Rapid increase in desertification is an environ-mental concern,especially for the health and sustainabil-ity of ecosystems in changing climates.How ecosystems respond to such changes may be partially understood by stu...Rapid increase in desertification is an environ-mental concern,especially for the health and sustainabil-ity of ecosystems in changing climates.How ecosystems respond to such changes may be partially understood by studying interactions and performance of critically impor-tant groups such as soil fungi functional groups.This study investigated variations in diversities of three soil fungi functional guilds(saprotrophic,symbiotic,pathogenic)and influencing abiotic factors in a Pinus densata forest on the southeast Tibetan Plateau where desertification is intense.The results indicate desertification significantly decreased the proportion of dominant fungal guild-symbiotic fungi(mean relative abundance decreasing from 97.0%to 68.3%),in contrast to saprotrophic fungi(increasing from 2.7%to 25.7%)and pathogenic(from 0.3%to 5.9%).Soil pH had the most significant impact on fungal community structure and negatively correlated with symbiotic fungal richness,which was significantly lower in arid soils,and positively correlated with saprotrophic and pathogenic fungal alpha-diversity,which were abundant.Different community struc-tures and regulators of the three fungi communities were observed,with pH,total phosphorus and ammonium(NH_(4)^(+))as the main determinants.This study links the biotic and abi-otic components during desertification and the interactions between them,and may be used as indicators of ecosystem health and for amendments to mitigate the effects of a chang-ing climate.展开更多
Background:More than a decade of fire suppression has changed the structure of fire-adapted shrubland ecosystems in Spain’s National Parks,which are now at extreme risk of uncontrolled wildfires.Prescribed burning ca...Background:More than a decade of fire suppression has changed the structure of fire-adapted shrubland ecosystems in Spain’s National Parks,which are now at extreme risk of uncontrolled wildfires.Prescribed burning can mitigate the risk of wildfires by reducing the fuel load but prescribed burning may also alter the soil properties and reduce microbial and fungal activity,causing changes in the availability of nutrients deep in the soil layer.Although fungal communities are a vital part of post-fire restoration,some fire effects remain unclear.To examine the short-term effects of prescribed burning on soil fungal communities in Doñana Biological Reserve(SW Spain),we collected soil samples pre-burn and 1 day,6 and 12 months post-burn from burned plots to perform physicochemical and metabarcode DNA analyses.Results:Prescribed burning had no significant effect on the total fungal operational taxonomic unit richness and abundance.However,changes in soil pH,nitrogen and potassium content post-burn affected fungal community composition.Small non-significant changes in pH and phosphorous affected the composition of ectomycorrhizal fungi.Conclusions:The ectomycorrhizal fungal community appears to be resilient to the effects of low-to moderate-intensity fires and saprotrophic taxa may benefit from this kind of fire.This finding revealed that prescribed burning is a potentially valuable management tool for reducing fire hazards in shrublands that has little effect on the total richness and abundance of fungal communities.展开更多
Background: Large-diameter trees have an outsized influence on aboveground forest dynamics, composition, and structure. Although their influence on aboveground processes is well studied, their role in shaping belowgro...Background: Large-diameter trees have an outsized influence on aboveground forest dynamics, composition, and structure. Although their influence on aboveground processes is well studied, their role in shaping belowground fungal communities is largely unknown. We sought to test if (i) fungal community spatial structure matched aboveground forest structure;(ii) fungal functional guilds exhibited differential associations to aboveground trees, snags, and deadwood;and (iii) that large-diameter trees and snags have a larger influence on fungal community richness than smaller-diameter trees. We used MiSeq sequencing of fungal communities collected from soils in a spatially intensive survey in a portion of Cedar Breaks National Monument, Utah, USA. We used random forest models to explore the spatial structure of fungal communities as they relate to explicitly mapped trees and deadwood distributed across 1.15 ha of a 15.32-ha mapped subalpine forest. Results: We found 6,177 fungal amplicon sequence variants across 117 sequenced samples. Tree diameter, dead-wood presence, and tree species identity explained more than twice as much variation (38.7% vs. 10.4%) for ectomy-corrhizal composition and diversity than for the total or saprotrophic fungal communities. Species identity and dis-tance to the nearest large-diameter tree (≥ 40.2 cm) were better predictors of fungal richness than were the identity and distance to the nearest tree. Soil nutrients, topography, and tree species differentially influenced the composition and diversity of each fungal guild. Locally rare tree species had an outsized influence on fungal community richness. Conclusions: These results highlight that fungal guilds are differentially associated with the location, size, and species of aboveground trees. Large-diameter trees are implicated as drivers of belowground fungal diversity, particularly for ectomycorrhizal fungi.展开更多
