In semi-arid areas of China,gravel and sand mulch is a farming technique with a long history.In this study,a sample survey was conducted on long term gravel sand mulch observational fields in the Northwest Loess Plate...In semi-arid areas of China,gravel and sand mulch is a farming technique with a long history.In this study,a sample survey was conducted on long term gravel sand mulch observational fields in the Northwest Loess Plateau to determine the effects of long term mulch on soil microbial and soil enzyme activities.We found that after long term gravel-sand mulch,compared with bare ground,soil organic matter,alkali nitrogen,conductivity decreased,while pH and soil moisture increased.Urease,saccharase and catalase decreased with increased mulch thickness,while alkaline phosphatase was reversed.The results of Illumina MiSeq sequencing shows that after gravel-sand mulch,the bacterial and fungal community structure was different from bare land,and the diversity was reduced.Compared with bare land,the bacteria Proteobacteria and Acidobacteria abundance increased with increased thickness,and Actinobacteria was opposite.Also,at the fungal genus level,Fusarium abundance was significantly reduced,and Remersonia was significantly increased,compared with bare land.Redundancy analysis(RDA)revealed that soil environmental factors were important drivers of bacterial community changes.Overall,this study revealed some of the reasons for soil degradation after long term gravel-sand mulch.Therefore,it is recommended that the addition of exogenous soil nutrients after long term gravel-sand can help improve soil quality.展开更多
The diversity of vegetation configuration is the key to ecological restoration in open-pit coal mine dump.However,the recovery outcomes of different areas with the same vegetation assemblage pattern are completely dif...The diversity of vegetation configuration is the key to ecological restoration in open-pit coal mine dump.However,the recovery outcomes of different areas with the same vegetation assemblage pattern are completely different after long-term evolution.Therefore,understanding the causes of differential vegetation recovery and the mechanism of plant succession is of great significance to the ecological restoration of mines.Three Pinus tabulaeformis plantations with similar initial site conditions and restoration measures but with different secondary succession processes were selected from the open-pit coal mine dump that has been restored for 30 years.Soil physicochemical properties,enzyme activities,vegetation and microbial features were investigated,while the structural equation models were established to explore the interactions between plants,soil and microbes.The results showed that original vegetation configuration and soil nutrient conditions were altered due to secondary succession.With the advancement of the secondary succession process,the coverage of plants increased from 34.8%to 95.5%(P<0.05),soil organic matter increased from 9.30 g kg^(-1)to 21.13 g kg^(-1)(P<0.05),and total nitrogen increased from 0.38 g kg^(-1)to 1.01 g kg^(-1)(P<0.05).The activities of soil urease and p-glucosidase were increased by 1.7-fold and 53.26%,respectively.Besides,the secondary succession also changed the soil microbial community structure and function.The relative abundance of Nitrospira genus which dominates the nitrification increased 5.2-fold.The results showed that urease andβ-glucosidase promoted the increase of vegetation diversity and biomass by promoting the accumulation of soil organic matter and nitrate nitrogen,which promoted the ecological restoration of mine dumps.展开更多
In the Loess Plateau of China,land-use pattern is a major factor in controlling underlying biological processes.Additionally,the process of land-use pattern was accompanied by abandoned lands,potentially impacting soi...In the Loess Plateau of China,land-use pattern is a major factor in controlling underlying biological processes.Additionally,the process of land-use pattern was accompanied by abandoned lands,potentially impacting soil microbe.However,limited researches were conducted to study the impacts of land-use patterns on the diversity and community of soil microorganisms in this area.The study aimed to investigate soil microbial community diversity and composition using high-throughput deoxyribonucleic acid(DNA)sequencing under different land-use patterns(apricot tree land,apple tree land,peach tree land,corn land,and abandoned land).The results showed a substantial difference(P<0.050)in bacterial alpha-diversity and beta-diversity between abandoned land and other land-use patterns,with the exception of Shannon index.While fungal beta-diversity was not considerably impacted by land-use patterns,fungal alpha-diversity indices varied significantly.The relative abundance of Actinobacteriota(34.90%),Proteobacteria(20.65%),and Ascomycota(77.42%)varied in soils with different land-use patterns.Soil pH exerted a dominant impact on the soil bacterial communities'composition,whereas soil available phosphorus was the main factor shaping the soil fungal communities'composition.These findings suggest that variations in land-use pattern had resulted in changes to soil properties,subsequently impacting diversity and structure of microbial community in the Loess Plateau.Given the strong interdependence between soil and its microbiota,it is imperative to reclaim abandoned lands to maintain soil fertility and sustain its function,which will have significant ecological service implications,particularly with regards to soil conservation in ecologically vulnerable areas.展开更多
Chlorine-containing disinfectants have been widely used around the world for the prevention and control of the COVID-19 pandemic.However,at present,little is known about the impact of residual chlorine on the soil mic...Chlorine-containing disinfectants have been widely used around the world for the prevention and control of the COVID-19 pandemic.However,at present,little is known about the impact of residual chlorine on the soil micro-ecological environment.Herein,we treated an experimental soil-plant-microbiome microcosm system by continuous irrigation with a low concentration of chlorine-containing water,and then analyzed the influence on the soil microbial community using metagenomics.After 14-d continuous chlorine treatment,there were no significant lasting effect on soil microbial community diversity and composition either in the rhizosphere or in bulk soil.Although metabolic functions of the rhizosphere microbial community were affected slightly by continuous chlorine treatment,it recovered to the original status.The abundance of several resistance genes changed by 7 d and recovered by 14 d.According to our results,the chlorine residue resulting from daily disinfection may present a slight long-term effect on plant growth(shoot length and fresh weight)and soil micro-ecology.In general,our study assisted with environmental risk assessments relating to the application of chlorine-containing disinfectants and minimization of risks to the environment during disease control,such as COVID-19.展开更多
