belowground plant residues,as well as the extent of nutrients and water acquisition.
基金This research was supported by the“Youth Talents”Project of Northeast Agricultural University,China(No.19QC12)the National Key Research and Development Program of China(No.2018 YFD0300106).
文摘As a sensitive biological indicator,earthworms are widely used to monitor various pollutants of soil and provide an early warning for soil pollution.However,because many indices are involved in the exposure-induced oxidative stress response,practical applications of these indices are quite inconvenient.Therefore,it is appropriate to investigate the key monitoring index for use in early warning and pollution monitoring.Using Eisenia fetida as an experimental model in an indoor simulation experiment,the mathematical modelling of the effect on oxidative stress in earthworms under cadmium(Cd)stress was studied.The test lasted 40 d,with the removal of one earthworm every 10 d.The Cd2+concentration gradient was set as 0,1,10,20,100,200,400,and 800 mg kg^(-1) dry weight.The earthworms were divided into two sections from the clitellum for the determination of total protein(TP)and peroxidase(POD),superoxide dismutase(SOD),glutathione-S-transferase(GST),glutathione peroxidase(GPX),catalase(CAT),malondialdehyde(MDA),and acetylcholinesterase(AChE)activities.Results showed that POD was the key index of oxidative stress in head tissues after 10 d of exposure,TP was the key index at 20 d,and POD became the key index again at 30 and 40 d.By contrast,in tail tissues,MDA and SOD were the key indices at an exposure time of 10 d,GPX at 20 d,CAT and TP at 30 d,and POD and MDA at 40 d.These results contribute to establishing a scientific method for ecotoxicological diagnosis and revealing the mechanism of soil Cd toxicity.
基金supported by Universiti Kebangsaan Malaysia through a research grant(GUP-2018-032).
文摘Background:Indoor air quality(IAQ)is a concern in kindergartens as children spend much of their time there.Yet,there is a shortage of biological indicators needed for assessing IAQ.Thus,this study evaluated IAQ using transplanted lichen Usnea misaminensis as a biological indicator.Methods:Lichen samples,collected from Bukit Larut,Perak,Malaysia,were exposed to indoor and outdoor environments in an urban area(Ummi Aiman Kindergarten)and a rural area(Ummi Qaseh Pelangi Kindergarten)for 2 months during August 15 to October 14,2019.The concentrations of 12 selected elements and the vitality of the lichens were then evaluated.Results:Increased concentrations of eleven of the twelve elements deposited in the lichen samples in both urban and rural areas were observed.For both areas,the element concentrations in the samples from the indoor environment was lower than those from the outdoor environment,and those in the rural area were lower than those from in the urban area,suggesting the impacts of traffic emissions.The vitality of the lichens showed no significant change in indoor environment,compared to that in outdoor environment,indicating that even exposed to indoor environment,the lichens remained effective biological indicators as same as they were in the outdoor environment.Conclusions:Lichens are effective biological indicators for both outdoor and indoor environments.Furthermore,outdoor emissions could influence IAQ,which could be problematic in densely populated areas such as kindergartens.Mitigation measures should be taken.
基金supported by the National Key Research and Development Plans(Grant No.2021YFC2300904)the National Natural Science Foundation of China(Grant Nos.U21A20176 and 42330410)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(Grant No.2019QZKK0503)。
文摘Ice core provides a valuable vertical timeline of past climates and anthropogenic activities.Environmental proxies have been widely used in these studies,but there are few biological indicators available.To address this gap,we investigated the bacterial community from a 74 m ice core of Muztag ata glacier on the Tibetan Plateau to link biological indicators with past climate and anthropogenic activities.By analyzing the portion of the ice core with environmental proxies available(corresponding to 1907 to 1991),we observed an increase in bacterial richness throughout the ice core,which was associated with higher NH_(4)^(+),an indicator of agricultural development.The bacterial community was jointly determined by human activity,natural input,and air temperature,with a strong human influence after the 1950s.Furthermore,the relative abundance of animal gut-associated bacteria,including Aerococcaceae,Nocardiaceae,Muribaculaceae,and Lachnospiraceae,was associated with livestock number changes in the Central Asian region.Together with other bacterial lineages,they jointly explained 59.8%of the livestock number changes.This study provides quantitative evidence of the associations between bacterial indicators and past climate and human activities,highlighting the potential of using bacterial proxies for ice core studies.