This study is unique as it compares traditional and high-resolution culture-independent approaches using the same set of samples to study the saprotrophic fungi on Vitis vinifera.We identified the saprotrophic communi...This study is unique as it compares traditional and high-resolution culture-independent approaches using the same set of samples to study the saprotrophic fungi on Vitis vinifera.We identified the saprotrophic communities of table grape(Red Globe)and wine grape(Carbanate Gernischet)in China using both traditional and culture-independent techniques.The traditional approach used direct observations based on morphology,single spore isolation and phylogenetic analysis yielding 45 taxa which 19 were commonly detected in both cultivars.The same set of samples were then used for Illumina sequencing which analyzed ITS1 sequence data and detected 226 fungal OTUs,of which 176 and 189 belong to the cultivars Carbanate Gernischet and Red Globe,respectively.There were 139 OTUs shared between the two V.vinifera cultivars and 37 and 50 OTUs were specific to Carbanate Gernischet and Red Globe cultivars respectively.In the Carbanate Gernischet cultivar,Ascomycota accounted for 77%of the OTUs and in Red Globe,almost all sequenced were Ascomycota.The fungal taxa overlap at the genus and species level between the traditional and culture-independent approach was relatively low.In the traditional approach we were able to identify the taxa to species level,while in the culture-independent method we were frequently able to identify the taxa to family or genus level.This is remarkable as we used the same set of samples collected in China for both approaches.We recommend the use of traditional techniques to accurately identify taxa.Culture-independent method can be used to get a better understanding about the organisms that are present in a host in its natural environment.We identified primary and secondary plant pathogens and endophytes in the saprotrophic fungal communities,which support previous observations,that dead plant material in grape vineyards can be the primary sources of disease.Finally,based on present and previous findings,we provide a worldwide checklist of 905 fungal taxa on Vitis species,which includes their mode of life and distribution.展开更多
Nitrogen(N)deposition and intensified rainfall can strongly affect soil microbial community,but compared with available studies on bacteria,those on soil fungi are quite limited.Here we carried out a field experiment ...Nitrogen(N)deposition and intensified rainfall can strongly affect soil microbial community,but compared with available studies on bacteria,those on soil fungi are quite limited.Here we carried out a field experiment in a mixed deciduous forest of China to study the influences of increased N deposition and rainfall on soil fungi by using quantitative PCR and high-throughput sequencing method.The results demonstrated that(1)N addition significantly increased fungal abundance and alpha diversity(richness,Shannon index and Invsimpson index),changed fungal community composition at OTU level,and marginally increased the relative abundance of Ascomycota and Zygomycota,while water addition showed no remarkable effects on fungal abundance,biodiversity and community composition.(2)N addition significantly increased the richness of saprotrophic fungi and pathogenic fungi,and the relative abundance of saprotrophic fungi,but water addition only slightly increased the abundance of pathogenic fungi.(3)Fungal composition dissimilarity closely correlated with the disparity of soil parameters as a whole.Soil NH_(4)^(+)-N exhibited strong positive correlation with the richness of pathogenic fungi and mycorrhizal fungi,while both soil moisture and NH_(4)^(+)-N tightly correlated with soil fungal abundance and alpha diversity indices.We concluded that in this N-limited but non-water-limited forest ecosystem,N deposition posed stronger effects on soil fungi than increased rainfall,partially mediated by changes in soil properties.展开更多
