Species diversity of angiosperms(flowering plants) varies greatly among regions.Geographic patterns of variation in species diversity are shaped by the interplay of ecological and evolutionary processes.Here,using a c...Species diversity of angiosperms(flowering plants) varies greatly among regions.Geographic patterns of variation in species diversity are shaped by the interplay of ecological and evolutionary processes.Here,using a comprehensive data set for regional angiosperm floras across the world,we show geographic patterns of taxonomic(species) diversity,phylogenetic diversity,phylogenetic dispersion,and phylogenetic deviation(i.e.,phylogenetic diversity after accounting for taxonomic diversity) across the world.Phylogenetic diversity is strongly and positively correlated with taxonomic diversity;as a result,geographic patterns of taxonomic and phylogenetic diversity across the world are highly similar.Areas with high taxonomic and phylogenetic diversity are located in tropical regions whereas areas with low taxonomic and phylogenetic diversity are located in temperate regions,particularly in Eurasia and North America,and in northern Africa.Similarly,phylogenetic dispersion is,in general,higher in tropical regions and lower in temperate regions.However,the geographic pattern of phylogenetic deviation differs substantially from those of taxonomic and phylogenetic diversity and phylogenetic dispersion.As a result,hotspots and coldspots of angiosperm diversity identified based on taxonomic and phylogenetic diversity and phylogenetic dispersion are incongruent with those identified based on phylogenetic deviations.Each of these metrics may be considered when selecting areas to be protected for their biodiversity.展开更多
The underlying causes of biodiversity disparities among geographic regions have long been a fundamental theme in ecology and evolution.However,the patterns of phylogenetic diversity(PD) and phylogenetic beta diversity...The underlying causes of biodiversity disparities among geographic regions have long been a fundamental theme in ecology and evolution.However,the patterns of phylogenetic diversity(PD) and phylogenetic beta diversity(PBD) of congeners that are disjunctly distributed between eastern Asia-eastern North America(EA-ENA disjuncts) and their associated factors remain unknown.Here we investigated the standardized effect size of PD(SES-PD),PBD,and potentially associated factors in 11natural mixed forest sites(five in EA and six in ENA) where abundant EA-ENA disjuncts occur.We found that the disjuncts in ENA possessed higher SES-PD than those in EA at the continental scale(1.96vs-1.12),even though the number of disjunct species in ENA is much lower than in EA(128 vs 263).SESPD of the EA-ENA disjuncts tended to decrease with increasing latitude in 11 sites.The latitudinal diversity gradient of SES-PD was stronger in EA sites than in ENA sites.Based on the unweighted unique fraction metric(UniFrac) distance and the phylogenetic community dissimilarity,PBD showed that the two northern sites in EA were more similar to the six-site ENA group than to the remaining southern EA sites.Based on the standardized effect size of mean pairwise distances(SES-MPD),nine of eleven studied sites showed a neutral community structure(-1.96 ≤SES-MPD ≤1.96).Both Pearson’s r and structural equation modeling suggested that SES-PD of the EA-ENA disjuncts was mostly associated with mean divergence time.Moreover,SES-PD of the EA-ENA disjuncts was positively correlated with temperaturerelated climatic factors,although negatively correlated with mean diversification rate and community structure.By applying approaches from phylogenetics and community ecology,our work sheds light on historical patterns of the EA-ENA disjunction and paves the way for further research.展开更多
Understanding the relationships between species, communities, and biodiversity are important challenges in conservation ecology. Current biodiversity conservation activities usually focus on species that are rare, end...Understanding the relationships between species, communities, and biodiversity are important challenges in conservation ecology. Current biodiversity conservation activities usually focus on species that are rare, endemic, distinctive, or at risk of extinction. However, empirical studies of whether such species contribute more to aspects of biodiversity than common species are still relatively rare. The aim of the present study was to assess the contribution of individual amphibian species to different facets of biodiversity, and to test whether species of conservation interest contribute more to taxonomic, functional, and phylogenetic diversity than do species without special conservation status. To answer these questions, 19 000 simulated random communities with a gradient of species richness were created by shuffling the regional pool of species inhabiting Emei Mountain. Differences of diversity values were then computed before and after removing individual species in these random communities. Our results indicated that although individual species contributed similarly to taxonomic diversity, their contribution to functional and phylogenetic diversity was more idiosyncratic. This was primarily driven by the diverse functional attributes of species and the differences in phylogenetic relationships among species. Additionally, species of conservation interest did not show a significantly higher contribution to any facet of biodiversity. Our results support the claims that the usefulness of metrics based only on species richness is limited. Instead, assemblages that include species with functional and phylogenetic diversity should be protected to maintain biodiversity.展开更多
It is well known that marine sponges harbor large numbers of bacteria,some of which have been proved to be sponge-specific.The diversity of bacteria in marine sponges distributed along the coast of South China Sea has...It is well known that marine sponges harbor large numbers of bacteria,some of which have been proved to be sponge-specific.The diversity of bacteria in marine sponges distributed along the coast of South China Sea has been previously studied but that of bacteria in sponges inhabiting the open sea has been rarely investigated.In this report,the diversity of bacteria associated with the marine sponge Agelas robusta from a remote coral reef in the South China Sea was documented employing 16S rDNA library construction,amplified ribosomal DNA restriction analysis(ARDRA) and phylogenetic analysis.A total of 32 phylotypes were finally categorized in nine phyla including Cyanobacteria,Proteobacteria,Chloroflexi,Firmicutes,Actinobacteria,Acidobacteria,Planctomycetes,Bacteroidetes and Gemmatimonadetes.The dominant phylum was Proteobacteria whereas the dominant genus was Synechococcus in Cyanobacteria.Some spongespecific bacteria were also found in the bacteria population,but the proportion(5 OTUs/32 OTUs) was much lower than other sponges.This study reveals the phylogenetic diversity of bacteria in A.robusta and confirms the presence of some sponge-specific bacteria in the South China Sea.Understanding the diversity of sponge-associated bacteria in China assists to exploit the bacteria resources for biotechnology.展开更多
The Drake Passage is located between the Antarctic Peninsula and Tierra del Fuego in the south of South America.Surface seawater samples were collected at seven sites in the Drake Passage during the austral summer of ...The Drake Passage is located between the Antarctic Peninsula and Tierra del Fuego in the south of South America.Surface seawater samples were collected at seven sites in the Drake Passage during the austral summer of 2012.The 16 S rRNA sequences were analyzed from 187 isolated bacterial strains.Three phyla,29 genera and 56 species were identified.The three phyla were Actinobacteria,Firmicutes and Proteobacteria;the Proteobacteria included a-Proteobacteria,P-Proteobacteria and y-Proteobacteria.y-Proteobacteria,Actinobacteria and Firmicutes were the dominant class or phyla in terms of quantity and species.Gram-positive bacteria(Actinobacteria and Firmicutes) accounted for 57.8% of all types identified.There were nine dominant genera,including Curtobacterium,Staphylococcus,and Halomonas,and 14 dominant species including Curtobacterium flaccumfaciens,Curtobacterium pusillum,and Staphylococcus sciuri.Of the strains identified,87.2% were catalase positive or weakly positive.展开更多
Deep-sea sediments are now recognized as a home for rich and largely microbial community.Recently,it has been believed in an increasing number of studies that bacteria could be abundant in deepsea sediments of many ty...Deep-sea sediments are now recognized as a home for rich and largely microbial community.Recently,it has been believed in an increasing number of studies that bacteria could be abundant in deepsea sediments of many types;however,fungi in deep-sea sediments remain relatively unknown.The phylogenetic diversity and bioactivity of culturable deep-sea-derived fungi from Okinawa Trough sediments were investigated in traditional method combined with fungal identification of molecular biology in this study.A total of 76 isolates belonged to 15 fungal taxa were recovered in a harsh condition of low nutrient and low temperature,indicating that the fungal communities in deep-sea sediments from Okinawa Trough were relatively abundant and diversified.Aspergillus,Cladosporium,and Penicillium were the dominant fungal genera,while Mycosphaerella,Purpureocillium,and Schizophyllum were relatively rare in the deep-sea sediments from Okinawa Trough.Among the six genera recovered,Mycosphaerella was firstly recovered from deep-sea sediments in this study.Moreover,about 75%of the extracts from the 15 fungal representative isolates displayed distinct bioactivity against at least one indicator bacterium or marine macrofouler,emphasizing the potentials of these deep-sea-derived fungi from Okinawa Trough as producers of bioactive metabolites.Notably,isolates Cladosporium oxysporum SCSIO z001 and Penicillium citrinum SCSIO z049 displayed a wide spectrum of bioactivities,isolates Cladosporium cladosporioides SCSIO z015,Cladosporium sphaerospermum SCSIO z030,and Penicillium verruculosum SCSIO z007 exhibited a strong anti-bacterial-growth activity,and isolate Penicillium chrysogenum SCSIO z062 displayed a strong anti-larval-settlement activity.These results suggest that these isolates deserved further study as potential sources of novel bioactive metabolites.展开更多
Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional biota.The Qinghai-Tibet Plateau(QTP)harbors a...Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional biota.The Qinghai-Tibet Plateau(QTP)harbors an exceptionally diverse flora,however,a phylogenetic perspective has rarely been used to investigate its beta diversity and floristic regions.In this study,we used a phylogenetic approach to identify patterns of beta diversity and quantitatively delimit floristic regions on the Qinghai-Tibet Plateau.We also examined the relationships between multifaceted beta diversity,geographical distance,and climatic difference,and evaluated the relative importance of various factors(i.e.,climate,topography and history)in shaping patterns of beta diversity.Sørensen dissimilarity indices indicated that patterns of species turnover among sites dominated the QTP.We also found that patterns of both taxonomic and phylogenetic beta diversity were significantly related to geographical distance and climatic difference.The environmental factors that contributed most to these patterns of beta diversity include annual precipitation,mean annual temperature,climatic gradients and climatic instability.Hierarchical dendrograms of dissimilarity and non-metric multidimensional scaling ordination based on phylogenetic beta diversity data identified ten floristic subregions in the QTP.Our results suggest that the contemporary environment and historical climate changes have filtered species composition among sites and eventually determined beta diversity patterns of plants in the QTP.展开更多
Bats are reservoirs for multiple coronaviruses(Co Vs).However,the phylogenetic diversity and transmission of global bat-borne Co Vs remain poorly understood.Here,we performed a Bayesian phylogeographic analysis based ...Bats are reservoirs for multiple coronaviruses(Co Vs).However,the phylogenetic diversity and transmission of global bat-borne Co Vs remain poorly understood.Here,we performed a Bayesian phylogeographic analysis based on 3,594 bat Co V Rd Rp gene sequences to study the phylogenetic diversity and transmission of bat-borne Co Vs and the underlying driving factors.We found that host-switching events occurred more frequently forα-Co Vs than forβ-Co Vs,and the latter was highly constrained by bat phylogeny.Bat species in the families Molossidae,Rhinolophidae,Miniopteridae,and Vespertilionidae had larger contributions to the cross-species transmission of bat Co Vs.Regions of eastern and southern Africa,southern South America,Western Europe,and Southeast Asia were more frequently involved in cross-region transmission events of bat Co Vs than other regions.Phylogenetic and geographic distances were the most important factors limiting Co V transmission.Bat taxa and global geographic hotspots associated with bat Co V phylogenetic diversity were identified,and bat species richness,mean annual temperature,global agricultural cropland,and human population density were strongly correlated with the phylogenetic diversity of bat Co Vs.These findings provide insight into bat Co Vevolution and ecological transmission among bat taxa.The identified hotspots of bat Co V evolution and transmission will guide early warnings of bat-borne Co V zoonotic diseases.展开更多
Environmental conditions can change markedly over geographical distances along elevation gradients,making them natural laboratories to study the processes that structure communities.This work aimed to assess the influ...Environmental conditions can change markedly over geographical distances along elevation gradients,making them natural laboratories to study the processes that structure communities.This work aimed to assess the influences of elevation on Tropical Montane Cloud Forest plant communities in the Brazilian Atlantic Forest,a historically neglected ecoregion.We evaluated the phylogenetic structure,forest structure(tree basal area and tree density)and species richness along an elevation gradient,as well as the evolutionary fingerprints of elevation-success on phylogenetic lineages from the tree communities.To do so,we assessed nine communities along an elevation gradient from 1210 to 2310 m a.s.l.without large elevation gaps.The relationships between elevation and phylogenetic structure,forest structure and species richness were investigated through Linear Models.The occurrence of evolutionary fingerprint on phylogenetic lineages was investigated by quantifying the extent of phylogenetic signal of elevation-success using a genus-level molecular phylogeny.Our results showed decreased species richness at higher elevations and independence between forest structure,phylogenetic structure and elevation.We also verified that there is a phylogenetic signal associated with elevation-success by lineages.We concluded that the elevation is associated with species richness and the occurrence of phylogenetic lineages in the tree communities evaluated in Mantiqueira Range.On the other hand,elevation is not associated with forest structure or phylogenetic structure.Furthermore,closely related taxa tend to have their higher ecological success in similar elevations.Finally,we highlight the fragility of the tropical montane cloud forests in the Mantiqueira Range in face of environmental changes(i.e.global warming)due to the occurrence of exclusive phylogenetic lineages evolutionarily adapted to environmental conditions(i.e.minimum temperature)associated with each elevation range.展开更多
Altitude and environmental variables such as edaphic properties are considered determinants of species distribution and community composition in mountain ecosystems.Here,we aimed to outline the effects of distinct mou...Altitude and environmental variables such as edaphic properties are considered determinants of species distribution and community composition in mountain ecosystems.Here,we aimed to outline the effects of distinct mountain peaks,altitude and soil properties on community composition,species density,phylogenetic structure and diversity of angiosperm páramo communities from the Serra do Brigadeiro State Park,Minas Gerais,southeastern Brazil.For that,we identified all angiosperm species found in 300 plots(1 m×1 m)from three mountain peaks,measured soil depth and analyzed soil fertility and texture in each plot.To reduce the number of soil variables and species composition,we computed principal coordinates based on soil properties and principal coordinates based on species-plot matrix for each plot.Furthermore,we computed the standard effect sizes of the mean phylogenetic pairwise distance and the mean nearest phylogenetic taxon distance for each plot to investigate differences in the degree of relatedness among coexisting species.We compared differences in response variables between peaks and modelled them in function of altitude and principle components of soil properties using mixed effect models.Species density and phylogenetic diversity differed between peaks,but,contrary to the previous findings,no relationships between species richness or phylogenetic diversity and altitude or soil properties were found,indicating that further investigations are necessary to understand the altitude-biodiversity relationship in Brazilian páramo vegetation.Community composition differed between peaks and depended on altitude,soil properties and interactions between them,indicating that upward shifting of bioclimatic conditions due to climate changes may alter communities of this ecosystem.Phylogenetic structure differed between peaks and was influenced by altitude and soil properties.As phylogenetic clustering increased with altitude,eventual upward movements of species in Brazilian páramo vegetation due to climate change may alter community composition and the degree of relatedness among coexisting species,increasing the risk of species from higher altitudes to disappear.Therefore,conservation priorities arise for higher landscape portions,where these high altitude species may find refuges.展开更多
