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
The original version of this article contains a mistake in font setting on p.350. The last part of Table 3 note, i.e. 'biomass…molluscs (Liang et al., 1995)' should belong to the paper body. Therefore, the la...The original version of this article contains a mistake in font setting on p.350. The last part of Table 3 note, i.e. 'biomass…molluscs (Liang et al., 1995)' should belong to the paper body. Therefore, the last sentence展开更多
The new urbanization is an important carrier of ecological civilization construction, and ecological old-age care is the concrete manifestation of the perfect combination of the two, the proper meaning of the new urba...The new urbanization is an important carrier of ecological civilization construction, and ecological old-age care is the concrete manifestation of the perfect combination of the two, the proper meaning of the new urbanization connotation and an inevitable trend of its development. Based on the analysis of the connotation and relationship between the new urbanization and ecological old-age care, together with the current situation and existing problems of the current nursing institutions and ecological old-age care in Xi'an area, this paper discusses the major issues that should be noticed when constructing the ecological old-age care community in Xi'an and three main construction modes.展开更多
Niche partitioning is a widespread ecological strategy within trophic guilds,ensuring the coexistence of sympatric species by reducing interspecific competition.Stable isotope analysis of carbon and nitrogen and isoto...Niche partitioning is a widespread ecological strategy within trophic guilds,ensuring the coexistence of sympatric species by reducing interspecific competition.Stable isotope analysis of carbon and nitrogen and isotopic niche metrics(width and overlap)are used as a proxy to investigate niche partitioning among species of a guild.In our study,we investigated if niche partitioning was an ecological mechanism contributing to the coexistence of granivorous birds from the same geographic region along time,employing an isotopic approach.We sampled and isotopically analyzed(δ^(13)C andδ^(15)N values)wing feathers from 58 specimens of granivorous birds collected between 1900 and 1966 in southeastern Brazil.We grouped birds according to the main habitat type used by them(forest:Cyanoloxia brissonii,Leptotila and Leptotila verreauxi;and grassland:Columbina squammata and Sicalis flaveola).We used the Isotopic Richness(IRic)metric to measure the isotopic niche width and the Isotopic Similarity(ISim)and Isotopic Nestedness(INes)metrics to measure the niche overlap between groups and species.The results of low isotopic niche overlap suggest that common granivorous birds had a clear niche partitioning in southeastern Brazil in the late past,especially through foraging in distinct habitat types(forest and grassland;ISim=0.1,INes=0.2).Niche overlaps in almost all species-by-species comparisons were low(ISim≤0.3,INes≤0.4),except between C.brissonii and L.verreauxi(ISim=0.6,INes=1.0).These results suggest that these birds,belonging to the same trophic guild,coexisted through niche and resource partitioning.Despite being considered a plastic trophic guild,the isotopic niche partitioning among granivorous birds indicates that each of these species uses a set of specific resources and habitats.This raises an ecological concern about the homogenization of landscapes across the Neotropics,oversimplifying food resources and habitats to granivorous birds.展开更多
Background:Mixed-species flocks(MSFs)have been well sampled in the South Asia,but there has been as yet surprisingly little work on MSFs of Nepal,despite a diverse and well-studied avifauna.We surveyed MSFs in two for...Background:Mixed-species flocks(MSFs)have been well sampled in the South Asia,but there has been as yet surprisingly little work on MSFs of Nepal,despite a diverse and well-studied avifauna.We surveyed MSFs in two forest types in and around the Important Bird Area of Chitwan National Park in Nepal,between 150 and 800 m a.s.l.,to provide a first description of the composition of MSFs in this area.We also aimed to understand which species should be considered‘nuclear species',important to forming MSFs or leading them forward.Results:In total,we collected records on 222 MSFs that included 100 species,and 6097 individuals.The MSFs were similar to worldwide patterns in being dominated by leaf-gleaning,non-terrestrial insectivores.However,the MSFs were more dominated by canopy species than usual,and did not have a clear gregarious,understory leading species.Rather drongos(Family Dicruridae)and minivets(Family Campephagidae,Genus Pericrocotus)acted as leaders,and a cluster analysis of composition showed one group of large body size MSFs particularly characterized by the presence of the Greater Racket-tailed Drongo(Dicrurus paradiseus).Conclusions:Drongos are known to provide both costs and benefits to other flock participants:they are aggressive birds that can steal food,and manipulate other species with their vocalizations,but at the same time they are‘sentinel species'that produce information about predation risk other species can use.This study demonstrates that drongos can be considered nuclear species for some types of MSFs,despite the potential costs of their presence.MSFs led by sentinel species thus may form in Asia,as well as in the Neotropics.展开更多