Aims Plant-soil interaction(PsI)has been implicated as a causative mechanism promoting plant invasions,and some mechanisms underlying PsI effects remain unclear.Here,we attempted to address how altered soil microbes a...Aims Plant-soil interaction(PsI)has been implicated as a causative mechanism promoting plant invasions,and some mechanisms underlying PsI effects remain unclear.Here,we attempted to address how altered soil microbes and nutrients influence PsI effects.Methods soil was cultured by an invasive forb Solidago canadensis for two years.We conducted an experiment,in which S.canadensis and Chinese natives were grown either alone or together in control and cultured soils,and determined the growth of S.canadensis and five natives and the competitive ability of S.canadensis.We ana-lyzed the microbial community composition and nutrients of two types of soils.Important Findings Compared to the control soil,the soil cultured by S.canadensis decreased the subsequent growth of S.canadensis and five Chinese natives,as well as the competitive ability of S.canadensis against Chinese natives.soil microbial community composition was significantly altered due to soil culturing.Total fatty acids,bacte-ria,gram-negative bacteria and gram-positive bacteria had no responses to soil culturing;fungi,aerobic bacteria and fungi/bacteria ratio significantly decreased with soil culturing;anaerobes and gram-negative/positive bacteria ratio greatly increased with soil culturing.soil nitrogen(N)dramatically decreased with soil culturing,whereas soil phosphorus(P)was unchanged.These results suggest that negative PsI effects may be linked to decreases in soil fungi,aerobic bacteria and soil N and increases in soil anaerobic bacteria and the ratio of gram-negative/positive bacteria.our find-ings provide an initial indication that S.canadensis-soil interaction alone could exhibit limited contributions to its success in the early stage of invasion.展开更多
Background:Soil respiration(S_(R))is a critical process for understanding the impact of climatic conditions and land degradation on the carbon cycle in terrestrial ecosystems.We measured the S_(R) and soil environment...Background:Soil respiration(S_(R))is a critical process for understanding the impact of climatic conditions and land degradation on the carbon cycle in terrestrial ecosystems.We measured the S_(R) and soil environmental factors over 1 year in four land uses with varying levels of disturbance and different vegetation types viz.,mixed forest cover(MFC),Prosopis juliflora(Sw.)forest cover(PFC),agricultural field(AF),and vegetable field(VF),in a semi-arid area of Delhi,India.Our primary aim was to assess the effects of soil moisture(S_(M)),soil temperature(S_(T)),and soil microbial activity(S_(MA))on the S_(R).Methods:The S_(R) was measured monthly using an LI-6400 with an infrared gas analyser and a soil chamber.The S_(M) was measured using the gravimetric method.The S_(T)(10 cm)was measured with a probe attached to the LI-6400.The S_(MA) was determined by fluorescein diacetate hydrolysis.Results:The S_(R) showed seasonal variations,with the mean annual S_(R) ranging from 3.22 to 5.78μmol m^(−2) s^(−1) and higher S_(R) rates of~15-55%in the cultivated fields(AF,VF)than in the forest sites(MFC,PFC).The VF had significantly higher S_(R)(P<0.05)than the other land uses(AF,PFC,MFC),which did not vary significantly from one another in S_(R)(P<0.05).The repeated measures ANOVA evaluated the significant differences(P<0.05)in the S_(R) for high precipitation months(July,August,September,February).The S_(M) as a single factor showed a strong significant relationship in all the land uses(R^(2)=0.67-0.91,P<0.001).The effect of the S_(T) on the S_(R) was found to be weak and non-significant in the PFC,MFC,and AF(R^(2)=0.14-0.31;P>0.05).Contrasting results were observed in the VF,which showed high S_(R) during summer(May;11.21μmol m^(−2) s^(−1))and a significant exponential relationship with the S_(T)(R^(2)=0.52;P<0.05).The S_(R) was positively related to the SMA(R2=0.44-0.5;P<0.001).The interactive equations based on the independent variables S_(M),S_(T),and S_(MA) explained 91-95%of the seasonal variation in S_(R) with better model performance in the cultivated land use sites(AF,VF).Conclusion:S_(M) was the key determining factor of the S_(R) in semi-arid ecosystems and explained~90%of the variation.Precipitation increased S_(R) by optimizing the S_(M) and microbial activity.The S_(MA),along with the other soil factors S_(M) and S_(T),improved the correlation with S_(R).Furthermore,the degraded land uses will be more susceptible to temporal variations in S_(R) under changing climatic scenarios,which may influence the carbon balance of these ecosystems.展开更多
Background:Land use/cover and management practices are widely known to influence soil organic matter(SOM)quality and quantity.The present study investigated the effect of different land use,i.e.,forests viz.mixed fore...Background:Land use/cover and management practices are widely known to influence soil organic matter(SOM)quality and quantity.The present study investigated the effect of different land use,i.e.,forests viz.mixed forest cover(MFC),Prosopis juliflora(Sw.)DC-dominated forest cover(PFC),and cultivated sites viz.agriculture field(AF),vegetable field(VF),respectively,on soil parameter,microbial activity,and enzymes involved in soil nutrient cycle in a semiarid region of India.Results:The results showed a significant reduction(P<0.05)in soil carbon(SC),soil nitrogen(SN)content(~30–80%)and consequently the soil microbial biomass carbon(SMBC)(~70–80%),soil basal respiration(SBR),soil substrate-induced respiration(SSIR),and soil enzyme activities(β-glucosidase,acid phosphatase,and dehydrogenase)under cultivated sites in comparison with forest sites.Pearson’s correlation showed that a positive correlation of SC with SMBC,SBR,SSIR(P<0.01),and enzymatic activities(i.e.,β-glucosidase,dehydrogenase)(P<0.05)may imply the critical role of SC in regulating microbial and enzymatic activity.Also,a positive correlation of soil moisture with urease activity(P<0.01)was found suggesting it as a significant abiotic factor for soil biological functions.Additionally,based on the PCA analysis,we observed the clustering of SMBC/SC ratio and qCO_(2) nearby AF.Conclusion:Our study suggests that soil microbial parameters(SMBC,SBR,SSIR,SMBC/SC,qCO_(2))and enzyme activity are key indicators of soil health and fertility.Land use/cover alters the SOM content and soil microbial functions.The management strategies focusing on the conservation of natural forest and minimizing the land disturbances will be effective in preventing soil carbon flux as CO_(2) and maintaining the SC stock.展开更多