Aims The relationship between biodiversity and ecological stability is a long-standing issue in ecology.Current diversity–stability studies,which have largely focused on species diversity,often report an increase in ...Aims The relationship between biodiversity and ecological stability is a long-standing issue in ecology.Current diversity–stability studies,which have largely focused on species diversity,often report an increase in the stability of aggregate community properties with increasing species diversity.Few studies have examined the linkage between phylogenetic diversity,another important dimension of biodiversity,and stability.By taking species evolutionary history into account,phylogenetic diversity may better capture the diversity of traits and niches of species in a community than species diversity and better relate to temporal stability.In this study,we investigated whether phylogenetic diversity could affect temporal stability of community biomass independent of species diversity.Methods We performed an experiment in laboratory microcosms with a pool of 12 bacterivorous ciliated protist species.To eliminate the possibility of species diversity effects confounding with phylogenetic diversity effects,we assembled communities that had the same number of species but varied in the level of phylogenetic diversity.Weekly disturbance,in the form of short-term temperature shock,was imposed on each microcosm and species abundances were monitored over time.We examined the relationship between temporal stability of community biomass and phylogenetic diversity and evaluated the role of several stabilizing mechanisms for explaining the influence of phylogenetic diversity on temporal stability.Important Findings Our results showed that increasing phylogenetic diversity promoted temporal stability of community biomass.Both total community biomass and summed variances showed a U-shaped relationship with phylogenetic diversity,driven by the presence of large,competitively superior species that attained large biomass and high temporal variation in their biomass in both low and high phylogenetic diversity communities.Communities without these species showed patterns consistent with the reduced strength of competition and increasingly asynchronous species responses to environmental changes under higher phylogenetic diversity,two mechanisms that can drive positive diversity–stability relationships.These results support the utility of species phylogenetic knowledge for predicting ecosystem functions and their stability.展开更多
Aims Theory predicts that the success of introduced species is related to the diversity of native species through trait-based processes.Abiotic site characteristics may also affect a site’s susceptibility to invasion...Aims Theory predicts that the success of introduced species is related to the diversity of native species through trait-based processes.Abiotic site characteristics may also affect a site’s susceptibility to invasion.We quantified resident plant species richness,phylogenetic diversity and several abiotic site characteristics for 24 oak forests in Minnesota,USA,to assess their impact on the abundance of a widespread,introduced terrestrial plant species,common buckthorn(Rhamnus cathartica L.).Specifically,we asked(1)whether resident species richness and phylogenetic diversity affected the abundance of R.cathartica and(2)what site characteristics explained the overall abundance of R.cathartica.Methods Our survey included 24 oak-dominated stands in Minnesota’s deciduous forests.In each stand,we identified all species in 16 plots.We also measured a series of environmental site characteristics,including canopy openness(a proxy for light availability),percent bare soil,soil pH,percent sand,an index of propagule availability,duff layer thickness(a proxy for earthworm activity),an index of insolation and slope.For all species present in at least one site,we estimated a community phylogeny.We combined all sitelevel characteristics,including phylogenetic diversity of the resident plant species,in a multiple regression model to examine site-level drivers of community invasibility.Important Findings Results indicate that sites with higher overall plant phylogenetic diversity harbor less R.cathartica,even though native species richness was not significantly related to R.cathartica abundance.Regression analyses indicated that,in addition to resident species phylogenetic diversity,the most important predictors of R.cathartica abundance were canopy openness and the amount of bare soil,both positively related to the abundance of the invader.By combining the effects of abiotic site characteristics and resident species phylogenetic diversity in a model that predicted the abundance of R.cathartica,we were able to simultaneously account for a wide range of factors that might influence invasibility.Overall,our results suggest that management strategies aimed at reducing disturbances that lead to increased bare soil and light levels may be more successful if they also maximize phylogenetic diversity of the resident plant community.展开更多
The loss of bird species diversity is a crucial problem in the European agricultural landscape.Change in the area coverage of major land cover types has been mentioned as one of the main factors responsible for bird b...The loss of bird species diversity is a crucial problem in the European agricultural landscape.Change in the area coverage of major land cover types has been mentioned as one of the main factors responsible for bird biodiversity impoverishment.In this study,we focused on the impact of landscape matrix characteristics on bird species richness and on Faith’s phylogenetic diversity index on a spatial scale of 1000-m radius around the measured occurrence points.We investigated how land cover composition affects bird diversity on the landscape scale using nationwide citizen science data.In total,168,739 records of bird occurrence in the South Moravian Region of the Czech Republic during growing season from 2009 to 2019 were evaluated.We found that the presence of water bodies and wetlands significantly corresponded to the areas of highest bird species richness.We also revealed that the presence of forests(~60%of the forest in the Czech Republic is occupied by commercial forests),urban areas and arable land were negatively associated with bird species richness and phylogenetic diversity.Forests(both coniferous and deciduous)and urban habitats were found to have a tendency to host a clustered phylogenetic community structure in comparison with wetland and arable land.A strong negative association between forest proportion and bird diversity led us to conclude that the expansion of the forest(with simple species composition,horizontal and vertical structure)could be one of the critical drivers of the decline of bird species diversity in the European agricultural landscape.On the other hand,our results also pointed out that small woody features(i.e.,woodlots)and scattered woodland shrub vegetation were one of the main landscape characteristics supporting a bird diversity in rural landscape.This is in concordance with other studies which mention these landscape structures as important elements for nesting and foraging of farmland birds.We thus recommend to maintain and restore scattered trees or woodlots with complex structure in agricultural landscape.展开更多
Aims Understanding what drives the variation in species composition and diversity among local communities can provide insights into the mechanisms of community assembly.Because ecological traits are often thought to b...Aims Understanding what drives the variation in species composition and diversity among local communities can provide insights into the mechanisms of community assembly.Because ecological traits are often thought to be phylogenetically conserved,there should be patterns in phylogenetic structure and phylogenetic diversity in local communities along ecological gradients.We investigate potential patterns in angiosperm assemblages along an elevational gradient with a steep ecological gradient in Changbaishan,China.Methods We used 13 angiosperm assemblages in forest plots(32×32 m)distributed along an elevational gradient from 720 to 1900 m above sea level.We used Faith’s phylogenetic diversity metric to quantify the phylogenetic alpha diversity of each forest plot,used the net relatedness index to quantify the degree of phylogenetic relatedness among angiosperm species within each forest plot and used a phylogenetic dissimilarity index to quantify phylogenetic beta diversity among forest plots.We related the measures of phylogenetic structure and phylogenetic diversity to environmental(climatic and edaphic)factors.Important Findings Our study showed that angiosperm assemblages tended to be more phylogenetically clustered at higher elevations in Changbaishan.This finding is consistent with the prediction of the phylogenetic niche conservatism hypothesis,which highlights the role of niche constraints in governing the phylogenetic structure of assemblages.Our study also showed that woody assemblages differ from herbaceous assemblages in several major aspects.First,phylogenetic clustering dominated in woody assemblages,whereas phylogenetic overdispersion dominated in herbaceous assemblages;second,patterns in phylogenetic relatedness along the elevational and temperature gradients of Changbaishan were stronger for woody assemblages than for herbaceous assemblages;third,environmental variables explained much more variations in phylogenetic relatedness,phylogenetic alpha diversity and phylogenetic beta diversity for woody assemblages than for herbaceous assemblages.展开更多
The Qinghai-Tibet Plateau(QTP)is an important cushion plant hotspot.However,the distribution of cushion plants on the QTP is unknown,as are the factors that drive cushion plant distribution,limiting our understanding ...The Qinghai-Tibet Plateau(QTP)is an important cushion plant hotspot.However,the distribution of cushion plants on the QTP is unknown,as are the factors that drive cushion plant distribution,limiting our understanding of the evolution of cushion species in the region.In this study,we assessed spatial patterns of total cushion plant diversity(including taxonomic and phylogenetic)over the entire QTP and compared patterns of diversity of cushion plants with different typologies(i.e.,compact vs.loose).We also examined how these patterns were related to climatic features.Our results indicate that the southern QTP hosts the highest total cushion plant richness,especially in the south-central Hengduan Mountains subregion.The total number of cushion species declines from south to north and from southeast to northwest.Compact cushion plants exhibit similar patterns as the total cushion plant richness,whereas loose cushion plants show random distribution.Cushion plant phylogenetic diversity showed a similar pattern as that of the total cushion plant richness.In addition,cushion plant phylogenetic community structure was clustered in the eastern and southwestern QTP,whereas random or overdispersed in other areas.Climatic features represented by annual energy and water trends,seasonality and extreme environmental factors,had significant effects on cushion plant diversity patterns but limited effects on the phylogenetic community structure,suggesting that climatic features indeed promote the formation of cushion plants.Because cushion plants play vital roles in alpine ecosystems,our findings not only promote our understanding of the evolution and formation of alpine cushion plant diversity but also provide an indispensable foundation for future studies on cushion plant functions and thus alpine ecosystem sustainability in the entire QTP region.展开更多
