In order to investigate the effect of invastion by pine wood nematode(PWN), this study analyzed several functional indices, i.e., the increment in DBH and stand volume and biomass, in the damaged stands with various m...In order to investigate the effect of invastion by pine wood nematode(PWN), this study analyzed several functional indices, i.e., the increment in DBH and stand volume and biomass, in the damaged stands with various mixed percentages of Pinus massoniana and P. thunbergii and with different levels of damage. According to the results of rate of change in increment of DBH and stand volume, the forest ecosystem resistance against PWN increased with a reduction in the mixed ratio of pine. The resistance was highest with a mixed percentage of 50%. The invasion of PWN changed the corresponding relationship of increment between DBH and stand volume(pure stands > 7:3 conifer and broadleaf > 6:4 conifer and broadleaf > 5:5 conifer and broadleaf) among the P. thunbergii stands when there is no damage, but for P. massoniana stands this phenomenon did not occur. For the increment rate of DBH and stand volume, this significant change in P. thunbergii forest indicates that the resistance of pure P. thunbergii forest was higher than that of P. massoniana. The invasion of PWN accelerates the succession from pure stands to mixed stands and then to the broadleaf evergreen stands.展开更多
Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing act...Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.展开更多
Crude oil pollution is a significant global environmental challenge.The eastern Gansu Province on the Loess Plateau,an important agricultural region containing the Changqing Oilfield,is facing increasing crude oil con...Crude oil pollution is a significant global environmental challenge.The eastern Gansu Province on the Loess Plateau,an important agricultural region containing the Changqing Oilfield,is facing increasing crude oil contamination.Understanding how microbial communities respond to varying pollution levels is critical for developing effective bioremediation strategies.This study examined how different concentrations of crude oil affect soil properties and microbial communities in Qingyang City,eastern Gansu Province,China by comparing lightly polluted(1895.84-2696.54 mg/kg total petroleum hydrocarbons(TPH)),heavily polluted(4964.25-7153.61 mg/kg TPH),and uncontaminated(CK)soils.Results revealed that petroleum contamination significantly increased total organic carbon(TOC),pH,C:N:P ratio,and the activities of dehydrogenase(DHA)and polyphenol oxidase(PPO),while reducing total nitrogen(TN),available nitrogen(AN),total phosphorus(TP),available phosphorus(AP),available potassium(AK),soil organic matter(SOM),soil water content(SWC),the activities of urease(URE)and alkaline phosphatase(APA),and microbial alpha diversity(P<0.050).Light pollution(LP)soils demonstrated an increase in culturable microorganisms,whereas heavy pollution(HP)soils exhibited increased hydrocarbon-degrading microbes and higher expression of key functional genes,such as alkane monooxygenase(AlkB),cytochrome P450 alkane hydroxylases(P450),catechol 2,3-dioxygenase(C23O),and naphthalene dioxygenase(Nah)(P<0.050).Non-metric multidimensional scaling(NMDS)and redundancy analysis(RDA)indicated evident variations in microbial community structure across different oil contamination levels.LP soils were dominated by bacterial genera Pseudoxanthomonas and Solimonadaceae,whereas Pseudomonas,Nocardioides,and hydrocarbon-degrading genera(Marinobacter,Idiomarina,and Halomonas)were predominant in HP soils.The fungal genus Pseudallescheria exhibited the most pronounced abundance shift between LP and HP soils(P<0.050).Environmental factor analysis identified AN,SWC,TN,SOM,and alpha diversity indices(Shannon index and Chao1 index)as the key differentiators of CK soils,whereas the pollutant levels and metal content were characterized in HP soils.Hydrocarbon-degrading microbial abundance was a defining trait of HP soils.Metabolic pathway analysis revealed enhanced aromatic hydrocarbon degradation in HP soils,indicating microbial adaptation to severe contamination.These findings demonstrated that crude oil pollution suppressed soil nutrients while reshaping the structure and function of microbial communities.Pollution intensity directly affected microbial composition and degradation potential.This study offers valuable insights into microbial responses across contamination gradients and supports the development of targeted bioremediation strategies for oil-contaminated loess soils.展开更多
This study was conducted to characterize the diversity and function of microbial communities in marine sediments of the Pearl River Mouth Basin(PRMB)in the South China Sea.The results showed that the bacterial and arc...This study was conducted to characterize the diversity and function of microbial communities in marine sediments of the Pearl River Mouth Basin(PRMB)in the South China Sea.The results showed that the bacterial and archaeal communities varied greatly with depth.Proteobacteria in bacterial communities and Nitrososphaeria and Woesearchaeota in archaeal communities were dominant in the shallow sediments(1-40 cm),while Chloroflexi in bacterial communities and Bathyarchaeia in archaeal communities were dominant in the deep sediments(50-200 cm).Regarding ecological functions based on the metatranscriptomic data,genes involved in various pathways of nitrogen metabolism and sulfur metabolism were observed in the tested sediment samples.Metagenomic analysis revealed that Proteobacteria contribute the most to nearly all genes involved in nitrogen and sulfur metabolism.Moreover,Thaumarchaeota contribute the most to certain genes involved in nitrification,denitrification and assimilatory sulfate reduction pathways.The most abundant bacterial genus,Candidatus Scalindua,is crucial for nitrification,dissimilatory nitrate reduction,denitrification and assimilatory sulfate reduction pathways.展开更多
Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small water...Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small watershed of subtropical region of China was selected for this study. Land uses covered paddy fields, vegetable farming, fruit trees, upland crops, bamboo stands, and forestry. Soil biological and biochemical properties included soil organic C and nutrient contents, mineralization of soil organic C, and soil microbial biomass and community functional diversity. Soil organic C and total N contents, microbial biomass C and N, and respiration intensity under different land uses were changed in the following order： paddy fields （and vegetable farming） 〉 bamboo stands 〉 fruit trccs （and upland）. The top surface （0-15 cm） paddy fields （and vegetable farming） were 76.4 and 80.8% higher in soil organic C and total N contents than fruit trees （and upland） soils, respectively. Subsurface paddy soils （15-30 cm） were 59.8 and 67.3% higher in organic C and total N than upland soils, respectively. Soil microbial C, N and respiration intensity in paddy soils （0-15 cm） were 6.36, 3.63 and 3.20 times those in fruit tree （and upland） soils respectively. Soil microbial metabolic quotient was in the order： fruit trees （and upland） 〉 forestry 〉 paddy fields. Metabolic quotient in paddy soils was only 47.7% of that in fruit tree （and upland） soils. Rates of soil organic C mineralization during incubation changed in the order： paddy fields 〉 bamboo stands 〉 fruit trees （and upland） and soil bacteria population： paddy fields 〉 fruit trees （and upland） 〉 forestry. No significant difference was found for fungi and actinomycetes populations. BIOLOG analysis indicated a changing order of paddy fields 〉 fruit trees （and upland） 〉 forestry in values of the average well cell development （AWCD） and functional diversity indexes of microbial community. Results also showed that the conversion from paddy fields to vegetable farming for 5 years resulted in a dramatic increase in soil available phosphorus content while insignificant changes in soil organic C and total N content due to a large inputs of phosphate fertilizers. This conversion caused 53, 41.5, and 41.3% decreases in soil microbial biomass C, N, and respiration intensity, respectively, while 23.6% increase in metabolic quotient and a decrease in soil organic C mineralization rate. Moreover, soil bacteria and actinomycetes populations were increased slightly, while fungi population increased dramatically. Functional diversity indexes of soil microbial community decreased significantly. It was concluded that land uses in the subtropical region of China strongly affected soil biological and biochemical properties. Soil organic C and nutrient contents, mineralization of organic C and functional diversity of microbial community in paddy fields were higher than those in upland and forestry. Overuse of chemical fertilizers in paddy fields with high fertility might degrade soil biological properties and biochemical function, resulting in deterioration of soil biological quality.展开更多
Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental ...Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included： a non-amended control（CK）, a commonly used application rate of inorganic fertilizer treatment（NPK）; a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment（NPKM）, and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment（NPKS）. Denaturing gradient gel electrophoresis（DGGE） of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term（NPKM, NPKS） significantly promoted soil bacterial structure than the application of inorganic fertilizer only（NPK）, and NPKM treatment was the most important driver for increases in the soil microbial community richness（S） and structural diversity（H）. Overall utilization of carbon sources by soil microbial communities（average well color development, AWCD） and microbial substrate utilization diversity and evenness indices（H＇ and E） indicated that long-term inorganic fertilizer with organic amendments incorporated（NPKM, NPKS） could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis（PCA） based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis（RDA） indicated that soil organic carbon（SOC） availability, especially soil microbial biomass carbon（Cmic） and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China＇s soil resource.展开更多
Urbanization often exerts multiple effects on aquatic and terrestrial organisms,including changes in biodiversity,species composition and ecosystem functions.However,the impacts of urbanization on river phytoplankton ...Urbanization often exerts multiple effects on aquatic and terrestrial organisms,including changes in biodiversity,species composition and ecosystem functions.However,the impacts of urbanization on river phytoplankton in subtropical urbanizing watersheds remain largely unknown.Here,we explored the effects of urbanization on phytoplankton community structure(i.e.,biomass,community composition and diversity)and function(i.e.,resource use efficiency)in a subtropical river at watershed scale in southeast China over 6 years.A total of 318 phytoplankton species belonging into 120 genera and 7 phyla were identified from 108 samples.Bacillariophyta biomass showed an increasing trend with increasing urbanization level.The phytoplankton community shifted from Chlorophyta dominance in rural upstream waters to Bacillariophyta dominance in urbanized downstream waters.Furthermore,phytoplankton diversity and resource use efficiency(RUE=phytoplankton biomass/total phosphorus)were significantly decreased with increasing urbanization level from upstream to downstream.Phytoplankton RUE exhibited a significant positive correlation with species richness,but a negative correlation with phytoplankton evenness.The variation in environmental factors(turbidity,total nitrogen,NH_(4)^(+)-N,total phosphorus,PO_(4)^(3-)-P and percentage urbanized area)was significantly correlated with phytoplankton diversity and RUE.Overall,our results revealed the influence of urbanization on phytoplankton community structure and ecosystem function was due to its altering the environmental conditions.Therefore,human-driven urbanization may play crucial roles in shaping the structure and function of phytoplankton communities in subtropical rivers,and the mechanism of this process can provide important information for freshwater sustainable uses,watershed management and conservation.展开更多
Boreal forests commonly suff er from nitrogen defi ciency due to low rate of nitrogen mineralization.Biochar may promote soil organic matter decomposition and accelerate nitrogen mineralization.In this study,Illumina ...Boreal forests commonly suff er from nitrogen defi ciency due to low rate of nitrogen mineralization.Biochar may promote soil organic matter decomposition and accelerate nitrogen mineralization.In this study,Illumina NovaSeq sequencing combined with functional annotation of prokaryotic taxa(FAPROTAX)analysis was used to investigate the eff ect of biochar pyrolysis temperatures,the amount of applied biochar,and the period since the biochar application(2-and 3-year)on soil bacterial communities.The results show that biochar pyrolysis temperatures(500℃ and 650℃)and the amount of applied biochar(0.5 kg m^(−2)and 1.0 kg m^(−2))did not change soil properties.Nevertheless,the interaction of biochar pyrolysis temperature and the amount had signifi cant eff ects on bacterial species richness and evenness(P<0.05).The application of biochar produced at 500℃ had a lower abundance of Actinobacteria and Verrucomicrobia,while that produced at 650℃ had a higher abundance of Conexibacter and Phenylobacterium.When biochar produced at 650℃ was applied,applying 0.5 kg m^(−2)had a higher abundance of Cyanobacteria,Conexibacter,and Phenylobacterium than that of 1.0 kg m^(−2)(P<0.05).Functionally,the abundance of the aromatic compound degradation group increased with the extension of application time and increase of pyrolysis temperature.The time since application played an important role in the formation of soil bacterial communities and their functional structure.Long-term studies are necessary to understand the consequence of biochar on bacterial communities in boreal forests.展开更多
The purpose of this study was to reveal how activated sludge communities respond to influent quality and indigenous communities by treating two produced waters from different origins in a batch reactor in succession. ...The purpose of this study was to reveal how activated sludge communities respond to influent quality and indigenous communities by treating two produced waters from different origins in a batch reactor in succession. The community shift and compositions were investigated using Polymerase Chain Reaction–denaturing gradient gel electrophoresis（PCR–DGGE） and further16 S ribosomal DNA（r DNA） clone library analysis. The abundance of targeted genes for polycyclic aromatic hydrocarbon（PAH） degradation, nah Ac/phn Ac and C12O/C23 O, was tracked to define the metabolic ability of the in situ microbial community by Most Probable Number（MPN） PCR. The biosystem performed almost the same for treatment of both produced waters in terms of removals of chemical oxygen demand（COD） and PAHs. Sludge communities were closely associated with the respective influent bacterial communities（similarity 〉 60%）, while one sludge clone library was dominated by the Betaproteobacteria（38%） and Bacteriodetes（30%）and the other was dominated by Gammaproteobacteria（52%）. This suggested that different influent and water quality have an effect on sludge community compositions. In addition, the existence of catabolic genes in sludge was consistent with the potential for degradation of PAHs in the treatment of both produced waters.展开更多
Phyllosphere microbiome plays an irreplaceable role in maintaining plant health under stress,but its structure and functions in heavy metal-hyperaccumulating plants remain elusive.Here,the phyllosphere microbiome,inha...Phyllosphere microbiome plays an irreplaceable role in maintaining plant health under stress,but its structure and functions in heavy metal-hyperaccumulating plants remain elusive.Here,the phyllosphere microbiome,inhabiting hyperaccumulating(HE)and non-hyperaccumulating ecotype(NHE)of Sedum alfredii grown in soils with varying heavy metal concentration,was characterized.Compared with NHE,the microbial communityα-diversity was greater in HE.Core phyllosphere taxa with high relative abundance(>10%),including Streptomyces and Nocardia(bacteria),Cladosporium and Acremonium(fungi),were significantly related to cadmium(Cd)and zinc(Zn)concentration and biomass of host plants.Moreover,microbial co-occurrence networks in HE exhibited greater complexity than those in NHE.Additionally,proportions of positive associations in HE bacterial networks increased with the rising heavy metal concentration,indicating a higher resistance of HE phyllosphere microbiome to heavy metal stress.Furthermore,in contrast to NHE,microbial community functions,primarily involved in heavy metal stress resistance,were more abundant in HE,in which microbiome assisted hosts to resist heavy metal stress better.Collectively,this study indicated that phyllosphere microbiome of the hyperaccumulator played an indispensable role in assisting hosts to resist heavy metal stress,and provided new insights into phyllosphere microbial application potential in phytoremediation.展开更多