Aims The aim of this article is 3-fold.First,we present an updated version of a published megaphylogeny of vascular plants that can be used in studies of plant ecology and biogeography.second,we develop a tool that ca...Aims The aim of this article is 3-fold.First,we present an updated version of a published megaphylogeny of vascular plants that can be used in studies of plant ecology and biogeography.second,we develop a tool that can be used by botanists and plant ecologists to generate phylogenetic hypotheses in three scenarios.Third,we use a set of regional assemblages of angiosperm trees in North america as a model system to evaluate the effect of differences in phylogenies generated using the three scenarios on the quantification of phylogenetic properties and the relationship between measures of phylogenetic properties and environment.Methods The taxonomy and nomenclature of plant species in the megaphy-logeny were standardized according to The Plant list(version 1.1).a tool for generating phylogenies was created using the r language.The robustness of derived phylogenies was evaluated using correlation and regression analyses.Important Findingsan updated megaphylogeny of vascular plants(PhytoPhylo)and a tool for reconstructing phylogenies of seed plants(s.Phylomaker)were generated.our study shows that phylogenies generated by s.Phylomaker using the PhytoPhylo megaphylogeny as a backbone are nearly as good as phylogeny resolved at the species level when using derived phylogenies to quantify phylogenetic properties(e.g.phylogenetic diversity and phylogenetic relatedness)of biological assemblages,and that s.Phylomaker-generated phylogenies are robust for studies of community ecology and biogeography,par-ticularly those seeking for patterns of phylogenetic properties along environmental gradients.展开更多
Aims Our aims were 3-fold:(i)to determine whether global change has altered the composition and structure of the plant community found in the sessile oak forests on the NE Iberian Peninsula over the last decades,(ii)t...Aims Our aims were 3-fold:(i)to determine whether global change has altered the composition and structure of the plant community found in the sessile oak forests on the NE Iberian Peninsula over the last decades,(ii)to establish whether the decline in forest exploitation activities that has taken place since the mid-20th century has had any effect on the forests and(iii)to ascertain whether there is any evidence of impact from climate warming.Methods We assess changes in the plant community by comparing a cur-rent survey of sessile oak forest with a historical data set obtained from previous regional studies dating from 1962 to 1977.We ana-lyse the regional changes in the community in terms of biodiversity variables,species composition and plant traits.Furthermore,plants traits such as plant life forms and chorological groups are used to discern any effects from land-use changes and climate warming on the plant community.Important Findingsthere has been a loss of diversity in the community and,in the hottest region,there is also a loss of species richness.the composition of the community suggests that,although significant changes have taken place over recent decades,these changes differ between regions as a result of the low impact global change has had in the western regions.For instance,while the tree canopy cover in the western sessile oak forests remains stable,the eastern sessile oak forests are still recovering from the former exploitation that led to a loss of their rich and abundant herbaceous stratum.In fact,the recovery process in the catalan Pre-coastal Range has constituted an increase in the Euro-Siberian plants typical to this community.Moreover,in the eastern forests,there is evidence that climate warming has impacted the thermophilization of the sessile oak forests found on the coastal Range.展开更多
As one of the last remaining naturally grazed ecosystems on Earth,the Serengeti National Park is an ideal location to study the influence of migratory mammals on the structure of microbial communities and the factors ...As one of the last remaining naturally grazed ecosystems on Earth,the Serengeti National Park is an ideal location to study the influence of migratory mammals on the structure of microbial communities and the factors that generate biogeography of soil microbes.Furthermore,volcanic inputs generate environmental gradients that may also structure microbial communities.We studied 16S rRNA amplicons in a 13-year herbivore removal experiment to examine the influence of grazing and environmental gradients on the natural distribution of soil microbes.Removal of mammalian herbivores shifted microbial community structure,with 31 taxa that were significant indicator taxa of the ungrazed treatment and three taxa that were indicators of the grazed treatment.The abundance of many taxa were correlated with soil texture,phosphorus,iron,calcium and rainfall,and the evenness of taxa within samples was also correlated with these variables.Bayesian general linear mixed effects models with single predictors of multiple,highly correlated variables of beta diversity were consistent with a significant,but weak(2%),effect of grazing,and stronger effects of phosphorus(14%).Beta diversity of microbial communities was greater in grazed than in ungrazed plots;suggesting that the impacts of grazing on community assembly of microbes results from deterministic environmental filtering caused by the influence of herbivores on plant communities and soil properties rather than stochastic dispersal via herds of large mammals.These herbivore effects are superimposed on deterministic environmental filtering by natural soil and precipitation gradients across the Serengeti.展开更多