Mountain systems harbor an evolutionarily unique and exceptionally rich biodiversity,especially for amphibians.However,the associated elevational gradients and underlying mechanisms of amphibian diversity in most moun...Mountain systems harbor an evolutionarily unique and exceptionally rich biodiversity,especially for amphibians.However,the associated elevational gradients and underlying mechanisms of amphibian diversity in most mountain systems remain poorly understood.Here,we explored amphibian phylogenetic and functional diversity along a 2600 m elevational gradient on Mount Emei on the eastern margin of the Qinghai-Tibetan Plateau in southwestern China.We also assessed the relative importance of spatial(area)and environmental factors(temperature,precipitation,solar radiation,normalized difference vegetation index,and potential evapotranspiration)in shaping amphibian distribution and community structure.Results showed that the phylogenetic and functional diversities were unimodal with elevation,while the standardized effect size of phylogenetic and functional diversity increased linearly with elevation.Phylogenetic net relatedness,nearest taxon index,and functional net relatedness index all showed a positive to negative trend with elevation,indicating a shift from clustering to overdispersion and suggesting a potential change in key processes from environmental filtering to competitive exclusion.Overall,our results illustrate the importance of deterministic processes in structuring amphibian communities in subtropical mountains,with the dominant role potentially switching with elevation.This study provides insights into the underlying assembly mechanisms of mountain amphibians,integrating multidimensional diversity.展开更多
Biodiversity distribution patterns are a basic and long-standing but crucial aspect of ecology research.These patterns form the primary source of data used to develop biodiversity protection practices,especially in mo...Biodiversity distribution patterns are a basic and long-standing but crucial aspect of ecology research.These patterns form the primary source of data used to develop biodiversity protection practices,especially in mountain ecosystems.Shrubs comprise one of the main types of vegetation on the Qinghai–Tibetan Plateau,where they serve vital ecological functions.In this study,we used a community phylogenetic approach to examine the distribution patterns of shrub communities along the longitudinal and latitudinal gradients on the northeastern Qinghai–Tibetan Plateau.We observed significant latitudinal trends in both the phylogenetic diversity(PD)and net relatedness index(NRI)values of shrub communities,such that the former decreased and the latter increased with increasing latitude.However,no significant PD,NRI and nearest taxon index(NTI)distribution patterns were observed along a longitudinal gradient.A further analysis revealed that the combination of temperature-related and precipitation-related climate variables most strongly affected the PD,NRI and NTI values of shrub communities,indicating that the latitudinal patterns in the PD,NRI and NTI of a shrub community may be determined mainly by interactions with these climate factors.展开更多
Phylogenies are essential to studies investigating the effect of evolutionary history on assembly of species in ecological communities and geographical and ecological patterns of phylogenetic structure of species asse...Phylogenies are essential to studies investigating the effect of evolutionary history on assembly of species in ecological communities and geographical and ecological patterns of phylogenetic structure of species assemblages.Because phylogenies well resolved at the species level are lacking for many major groups of organisms such as vascular plants,researchers often generate a species-level phylogenies using a phylogeny well resolved at the genus level as a backbone and attaching species to their respective genera in the phylogeny as polytomies or by using a megaphylogeny well resolved at the genus level as a backbone and adding additional species to the megaphylogeny as polytomies of their respective genera.However,whether the result of a study using species-level phylogenies generated in these ways is robust,compared to that based on phylogenies fully resolved at the species level,has not been assessed.Here,we use 1093 angiosperm tree assemblages(each in a 110110 km quadrat)in North America as a model system to address this question,by examining six commonly used metrics of phylogenetic structure(phylogenetic diversity and phylogenetic relatedness)and six climate variables commonly used in ecology.Our results showed that(1)the scores of phylogenetic metrics derived from species-level phylogenies resolved at the genus level with species being attached to their respective genera as polytomies are very strongly or perfectly correlated to those derived from a phylogeny fully resolved at the species level(the mean of correlation coefficients is 0.973),and(2)the relationships between the scores of phylogenetic metrics and climate variables are consistent between the two sets of analyses based on the two types of phylogeny.Our study suggests that using species-level phylogenies resolved at the genus level with species being attached to their genera as polytomies is appropriate in studies exploring patterns of phylogenetic structure of species in ecological communities across geographical and ecological gradients.展开更多
Granite-gneiss rock outcrop inselbergs are ancient stable ecosystems with old,climaticallybuffered infertile landscapes(OCBILs).Although inselbergs provide key ecosystem services,little is done for their conservation ...Granite-gneiss rock outcrop inselbergs are ancient stable ecosystems with old,climaticallybuffered infertile landscapes(OCBILs).Although inselbergs provide key ecosystem services,little is done for their conservation and,so far,a lot of their unknown evolutionary history has already been lost by human activities.Using a fine-scale approach,here we tested if habitat and environmental filtering(the inselberg’s harshness)affect the evolutionary diversity of an Atlantic Forest inselberg in Brazil.We recorded all trees with a diameter at breast height≥5cm in 20 plots in four habitat types(total sampled area of 0.8 hectares),from highest to lowest:island,hillside,foothill,and semideciduous forest(matrix).We also collected soil samples for chemical,textural and physical soil characterization.We fitted linear models to test the effects of soil and habitat on plotlevel metrics of phylogenetic diversity and structure,lineage diversity,phylogeneticβ-diversity,and evolutionary distinctiveness.We found that the upper inselberg habitats contain a distinct set of ancient,closely related,harsh-tolerant lineages,as well as a subset of lineages that persist under harsh conditions with a certain degree of water availability.The inferior inselberg habitats harbor higher lineage diversity than expected by chance.Soil strongly predicted evolutionary diversity.We concluded that soil depth,slope,nutrients and texture(environmental filtering)and habitat types and topography(habitat filtering)shape the evolutionary history contained in fine-scale inselberg habitats,which should encourage the conservation of these ancient ecosystems.展开更多
The genetic variation and phylogenetic relationships of Citrus tristeza virus (CTV) isolates collected from Chinese wild type citrus were analyzed by comparing the sequences of nine genomic regions (p23, p20, p13, ...The genetic variation and phylogenetic relationships of Citrus tristeza virus (CTV) isolates collected from Chinese wild type citrus were analyzed by comparing the sequences of nine genomic regions (p23, p20, p13, p18, p25, p27, POL, HEL and k17) with the CTV isolates of cultivated citrus from different countries. The results showed that the divergence pattern of genomic RNA of the CTV isolates from wild type citrus was similar to that of other isolates from cultivated citrus, the 3′ proximal region was relatively conserved, and the 5′ proximal region had greater variability. The nine genomic regions of CTV isolates analyzed were found to have been under purifying selection in the evolution process. Phylogenetic analysis showed that the eleven Chinese wild CTV isolates were located at different clades and did not relfect their geographical origins, suggesting genetic diversity among the Chinese wild CTV populations. These results will aid in the understanding of molecular evolution of the Chinese CTV populations.展开更多
基金This research was partly supported by the Shanghai Municipal Natural Science Foundation(Grant No.20ZR1418100)National Natural Science Foundation of China(Grant No.32030068)to J.Z.