Introduction:Whether invasive plants stimulate or inhibit the soil microbial diversity is still an open question.Despite large-scale invasion by Conyza sumatrensis(Retz.)E.Walker in the urban ecosystems of the Srinaga...Introduction:Whether invasive plants stimulate or inhibit the soil microbial diversity is still an open question.Despite large-scale invasion by Conyza sumatrensis(Retz.)E.Walker in the urban ecosystems of the Srinagar city of the Kashmir Himalayan region,limited information exists on its impact,particularly,on the belowground microbial diversity.The present study was thus conducted to compare the soil microbial(bacterial and ascomycetous fungal)diversity between the sites invaded by C.sumatrensis and un-invaded(control)sites.Methods:Soil metagenome was extracted from C.sumatrensis invaded and un-invaded plots at the three study sites.A total of six plots(5×5 m each in size),including three invaded by C.sumatrensis and three un-invaded plots were nested within each study site.DNA after amplification was subject to denaturing gradient gel electrophoresis(DGGE);the bands were extracted from the DGGE gel,re-amplified,and sequenced for identification of the species.Results:The number of bacterial species was reduced in the invaded plots at two out of the three sites while as it was relatively higher in the un-invaded plots with many species exclusively found in these plots.Fungal species richness was higher in the invaded plots compared to the un-invaded plots at all the three sites.Also,more fungal species were found to occur exclusively in the invaded plots without being represented in the un-invaded plots.Conclusions:Invasion by C.sumatrensis alters soil microbial community structure in the urban ecosystems in the Kashmir Himalaya.How this species does so and what benefits does it draw from such alteration promise to be an interesting future discourse.展开更多
Background:Most studies on plant invasion consider the enemy release hypothesis when analyzing native habitats.However,the lower performance of invasive species in the native habitats can be the result of unfavorable ...Background:Most studies on plant invasion consider the enemy release hypothesis when analyzing native habitats.However,the lower performance of invasive species in the native habitats can be the result of unfavorable soil conditions in the native habitats.While soil biotic and abiotic factors have a potential to restrict the growth of invasive species in their native habitats,our understanding of belowground environment of invasive species in their native habitats is very limited.In this study,we analyzed soil characteristics associated with an exotic invasive plant,Old World Climbing Fern(Lygodium microphyllum),in its native habitat in Australia and the recipient habitat in South Florida.Rhizosphere soil samples from both habitats were analyzed for soil physical,chemical and biological characteristics.Results:Soil characteristics in the recipient habitats were significantly different compared to those in the native habitats.Soil samples from the native habitat had low soil pH,and high concentrations of elements such as aluminum and zinc which are phytotoxic in acidic soil environments.Additionally,mycorrhizal fungi spores were more diverse in the recipient habitat in Florida compared to the native habitat in Australia.Conclusion:Overall,our results indicate that growth of an invasive plant in its native habitats could be restricted by the toxic effects associated with strong soil acidity.Results from this study indicate that invasive plants not only escape from their natural herbivores but also from toxic soil environment in their native habitats.展开更多
Aims Changes in soil microbial communities after occupation by invasive alien plants can represent legacy effects of invasion that may limit recolonization and establishment of native plant species in soils previously...Aims Changes in soil microbial communities after occupation by invasive alien plants can represent legacy effects of invasion that may limit recolonization and establishment of native plant species in soils previously occupied by the invader.In this study,for three sites in southern Germany,we investigated whether invasion by giant goldenrod(Solidago gigantea)leads to changes in soil biota that result in reduced growth of native plants compared with neighbouring uninvaded soils.Methods We grew four native plant species as a community and treated those plants with soil solutions from invaded or uninvaded soils that were sterilized,or live,with live solutions containing different fractions of the soil biota using a decreasing sieve mesh-size approach.We measured aboveground biomass of the plants in the communities after a 10-week growth period.Main FindingsAcross all three sites and regardless of invasion,communities treated with<20μm soil biota or sterilized soil solutions had significantly greater biomass than communities treated with the complete soil biota solution.This indicates that soil biota>20μm are more pathogenic to the native plants than smaller organisms in these soils.Across all three sites,there was only a non-significant tendency for the native community biomass to differ among soil solution types,depending on whether or not the soil was invaded.Only one site showed significant differences in community biomass among soil solution types,depending on whether or not the soil was invaded;community biomass was significantly lower when treated with the complete soil biota solution than with soil biota<20μm or sterilized soil solutions,but only for the invaded soil.Our findings suggest that efforts to restore native communities on soils previously invaded by Solidago gigantea are unlikely to be hindered by changes in soil microbial community composition as a result of previous invasion.展开更多