With the rapid development of molecular biology technology,especially the application of metagenomics,many challenges in groundwater microbial research have been overcome.Metagenomics has enabled the exploration of th...With the rapid development of molecular biology technology,especially the application of metagenomics,many challenges in groundwater microbial research have been overcome.Metagenomics has enabled the exploration of the diversity of unculturable microorganisms in groundwater.This paper reviews macro genomics 16S rRNA and metagenomics sequencing data,highlighting recent applications of metagenomics in investigating groundwater microbial communities.It also examines the relationship between microbial diversity and environmental factors,the identification of functional microbial groups,the role of microorganisms in groundwater pollution remediation,and their contribution to the hydrogeochemi-cal cycle.Finally,it provide insights into future research directions in groundwater microbiology.展开更多
On the basis of a long-term（30 years） field experiment that involved four rotation systems, rice-rice-winter fallow（RRF）, rice-rice-ryegrass（RRG）, rice-rice-rape（RRP）, and rice-rice-milk vetch（RRV）, this stu...On the basis of a long-term（30 years） field experiment that involved four rotation systems, rice-rice-winter fallow（RRF）, rice-rice-ryegrass（RRG）, rice-rice-rape（RRP）, and rice-rice-milk vetch（RRV）, this study described the effects of green manure on the microbial communities in the red paddy soils using 454 pyrosequencing for the 16 S r RNA gene. The Chao1 richness and non-parametric Shannon＇s index increased in all soil samples that received green manure treatments. The communities＇ structures with the green manure applications were significantly dissimilar from that under the winter fallow. Using Metastats tests, many genera in the RRG, RRP and RRV soils were significantly different from those in the RRF soil, including a number of genera that functioned in the nitrogen and sulfur cycles. Analyses of the genera with these functions revealed the shifts in microbial ecosystem functions after long-term green manuring. Changes in the microbial communities increased the ammonium supply and decreased the soil acidification in green-manure-amended soils. Together, these data suggested powerful effects of green manure on both the microbial communities and the biogeochemical cycle driven by the shifts in bacterial functional groups.展开更多
Fruit production is an important strategy for alleviating poverty on the Tibetan Plateau and leads to the conversion of natural barren land into orchards.This study aimed to understand how the conversion of barren lan...Fruit production is an important strategy for alleviating poverty on the Tibetan Plateau and leads to the conversion of natural barren land into orchards.This study aimed to understand how the conversion of barren land to peach(Prunus persica)orchards affects soil nutrients,heavy metals,and fungal communities in the 0–40 cm profile(at 20 cm intervals)in an experiment including three treatments,barren land(BL),peach orchards planting for 4 years(Y4),and peach orchards planting for 10 years(Y10).Results of the experiment showed that compared with BL,Y4 reduced the availability of some macronutrients(N and K)and micronutrients(Fe and Mn)due to the exclusive application of chemical fertilizer at the seedling stage.Conversely,Y10,which included six years of green cultivation management,using a combination of sheep manure and chemical fertilizer as well as alfalfa(Medicago sativa Linn)intercropping,effectively improved soil macronutrients,but did not enhance the availability of Fe and Mn.Although the investigated heavy metals(As,Hg,Pb,Cr,and Cd)in both the Y4 and Y10 soils were found to pose a low risk to food safety and soil environment,Hg,Cr,and As tended to accumulate in the subsoil(20–40 cm).Furthermore,the variations in the fungal community composition and functional groups were mainly driven by the interaction effects of macronutrients,micronutrients,and heavy metals,but their independent contribution to specific key functional groups cannot be overlooked.For example,Y4 and Y10 decreased the relative abundance of soil saprotrophic and lichenized fungi,mainly due to the loss of micronutrients(Fe and Mn).However,as a result of macronutrient input and dung saprotrophic fungi enrichment,orchard soils promoted the growth of pathogens that play critical roles in fungal co-occurrence networks.These findings indicate that supplementation with N or K fertilizer or manure at the seedling stage and fertilizers rich in Fe and Mn throughout the growth period would be beneficial to the balance of soil nutrients and provide insights into linking the variations in soil nutrients and heavy metals to the function of the fungal community during the conversion of barren land to orchards in alpine soil ecosystems.The risks posed by heavy metal accumulation and fungal pathogen enrichment should be actively prevented.展开更多
Coastal dunes represent priority habitats for conservation due to the provision of valuable ecosystem services such as land protection,water supply or biodiversity conservation.Soil microbial communities are of crucia...Coastal dunes represent priority habitats for conservation due to the provision of valuable ecosystem services such as land protection,water supply or biodiversity conservation.Soil microbial communities are of crucial importance to maintain plant diversity due to harsh environmental conditions,water limitation and nutrient scarcity.Invasive alien plants represent a major threat to ecosystem conservation.Here,we explored different impacts of Carpobrotus edulis,a succulent plant invading coastal areas worldwide,on the function and structure of bacterial communities.Sand represents a challenging substrate due to low organic matter content and limited microbial activity.We optimized bacterial extraction for functional evaluation before assessing ecosystem impacts produced by C.edulis.We compared 12 extracting procedures combining different soil storage,sample amount and extracting solutions on the functional activity of sand communities through the community-level physiological profile.We further explored the function(using Biolog Ecoplates)and structure[using polymerase chain reaction–denaturing gradient gel electrophoresis(PCR-DGGE)]of bacterial communities from dunes invaded by C.edulis.Saline solution consistently increased bacterial cells detected by cytometry(P≤0.001).Principal component analysis suggested a limited temporal framework(0–24 h)in which community function can be explored without significant alterations in C substrate consumption.Changes under C.edulis invasion exhibited a different pattern of C substrate utilization comparing native and non-native zones(interspecific),but also between native zones(intraspecific),suggesting that functional impacts are site-dependent.Complementary,results obtained from PCR-DGGE indicated that the bacterial community structure of native dunes significantly differed from dunes invaded by C.edulis.展开更多
The stability mechanisms of ecosystem functions have been a hot topic in ecology. However, in wetland ecosystems, the mechanisms by which biotic and abiotic factors interact to affect ecosystem stability in changing e...The stability mechanisms of ecosystem functions have been a hot topic in ecology. However, in wetland ecosystems, the mechanisms by which biotic and abiotic factors interact to affect ecosystem stability in changing environments remain largely unclear. This study investigated the key factors and underlying mechanisms that regulate the spatial variability of wetland productivity by measuring community productivity, multiple components of biodiversity (i.e. species diversity, community functional composition and diversity) and environmental factors along a well-characterized gradient of wetland degradation in the lower reaches of the Yellow River. The results showed that the spatial variability of productivity in wetlands increased with intensified degradation. The spatial variability of wetland productivity was not related to species richness but was mainly affected by changes in community functional composition and diversity. Furthermore, degradation-induced changes in soil nutrients drove the spatial variability of productivity to increase with shifts in functional composition towards more conservative traits (i.e. higher leaf dry matter content and root tissue density), and to decrease with higher functional trait diversity. These findings reveal the driving mechanism of spatial variability in wetland productivity under degradation, and suggest that reduced nutrient availability, by altering plant resource strategies, can affect the spatial reliability of key ecosystem functions in wetlands.展开更多