文摘Species diversity of angiosperms(flowering plants) varies greatly among regions.Geographic patterns of variation in species diversity are shaped by the interplay of ecological and evolutionary processes.Here,using a comprehensive data set for regional angiosperm floras across the world,we show geographic patterns of taxonomic(species) diversity,phylogenetic diversity,phylogenetic dispersion,and phylogenetic deviation(i.e.,phylogenetic diversity after accounting for taxonomic diversity) across the world.Phylogenetic diversity is strongly and positively correlated with taxonomic diversity;as a result,geographic patterns of taxonomic and phylogenetic diversity across the world are highly similar.Areas with high taxonomic and phylogenetic diversity are located in tropical regions whereas areas with low taxonomic and phylogenetic diversity are located in temperate regions,particularly in Eurasia and North America,and in northern Africa.Similarly,phylogenetic dispersion is,in general,higher in tropical regions and lower in temperate regions.However,the geographic pattern of phylogenetic deviation differs substantially from those of taxonomic and phylogenetic diversity and phylogenetic dispersion.As a result,hotspots and coldspots of angiosperm diversity identified based on taxonomic and phylogenetic diversity and phylogenetic dispersion are incongruent with those identified based on phylogenetic deviations.Each of these metrics may be considered when selecting areas to be protected for their biodiversity.
基金supported by the National Natural Science Foundation of China (Grant No.31461123001 to C.X.F.)the US National Science Foundation Dimensions of Biodiversity US-China Program (DEB-1442280 to P.S.S.and D.E.S.)+1 种基金the HZAU Talent Start-up Fund (Grant no.11042210014 to M.S.)the China Scholarship Council (Grant no.201806320056 to H.Y.L.)。
文摘The underlying causes of biodiversity disparities among geographic regions have long been a fundamental theme in ecology and evolution.However,the patterns of phylogenetic diversity(PD) and phylogenetic beta diversity(PBD) of congeners that are disjunctly distributed between eastern Asia-eastern North America(EA-ENA disjuncts) and their associated factors remain unknown.Here we investigated the standardized effect size of PD(SES-PD),PBD,and potentially associated factors in 11natural mixed forest sites(five in EA and six in ENA) where abundant EA-ENA disjuncts occur.We found that the disjuncts in ENA possessed higher SES-PD than those in EA at the continental scale(1.96vs-1.12),even though the number of disjunct species in ENA is much lower than in EA(128 vs 263).SESPD of the EA-ENA disjuncts tended to decrease with increasing latitude in 11 sites.The latitudinal diversity gradient of SES-PD was stronger in EA sites than in ENA sites.Based on the unweighted unique fraction metric(UniFrac) distance and the phylogenetic community dissimilarity,PBD showed that the two northern sites in EA were more similar to the six-site ENA group than to the remaining southern EA sites.Based on the standardized effect size of mean pairwise distances(SES-MPD),nine of eleven studied sites showed a neutral community structure(-1.96 ≤SES-MPD ≤1.96).Both Pearson’s r and structural equation modeling suggested that SES-PD of the EA-ENA disjuncts was mostly associated with mean divergence time.Moreover,SES-PD of the EA-ENA disjuncts was positively correlated with temperaturerelated climatic factors,although negatively correlated with mean diversification rate and community structure.By applying approaches from phylogenetics and community ecology,our work sheds light on historical patterns of the EA-ENA disjunction and paves the way for further research.
基金supported by China Scholarship Council (CSC)supported by the National Natural Science Foundation of China (31700353)+2 种基金the National Key Research and Development Program of China (2017YFC0505202)the West Light Foundation of Chinese Academy of Sciences (2016XBZG_XBQNXZ_ B_007)China Biodiversity Observation Networks (Sino BON)
文摘Understanding the relationships between species, communities, and biodiversity are important challenges in conservation ecology. Current biodiversity conservation activities usually focus on species that are rare, endemic, distinctive, or at risk of extinction. However, empirical studies of whether such species contribute more to aspects of biodiversity than common species are still relatively rare. The aim of the present study was to assess the contribution of individual amphibian species to different facets of biodiversity, and to test whether species of conservation interest contribute more to taxonomic, functional, and phylogenetic diversity than do species without special conservation status. To answer these questions, 19 000 simulated random communities with a gradient of species richness were created by shuffling the regional pool of species inhabiting Emei Mountain. Differences of diversity values were then computed before and after removing individual species in these random communities. Our results indicated that although individual species contributed similarly to taxonomic diversity, their contribution to functional and phylogenetic diversity was more idiosyncratic. This was primarily driven by the diverse functional attributes of species and the differences in phylogenetic relationships among species. Additionally, species of conservation interest did not show a significantly higher contribution to any facet of biodiversity. Our results support the claims that the usefulness of metrics based only on species richness is limited. Instead, assemblages that include species with functional and phylogenetic diversity should be protected to maintain biodiversity.
基金This research was partially funded by the State Principal and Basic Research and Development Program of the Ministry of Sciences and Technology of China under contract No. 2010CB833801the Provincial Collaborative Foundation Project of Guangdong under contract Nos 9351007002000001 and 2008A030203004
文摘It is well known that marine sponges harbor large numbers of bacteria,some of which have been proved to be sponge-specific.The diversity of bacteria in marine sponges distributed along the coast of South China Sea has been previously studied but that of bacteria in sponges inhabiting the open sea has been rarely investigated.In this report,the diversity of bacteria associated with the marine sponge Agelas robusta from a remote coral reef in the South China Sea was documented employing 16S rDNA library construction,amplified ribosomal DNA restriction analysis(ARDRA) and phylogenetic analysis.A total of 32 phylotypes were finally categorized in nine phyla including Cyanobacteria,Proteobacteria,Chloroflexi,Firmicutes,Actinobacteria,Acidobacteria,Planctomycetes,Bacteroidetes and Gemmatimonadetes.The dominant phylum was Proteobacteria whereas the dominant genus was Synechococcus in Cyanobacteria.Some spongespecific bacteria were also found in the bacteria population,but the proportion(5 OTUs/32 OTUs) was much lower than other sponges.This study reveals the phylogenetic diversity of bacteria in A.robusta and confirms the presence of some sponge-specific bacteria in the South China Sea.Understanding the diversity of sponge-associated bacteria in China assists to exploit the bacteria resources for biotechnology.
基金Supported by the Natural Science Foundation of China-United Fund(No.U1406402-5)the Postdoctoral Researcher Applied Research Project Funding of Qingdao,China(No.Q51201407)the International Cooperation and Exchanges in Science and Technology(No.2014DFG30890)
文摘The Drake Passage is located between the Antarctic Peninsula and Tierra del Fuego in the south of South America.Surface seawater samples were collected at seven sites in the Drake Passage during the austral summer of 2012.The 16 S rRNA sequences were analyzed from 187 isolated bacterial strains.Three phyla,29 genera and 56 species were identified.The three phyla were Actinobacteria,Firmicutes and Proteobacteria;the Proteobacteria included a-Proteobacteria,P-Proteobacteria and y-Proteobacteria.y-Proteobacteria,Actinobacteria and Firmicutes were the dominant class or phyla in terms of quantity and species.Gram-positive bacteria(Actinobacteria and Firmicutes) accounted for 57.8% of all types identified.There were nine dominant genera,including Curtobacterium,Staphylococcus,and Halomonas,and 14 dominant species including Curtobacterium flaccumfaciens,Curtobacterium pusillum,and Staphylococcus sciuri.Of the strains identified,87.2% were catalase positive or weakly positive.
基金Supported by the National Natural Science Foundation of China(No.81673326)the Foundation of Key Laboratory of Tropical Marine Bioresources and Ecology,Chinese Academy of Sciences(No.LMB20191006)。
文摘Deep-sea sediments are now recognized as a home for rich and largely microbial community.Recently,it has been believed in an increasing number of studies that bacteria could be abundant in deepsea sediments of many types;however,fungi in deep-sea sediments remain relatively unknown.The phylogenetic diversity and bioactivity of culturable deep-sea-derived fungi from Okinawa Trough sediments were investigated in traditional method combined with fungal identification of molecular biology in this study.A total of 76 isolates belonged to 15 fungal taxa were recovered in a harsh condition of low nutrient and low temperature,indicating that the fungal communities in deep-sea sediments from Okinawa Trough were relatively abundant and diversified.Aspergillus,Cladosporium,and Penicillium were the dominant fungal genera,while Mycosphaerella,Purpureocillium,and Schizophyllum were relatively rare in the deep-sea sediments from Okinawa Trough.Among the six genera recovered,Mycosphaerella was firstly recovered from deep-sea sediments in this study.Moreover,about 75%of the extracts from the 15 fungal representative isolates displayed distinct bioactivity against at least one indicator bacterium or marine macrofouler,emphasizing the potentials of these deep-sea-derived fungi from Okinawa Trough as producers of bioactive metabolites.Notably,isolates Cladosporium oxysporum SCSIO z001 and Penicillium citrinum SCSIO z049 displayed a wide spectrum of bioactivities,isolates Cladosporium cladosporioides SCSIO z015,Cladosporium sphaerospermum SCSIO z030,and Penicillium verruculosum SCSIO z007 exhibited a strong anti-bacterial-growth activity,and isolate Penicillium chrysogenum SCSIO z062 displayed a strong anti-larval-settlement activity.These results suggest that these isolates deserved further study as potential sources of novel bioactive metabolites.