Bradysia cellarum Frey (Diptera: Sciaridae) is an important subterranean pestand is especially damaging to Chinese chive. An effective and moreenvironmentally safe method than pesticides is needed for its control. The...Bradysia cellarum Frey (Diptera: Sciaridae) is an important subterranean pestand is especially damaging to Chinese chive. An effective and moreenvironmentally safe method than pesticides is needed for its control. Theefficacy of B. cellarum control, growth of Chinese chive and soil microbialdiversity were investigated after uae of soil solarization to exterminate thisinsect pest. The results show that on the first day after soil solarization 100%control of B. cellarum was achieved. Growth of Chinese chive was lower insolarized plots than in control plots over the first 10 days after treatment. Chivegrowth in solarized plots increased subsequently to match that in the controlplots. Moreover, the soil microbial community diversity in the treatment groupdecreased initially before gradually recovering. In addition, the abundance ofbeneficial microorganisms in the genus Bacillus and the phyla Proteobacteria,Chloroflexi and Firmicutes increased significantly. Soil solarization is thereforepractical and worthy of promotion in Chinese chive-growing regions.展开更多
The Tibetan Plateau of China is uniquely vulnerable to the global climate change and anthropogenic disturbances.As soil bacteria exert a considerable influence on the ecosystem function,understanding their response to...The Tibetan Plateau of China is uniquely vulnerable to the global climate change and anthropogenic disturbances.As soil bacteria exert a considerable influence on the ecosystem function,understanding their response to different climates and land-use types is important.Here,we characterized the bacterial community composition and diversity across three major ecosystems(cropland,forest,and grassland)in the Sygera Mountains of Tibet,along a typical elevational gradient(3300–4600 m).The abundance of taxa that preferentially inhabit neutral or weak alkaline soil environments(such as Actinobacteria,Thermoleophilia,and some non-acidophilus Acidobacteria)was significantly greater in the cropland than in the forest and grassland.Furthermore,the diversity of soil bacterial communities was also significantly greater in the cropland than in the forest and grassland.We observed a unimodal distribution of bacterial species diversity along the elevation gradient.The dominant phyla Acidobacteria and Proteobacteria exhibited consistent elevational distribution patterns that mirrored the abundance of their most abundant classes,while different patterns were observed for Acidobacteria and Proteobacteria at the class level.Soil pH was the primary edaphic property that regulated bacterial community composition across the different land-use types.Additionally,soil pH was the main factor distinguishing bacterial communities in managed soils(i.e.,cropland)from the communities in the natural environments(i.e.,forest and grassland).In conclusion,land use(particularly anthropogenic disturbances such as cropping)largely controlled soil environment,played a major role in driving bacterial community composition and distribution,and also surpassed climate in affecting bacterial community distribution.展开更多
Intercropping with eco-friendly crops is a well-known strategy for improving agriculture sustainability with benefits throughout the soil community,though the range of crop impacts on soil microbiota and extent of fee...Intercropping with eco-friendly crops is a well-known strategy for improving agriculture sustainability with benefits throughout the soil community,though the range of crop impacts on soil microbiota and extent of feedbacks to crops remain largely unclear.This study evaluated the impacts of different intercropping systems on soil bacterial community composition,diversity,and potential functions in tea gardens.Intercropping systems were found to be significantly influenced soil microbiota.Within the three tested intercropping systems(tea-soybean,tea-rapeseed and tea-soybean-rapeseed),the teasoybean-rapeseed intercropping system had the most dramatic influence on soil microbiota,with increases in richness accompanied by shifts in the structure of tea garden soil bacterial networks.Specifically,relative abundance of potentially beneficial bacteria associated with essential mineral nutrient cycling increased significantly in the tea-soybean-rapeseed intercropping system.In addition,soil microbial functions related to nutrient cycling functions were significantly enhanced.This was in accordance with increasing relative abundance of nitrogen cycling bacteria,including Burkholderia spp.and Rhodanobacter spp.Based on these results,it is proposed that intercropping tea plantation with soybean and rapeseed may benefit soil microbiota,and thereby promises to be an important strategy for improving soil health in ecologically sound tea production systems.展开更多
Background:Using native wildflowers for restoring marginal lands has gained considerable popularity.Establishment of wildflowers can be challenging due to several environmental factors.Restoring the microbial communit...Background:Using native wildflowers for restoring marginal lands has gained considerable popularity.Establishment of wildflowers can be challenging due to several environmental factors.Restoring the microbial community in degraded habitats can potentially result in the native plant performance and habitat restoration.This study was conducted to investigate the impact of native soil microbes and seeding depth on germination of south Texas native wildflowers.Two wildflower species,Ratibida columnifera(Nutt.)(Mexican Hat)and Verbesina encelioides(Cav.)(cowpen daisy),were treated with microbial wash extracted from native soils,and germination rate was recorded for 14-day period.We further analyzed the growth,biomass allocation,and root colonization by mycorrhizal fungi in these two plants growing them in a plant growth chamber for 6 weeks.To determine the impact of seeding depth,we planted the seeds of the two plant species at 2-cm,6-cm,and 12-cm depth and monitored germination and plant growth.Results:The two species responded differently to the seeding depth and microbial wash treatments.Microbial wash treatment resulted in higher germination rate in R.columnifera compared to control,while it did not have any impact on V.encelioides seed germination.While microbial treatment did not influence the total biomass,it had a significant impact on the biomass allocation in both the plant species.R.columnifera seeds germinated at both 2-cm and 6-cm depth and did not germinate at 12 cm,while the V.encelioides seeds germinated only at 2 cm and did not germinate at 6-cm or 12-cm seeding depth.Conclusions:While our results are species specific,our results indicate that native soil microbes can potentially improve the seed germination and growth of wildflowers.Our results also indicate the importance of specific seeding depth when sowing wildflower seeds for habitat restoration.展开更多
基金This study was funded by the National Key R&D Program(Grant No.2016YFC0501403-3).