A better understanding the mechanisms driving plant biomass allocation in different ecosystems is an important theoretical basis for ilustrating the adaptive strategies of plants.To date,the effects of habitat conditi...A better understanding the mechanisms driving plant biomass allocation in different ecosystems is an important theoretical basis for ilustrating the adaptive strategies of plants.To date,the effects of habitat conditions on plant biomass allocation have been widely studied.However,it is less known how plant community traits and functions(PCTF)affect biomass allocation,particularly in alpine grassland ecosystems.In this study,community-weighted means(CWM)were calculated at the community level using five leaf functional traits,and the relationships between PCTF and biomass trade-offs were explored using correlation analysis,variation partitioning analysis and structural equation modeling.We found that the trade-off values were greater than zero in both alpine meadow(AM)and alpine steppe(AS)across the Tibetan Plateau,with different values of 0.203 and 0.088 for AM and AS,respectively.Moreover,the critical factors determining biomass allocation in AS were species richness(SR;scored at 0.69)and leaf dry matter content of CWM(CWM_(LDMC),scored at 0.42),while in AM,the key factors were leaf dry matter content(CWM.pMC scored at 0.48)and leaf carbon content of CWM(CWM_(LC),scored at-0.45).In particular,both CWM_(LDMC)and SR in AS,as well as CWM_(LDMC)and CWM_(LDMC)in AM were primarily regulated by precipitation.In summary,precipitation tends to drive biomass allocation in alpine grasslands through its effects on PCTF,hence highlighting the importance of PCTF in regulating plant biomass allocation strategies along precipitation gradients.展开更多
Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficien...Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficiency for chemical fertilizers. Therefore, we conducted an incubation experiment using an alkaline soil from Tianjin（p H 8.37–8.43） to evaluate the suppression effect of Trichoderma viride（T. viride） biofertilizer on NH3 volatilization, and compared the differences in microbial community structure among all samples. The results showed that viable T. viride biofertilizer（T） decreased NH3 volatilization by 42.21% compared with conventional fertilizer（（CK）, urea）, while nonviable T. viride biofertilizer（TS） decreased NH3 volatilization by 32.42%. NH3 volatilization was significantly higher in CK and sweet potato starch wastewater（SPSW） treatments during the peak period. T. viride biofertilizer also improved the transfer of ammonium from soil to sweet sorghum. Plant dry weights increased 91.23% and 61.08% for T and TS, respectively, compared to CK. Moreover, T. viride biofertilizer enhanced nitrification by increasing the abundance of ammonium-oxidizing archaea（AOA） and ammonium-oxidizing bacteria（AOB）. The results of high-throughput sequencing indicated that the microbial community structure and composition were significantly changed by the application of T. viride biofertilizer. This study demonstrated the immense potential of T. viride biofertilizer in reducing NH3 volatilization from alkaline soil and simultaneously improving the utilization of fertilizer N by sweet sorghum.展开更多
Alpine wetlands are hotspots of carbon(C)storage and methane emission,and they could be key contributors to global warming.In recent years,rapid warming has lowered the water table in alpine wetlands on the Tibetan Pl...Alpine wetlands are hotspots of carbon(C)storage and methane emission,and they could be key contributors to global warming.In recent years,rapid warming has lowered the water table in alpine wetlands on the Tibetan Plateau,concurrent with intensified nitrogen(N)deposition via anthropogenic activities.We carried out a field experiment to investigate the ecological impacts of these two factors on soil bacterial and functional communities,which are essential drivers of greenhouse gas emissions.Nitrogen amendment alone decreased the phylogenetic alpha-diversity of bacterial communities which could be offset by lowered water table.In contrast,microbial functional alpha-diversity,revealed by a high-throughput microarray,remained unchanged.Both bacterial and functional beta-diversity responded to lowered water table,but only bacterial community responded to N amendment.The alpha-Proteobacteria,beta-Proteobacteria,and Bacteroidetes were the major responsive bacterial lineages,and C degradation,methanogenesis,alkaline shock,and phosphorus oxidation were the major responsive functional processes.Partitioning analysis revealed that N amendment changed bacterial community structure mainly via species loss processes but did not affect bacterial functional communities,with soil pH and ammonium as the key factors influencing changes in bacterial community structure.Conversely,lowered water table altered bacterial and functional communities through species substitution processes linked to soil pH and soil moisture.According to our results,the response mechanisms of microbial communities to lowered water table and N amendment are fundamentally different in alpine wetlands.展开更多
Shifts in hydrological regimes alter river flow rates and flood pulses, decrease environmental heterogeneity and the floristic-structural complexity of associated plant communities. We tested the hypothesis that droug...Shifts in hydrological regimes alter river flow rates and flood pulses, decrease environmental heterogeneity and the floristic-structural complexity of associated plant communities. We tested the hypothesis that drought events affect plant community composition and structure at a small-scale within a riparian fragment towards a reduction in floristic-structural complexity. The tree community was sampled in three habitats (wet, transitional and dry) and monitored in seven inventories carried out between 1991 and 2018. Hydrological variations were evaluated through annual rainfalls, river flow rates and water level data. The species richness and the detrended correspondence analysis axes were used to characterise the temporal modifications in floristic composition. Community structure was described in terms of biomass: accumulated, growth of survivors, mortality and recruitment. Generalised linear mixed models were fitted to evaluate the effects of time and environment in community. It was concluded that the climate has become drier in recent years due to declining precipitation that has affected flow rates and water levels. The floristic-structural complexity of the study fragment was maintained during the monitoring period. However, prolonged and extreme drought events displayed the potential to impact floristic-structural patterns.展开更多
基金financially supported by the National Key Basic Research Development Program (No.2009CB119200)the Forestry Public Welfare Industry Scientific Research Project (No.200904029-3)
文摘In order to investigate the effect of invastion by pine wood nematode(PWN), this study analyzed several functional indices, i.e., the increment in DBH and stand volume and biomass, in the damaged stands with various mixed percentages of Pinus massoniana and P. thunbergii and with different levels of damage. According to the results of rate of change in increment of DBH and stand volume, the forest ecosystem resistance against PWN increased with a reduction in the mixed ratio of pine. The resistance was highest with a mixed percentage of 50%. The invasion of PWN changed the corresponding relationship of increment between DBH and stand volume(pure stands > 7:3 conifer and broadleaf > 6:4 conifer and broadleaf > 5:5 conifer and broadleaf) among the P. thunbergii stands when there is no damage, but for P. massoniana stands this phenomenon did not occur. For the increment rate of DBH and stand volume, this significant change in P. thunbergii forest indicates that the resistance of pure P. thunbergii forest was higher than that of P. massoniana. The invasion of PWN accelerates the succession from pure stands to mixed stands and then to the broadleaf evergreen stands.
基金Supported by the Scientifi c Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources(MNR)(Nos.JB1906,JG1616,JG1910)the Zhejiang Qingshan Lake Innovation Platform for Marine Science and Technology(No.2017E80001)+4 种基金the Key Projects of Philosophy and Social Sciences Research,Ministry of Education(No.18JZD059)the National Key Technology Research and Development Program of the Ministry of Science and Technology of the China(No.2015BAD08B01)the State Key Laboratory of Satellite Ocean Environment Dynamics(No.SOEDZZ1902)the National Natural Science Foundation of China(No.41806136)the Project of Long Term Observation and Research Plan in the Changjiang Estuary and the Adjacent East China Sea(LORCE,14282)。
文摘Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.