基金This study was funded by the National Natural Science Foundation of China(grant no.31901212)Talent Start-up Foundation of Guangzhou University(grant no.RP2020079).
文摘Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional biota.The Qinghai-Tibet Plateau(QTP)harbors an exceptionally diverse flora,however,a phylogenetic perspective has rarely been used to investigate its beta diversity and floristic regions.In this study,we used a phylogenetic approach to identify patterns of beta diversity and quantitatively delimit floristic regions on the Qinghai-Tibet Plateau.We also examined the relationships between multifaceted beta diversity,geographical distance,and climatic difference,and evaluated the relative importance of various factors(i.e.,climate,topography and history)in shaping patterns of beta diversity.Sørensen dissimilarity indices indicated that patterns of species turnover among sites dominated the QTP.We also found that patterns of both taxonomic and phylogenetic beta diversity were significantly related to geographical distance and climatic difference.The environmental factors that contributed most to these patterns of beta diversity include annual precipitation,mean annual temperature,climatic gradients and climatic instability.Hierarchical dendrograms of dissimilarity and non-metric multidimensional scaling ordination based on phylogenetic beta diversity data identified ten floristic subregions in the QTP.Our results suggest that the contemporary environment and historical climate changes have filtered species composition among sites and eventually determined beta diversity patterns of plants in the QTP.
基金supported by the National Natural Science Foundation of China(32192420)the Special Foundation for National Science and Technology Basic Research Program of China(2021FY100304)。
文摘Bats are reservoirs for multiple coronaviruses(Co Vs).However,the phylogenetic diversity and transmission of global bat-borne Co Vs remain poorly understood.Here,we performed a Bayesian phylogeographic analysis based on 3,594 bat Co V Rd Rp gene sequences to study the phylogenetic diversity and transmission of bat-borne Co Vs and the underlying driving factors.We found that host-switching events occurred more frequently forα-Co Vs than forβ-Co Vs,and the latter was highly constrained by bat phylogeny.Bat species in the families Molossidae,Rhinolophidae,Miniopteridae,and Vespertilionidae had larger contributions to the cross-species transmission of bat Co Vs.Regions of eastern and southern Africa,southern South America,Western Europe,and Southeast Asia were more frequently involved in cross-region transmission events of bat Co Vs than other regions.Phylogenetic and geographic distances were the most important factors limiting Co V transmission.Bat taxa and global geographic hotspots associated with bat Co V phylogenetic diversity were identified,and bat species richness,mean annual temperature,global agricultural cropland,and human population density were strongly correlated with the phylogenetic diversity of bat Co Vs.These findings provide insight into bat Co Vevolution and ecological transmission among bat taxa.The identified hotspots of bat Co V evolution and transmission will guide early warnings of bat-borne Co V zoonotic diseases.
基金supported this work by granting the doctoral scholarship to Ravi Fernandes Mariano,Carolina Njaime Mendes and Cléber Rodrigo de Souza,and through the master’s scholarship to Aloysio Souza de Mourathe postdoctoral scholarship to Vanessa Leite Rezende+2 种基金The authors also thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPQ)by project funding(Edital Universal 2014,Process 459739/2014-0)the Instituto Alto-Montana da Serra Fina,the Fundação de AmparoàPesquisa do Estado de Minas Gerais(FAPEMIG)the Fundação Grupo Boticário de ProteçãoàNatureza,and finally the Fundo de Recuperação,Proteção e Desenvolvimento Sustentável das Bacias Hidrográficas do Estado de Minas Gerais(Fhidro).
文摘Environmental conditions can change markedly over geographical distances along elevation gradients,making them natural laboratories to study the processes that structure communities.This work aimed to assess the influences of elevation on Tropical Montane Cloud Forest plant communities in the Brazilian Atlantic Forest,a historically neglected ecoregion.We evaluated the phylogenetic structure,forest structure(tree basal area and tree density)and species richness along an elevation gradient,as well as the evolutionary fingerprints of elevation-success on phylogenetic lineages from the tree communities.To do so,we assessed nine communities along an elevation gradient from 1210 to 2310 m a.s.l.without large elevation gaps.The relationships between elevation and phylogenetic structure,forest structure and species richness were investigated through Linear Models.The occurrence of evolutionary fingerprint on phylogenetic lineages was investigated by quantifying the extent of phylogenetic signal of elevation-success using a genus-level molecular phylogeny.Our results showed decreased species richness at higher elevations and independence between forest structure,phylogenetic structure and elevation.We also verified that there is a phylogenetic signal associated with elevation-success by lineages.We concluded that the elevation is associated with species richness and the occurrence of phylogenetic lineages in the tree communities evaluated in Mantiqueira Range.On the other hand,elevation is not associated with forest structure or phylogenetic structure.Furthermore,closely related taxa tend to have their higher ecological success in similar elevations.Finally,we highlight the fragility of the tropical montane cloud forests in the Mantiqueira Range in face of environmental changes(i.e.global warming)due to the occurrence of exclusive phylogenetic lineages evolutionarily adapted to environmental conditions(i.e.minimum temperature)associated with each elevation range.
基金Fapemig(APQ-01833-11)for founding the field worka CNPq post-doc fellowship(153535/2018-0)CNPq(206814/2014-3)Post-doctorate scholarship
文摘Altitude and environmental variables such as edaphic properties are considered determinants of species distribution and community composition in mountain ecosystems.Here,we aimed to outline the effects of distinct mountain peaks,altitude and soil properties on community composition,species density,phylogenetic structure and diversity of angiosperm páramo communities from the Serra do Brigadeiro State Park,Minas Gerais,southeastern Brazil.For that,we identified all angiosperm species found in 300 plots(1 m×1 m)from three mountain peaks,measured soil depth and analyzed soil fertility and texture in each plot.To reduce the number of soil variables and species composition,we computed principal coordinates based on soil properties and principal coordinates based on species-plot matrix for each plot.Furthermore,we computed the standard effect sizes of the mean phylogenetic pairwise distance and the mean nearest phylogenetic taxon distance for each plot to investigate differences in the degree of relatedness among coexisting species.We compared differences in response variables between peaks and modelled them in function of altitude and principle components of soil properties using mixed effect models.Species density and phylogenetic diversity differed between peaks,but,contrary to the previous findings,no relationships between species richness or phylogenetic diversity and altitude or soil properties were found,indicating that further investigations are necessary to understand the altitude-biodiversity relationship in Brazilian páramo vegetation.Community composition differed between peaks and depended on altitude,soil properties and interactions between them,indicating that upward shifting of bioclimatic conditions due to climate changes may alter communities of this ecosystem.Phylogenetic structure differed between peaks and was influenced by altitude and soil properties.As phylogenetic clustering increased with altitude,eventual upward movements of species in Brazilian páramo vegetation due to climate change may alter community composition and the degree of relatedness among coexisting species,increasing the risk of species from higher altitudes to disappear.Therefore,conservation priorities arise for higher landscape portions,where these high altitude species may find refuges.
基金US National Science Foundation(DEB-1120281,DEB-1257858)Summer Undergraduate Research Fellowship from California Institute of Technology(to P.D.).