To understand nutrient cycling in soils, soil processes and microorganisms need be better characterized. To determine whether specific trophic groups of fungi are associated with soil enzyme activity, we used soil imp...To understand nutrient cycling in soils, soil processes and microorganisms need be better characterized. To determine whether specific trophic groups of fungi are associated with soil enzyme activity, we used soil imprinting to guide mm-scale sampling from microsites with high and low phosphatase activities in birch/Douglas-fir stands. Study 1 involved sampling one root window per site at 12 sites of different ages(stands);study 2 was conducted at one of the stem-exclusion stands, at which 5 root windows had been installed. Total fungal and ectomycorrhizal(EM) fungal terminal-restriction fragment length polymorphism(TRFLP)fingerprints differed between high-and low-phosphatase activity microsites at 8 of 12 root windows across 12 sites. Where differences were detected, fewer EM fungi were detected in high-than low-phosphatase activity microsites. Using 5 root windows at one site,next-generation sequencing detected similar fungal communities across microsites, but the ratio of saprotrophic to EM fungal reads was higher in high-phosphatase activity microsites in the two windows that had low EM fungal richness. In windows with differences in fungal communities, both studies indicated that EM fungi were less successful than saprotrophic fungi in colonizing fine-scale,organic matter-rich microsites. Fine-scale sampling linked with in situ detection of enzyme activity revealed relationships between soil fungal communities and phosphatase activity that could not be observed at the scales employed by conventional approaches, thereby contributing to the understanding of fine-scale phosphorus cycling in forest soils.展开更多
The decomposition of plant litter is a major process of equivalent status to primary production in ecosystem functioning.The spatiotemporal changes in the composition and dynamics of litter fungal community along a cl...The decomposition of plant litter is a major process of equivalent status to primary production in ecosystem functioning.The spatiotemporal changes in the composition and dynamics of litter fungal community along a climate gradient ranging from arid desert to humid-Mediterranean regions in Israel was examined using wheat straw litter bags placed at four selected sites along the climate gradient,arid,semi-arid,Mediterranean,and humid-Mediterranean sites.Litter samples were collected over a two-year decomposition period to evaluate litter weight loss,moisture,C:N ratio,fungal composition,and isolate density.The litter decomposition rate was found to be the highest during the first year of the study at the Mediterranean and arid sites.Although the Shannon-Wiener index values of the fungal communities in the litter samples were the highest at the humid-Mediterranean site,the number of fungal species was not significantly different between the four study sites.Different fungal groups were found to be related to different study sites:Basidiomycota,Mucoromycotina,and teleomorphic Ascomycota were associated with the humid-Mediterranean site,while Coelomycetes were mostly affected by the arid site.Our results indicate that climate factors play an important role in determining the structure of saprotrophic fungal communities in the decomposing litter and in mediating plant litter decomposition processes.展开更多
Aims Plant–soil feedback(PSF)is a key mechanism that can facilitate tree species coexistence and diversity.Substantial evidence suggests that species-specific soil-borne pathogens around adult trees limit the perform...Aims Plant–soil feedback(PSF)is a key mechanism that can facilitate tree species coexistence and diversity.Substantial evidence suggests that species-specific soil-borne pathogens around adult trees limit the performance of home(conspecific)seedlings relative to foreign(heterospecific)seedlings.However,the underlying mechanism remains largely elusive.Methods Here,we conducted a reciprocal transplant pot experiment using seedlings and from two tree species,Pinus massoniana and Lithocarpus glaber that are dominant and coexist in a subtropical,evergreen,broad-leaf forest in Gutianshan,Zhejiang Province of eastern China.We examined how seedlings from the two tree species responded to soils originating from underneath their own versus the other tree species,using a full-factorial design.Additionally,we added a fungicide(benomyl)to half of the pots to evaluate the role of soil-borne fungi on seedling growth.Important Findings We found that the seedlings from L.glaber grew better in soils that were collected from beneath the canopy of P.massoniana,while seedling growth of P.massioniana was not affected by soil origin.The addition of fungicide benomyl resulted in a shift towards more positive PSF effects for L.glaber,indicating that L.glaber seedlings performed better in their own soils than in soils from P.massoniana in the absence of fungi.Our findings highlight the importance of soil-borne pathogenic and ectomycorrhizal fungi in driving PSF,and indicate that PSF may promote the coexistence of two subtropical tree species by reducing the performance of L.glaber in own soils.展开更多