文摘In semi-arid areas of China,gravel and sand mulch is a farming technique with a long history.In this study,a sample survey was conducted on long term gravel sand mulch observational fields in the Northwest Loess Plateau to determine the effects of long term mulch on soil microbial and soil enzyme activities.We found that after long term gravel-sand mulch,compared with bare ground,soil organic matter,alkali nitrogen,conductivity decreased,while pH and soil moisture increased.Urease,saccharase and catalase decreased with increased mulch thickness,while alkaline phosphatase was reversed.The results of Illumina MiSeq sequencing shows that after gravel-sand mulch,the bacterial and fungal community structure was different from bare land,and the diversity was reduced.Compared with bare land,the bacteria Proteobacteria and Acidobacteria abundance increased with increased thickness,and Actinobacteria was opposite.Also,at the fungal genus level,Fusarium abundance was significantly reduced,and Remersonia was significantly increased,compared with bare land.Redundancy analysis(RDA)revealed that soil environmental factors were important drivers of bacterial community changes.Overall,this study revealed some of the reasons for soil degradation after long term gravel-sand mulch.Therefore,it is recommended that the addition of exogenous soil nutrients after long term gravel-sand can help improve soil quality.
基金supported by the National Natural Science Foundation of China(Grant Nos.41807515,41907405,and 51974313)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX21-2118).
文摘The diversity of vegetation configuration is the key to ecological restoration in open-pit coal mine dump.However,the recovery outcomes of different areas with the same vegetation assemblage pattern are completely different after long-term evolution.Therefore,understanding the causes of differential vegetation recovery and the mechanism of plant succession is of great significance to the ecological restoration of mines.Three Pinus tabulaeformis plantations with similar initial site conditions and restoration measures but with different secondary succession processes were selected from the open-pit coal mine dump that has been restored for 30 years.Soil physicochemical properties,enzyme activities,vegetation and microbial features were investigated,while the structural equation models were established to explore the interactions between plants,soil and microbes.The results showed that original vegetation configuration and soil nutrient conditions were altered due to secondary succession.With the advancement of the secondary succession process,the coverage of plants increased from 34.8%to 95.5%(P<0.05),soil organic matter increased from 9.30 g kg^(-1)to 21.13 g kg^(-1)(P<0.05),and total nitrogen increased from 0.38 g kg^(-1)to 1.01 g kg^(-1)(P<0.05).The activities of soil urease and p-glucosidase were increased by 1.7-fold and 53.26%,respectively.Besides,the secondary succession also changed the soil microbial community structure and function.The relative abundance of Nitrospira genus which dominates the nitrification increased 5.2-fold.The results showed that urease andβ-glucosidase promoted the increase of vegetation diversity and biomass by promoting the accumulation of soil organic matter and nitrate nitrogen,which promoted the ecological restoration of mine dumps.
基金supported by the Science and Technology Planning Project of Gansu Province,China(23ZDKA017).
文摘In the Loess Plateau of China,land-use pattern is a major factor in controlling underlying biological processes.Additionally,the process of land-use pattern was accompanied by abandoned lands,potentially impacting soil microbe.However,limited researches were conducted to study the impacts of land-use patterns on the diversity and community of soil microorganisms in this area.The study aimed to investigate soil microbial community diversity and composition using high-throughput deoxyribonucleic acid(DNA)sequencing under different land-use patterns(apricot tree land,apple tree land,peach tree land,corn land,and abandoned land).The results showed a substantial difference(P<0.050)in bacterial alpha-diversity and beta-diversity between abandoned land and other land-use patterns,with the exception of Shannon index.While fungal beta-diversity was not considerably impacted by land-use patterns,fungal alpha-diversity indices varied significantly.The relative abundance of Actinobacteriota(34.90%),Proteobacteria(20.65%),and Ascomycota(77.42%)varied in soils with different land-use patterns.Soil pH exerted a dominant impact on the soil bacterial communities'composition,whereas soil available phosphorus was the main factor shaping the soil fungal communities'composition.These findings suggest that variations in land-use pattern had resulted in changes to soil properties,subsequently impacting diversity and structure of microbial community in the Loess Plateau.Given the strong interdependence between soil and its microbiota,it is imperative to reclaim abandoned lands to maintain soil fertility and sustain its function,which will have significant ecological service implications,particularly with regards to soil conservation in ecologically vulnerable areas.
基金financially supported by the National Natural Science Foundation of China(41907210,71903079,21976161,21777144).
文摘Chlorine-containing disinfectants have been widely used around the world for the prevention and control of the COVID-19 pandemic.However,at present,little is known about the impact of residual chlorine on the soil micro-ecological environment.Herein,we treated an experimental soil-plant-microbiome microcosm system by continuous irrigation with a low concentration of chlorine-containing water,and then analyzed the influence on the soil microbial community using metagenomics.After 14-d continuous chlorine treatment,there were no significant lasting effect on soil microbial community diversity and composition either in the rhizosphere or in bulk soil.Although metabolic functions of the rhizosphere microbial community were affected slightly by continuous chlorine treatment,it recovered to the original status.The abundance of several resistance genes changed by 7 d and recovered by 14 d.According to our results,the chlorine residue resulting from daily disinfection may present a slight long-term effect on plant growth(shoot length and fresh weight)and soil micro-ecology.In general,our study assisted with environmental risk assessments relating to the application of chlorine-containing disinfectants and minimization of risks to the environment during disease control,such as COVID-19.