文摘Aims The relationship between biodiversity and ecological stability is a long-standing issue in ecology.Current diversity–stability studies,which have largely focused on species diversity,often report an increase in the stability of aggregate community properties with increasing species diversity.Few studies have examined the linkage between phylogenetic diversity,another important dimension of biodiversity,and stability.By taking species evolutionary history into account,phylogenetic diversity may better capture the diversity of traits and niches of species in a community than species diversity and better relate to temporal stability.In this study,we investigated whether phylogenetic diversity could affect temporal stability of community biomass independent of species diversity.Methods We performed an experiment in laboratory microcosms with a pool of 12 bacterivorous ciliated protist species.To eliminate the possibility of species diversity effects confounding with phylogenetic diversity effects,we assembled communities that had the same number of species but varied in the level of phylogenetic diversity.Weekly disturbance,in the form of short-term temperature shock,was imposed on each microcosm and species abundances were monitored over time.We examined the relationship between temporal stability of community biomass and phylogenetic diversity and evaluated the role of several stabilizing mechanisms for explaining the influence of phylogenetic diversity on temporal stability.Important Findings Our results showed that increasing phylogenetic diversity promoted temporal stability of community biomass.Both total community biomass and summed variances showed a U-shaped relationship with phylogenetic diversity,driven by the presence of large,competitively superior species that attained large biomass and high temporal variation in their biomass in both low and high phylogenetic diversity communities.Communities without these species showed patterns consistent with the reduced strength of competition and increasingly asynchronous species responses to environmental changes under higher phylogenetic diversity,two mechanisms that can drive positive diversity–stability relationships.These results support the utility of species phylogenetic knowledge for predicting ecosystem functions and their stability.
基金Legislative-Citizen Commission on Minnesota Resources(M.L.2010,Chp.362,Sec.2,Subd.6c‘Healthy Forests to Resist Invasion’,to P.B.R.)Integrative Graduate Education and Research Traineeship:Risk Analysis for Introduced Species and Genotypes(NSF DGE-0653827)+2 种基金University of Minnesota Graduate School Fellowshipthe Hubachek Wilderness Research Foundationthe Dayton Fund of the Bell Museum of Natural History.
文摘Aims Theory predicts that the success of introduced species is related to the diversity of native species through trait-based processes.Abiotic site characteristics may also affect a site’s susceptibility to invasion.We quantified resident plant species richness,phylogenetic diversity and several abiotic site characteristics for 24 oak forests in Minnesota,USA,to assess their impact on the abundance of a widespread,introduced terrestrial plant species,common buckthorn(Rhamnus cathartica L.).Specifically,we asked(1)whether resident species richness and phylogenetic diversity affected the abundance of R.cathartica and(2)what site characteristics explained the overall abundance of R.cathartica.Methods Our survey included 24 oak-dominated stands in Minnesota’s deciduous forests.In each stand,we identified all species in 16 plots.We also measured a series of environmental site characteristics,including canopy openness(a proxy for light availability),percent bare soil,soil pH,percent sand,an index of propagule availability,duff layer thickness(a proxy for earthworm activity),an index of insolation and slope.For all species present in at least one site,we estimated a community phylogeny.We combined all sitelevel characteristics,including phylogenetic diversity of the resident plant species,in a multiple regression model to examine site-level drivers of community invasibility.Important Findings Results indicate that sites with higher overall plant phylogenetic diversity harbor less R.cathartica,even though native species richness was not significantly related to R.cathartica abundance.Regression analyses indicated that,in addition to resident species phylogenetic diversity,the most important predictors of R.cathartica abundance were canopy openness and the amount of bare soil,both positively related to the abundance of the invader.By combining the effects of abiotic site characteristics and resident species phylogenetic diversity in a model that predicted the abundance of R.cathartica,we were able to simultaneously account for a wide range of factors that might influence invasibility.Overall,our results suggest that management strategies aimed at reducing disturbances that lead to increased bare soil and light levels may be more successful if they also maximize phylogenetic diversity of the resident plant community.
基金supported by the internal grant agency of the Faculty of AgriSciences of Mendel University in Brno(AF-IGA2022-IP-034).
文摘The loss of bird species diversity is a crucial problem in the European agricultural landscape.Change in the area coverage of major land cover types has been mentioned as one of the main factors responsible for bird biodiversity impoverishment.In this study,we focused on the impact of landscape matrix characteristics on bird species richness and on Faith’s phylogenetic diversity index on a spatial scale of 1000-m radius around the measured occurrence points.We investigated how land cover composition affects bird diversity on the landscape scale using nationwide citizen science data.In total,168,739 records of bird occurrence in the South Moravian Region of the Czech Republic during growing season from 2009 to 2019 were evaluated.We found that the presence of water bodies and wetlands significantly corresponded to the areas of highest bird species richness.We also revealed that the presence of forests(~60%of the forest in the Czech Republic is occupied by commercial forests),urban areas and arable land were negatively associated with bird species richness and phylogenetic diversity.Forests(both coniferous and deciduous)and urban habitats were found to have a tendency to host a clustered phylogenetic community structure in comparison with wetland and arable land.A strong negative association between forest proportion and bird diversity led us to conclude that the expansion of the forest(with simple species composition,horizontal and vertical structure)could be one of the critical drivers of the decline of bird species diversity in the European agricultural landscape.On the other hand,our results also pointed out that small woody features(i.e.,woodlots)and scattered woodland shrub vegetation were one of the main landscape characteristics supporting a bird diversity in rural landscape.This is in concordance with other studies which mention these landscape structures as important elements for nesting and foraging of farmland birds.We thus recommend to maintain and restore scattered trees or woodlots with complex structure in agricultural landscape.
基金China National Scientific and Technical Foundation Project(2012FY112000 to Z.H.)。
文摘Aims Understanding what drives the variation in species composition and diversity among local communities can provide insights into the mechanisms of community assembly.Because ecological traits are often thought to be phylogenetically conserved,there should be patterns in phylogenetic structure and phylogenetic diversity in local communities along ecological gradients.We investigate potential patterns in angiosperm assemblages along an elevational gradient with a steep ecological gradient in Changbaishan,China.Methods We used 13 angiosperm assemblages in forest plots(32×32 m)distributed along an elevational gradient from 720 to 1900 m above sea level.We used Faith’s phylogenetic diversity metric to quantify the phylogenetic alpha diversity of each forest plot,used the net relatedness index to quantify the degree of phylogenetic relatedness among angiosperm species within each forest plot and used a phylogenetic dissimilarity index to quantify phylogenetic beta diversity among forest plots.We related the measures of phylogenetic structure and phylogenetic diversity to environmental(climatic and edaphic)factors.Important Findings Our study showed that angiosperm assemblages tended to be more phylogenetically clustered at higher elevations in Changbaishan.This finding is consistent with the prediction of the phylogenetic niche conservatism hypothesis,which highlights the role of niche constraints in governing the phylogenetic structure of assemblages.Our study also showed that woody assemblages differ from herbaceous assemblages in several major aspects.First,phylogenetic clustering dominated in woody assemblages,whereas phylogenetic overdispersion dominated in herbaceous assemblages;second,patterns in phylogenetic relatedness along the elevational and temperature gradients of Changbaishan were stronger for woody assemblages than for herbaceous assemblages;third,environmental variables explained much more variations in phylogenetic relatedness,phylogenetic alpha diversity and phylogenetic beta diversity for woody assemblages than for herbaceous assemblages.
基金supported by grants from the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)the Strategic Priority Research Program of Chinese Academy of Sciences(XDA20050203)+1 种基金the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U1802232)the Yunnan Applied Basic Research Project(202001AT070060).