Land filling is the main method to dispose municipal solid waste in China.During the decomposition of organic waste in landfills,fungi play an important role in organic carbon degradation and nitrogen cycling.However,...Land filling is the main method to dispose municipal solid waste in China.During the decomposition of organic waste in landfills,fungi play an important role in organic carbon degradation and nitrogen cycling.However,fungal composition and potential functions in landfill have not yet been characterized.In this study,refuse and leachate samples with different areas and depths were taken from a large sanitary landfill in Beijing to identify fungal communities in landfills.In high-throughput sequencing of ITS region,474 operational taxonomic units(OTUs)were obtained from landfill samples with a cutoff level of 3%and a sequencing depth of 19962.The results indicates that Ascomycota,with the average relative abundance of 84.9%,was the predominant phylum in landfill fungal communities.At the genus level,Family Hypocreaceae unclassified(15.7%),Fusarium(9.9%)and Aspergillus(8.3%)were the most abundant fungi found in the landfill and most of them are of saprotrophic lifestyle,which plays a big role in nutrient cycling in ecosystem.Fungi existed both in landfilled refuse and leachate while both the richness and evenness of fungal communities were higher in the former.In addition,fungal communities in landfilled refuse presented geographic variances,which could be partly attributed to physical habitat properties(pH,dissolved organic carbon,volatile solid,NH_(4)^(+),NO_(2)^(−)and NO_(3)^(−)),while NO_(3)^(−)was considered the most significant factor(p<0.05)in shaping fungal community.展开更多
Conventional clear-cut timber harvest is a widespread industrial practice across the Pacific Northwest;however,information regarding how these practices impact soil microbial community structure at the regional scale ...Conventional clear-cut timber harvest is a widespread industrial practice across the Pacific Northwest;however,information regarding how these practices impact soil microbial community structure at the regional scale is limited.With evidence of consistent and substantial impact of harvest on soil microbial functional profiles across the region(despite a range of environmental conditions),the objective of this study was to determine the extent to which harvest also influences the structure of prokaryotic and fungal soil microbial communities,and how generalized these trends are throughout the geographic region.Paired soil samples were collected one year before and after harvest across nine second-growth Douglas-fir forests in the Pacific Northwest.Total community DNA was extracted from the soils,and high-throughput targeted gene sequencing of the 16 S r RNA gene for prokaryotes and the internal transcribed spacer(ITS)gene for fungi was performed.Alpha diversity was consistently and significantly higher after harvest;it was moderately so for fungal communities(+14.6%),but only marginally so for prokaryotic communities(+2.0%).Similarly,on average,a greater proportion of the variation in the community structure of fungi(20.1%)at each site was associated with forest harvest compared to that of prokaryotes(13.2%).Overall,the greatest influence of timber harvest on soil microbial communities appeared to be a relative depletion of ectomycorrhizal fungi,with a concomitant enrichment of saprotrophic fungi.Understanding the short-term responses of soil microbial communities across the region,particularly those of tree root-associated symbionts,may aid our understanding of the role soil microbial communities play in ecological succession.展开更多
We assess the composition of corticioid fungi in the Caucasus region for the first time.The Caucasian corticioids were compared with those of well-documented areas in the Northern Hemisphere using the Tripartite simil...We assess the composition of corticioid fungi in the Caucasus region for the first time.The Caucasian corticioids were compared with those of well-documented areas in the Northern Hemisphere using the Tripartite similarity index and cluster analysis.To investigate the significance of the Caucasus region as a possible contributor to the colonization of wood-inhabiting basidiomycetes in Europe,DNA sequences of nuclear ribosomal internal transcribed spacers(ITS1 and ITS2)belonging to the corticioid fungus Peniophorella praetermissa were analysed for comparisons of genetic diversity within and differentiation between geographical regions.Putative species endemism and disjunction of corticioids in the Caucasus region is also discussed.The composition of corticioid fungi in the Caucasus region was found to be distinctly more similar to Europe and North America than to East Asia and India.Similarity tests and molecular Fsts both point to a strong connection between the Caucasus and Europe.The highest molecular diversity in P.praetermissa was in the Caucasus and East Asia as compared with other regions studied.The Caucasus and East Asia were significantly differentiated from each other,and unlike Caucasian samples,East Asian sequences were highly divergent from the European ones.This result suggests that the Caucasus might have been a source of colonization for Europe.Endemism is very low,possibly a common feature for wood-inhabiting saprotrophic fungi.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB31000000)the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0307)+1 种基金the Key Project of the Open Competition in Jiangsu Forestry(No.LYKJ[2022]01)the Jiangsu Social Development Project(BE2022792).