基金supported by the Natural Science Foundation of Gansu Province(23JRRM0752,22JR5RA345,21JR1RM333)the Project of Science and Technology Specialist in Gansu Province(24CXGM002)+2 种基金the National Natural Science Foundation of China(31860148)the Research Fund Project for PhD of Longdong University(XYBYZK2208)the Natural Science Foundation of Longdong University(HXZK2488).
文摘Crude oil pollution is a significant global environmental challenge.The eastern Gansu Province on the Loess Plateau,an important agricultural region containing the Changqing Oilfield,is facing increasing crude oil contamination.Understanding how microbial communities respond to varying pollution levels is critical for developing effective bioremediation strategies.This study examined how different concentrations of crude oil affect soil properties and microbial communities in Qingyang City,eastern Gansu Province,China by comparing lightly polluted(1895.84-2696.54 mg/kg total petroleum hydrocarbons(TPH)),heavily polluted(4964.25-7153.61 mg/kg TPH),and uncontaminated(CK)soils.Results revealed that petroleum contamination significantly increased total organic carbon(TOC),pH,C:N:P ratio,and the activities of dehydrogenase(DHA)and polyphenol oxidase(PPO),while reducing total nitrogen(TN),available nitrogen(AN),total phosphorus(TP),available phosphorus(AP),available potassium(AK),soil organic matter(SOM),soil water content(SWC),the activities of urease(URE)and alkaline phosphatase(APA),and microbial alpha diversity(P<0.050).Light pollution(LP)soils demonstrated an increase in culturable microorganisms,whereas heavy pollution(HP)soils exhibited increased hydrocarbon-degrading microbes and higher expression of key functional genes,such as alkane monooxygenase(AlkB),cytochrome P450 alkane hydroxylases(P450),catechol 2,3-dioxygenase(C23O),and naphthalene dioxygenase(Nah)(P<0.050).Non-metric multidimensional scaling(NMDS)and redundancy analysis(RDA)indicated evident variations in microbial community structure across different oil contamination levels.LP soils were dominated by bacterial genera Pseudoxanthomonas and Solimonadaceae,whereas Pseudomonas,Nocardioides,and hydrocarbon-degrading genera(Marinobacter,Idiomarina,and Halomonas)were predominant in HP soils.The fungal genus Pseudallescheria exhibited the most pronounced abundance shift between LP and HP soils(P<0.050).Environmental factor analysis identified AN,SWC,TN,SOM,and alpha diversity indices(Shannon index and Chao1 index)as the key differentiators of CK soils,whereas the pollutant levels and metal content were characterized in HP soils.Hydrocarbon-degrading microbial abundance was a defining trait of HP soils.Metabolic pathway analysis revealed enhanced aromatic hydrocarbon degradation in HP soils,indicating microbial adaptation to severe contamination.These findings demonstrated that crude oil pollution suppressed soil nutrients while reshaping the structure and function of microbial communities.Pollution intensity directly affected microbial composition and degradation potential.This study offers valuable insights into microbial responses across contamination gradients and supports the development of targeted bioremediation strategies for oil-contaminated loess soils.
基金the National Natural Science Foundation of China(Nos.41620104001 and 41806131)the Scientific and Technological Innovation Project of the Qingdao National Laboratory for Marine Science and Technology(No.2016 ASKJ02).
文摘This study was conducted to characterize the diversity and function of microbial communities in marine sediments of the Pearl River Mouth Basin(PRMB)in the South China Sea.The results showed that the bacterial and archaeal communities varied greatly with depth.Proteobacteria in bacterial communities and Nitrososphaeria and Woesearchaeota in archaeal communities were dominant in the shallow sediments(1-40 cm),while Chloroflexi in bacterial communities and Bathyarchaeia in archaeal communities were dominant in the deep sediments(50-200 cm).Regarding ecological functions based on the metatranscriptomic data,genes involved in various pathways of nitrogen metabolism and sulfur metabolism were observed in the tested sediment samples.Metagenomic analysis revealed that Proteobacteria contribute the most to nearly all genes involved in nitrogen and sulfur metabolism.Moreover,Thaumarchaeota contribute the most to certain genes involved in nitrification,denitrification and assimilatory sulfate reduction pathways.The most abundant bacterial genus,Candidatus Scalindua,is crucial for nitrification,dissimilatory nitrate reduction,denitrification and assimilatory sulfate reduction pathways.
基金the National Natural Science Foundation of China （40471066） the Knowledge Innovation Program of the Chinese Academy of Sciences （KZCX3-SW-417）.
文摘Changes in soil biological and biochemical properties under different land uses in the subtropical region of China were investigated in order to develop rational cultivation and fertilization management. A small watershed of subtropical region of China was selected for this study. Land uses covered paddy fields, vegetable farming, fruit trees, upland crops, bamboo stands, and forestry. Soil biological and biochemical properties included soil organic C and nutrient contents, mineralization of soil organic C, and soil microbial biomass and community functional diversity. Soil organic C and total N contents, microbial biomass C and N, and respiration intensity under different land uses were changed in the following order： paddy fields （and vegetable farming） 〉 bamboo stands 〉 fruit trccs （and upland）. The top surface （0-15 cm） paddy fields （and vegetable farming） were 76.4 and 80.8% higher in soil organic C and total N contents than fruit trees （and upland） soils, respectively. Subsurface paddy soils （15-30 cm） were 59.8 and 67.3% higher in organic C and total N than upland soils, respectively. Soil microbial C, N and respiration intensity in paddy soils （0-15 cm） were 6.36, 3.63 and 3.20 times those in fruit tree （and upland） soils respectively. Soil microbial metabolic quotient was in the order： fruit trees （and upland） 〉 forestry 〉 paddy fields. Metabolic quotient in paddy soils was only 47.7% of that in fruit tree （and upland） soils. Rates of soil organic C mineralization during incubation changed in the order： paddy fields 〉 bamboo stands 〉 fruit trees （and upland） and soil bacteria population： paddy fields 〉 fruit trees （and upland） 〉 forestry. No significant difference was found for fungi and actinomycetes populations. BIOLOG analysis indicated a changing order of paddy fields 〉 fruit trees （and upland） 〉 forestry in values of the average well cell development （AWCD） and functional diversity indexes of microbial community. Results also showed that the conversion from paddy fields to vegetable farming for 5 years resulted in a dramatic increase in soil available phosphorus content while insignificant changes in soil organic C and total N content due to a large inputs of phosphate fertilizers. This conversion caused 53, 41.5, and 41.3% decreases in soil microbial biomass C, N, and respiration intensity, respectively, while 23.6% increase in metabolic quotient and a decrease in soil organic C mineralization rate. Moreover, soil bacteria and actinomycetes populations were increased slightly, while fungi population increased dramatically. Functional diversity indexes of soil microbial community decreased significantly. It was concluded that land uses in the subtropical region of China strongly affected soil biological and biochemical properties. Soil organic C and nutrient contents, mineralization of organic C and functional diversity of microbial community in paddy fields were higher than those in upland and forestry. Overuse of chemical fertilizers in paddy fields with high fertility might degrade soil biological properties and biochemical function, resulting in deterioration of soil biological quality.