文摘The Qinghai-Tibet Plateau(QTP)is an important cushion plant hotspot.However,the distribution of cushion plants on the QTP is unknown,as are the factors that drive cushion plant distribution,limiting our understanding of the evolution of cushion species in the region.In this study,we assessed spatial patterns of total cushion plant diversity(including taxonomic and phylogenetic)over the entire QTP and compared patterns of diversity of cushion plants with different typologies(i.e.,compact vs.loose).We also examined how these patterns were related to climatic features.Our results indicate that the southern QTP hosts the highest total cushion plant richness,especially in the south-central Hengduan Mountains subregion.The total number of cushion species declines from south to north and from southeast to northwest.Compact cushion plants exhibit similar patterns as the total cushion plant richness,whereas loose cushion plants show random distribution.Cushion plant phylogenetic diversity showed a similar pattern as that of the total cushion plant richness.In addition,cushion plant phylogenetic community structure was clustered in the eastern and southwestern QTP,whereas random or overdispersed in other areas.Climatic features represented by annual energy and water trends,seasonality and extreme environmental factors,had significant effects on cushion plant diversity patterns but limited effects on the phylogenetic community structure,suggesting that climatic features indeed promote the formation of cushion plants.Because cushion plants play vital roles in alpine ecosystems,our findings not only promote our understanding of the evolution and formation of alpine cushion plant diversity but also provide an indispensable foundation for future studies on cushion plant functions and thus alpine ecosystem sustainability in the entire QTP region.
基金supported by the National Natural Science Foundation of China(31770568,32071544)Natural Science Foundation of Shanghai(20ZR1418100)“Light of West China”Program of the Chinese Academy of Sciences。
文摘Mountain systems harbor an evolutionarily unique and exceptionally rich biodiversity,especially for amphibians.However,the associated elevational gradients and underlying mechanisms of amphibian diversity in most mountain systems remain poorly understood.Here,we explored amphibian phylogenetic and functional diversity along a 2600 m elevational gradient on Mount Emei on the eastern margin of the Qinghai-Tibetan Plateau in southwestern China.We also assessed the relative importance of spatial(area)and environmental factors(temperature,precipitation,solar radiation,normalized difference vegetation index,and potential evapotranspiration)in shaping amphibian distribution and community structure.Results showed that the phylogenetic and functional diversities were unimodal with elevation,while the standardized effect size of phylogenetic and functional diversity increased linearly with elevation.Phylogenetic net relatedness,nearest taxon index,and functional net relatedness index all showed a positive to negative trend with elevation,indicating a shift from clustering to overdispersion and suggesting a potential change in key processes from environmental filtering to competitive exclusion.Overall,our results illustrate the importance of deterministic processes in structuring amphibian communities in subtropical mountains,with the dominant role potentially switching with elevation.This study provides insights into the underlying assembly mechanisms of mountain amphibians,integrating multidimensional diversity.
基金funded jointly by the Natural Science Foundation of Qinghai Province(2019-ZJ-910)the International Communication and Cooperation Project of Qinghai Province(2019-HZ-807)+1 种基金the National Program on Basic Work Project of China(2015FY11030001)the Qinghai Province High-level Innovative Talents Program
文摘Biodiversity distribution patterns are a basic and long-standing but crucial aspect of ecology research.These patterns form the primary source of data used to develop biodiversity protection practices,especially in mountain ecosystems.Shrubs comprise one of the main types of vegetation on the Qinghai–Tibetan Plateau,where they serve vital ecological functions.In this study,we used a community phylogenetic approach to examine the distribution patterns of shrub communities along the longitudinal and latitudinal gradients on the northeastern Qinghai–Tibetan Plateau.We observed significant latitudinal trends in both the phylogenetic diversity(PD)and net relatedness index(NRI)values of shrub communities,such that the former decreased and the latter increased with increasing latitude.However,no significant PD,NRI and nearest taxon index(NTI)distribution patterns were observed along a longitudinal gradient.A further analysis revealed that the combination of temperature-related and precipitation-related climate variables most strongly affected the PD,NRI and NTI values of shrub communities,indicating that the latitudinal patterns in the PD,NRI and NTI of a shrub community may be determined mainly by interactions with these climate factors.
文摘Phylogenies are essential to studies investigating the effect of evolutionary history on assembly of species in ecological communities and geographical and ecological patterns of phylogenetic structure of species assemblages.Because phylogenies well resolved at the species level are lacking for many major groups of organisms such as vascular plants,researchers often generate a species-level phylogenies using a phylogeny well resolved at the genus level as a backbone and attaching species to their respective genera in the phylogeny as polytomies or by using a megaphylogeny well resolved at the genus level as a backbone and adding additional species to the megaphylogeny as polytomies of their respective genera.However,whether the result of a study using species-level phylogenies generated in these ways is robust,compared to that based on phylogenies fully resolved at the species level,has not been assessed.Here,we use 1093 angiosperm tree assemblages(each in a 110110 km quadrat)in North America as a model system to address this question,by examining six commonly used metrics of phylogenetic structure(phylogenetic diversity and phylogenetic relatedness)and six climate variables commonly used in ecology.Our results showed that(1)the scores of phylogenetic metrics derived from species-level phylogenies resolved at the genus level with species being attached to their respective genera as polytomies are very strongly or perfectly correlated to those derived from a phylogeny fully resolved at the species level(the mean of correlation coefficients is 0.973),and(2)the relationships between the scores of phylogenetic metrics and climate variables are consistent between the two sets of analyses based on the two types of phylogeny.Our study suggests that using species-level phylogenies resolved at the genus level with species being attached to their genera as polytomies is appropriate in studies exploring patterns of phylogenetic structure of species in ecological communities across geographical and ecological gradients.
基金Coordination for the Improvement of Higher Education Personnel(CAPES)the National Council for Scientific and Technological Development(CNPq)the Minas Gerais State Research Foundation(FAPEMIG)for research funding and scholarships to the authors。
文摘Granite-gneiss rock outcrop inselbergs are ancient stable ecosystems with old,climaticallybuffered infertile landscapes(OCBILs).Although inselbergs provide key ecosystem services,little is done for their conservation and,so far,a lot of their unknown evolutionary history has already been lost by human activities.Using a fine-scale approach,here we tested if habitat and environmental filtering(the inselberg’s harshness)affect the evolutionary diversity of an Atlantic Forest inselberg in Brazil.We recorded all trees with a diameter at breast height≥5cm in 20 plots in four habitat types(total sampled area of 0.8 hectares),from highest to lowest:island,hillside,foothill,and semideciduous forest(matrix).We also collected soil samples for chemical,textural and physical soil characterization.We fitted linear models to test the effects of soil and habitat on plotlevel metrics of phylogenetic diversity and structure,lineage diversity,phylogeneticβ-diversity,and evolutionary distinctiveness.We found that the upper inselberg habitats contain a distinct set of ancient,closely related,harsh-tolerant lineages,as well as a subset of lineages that persist under harsh conditions with a certain degree of water availability.The inferior inselberg habitats harbor higher lineage diversity than expected by chance.Soil strongly predicted evolutionary diversity.We concluded that soil depth,slope,nutrients and texture(environmental filtering)and habitat types and topography(habitat filtering)shape the evolutionary history contained in fine-scale inselberg habitats,which should encourage the conservation of these ancient ecosystems.
基金supported by the National Natural Science Foundation of China (30900977)the Program for Changjiang Scholars and Innovative Research Team in Universities, China (PCSIRT, IRT0976)+1 种基金the Key Project 210111 of Ministry of Education of Chinathe Young Scientist Cultivation Program of Jiangxi, China (2010DQ02300)
文摘The genetic variation and phylogenetic relationships of Citrus tristeza virus (CTV) isolates collected from Chinese wild type citrus were analyzed by comparing the sequences of nine genomic regions (p23, p20, p13, p18, p25, p27, POL, HEL and k17) with the CTV isolates of cultivated citrus from different countries. The results showed that the divergence pattern of genomic RNA of the CTV isolates from wild type citrus was similar to that of other isolates from cultivated citrus, the 3′ proximal region was relatively conserved, and the 5′ proximal region had greater variability. The nine genomic regions of CTV isolates analyzed were found to have been under purifying selection in the evolution process. Phylogenetic analysis showed that the eleven Chinese wild CTV isolates were located at different clades and did not relfect their geographical origins, suggesting genetic diversity among the Chinese wild CTV populations. These results will aid in the understanding of molecular evolution of the Chinese CTV populations.