文摘Rapid increase in desertification is an environ-mental concern,especially for the health and sustainabil-ity of ecosystems in changing climates.How ecosystems respond to such changes may be partially understood by studying interactions and performance of critically impor-tant groups such as soil fungi functional groups.This study investigated variations in diversities of three soil fungi functional guilds(saprotrophic,symbiotic,pathogenic)and influencing abiotic factors in a Pinus densata forest on the southeast Tibetan Plateau where desertification is intense.The results indicate desertification significantly decreased the proportion of dominant fungal guild-symbiotic fungi(mean relative abundance decreasing from 97.0%to 68.3%),in contrast to saprotrophic fungi(increasing from 2.7%to 25.7%)and pathogenic(from 0.3%to 5.9%).Soil pH had the most significant impact on fungal community structure and negatively correlated with symbiotic fungal richness,which was significantly lower in arid soils,and positively correlated with saprotrophic and pathogenic fungal alpha-diversity,which were abundant.Different community struc-tures and regulators of the three fungi communities were observed,with pH,total phosphorus and ammonium(NH_(4)^(+))as the main determinants.This study links the biotic and abi-otic components during desertification and the interactions between them,and may be used as indicators of ecosystem health and for amendments to mitigate the effects of a chang-ing climate.
基金Spanish R&D projects MYCOINFOR(Mycosilviculture Applied to Forest Fire Prevention in Mediterranean SystemsPID2019-105188RB-I00)+4 种基金VIS4FIRE(Comprehensive vulnerability of forest systems to fire:implications for forest management toolsRTA2017-00042-C05-01)Interreg-POCTEP CILIFO(Iberian Centre for Research and Forest Firefighting0753-CILIFO-5-E)financed by European Social Fund“NextGenerationEU”through a grant“Margarita Salas”awarded to Juncal Espinosa into the project GFIRE。
文摘Background:More than a decade of fire suppression has changed the structure of fire-adapted shrubland ecosystems in Spain’s National Parks,which are now at extreme risk of uncontrolled wildfires.Prescribed burning can mitigate the risk of wildfires by reducing the fuel load but prescribed burning may also alter the soil properties and reduce microbial and fungal activity,causing changes in the availability of nutrients deep in the soil layer.Although fungal communities are a vital part of post-fire restoration,some fire effects remain unclear.To examine the short-term effects of prescribed burning on soil fungal communities in Doñana Biological Reserve(SW Spain),we collected soil samples pre-burn and 1 day,6 and 12 months post-burn from burned plots to perform physicochemical and metabarcode DNA analyses.Results:Prescribed burning had no significant effect on the total fungal operational taxonomic unit richness and abundance.However,changes in soil pH,nitrogen and potassium content post-burn affected fungal community composition.Small non-significant changes in pH and phosphorous affected the composition of ectomycorrhizal fungi.Conclusions:The ectomycorrhizal fungal community appears to be resilient to the effects of low-to moderate-intensity fires and saprotrophic taxa may benefit from this kind of fire.This finding revealed that prescribed burning is a potentially valuable management tool for reducing fire hazards in shrublands that has little effect on the total richness and abundance of fungal communities.
基金Funding was received from the Natural Science and Engineering Council of Canada to JK and the Utah Agricultural Experiment Station(Projects 1153,1398 and 1423 to JAL)which has designated this as Journal Paper 9626.