基金funded by the National Natural Science Foundation of China(NSFC31301843)the National Nonprofit Institute Research Grant of Chinese Academy of Agricultural Sciences(IARRP-202-5)
文摘Exploration of soil environmental characteristics governing soil microbial community structure and activity may improve our understanding of biogeochemical processes and soil quality. The impact of soil environmental characteristics especially organic carbon availability after 15-yr different organic and inorganic fertilizer inputs on soil bacterial community structure and functional metabolic diversity of soil microbial communities were evaluated in a 15-yr fertilizer experiment in Changping County, Beijing, China. The experiment was a wheat-maize rotation system which was established in 1991 including four different fertilizer treatments. These treatments included： a non-amended control（CK）, a commonly used application rate of inorganic fertilizer treatment（NPK）; a commonly used application rate of inorganic fertilizer with swine manure incorporated treatment（NPKM）, and a commonly used application rate of inorganic fertilizer with maize straw incorporated treatment（NPKS）. Denaturing gradient gel electrophoresis（DGGE） of the 16 S r RNA gene was used to determine the bacterial community structure and single carbon source utilization profiles were determined to characterize the microbial community functional metabolic diversity of different fertilizer treatments using Biolog Eco plates. The results indicated that long-term fertilized treatments significantly increased soil bacterial community structure compared to CK. The use of inorganic fertilizer with organic amendments incorporated for long term（NPKM, NPKS） significantly promoted soil bacterial structure than the application of inorganic fertilizer only（NPK）, and NPKM treatment was the most important driver for increases in the soil microbial community richness（S） and structural diversity（H）. Overall utilization of carbon sources by soil microbial communities（average well color development, AWCD） and microbial substrate utilization diversity and evenness indices（H＇ and E） indicated that long-term inorganic fertilizer with organic amendments incorporated（NPKM, NPKS） could significantly stimulate soil microbial metabolic activity and functional diversity relative to CK, while no differences of them were found between NPKS and NPK treatments. Principal component analysis（PCA） based on carbon source utilization profiles also showed significant separation of soil microbial community under long-term fertilization regimes and NPKM treatment was significantly separated from the other three treatments primarily according to the higher microbial utilization of carbohydrates, carboxylic acids, polymers, phenolic compounds, and amino acid, while higher utilization of amines/amides differed soil microbial community in NPKS treatment from those in the other three treatments. Redundancy analysis（RDA） indicated that soil organic carbon（SOC） availability, especially soil microbial biomass carbon（Cmic） and Cmic/SOC ratio are the key factors of soil environmental characteristics contributing to the increase of both soil microbial community structure and functional metabolic diversity in the long-term fertilization trial. Our results showed that long-term inorganic fertilizer and swine manure application could significantly improve soil bacterial community structure and soil microbial metabolic activity through the increases in SOC availability, which could provide insights into the sustainable management of China＇s soil resource.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23040302)the National Natural Science Foundation of China(No.91851104)the Natural Science Foundation of Fujian Province of China(No.2019J02016)。
文摘Urbanization often exerts multiple effects on aquatic and terrestrial organisms,including changes in biodiversity,species composition and ecosystem functions.However,the impacts of urbanization on river phytoplankton in subtropical urbanizing watersheds remain largely unknown.Here,we explored the effects of urbanization on phytoplankton community structure(i.e.,biomass,community composition and diversity)and function(i.e.,resource use efficiency)in a subtropical river at watershed scale in southeast China over 6 years.A total of 318 phytoplankton species belonging into 120 genera and 7 phyla were identified from 108 samples.Bacillariophyta biomass showed an increasing trend with increasing urbanization level.The phytoplankton community shifted from Chlorophyta dominance in rural upstream waters to Bacillariophyta dominance in urbanized downstream waters.Furthermore,phytoplankton diversity and resource use efficiency(RUE=phytoplankton biomass/total phosphorus)were significantly decreased with increasing urbanization level from upstream to downstream.Phytoplankton RUE exhibited a significant positive correlation with species richness,but a negative correlation with phytoplankton evenness.The variation in environmental factors(turbidity,total nitrogen,NH_(4)^(+)-N,total phosphorus,PO_(4)^(3-)-P and percentage urbanized area)was significantly correlated with phytoplankton diversity and RUE.Overall,our results revealed the influence of urbanization on phytoplankton community structure and ecosystem function was due to its altering the environmental conditions.Therefore,human-driven urbanization may play crucial roles in shaping the structure and function of phytoplankton communities in subtropical rivers,and the mechanism of this process can provide important information for freshwater sustainable uses,watershed management and conservation.
基金funded by The Foundation for Research of Natural Resources in Finland(2016085)supported by the Academy of Finland(286685,294600,307222,277623)the FCoE of atmospheric sciences(Center of Excellence(1118615)).
文摘Boreal forests commonly suff er from nitrogen defi ciency due to low rate of nitrogen mineralization.Biochar may promote soil organic matter decomposition and accelerate nitrogen mineralization.In this study,Illumina NovaSeq sequencing combined with functional annotation of prokaryotic taxa(FAPROTAX)analysis was used to investigate the eff ect of biochar pyrolysis temperatures,the amount of applied biochar,and the period since the biochar application(2-and 3-year)on soil bacterial communities.The results show that biochar pyrolysis temperatures(500℃ and 650℃)and the amount of applied biochar(0.5 kg m^(−2)and 1.0 kg m^(−2))did not change soil properties.Nevertheless,the interaction of biochar pyrolysis temperature and the amount had signifi cant eff ects on bacterial species richness and evenness(P<0.05).The application of biochar produced at 500℃ had a lower abundance of Actinobacteria and Verrucomicrobia,while that produced at 650℃ had a higher abundance of Conexibacter and Phenylobacterium.When biochar produced at 650℃ was applied,applying 0.5 kg m^(−2)had a higher abundance of Cyanobacteria,Conexibacter,and Phenylobacterium than that of 1.0 kg m^(−2)(P<0.05).Functionally,the abundance of the aromatic compound degradation group increased with the extension of application time and increase of pyrolysis temperature.The time since application played an important role in the formation of soil bacterial communities and their functional structure.Long-term studies are necessary to understand the consequence of biochar on bacterial communities in boreal forests.
基金supported by the Funds for the Creative Research Groups of China (No. 51221892)State Hi-tech Research and Development Project of the Ministry of Science and Technology, China (No. 2012AA063401)
文摘The purpose of this study was to reveal how activated sludge communities respond to influent quality and indigenous communities by treating two produced waters from different origins in a batch reactor in succession. The community shift and compositions were investigated using Polymerase Chain Reaction–denaturing gradient gel electrophoresis（PCR–DGGE） and further16 S ribosomal DNA（r DNA） clone library analysis. The abundance of targeted genes for polycyclic aromatic hydrocarbon（PAH） degradation, nah Ac/phn Ac and C12O/C23 O, was tracked to define the metabolic ability of the in situ microbial community by Most Probable Number（MPN） PCR. The biosystem performed almost the same for treatment of both produced waters in terms of removals of chemical oxygen demand（COD） and PAHs. Sludge communities were closely associated with the respective influent bacterial communities（similarity 〉 60%）, while one sludge clone library was dominated by the Betaproteobacteria（38%） and Bacteriodetes（30%）and the other was dominated by Gammaproteobacteria（52%）. This suggested that different influent and water quality have an effect on sludge community compositions. In addition, the existence of catabolic genes in sludge was consistent with the potential for degradation of PAHs in the treatment of both produced waters.
基金supported by the National Natural Science Foundation of China(Nos.42177008,and 42377005)the fellowship of China Postdoctoral Science Foundation(No.2022M712770)the Fundamental Research Funds for the Central Universities.