基金This research was funded by two grants from Ministry of Science and Technology of China(2015BAC02B05)National Natural Science Foundation of China(31170507).
文摘Aims Plant-soil interaction(PsI)has been implicated as a causative mechanism promoting plant invasions,and some mechanisms underlying PsI effects remain unclear.Here,we attempted to address how altered soil microbes and nutrients influence PsI effects.Methods soil was cultured by an invasive forb Solidago canadensis for two years.We conducted an experiment,in which S.canadensis and Chinese natives were grown either alone or together in control and cultured soils,and determined the growth of S.canadensis and five natives and the competitive ability of S.canadensis.We ana-lyzed the microbial community composition and nutrients of two types of soils.Important Findings Compared to the control soil,the soil cultured by S.canadensis decreased the subsequent growth of S.canadensis and five Chinese natives,as well as the competitive ability of S.canadensis against Chinese natives.soil microbial community composition was significantly altered due to soil culturing.Total fatty acids,bacte-ria,gram-negative bacteria and gram-positive bacteria had no responses to soil culturing;fungi,aerobic bacteria and fungi/bacteria ratio significantly decreased with soil culturing;anaerobes and gram-negative/positive bacteria ratio greatly increased with soil culturing.soil nitrogen(N)dramatically decreased with soil culturing,whereas soil phosphorus(P)was unchanged.These results suggest that negative PsI effects may be linked to decreases in soil fungi,aerobic bacteria and soil N and increases in soil anaerobic bacteria and the ratio of gram-negative/positive bacteria.our find-ings provide an initial indication that S.canadensis-soil interaction alone could exhibit limited contributions to its success in the early stage of invasion.
基金We thank Council of Scientific and Industrial Research(CSIR,Ref No.20-12/2009(ii)EU-IV),University Grants Commission(UGC,Ref No.20-6/2009(ii)EU-IV)and Science and Engineering Research Board(SERB),Department of Science and Technology(DST,SR/FT/LS-59/2012),India for financial supportWe also thank University of Delhi for providing Research and Development for providing grant for doctoral research program.
文摘Background:Soil respiration(S_(R))is a critical process for understanding the impact of climatic conditions and land degradation on the carbon cycle in terrestrial ecosystems.We measured the S_(R) and soil environmental factors over 1 year in four land uses with varying levels of disturbance and different vegetation types viz.,mixed forest cover(MFC),Prosopis juliflora(Sw.)forest cover(PFC),agricultural field(AF),and vegetable field(VF),in a semi-arid area of Delhi,India.Our primary aim was to assess the effects of soil moisture(S_(M)),soil temperature(S_(T)),and soil microbial activity(S_(MA))on the S_(R).Methods:The S_(R) was measured monthly using an LI-6400 with an infrared gas analyser and a soil chamber.The S_(M) was measured using the gravimetric method.The S_(T)(10 cm)was measured with a probe attached to the LI-6400.The S_(MA) was determined by fluorescein diacetate hydrolysis.Results:The S_(R) showed seasonal variations,with the mean annual S_(R) ranging from 3.22 to 5.78μmol m^(−2) s^(−1) and higher S_(R) rates of~15-55%in the cultivated fields(AF,VF)than in the forest sites(MFC,PFC).The VF had significantly higher S_(R)(P<0.05)than the other land uses(AF,PFC,MFC),which did not vary significantly from one another in S_(R)(P<0.05).The repeated measures ANOVA evaluated the significant differences(P<0.05)in the S_(R) for high precipitation months(July,August,September,February).The S_(M) as a single factor showed a strong significant relationship in all the land uses(R^(2)=0.67-0.91,P<0.001).The effect of the S_(T) on the S_(R) was found to be weak and non-significant in the PFC,MFC,and AF(R^(2)=0.14-0.31;P>0.05).Contrasting results were observed in the VF,which showed high S_(R) during summer(May;11.21μmol m^(−2) s^(−1))and a significant exponential relationship with the S_(T)(R^(2)=0.52;P<0.05).The S_(R) was positively related to the SMA(R2=0.44-0.5;P<0.001).The interactive equations based on the independent variables S_(M),S_(T),and S_(MA) explained 91-95%of the seasonal variation in S_(R) with better model performance in the cultivated land use sites(AF,VF).Conclusion:S_(M) was the key determining factor of the S_(R) in semi-arid ecosystems and explained~90%of the variation.Precipitation increased S_(R) by optimizing the S_(M) and microbial activity.The S_(MA),along with the other soil factors S_(M) and S_(T),improved the correlation with S_(R).Furthermore,the degraded land uses will be more susceptible to temporal variations in S_(R) under changing climatic scenarios,which may influence the carbon balance of these ecosystems.