文摘Background: Large-diameter trees have an outsized influence on aboveground forest dynamics, composition, and structure. Although their influence on aboveground processes is well studied, their role in shaping belowground fungal communities is largely unknown. We sought to test if (i) fungal community spatial structure matched aboveground forest structure;(ii) fungal functional guilds exhibited differential associations to aboveground trees, snags, and deadwood;and (iii) that large-diameter trees and snags have a larger influence on fungal community richness than smaller-diameter trees. We used MiSeq sequencing of fungal communities collected from soils in a spatially intensive survey in a portion of Cedar Breaks National Monument, Utah, USA. We used random forest models to explore the spatial structure of fungal communities as they relate to explicitly mapped trees and deadwood distributed across 1.15 ha of a 15.32-ha mapped subalpine forest. Results: We found 6,177 fungal amplicon sequence variants across 117 sequenced samples. Tree diameter, dead-wood presence, and tree species identity explained more than twice as much variation (38.7% vs. 10.4%) for ectomy-corrhizal composition and diversity than for the total or saprotrophic fungal communities. Species identity and dis-tance to the nearest large-diameter tree (≥ 40.2 cm) were better predictors of fungal richness than were the identity and distance to the nearest tree. Soil nutrients, topography, and tree species differentially influenced the composition and diversity of each fungal guild. Locally rare tree species had an outsized influence on fungal community richness. Conclusions: These results highlight that fungal guilds are differentially associated with the location, size, and species of aboveground trees. Large-diameter trees are implicated as drivers of belowground fungal diversity, particularly for ectomycorrhizal fungi.
基金s This work was financially supported by Beijing Talent Programm for Jiye Yan,CARS-29 and JNKYT201605.
文摘This study is unique as it compares traditional and high-resolution culture-independent approaches using the same set of samples to study the saprotrophic fungi on Vitis vinifera.We identified the saprotrophic communities of table grape(Red Globe)and wine grape(Carbanate Gernischet)in China using both traditional and culture-independent techniques.The traditional approach used direct observations based on morphology,single spore isolation and phylogenetic analysis yielding 45 taxa which 19 were commonly detected in both cultivars.The same set of samples were then used for Illumina sequencing which analyzed ITS1 sequence data and detected 226 fungal OTUs,of which 176 and 189 belong to the cultivars Carbanate Gernischet and Red Globe,respectively.There were 139 OTUs shared between the two V.vinifera cultivars and 37 and 50 OTUs were specific to Carbanate Gernischet and Red Globe cultivars respectively.In the Carbanate Gernischet cultivar,Ascomycota accounted for 77%of the OTUs and in Red Globe,almost all sequenced were Ascomycota.The fungal taxa overlap at the genus and species level between the traditional and culture-independent approach was relatively low.In the traditional approach we were able to identify the taxa to species level,while in the culture-independent method we were frequently able to identify the taxa to family or genus level.This is remarkable as we used the same set of samples collected in China for both approaches.We recommend the use of traditional techniques to accurately identify taxa.Culture-independent method can be used to get a better understanding about the organisms that are present in a host in its natural environment.We identified primary and secondary plant pathogens and endophytes in the saprotrophic fungal communities,which support previous observations,that dead plant material in grape vineyards can be the primary sources of disease.Finally,based on present and previous findings,we provide a worldwide checklist of 905 fungal taxa on Vitis species,which includes their mode of life and distribution.
基金supported by the National Natural Science Foundation of China(41877050,31300446,41401286).
文摘Nitrogen(N)deposition and intensified rainfall can strongly affect soil microbial community,but compared with available studies on bacteria,those on soil fungi are quite limited.Here we carried out a field experiment in a mixed deciduous forest of China to study the influences of increased N deposition and rainfall on soil fungi by using quantitative PCR and high-throughput sequencing method.The results demonstrated that(1)N addition significantly increased fungal abundance and alpha diversity(richness,Shannon index and Invsimpson index),changed fungal community composition at OTU level,and marginally increased the relative abundance of Ascomycota and Zygomycota,while water addition showed no remarkable effects on fungal abundance,biodiversity and community composition.(2)N addition significantly increased the richness of saprotrophic fungi and pathogenic fungi,and the relative abundance of saprotrophic fungi,but water addition only slightly increased the abundance of pathogenic fungi.(3)Fungal composition dissimilarity closely correlated with the disparity of soil parameters as a whole.Soil NH_(4)^(+)-N exhibited strong positive correlation with the richness of pathogenic fungi and mycorrhizal fungi,while both soil moisture and NH_(4)^(+)-N tightly correlated with soil fungal abundance and alpha diversity indices.We concluded that in this N-limited but non-water-limited forest ecosystem,N deposition posed stronger effects on soil fungi than increased rainfall,partially mediated by changes in soil properties.