文摘Phyllosphere microbiome plays an irreplaceable role in maintaining plant health under stress,but its structure and functions in heavy metal-hyperaccumulating plants remain elusive.Here,the phyllosphere microbiome,inhabiting hyperaccumulating(HE)and non-hyperaccumulating ecotype(NHE)of Sedum alfredii grown in soils with varying heavy metal concentration,was characterized.Compared with NHE,the microbial communityα-diversity was greater in HE.Core phyllosphere taxa with high relative abundance(>10%),including Streptomyces and Nocardia(bacteria),Cladosporium and Acremonium(fungi),were significantly related to cadmium(Cd)and zinc(Zn)concentration and biomass of host plants.Moreover,microbial co-occurrence networks in HE exhibited greater complexity than those in NHE.Additionally,proportions of positive associations in HE bacterial networks increased with the rising heavy metal concentration,indicating a higher resistance of HE phyllosphere microbiome to heavy metal stress.Furthermore,in contrast to NHE,microbial community functions,primarily involved in heavy metal stress resistance,were more abundant in HE,in which microbiome assisted hosts to resist heavy metal stress better.Collectively,this study indicated that phyllosphere microbiome of the hyperaccumulator played an indispensable role in assisting hosts to resist heavy metal stress,and provided new insights into phyllosphere microbial application potential in phytoremediation.
基金funded by Basic Research Funds of Chinese Academy of Geological Sciences(CSJ-2021-10).
文摘With the rapid development of molecular biology technology,especially the application of metagenomics,many challenges in groundwater microbial research have been overcome.Metagenomics has enabled the exploration of the diversity of unculturable microorganisms in groundwater.This paper reviews macro genomics 16S rRNA and metagenomics sequencing data,highlighting recent applications of metagenomics in investigating groundwater microbial communities.It also examines the relationship between microbial diversity and environmental factors,the identification of functional microbial groups,the role of microorganisms in groundwater pollution remediation,and their contribution to the hydrogeochemi-cal cycle.Finally,it provide insights into future research directions in groundwater microbiology.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest of China(201103005)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(2013–2017)
文摘On the basis of a long-term（30 years） field experiment that involved four rotation systems, rice-rice-winter fallow（RRF）, rice-rice-ryegrass（RRG）, rice-rice-rape（RRP）, and rice-rice-milk vetch（RRV）, this study described the effects of green manure on the microbial communities in the red paddy soils using 454 pyrosequencing for the 16 S r RNA gene. The Chao1 richness and non-parametric Shannon＇s index increased in all soil samples that received green manure treatments. The communities＇ structures with the green manure applications were significantly dissimilar from that under the winter fallow. Using Metastats tests, many genera in the RRG, RRP and RRV soils were significantly different from those in the RRF soil, including a number of genera that functioned in the nitrogen and sulfur cycles. Analyses of the genera with these functions revealed the shifts in microbial ecosystem functions after long-term green manuring. Changes in the microbial communities increased the ammonium supply and decreased the soil acidification in green-manure-amended soils. Together, these data suggested powerful effects of green manure on both the microbial communities and the biogeochemical cycle driven by the shifts in bacterial functional groups.
基金supported by the local scientific and technological innovation projects of the central government,China(No.YDZX2018540C004077).
文摘Fruit production is an important strategy for alleviating poverty on the Tibetan Plateau and leads to the conversion of natural barren land into orchards.This study aimed to understand how the conversion of barren land to peach(Prunus persica)orchards affects soil nutrients,heavy metals,and fungal communities in the 0–40 cm profile(at 20 cm intervals)in an experiment including three treatments,barren land(BL),peach orchards planting for 4 years(Y4),and peach orchards planting for 10 years(Y10).Results of the experiment showed that compared with BL,Y4 reduced the availability of some macronutrients(N and K)and micronutrients(Fe and Mn)due to the exclusive application of chemical fertilizer at the seedling stage.Conversely,Y10,which included six years of green cultivation management,using a combination of sheep manure and chemical fertilizer as well as alfalfa(Medicago sativa Linn)intercropping,effectively improved soil macronutrients,but did not enhance the availability of Fe and Mn.Although the investigated heavy metals(As,Hg,Pb,Cr,and Cd)in both the Y4 and Y10 soils were found to pose a low risk to food safety and soil environment,Hg,Cr,and As tended to accumulate in the subsoil(20–40 cm).Furthermore,the variations in the fungal community composition and functional groups were mainly driven by the interaction effects of macronutrients,micronutrients,and heavy metals,but their independent contribution to specific key functional groups cannot be overlooked.For example,Y4 and Y10 decreased the relative abundance of soil saprotrophic and lichenized fungi,mainly due to the loss of micronutrients(Fe and Mn).However,as a result of macronutrient input and dung saprotrophic fungi enrichment,orchard soils promoted the growth of pathogens that play critical roles in fungal co-occurrence networks.These findings indicate that supplementation with N or K fertilizer or manure at the seedling stage and fertilizers rich in Fe and Mn throughout the growth period would be beneficial to the balance of soil nutrients and provide insights into linking the variations in soil nutrients and heavy metals to the function of the fungal community during the conversion of barren land to orchards in alpine soil ecosystems.The risks posed by heavy metal accumulation and fungal pathogen enrichment should be actively prevented.
基金P.S.-A.was funded by the Regional Council of Education,University and Professional Training(Conselleria de Educacion,Universidade e Formacion Profesional)from the Government of Galicia(Xunta de Galicia)through the annual Postdoctoral Plan'Axudas de apoio a etapa de formacion posdoutoral nas universidades doSistema universitario de Galicia'(grant ref.ED481B-2019-088)L.G.was funded by Xunta de Galicia,Spain(CITACA Strategic Partnership,grantref.:ED431E2018/07).
文摘Coastal dunes represent priority habitats for conservation due to the provision of valuable ecosystem services such as land protection,water supply or biodiversity conservation.Soil microbial communities are of crucial importance to maintain plant diversity due to harsh environmental conditions,water limitation and nutrient scarcity.Invasive alien plants represent a major threat to ecosystem conservation.Here,we explored different impacts of Carpobrotus edulis,a succulent plant invading coastal areas worldwide,on the function and structure of bacterial communities.Sand represents a challenging substrate due to low organic matter content and limited microbial activity.We optimized bacterial extraction for functional evaluation before assessing ecosystem impacts produced by C.edulis.We compared 12 extracting procedures combining different soil storage,sample amount and extracting solutions on the functional activity of sand communities through the community-level physiological profile.We further explored the function(using Biolog Ecoplates)and structure[using polymerase chain reaction–denaturing gradient gel electrophoresis(PCR-DGGE)]of bacterial communities from dunes invaded by C.edulis.Saline solution consistently increased bacterial cells detected by cytometry(P≤0.001).Principal component analysis suggested a limited temporal framework(0–24 h)in which community function can be explored without significant alterations in C substrate consumption.Changes under C.edulis invasion exhibited a different pattern of C substrate utilization comparing native and non-native zones(interspecific),but also between native zones(intraspecific),suggesting that functional impacts are site-dependent.Complementary,results obtained from PCR-DGGE indicated that the bacterial community structure of native dunes significantly differed from dunes invaded by C.edulis.