文摘Background:Land use/cover and management practices are widely known to influence soil organic matter(SOM)quality and quantity.The present study investigated the effect of different land use,i.e.,forests viz.mixed forest cover(MFC),Prosopis juliflora(Sw.)DC-dominated forest cover(PFC),and cultivated sites viz.agriculture field(AF),vegetable field(VF),respectively,on soil parameter,microbial activity,and enzymes involved in soil nutrient cycle in a semiarid region of India.Results:The results showed a significant reduction(P<0.05)in soil carbon(SC),soil nitrogen(SN)content(~30–80%)and consequently the soil microbial biomass carbon(SMBC)(~70–80%),soil basal respiration(SBR),soil substrate-induced respiration(SSIR),and soil enzyme activities(β-glucosidase,acid phosphatase,and dehydrogenase)under cultivated sites in comparison with forest sites.Pearson’s correlation showed that a positive correlation of SC with SMBC,SBR,SSIR(P<0.01),and enzymatic activities(i.e.,β-glucosidase,dehydrogenase)(P<0.05)may imply the critical role of SC in regulating microbial and enzymatic activity.Also,a positive correlation of soil moisture with urease activity(P<0.01)was found suggesting it as a significant abiotic factor for soil biological functions.Additionally,based on the PCA analysis,we observed the clustering of SMBC/SC ratio and qCO_(2) nearby AF.Conclusion:Our study suggests that soil microbial parameters(SMBC,SBR,SSIR,SMBC/SC,qCO_(2))and enzyme activity are key indicators of soil health and fertility.Land use/cover alters the SOM content and soil microbial functions.The management strategies focusing on the conservation of natural forest and minimizing the land disturbances will be effective in preventing soil carbon flux as CO_(2) and maintaining the SC stock.
基金The grant provided by the Canadian Bureau of International Education(CBIE)to NR for conducting the present study is gratefully acknowledged.
文摘Introduction:Whether invasive plants stimulate or inhibit the soil microbial diversity is still an open question.Despite large-scale invasion by Conyza sumatrensis(Retz.)E.Walker in the urban ecosystems of the Srinagar city of the Kashmir Himalayan region,limited information exists on its impact,particularly,on the belowground microbial diversity.The present study was thus conducted to compare the soil microbial(bacterial and ascomycetous fungal)diversity between the sites invaded by C.sumatrensis and un-invaded(control)sites.Methods:Soil metagenome was extracted from C.sumatrensis invaded and un-invaded plots at the three study sites.A total of six plots(5×5 m each in size),including three invaded by C.sumatrensis and three un-invaded plots were nested within each study site.DNA after amplification was subject to denaturing gradient gel electrophoresis(DGGE);the bands were extracted from the DGGE gel,re-amplified,and sequenced for identification of the species.Results:The number of bacterial species was reduced in the invaded plots at two out of the three sites while as it was relatively higher in the un-invaded plots with many species exclusively found in these plots.Fungal species richness was higher in the invaded plots compared to the un-invaded plots at all the three sites.Also,more fungal species were found to occur exclusively in the invaded plots without being represented in the un-invaded plots.Conclusions:Invasion by C.sumatrensis alters soil microbial community structure in the urban ecosystems in the Kashmir Himalaya.How this species does so and what benefits does it draw from such alteration promise to be an interesting future discourse.
基金This study was funded by the Dissertation Evidence Acquisition Fellowship,Florida International University to P.Soti.
文摘Background:Most studies on plant invasion consider the enemy release hypothesis when analyzing native habitats.However,the lower performance of invasive species in the native habitats can be the result of unfavorable soil conditions in the native habitats.While soil biotic and abiotic factors have a potential to restrict the growth of invasive species in their native habitats,our understanding of belowground environment of invasive species in their native habitats is very limited.In this study,we analyzed soil characteristics associated with an exotic invasive plant,Old World Climbing Fern(Lygodium microphyllum),in its native habitat in Australia and the recipient habitat in South Florida.Rhizosphere soil samples from both habitats were analyzed for soil physical,chemical and biological characteristics.Results:Soil characteristics in the recipient habitats were significantly different compared to those in the native habitats.Soil samples from the native habitat had low soil pH,and high concentrations of elements such as aluminum and zinc which are phytotoxic in acidic soil environments.Additionally,mycorrhizal fungi spores were more diverse in the recipient habitat in Florida compared to the native habitat in Australia.Conclusion:Overall,our results indicate that growth of an invasive plant in its native habitats could be restricted by the toxic effects associated with strong soil acidity.Results from this study indicate that invasive plants not only escape from their natural herbivores but also from toxic soil environment in their native habitats.
基金funding from the Deutsche Forschungsgemeinschaft(AZ DA 1502/1-1).
文摘Aims Changes in soil microbial communities after occupation by invasive alien plants can represent legacy effects of invasion that may limit recolonization and establishment of native plant species in soils previously occupied by the invader.In this study,for three sites in southern Germany,we investigated whether invasion by giant goldenrod(Solidago gigantea)leads to changes in soil biota that result in reduced growth of native plants compared with neighbouring uninvaded soils.Methods We grew four native plant species as a community and treated those plants with soil solutions from invaded or uninvaded soils that were sterilized,or live,with live solutions containing different fractions of the soil biota using a decreasing sieve mesh-size approach.We measured aboveground biomass of the plants in the communities after a 10-week growth period.Main FindingsAcross all three sites and regardless of invasion,communities treated with<20μm soil biota or sterilized soil solutions had significantly greater biomass than communities treated with the complete soil biota solution.This indicates that soil biota>20μm are more pathogenic to the native plants than smaller organisms in these soils.Across all three sites,there was only a non-significant tendency for the native community biomass to differ among soil solution types,depending on whether or not the soil was invaded.Only one site showed significant differences in community biomass among soil solution types,depending on whether or not the soil was invaded;community biomass was significantly lower when treated with the complete soil biota solution than with soil biota<20μm or sterilized soil solutions,but only for the invaded soil.Our findings suggest that efforts to restore native communities on soils previously invaded by Solidago gigantea are unlikely to be hindered by changes in soil microbial community composition as a result of previous invasion.
基金This research was supported by grants from the National Natural Science Foundation of China(31772170)the Project of the Education Department in Hubei Province(B2020038)+3 种基金the Natural Science Foundation of Jingzhou City(2020CB21-30)the China Agriculture Research System(CARS-24-C-02)the Beijing Key Laboratory for Pest Control and Sustainable Cultivation of Vegetablesthe Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(AAS-ASTIP-IVFCAAS).