基金supported by the Natural Sciences and Engineering Research Council of Canada (RGPIN170627-03, RGPIN170627-08 to M. D. Jones)the British Columbia Forest Innovation Investment—Forest Science Program (Y051064 to Suzanne Simard and M. D. Jones, Y081186 to M. D. Jones and S. J. Grayston)
文摘To understand nutrient cycling in soils, soil processes and microorganisms need be better characterized. To determine whether specific trophic groups of fungi are associated with soil enzyme activity, we used soil imprinting to guide mm-scale sampling from microsites with high and low phosphatase activities in birch/Douglas-fir stands. Study 1 involved sampling one root window per site at 12 sites of different ages(stands);study 2 was conducted at one of the stem-exclusion stands, at which 5 root windows had been installed. Total fungal and ectomycorrhizal(EM) fungal terminal-restriction fragment length polymorphism(TRFLP)fingerprints differed between high-and low-phosphatase activity microsites at 8 of 12 root windows across 12 sites. Where differences were detected, fewer EM fungi were detected in high-than low-phosphatase activity microsites. Using 5 root windows at one site,next-generation sequencing detected similar fungal communities across microsites, but the ratio of saprotrophic to EM fungal reads was higher in high-phosphatase activity microsites in the two windows that had low EM fungal richness. In windows with differences in fungal communities, both studies indicated that EM fungi were less successful than saprotrophic fungi in colonizing fine-scale,organic matter-rich microsites. Fine-scale sampling linked with in situ detection of enzyme activity revealed relationships between soil fungal communities and phosphatase activity that could not be observed at the scales employed by conventional approaches, thereby contributing to the understanding of fine-scale phosphorus cycling in forest soils.
文摘The decomposition of plant litter is a major process of equivalent status to primary production in ecosystem functioning.The spatiotemporal changes in the composition and dynamics of litter fungal community along a climate gradient ranging from arid desert to humid-Mediterranean regions in Israel was examined using wheat straw litter bags placed at four selected sites along the climate gradient,arid,semi-arid,Mediterranean,and humid-Mediterranean sites.Litter samples were collected over a two-year decomposition period to evaluate litter weight loss,moisture,C:N ratio,fungal composition,and isolate density.The litter decomposition rate was found to be the highest during the first year of the study at the Mediterranean and arid sites.Although the Shannon-Wiener index values of the fungal communities in the litter samples were the highest at the humid-Mediterranean site,the number of fungal species was not significantly different between the four study sites.Different fungal groups were found to be related to different study sites:Basidiomycota,Mucoromycotina,and teleomorphic Ascomycota were associated with the humid-Mediterranean site,while Coelomycetes were mostly affected by the arid site.Our results indicate that climate factors play an important role in determining the structure of saprotrophic fungal communities in the decomposing litter and in mediating plant litter decomposition processes.
基金This research was supported by the National Natural Science Foundation of China(32071644,31670535 and 31270559)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB31030000)the National Key Research and Development Project of China(2017YFA0605103).
文摘Aims Plant–soil feedback(PSF)is a key mechanism that can facilitate tree species coexistence and diversity.Substantial evidence suggests that species-specific soil-borne pathogens around adult trees limit the performance of home(conspecific)seedlings relative to foreign(heterospecific)seedlings.However,the underlying mechanism remains largely elusive.Methods Here,we conducted a reciprocal transplant pot experiment using seedlings and from two tree species,Pinus massoniana and Lithocarpus glaber that are dominant and coexist in a subtropical,evergreen,broad-leaf forest in Gutianshan,Zhejiang Province of eastern China.We examined how seedlings from the two tree species responded to soils originating from underneath their own versus the other tree species,using a full-factorial design.Additionally,we added a fungicide(benomyl)to half of the pots to evaluate the role of soil-borne fungi on seedling growth.Important Findings We found that the seedlings from L.glaber grew better in soils that were collected from beneath the canopy of P.massoniana,while seedling growth of P.massioniana was not affected by soil origin.The addition of fungicide benomyl resulted in a shift towards more positive PSF effects for L.glaber,indicating that L.glaber seedlings performed better in their own soils than in soils from P.massoniana in the absence of fungi.Our findings highlight the importance of soil-borne pathogenic and ectomycorrhizal fungi in driving PSF,and indicate that PSF may promote the coexistence of two subtropical tree species by reducing the performance of L.glaber in own soils.