基金supported jointly by Henan Province Xixiayuan Water Conservancy Hub Water Supply and Irrigation District Engineering Research ProjectHenan Province Natural Resources Research Project(2023-382-4)+3 种基金Sichuan Science and Technology Program (2023ZYD0102)China Postdoctoral Science Foundation (2023M743206)the Scientific Research Foundation for Academician of CAS Teamof Zhengzhou University (13432340370)the National Natural Science Foundation of China(32201517)。
文摘The stability mechanisms of ecosystem functions have been a hot topic in ecology. However, in wetland ecosystems, the mechanisms by which biotic and abiotic factors interact to affect ecosystem stability in changing environments remain largely unclear. This study investigated the key factors and underlying mechanisms that regulate the spatial variability of wetland productivity by measuring community productivity, multiple components of biodiversity (i.e. species diversity, community functional composition and diversity) and environmental factors along a well-characterized gradient of wetland degradation in the lower reaches of the Yellow River. The results showed that the spatial variability of productivity in wetlands increased with intensified degradation. The spatial variability of wetland productivity was not related to species richness but was mainly affected by changes in community functional composition and diversity. Furthermore, degradation-induced changes in soil nutrients drove the spatial variability of productivity to increase with shifts in functional composition towards more conservative traits (i.e. higher leaf dry matter content and root tissue density), and to decrease with higher functional trait diversity. These findings reveal the driving mechanism of spatial variability in wetland productivity under degradation, and suggest that reduced nutrient availability, by altering plant resource strategies, can affect the spatial reliability of key ecosystem functions in wetlands.
基金the National Science Foundation of China(41871040)the Second Tibetan Plateau Scientific Expedition and Research(2019QZKK0405)Joint Research Project of Three-River-Resource National Park funded by the Chinese Academy of Sciences and Qinghai Provincial People's Government(LHZX-2020-08).
文摘A better understanding the mechanisms driving plant biomass allocation in different ecosystems is an important theoretical basis for ilustrating the adaptive strategies of plants.To date,the effects of habitat conditions on plant biomass allocation have been widely studied.However,it is less known how plant community traits and functions(PCTF)affect biomass allocation,particularly in alpine grassland ecosystems.In this study,community-weighted means(CWM)were calculated at the community level using five leaf functional traits,and the relationships between PCTF and biomass trade-offs were explored using correlation analysis,variation partitioning analysis and structural equation modeling.We found that the trade-off values were greater than zero in both alpine meadow(AM)and alpine steppe(AS)across the Tibetan Plateau,with different values of 0.203 and 0.088 for AM and AS,respectively.Moreover,the critical factors determining biomass allocation in AS were species richness(SR;scored at 0.69)and leaf dry matter content of CWM(CWM_(LDMC),scored at 0.42),while in AM,the key factors were leaf dry matter content(CWM.pMC scored at 0.48)and leaf carbon content of CWM(CWM_(LC),scored at-0.45).In particular,both CWM_(LDMC)and SR in AS,as well as CWM_(LDMC)and CWM_(LDMC)in AM were primarily regulated by precipitation.In summary,precipitation tends to drive biomass allocation in alpine grasslands through its effects on PCTF,hence highlighting the importance of PCTF in regulating plant biomass allocation strategies along precipitation gradients.
基金supported by the National Science Fund Projects (Nos. 41371266 and 31670507)Innovation in Cross-functional Team Program of the Chinese Academy of Sciences (No. 2015)+1 种基金the Key Research Program of Chinese Academy of Sciences (No. ZDRW-ZS-2016-5)the Key State Science and Technology Program of China (No. 2015ZX07206-006)
文摘Ammonia（NH3） volatilization is one of the primary pathways of nitrogen（N） loss from soils after chemical fertilizer is applied, especially from the alkaline soils in Northern China, which results in lower efficiency for chemical fertilizers. Therefore, we conducted an incubation experiment using an alkaline soil from Tianjin（p H 8.37–8.43） to evaluate the suppression effect of Trichoderma viride（T. viride） biofertilizer on NH3 volatilization, and compared the differences in microbial community structure among all samples. The results showed that viable T. viride biofertilizer（T） decreased NH3 volatilization by 42.21% compared with conventional fertilizer（（CK）, urea）, while nonviable T. viride biofertilizer（TS） decreased NH3 volatilization by 32.42%. NH3 volatilization was significantly higher in CK and sweet potato starch wastewater（SPSW） treatments during the peak period. T. viride biofertilizer also improved the transfer of ammonium from soil to sweet sorghum. Plant dry weights increased 91.23% and 61.08% for T and TS, respectively, compared to CK. Moreover, T. viride biofertilizer enhanced nitrification by increasing the abundance of ammonium-oxidizing archaea（AOA） and ammonium-oxidizing bacteria（AOB）. The results of high-throughput sequencing indicated that the microbial community structure and composition were significantly changed by the application of T. viride biofertilizer. This study demonstrated the immense potential of T. viride biofertilizer in reducing NH3 volatilization from alkaline soil and simultaneously improving the utilization of fertilizer N by sweet sorghum.
文摘Alpine wetlands are hotspots of carbon(C)storage and methane emission,and they could be key contributors to global warming.In recent years,rapid warming has lowered the water table in alpine wetlands on the Tibetan Plateau,concurrent with intensified nitrogen(N)deposition via anthropogenic activities.We carried out a field experiment to investigate the ecological impacts of these two factors on soil bacterial and functional communities,which are essential drivers of greenhouse gas emissions.Nitrogen amendment alone decreased the phylogenetic alpha-diversity of bacterial communities which could be offset by lowered water table.In contrast,microbial functional alpha-diversity,revealed by a high-throughput microarray,remained unchanged.Both bacterial and functional beta-diversity responded to lowered water table,but only bacterial community responded to N amendment.The alpha-Proteobacteria,beta-Proteobacteria,and Bacteroidetes were the major responsive bacterial lineages,and C degradation,methanogenesis,alkaline shock,and phosphorus oxidation were the major responsive functional processes.Partitioning analysis revealed that N amendment changed bacterial community structure mainly via species loss processes but did not affect bacterial functional communities,with soil pH and ammonium as the key factors influencing changes in bacterial community structure.Conversely,lowered water table altered bacterial and functional communities through species substitution processes linked to soil pH and soil moisture.According to our results,the response mechanisms of microbial communities to lowered water table and N amendment are fundamentally different in alpine wetlands.
基金supported by the CAPES(Coordenação de Aperfeiçoamento de Pessoal de Nível Superior,Coordination for the Improvement of Higher Education Personnel)CNPq(Conselho Nacional de Desenvolvimento Científi co e Tecnológico,National Council for Scientifi c and Technological Development)+1 种基金FAPEMIG(Fundação de Amparo à Pesquisa do Estado de Minas Gerais,Foundation for Supporting Research of the State of Minas Gerais)scholarship grant of the Federal University of Lavras(Universidade Federal de Lavras).
文摘Shifts in hydrological regimes alter river flow rates and flood pulses, decrease environmental heterogeneity and the floristic-structural complexity of associated plant communities. We tested the hypothesis that drought events affect plant community composition and structure at a small-scale within a riparian fragment towards a reduction in floristic-structural complexity. The tree community was sampled in three habitats (wet, transitional and dry) and monitored in seven inventories carried out between 1991 and 2018. Hydrological variations were evaluated through annual rainfalls, river flow rates and water level data. The species richness and the detrended correspondence analysis axes were used to characterise the temporal modifications in floristic composition. Community structure was described in terms of biomass: accumulated, growth of survivors, mortality and recruitment. Generalised linear mixed models were fitted to evaluate the effects of time and environment in community. It was concluded that the climate has become drier in recent years due to declining precipitation that has affected flow rates and water levels. The floristic-structural complexity of the study fragment was maintained during the monitoring period. However, prolonged and extreme drought events displayed the potential to impact floristic-structural patterns.