文摘Bradysia cellarum Frey (Diptera: Sciaridae) is an important subterranean pestand is especially damaging to Chinese chive. An effective and moreenvironmentally safe method than pesticides is needed for its control. Theefficacy of B. cellarum control, growth of Chinese chive and soil microbialdiversity were investigated after uae of soil solarization to exterminate thisinsect pest. The results show that on the first day after soil solarization 100%control of B. cellarum was achieved. Growth of Chinese chive was lower insolarized plots than in control plots over the first 10 days after treatment. Chivegrowth in solarized plots increased subsequently to match that in the controlplots. Moreover, the soil microbial community diversity in the treatment groupdecreased initially before gradually recovering. In addition, the abundance ofbeneficial microorganisms in the genus Bacillus and the phyla Proteobacteria,Chloroflexi and Firmicutes increased significantly. Soil solarization is thereforepractical and worthy of promotion in Chinese chive-growing regions.
基金supported by the National Natural Science Foundation of China(Nos.41930754 and 41661061)the Natural Science Foundation of Tibet Autonomous Region of China(Nos.XZ2018ZRG-34(Z))
文摘The Tibetan Plateau of China is uniquely vulnerable to the global climate change and anthropogenic disturbances.As soil bacteria exert a considerable influence on the ecosystem function,understanding their response to different climates and land-use types is important.Here,we characterized the bacterial community composition and diversity across three major ecosystems(cropland,forest,and grassland)in the Sygera Mountains of Tibet,along a typical elevational gradient(3300–4600 m).The abundance of taxa that preferentially inhabit neutral or weak alkaline soil environments(such as Actinobacteria,Thermoleophilia,and some non-acidophilus Acidobacteria)was significantly greater in the cropland than in the forest and grassland.Furthermore,the diversity of soil bacterial communities was also significantly greater in the cropland than in the forest and grassland.We observed a unimodal distribution of bacterial species diversity along the elevation gradient.The dominant phyla Acidobacteria and Proteobacteria exhibited consistent elevational distribution patterns that mirrored the abundance of their most abundant classes,while different patterns were observed for Acidobacteria and Proteobacteria at the class level.Soil pH was the primary edaphic property that regulated bacterial community composition across the different land-use types.Additionally,soil pH was the main factor distinguishing bacterial communities in managed soils(i.e.,cropland)from the communities in the natural environments(i.e.,forest and grassland).In conclusion,land use(particularly anthropogenic disturbances such as cropping)largely controlled soil environment,played a major role in driving bacterial community composition and distribution,and also surpassed climate in affecting bacterial community distribution.
基金funded by the Science and Technology Commissioner’s On-site Teaching Renovation and Promotion Project of Nanping City (NP2021KTS05)the Modern Agricultural Talents Support Project of Ministry of Agriculture and Rural Affairs of China。
文摘Intercropping with eco-friendly crops is a well-known strategy for improving agriculture sustainability with benefits throughout the soil community,though the range of crop impacts on soil microbiota and extent of feedbacks to crops remain largely unclear.This study evaluated the impacts of different intercropping systems on soil bacterial community composition,diversity,and potential functions in tea gardens.Intercropping systems were found to be significantly influenced soil microbiota.Within the three tested intercropping systems(tea-soybean,tea-rapeseed and tea-soybean-rapeseed),the teasoybean-rapeseed intercropping system had the most dramatic influence on soil microbiota,with increases in richness accompanied by shifts in the structure of tea garden soil bacterial networks.Specifically,relative abundance of potentially beneficial bacteria associated with essential mineral nutrient cycling increased significantly in the tea-soybean-rapeseed intercropping system.In addition,soil microbial functions related to nutrient cycling functions were significantly enhanced.This was in accordance with increasing relative abundance of nitrogen cycling bacteria,including Burkholderia spp.and Rhodanobacter spp.Based on these results,it is proposed that intercropping tea plantation with soybean and rapeseed may benefit soil microbiota,and thereby promises to be an important strategy for improving soil health in ecologically sound tea production systems.
文摘Background:Using native wildflowers for restoring marginal lands has gained considerable popularity.Establishment of wildflowers can be challenging due to several environmental factors.Restoring the microbial community in degraded habitats can potentially result in the native plant performance and habitat restoration.This study was conducted to investigate the impact of native soil microbes and seeding depth on germination of south Texas native wildflowers.Two wildflower species,Ratibida columnifera(Nutt.)(Mexican Hat)and Verbesina encelioides(Cav.)(cowpen daisy),were treated with microbial wash extracted from native soils,and germination rate was recorded for 14-day period.We further analyzed the growth,biomass allocation,and root colonization by mycorrhizal fungi in these two plants growing them in a plant growth chamber for 6 weeks.To determine the impact of seeding depth,we planted the seeds of the two plant species at 2-cm,6-cm,and 12-cm depth and monitored germination and plant growth.Results:The two species responded differently to the seeding depth and microbial wash treatments.Microbial wash treatment resulted in higher germination rate in R.columnifera compared to control,while it did not have any impact on V.encelioides seed germination.While microbial treatment did not influence the total biomass,it had a significant impact on the biomass allocation in both the plant species.R.columnifera seeds germinated at both 2-cm and 6-cm depth and did not germinate at 12 cm,while the V.encelioides seeds germinated only at 2 cm and did not germinate at 6-cm or 12-cm seeding depth.Conclusions:While our results are species specific,our results indicate that native soil microbes can potentially improve the seed germination and growth of wildflowers.Our results also indicate the importance of specific seeding depth when sowing wildflower seeds for habitat restoration.