基金This work was supported by National Key R&D Program of China(2018YFD1100600)National Natural Science Foundation of China(Grant No.21976101).
文摘Land filling is the main method to dispose municipal solid waste in China.During the decomposition of organic waste in landfills,fungi play an important role in organic carbon degradation and nitrogen cycling.However,fungal composition and potential functions in landfill have not yet been characterized.In this study,refuse and leachate samples with different areas and depths were taken from a large sanitary landfill in Beijing to identify fungal communities in landfills.In high-throughput sequencing of ITS region,474 operational taxonomic units(OTUs)were obtained from landfill samples with a cutoff level of 3%and a sequencing depth of 19962.The results indicates that Ascomycota,with the average relative abundance of 84.9%,was the predominant phylum in landfill fungal communities.At the genus level,Family Hypocreaceae unclassified(15.7%),Fusarium(9.9%)and Aspergillus(8.3%)were the most abundant fungi found in the landfill and most of them are of saprotrophic lifestyle,which plays a big role in nutrient cycling in ecosystem.Fungi existed both in landfilled refuse and leachate while both the richness and evenness of fungal communities were higher in the former.In addition,fungal communities in landfilled refuse presented geographic variances,which could be partly attributed to physical habitat properties(pH,dissolved organic carbon,volatile solid,NH_(4)^(+),NO_(2)^(−)and NO_(3)^(−)),while NO_(3)^(−)was considered the most significant factor(p<0.05)in shaping fungal community.
基金supported by Weyerhaeuser Natural Resource Company.
文摘Conventional clear-cut timber harvest is a widespread industrial practice across the Pacific Northwest;however,information regarding how these practices impact soil microbial community structure at the regional scale is limited.With evidence of consistent and substantial impact of harvest on soil microbial functional profiles across the region(despite a range of environmental conditions),the objective of this study was to determine the extent to which harvest also influences the structure of prokaryotic and fungal soil microbial communities,and how generalized these trends are throughout the geographic region.Paired soil samples were collected one year before and after harvest across nine second-growth Douglas-fir forests in the Pacific Northwest.Total community DNA was extracted from the soils,and high-throughput targeted gene sequencing of the 16 S r RNA gene for prokaryotes and the internal transcribed spacer(ITS)gene for fungi was performed.Alpha diversity was consistently and significantly higher after harvest;it was moderately so for fungal communities(+14.6%),but only marginally so for prokaryotic communities(+2.0%).Similarly,on average,a greater proportion of the variation in the community structure of fungi(20.1%)at each site was associated with forest harvest compared to that of prokaryotes(13.2%).Overall,the greatest influence of timber harvest on soil microbial communities appeared to be a relative depletion of ectomycorrhizal fungi,with a concomitant enrichment of saprotrophic fungi.Understanding the short-term responses of soil microbial communities across the region,particularly those of tree root-associated symbionts,may aid our understanding of the role soil microbial communities play in ecological succession.
文摘We assess the composition of corticioid fungi in the Caucasus region for the first time.The Caucasian corticioids were compared with those of well-documented areas in the Northern Hemisphere using the Tripartite similarity index and cluster analysis.To investigate the significance of the Caucasus region as a possible contributor to the colonization of wood-inhabiting basidiomycetes in Europe,DNA sequences of nuclear ribosomal internal transcribed spacers(ITS1 and ITS2)belonging to the corticioid fungus Peniophorella praetermissa were analysed for comparisons of genetic diversity within and differentiation between geographical regions.Putative species endemism and disjunction of corticioids in the Caucasus region is also discussed.The composition of corticioid fungi in the Caucasus region was found to be distinctly more similar to Europe and North America than to East Asia and India.Similarity tests and molecular Fsts both point to a strong connection between the Caucasus and Europe.The highest molecular diversity in P.praetermissa was in the Caucasus and East Asia as compared with other regions studied.The Caucasus and East Asia were significantly differentiated from each other,and unlike Caucasian samples,East Asian sequences were highly divergent from the European ones.This result suggests that the Caucasus might have been a source of colonization for Europe.Endemism is very low,possibly a common feature for wood-inhabiting saprotrophic fungi.