Aims Conduct a quantitative,but rapid,regional-level assessment of the alpine flora across northwest Yunnan(NWY)to provide a broadbased understanding of local and regional patterns of the composition,diversity and hea...Aims Conduct a quantitative,but rapid,regional-level assessment of the alpine flora across northwest Yunnan(NWY)to provide a broadbased understanding of local and regional patterns of the composition,diversity and health of alpine ecosystems across NWY.Methods A stratified random sampling design was employed to select sites across the different mountain ranges of NWY.Vegetation was sampled by stratifying each site by the three major alpine vegetation community types:meadow,dwarf shrub and scree.Two 50-m transects were randomly located within each community type at each sampling site with 101-m^(2) subplots systematically placed along each transect.Environmental variables were recorded at each transect.Multivariate analyses were used to classify the major plant community assemblages and link community patterns to environmental and habitat variables.Important Findings Forb species richness varied from 19 to 105 species per site(21 sites total)with an average of 59 species per site(60 m^(2) sampled per site).Most species were patchily distributed with narrow distributions and/or small population sizes;over half the species occurred at only one or two sites.Distinct species assemblages were identified in the meadow vegetation that was strongly aggregated by geographic location suggesting the presence of distinct phytogeographic zones of the meadow alpine flora.Elevation and geographic location were the dominant environmental gradients underlying the variations in species composition.Jaccard’s coefficient of similarity averaged only 10%among sites indicating there was little similarity in the alpine flora across the region.The alpine vegetation is highly heterogeneous across the complex landscape of the Hengduan Mountains of NWY.Conservation strategies need to take into account the large geographic differences in the flora to maximize protection of biodiversity.展开更多
The global decline of freshwater biodiversity caused by climate change and human activities are supposed to disrupt ecosystem services related to water quality and alter the structure and function of aquatic communiti...The global decline of freshwater biodiversity caused by climate change and human activities are supposed to disrupt ecosystem services related to water quality and alter the structure and function of aquatic communities across space and time,yet the effects of the combination of these factors on plankton community ecosystem has received relatively little attention.This study aimed to explore the impacts of disturbances(e.g.human activity,temperature,precipitation,and water level)on phytoplankton community structure(i.e.community evenness and community composition)and function(i.e.resource use efficiency)in four subtropical reservoirs over 7 years from 2010 to 2016.Our results showed that community turnover(measured as community dissimilarity)was positively related to disturbance frequency,but no significant correlation was found between phytoplankton biodiversity(i.e.evenness)and disturbance frequency.Phytoplankton resource use efficiency(RUE=phytoplankton biomass/total phosphorus)was increased with a higher frequency of disturbance with an exception of cyanobacteria.The RUE of Cyanobacteria and diatoms showed significantly negative correlations with their community evenness,while the RUE of Chlorophyta exhibited a positive correlation with their community turnover.We suggest that multiple environmental disturbances may play crucial roles in shaping the structure and functioning of plankton communities in subtropical reservoirs,and mechanism of this process can provide key information for freshwater uses,management and conservation.展开更多
The cryptic lifestyle of most fungi necessitates molecular identification of the guild in environmental studies.Over the past decades,rapid development and affordability of molecular tools have tremendously improved i...The cryptic lifestyle of most fungi necessitates molecular identification of the guild in environmental studies.Over the past decades,rapid development and affordability of molecular tools have tremendously improved insights of the fungal diversity in all ecosystems and habitats.Yet,in spite of the progress of molecular methods,knowledge about functional properties of the fungal taxa is vague and interpretation of environmental studies in an ecologically meaningful manner remains challenging.In order to facilitate functional assignments and ecological interpretation of environmental studies we introduce a user friendly traits and character database FungalTraits operating at genus and species hypothesis levels.Combining the information from previous efforts such as FUNGuild and FunFun together with involvement of expert knowledge,we reannotated 10,210 and 151 fungal and Stramenopila genera,respectively.This resulted in a stand-alone spreadsheet dataset covering 17 lifestyle related traits of fungal and Stramenopila genera,designed for rapid functional assignments of environmental stud-ies.In order to assign the trait states to fungal species hypotheses,the scientific community of experts manually categorised and assigned available trait information to 697,413 fungal ITS sequences.On the basis of those sequences we were able to summarise trait and host information into 92,623 fungal species hypotheses at 1%dissimilarity threshold.展开更多
Aims In arid communities,it has been proposed that individual plants can extend their roots beyond their canopy exploring neighbour-ing bare ground areas.This becomes relevant in systems where the vegetation is distri...Aims In arid communities,it has been proposed that individual plants can extend their roots beyond their canopy exploring neighbour-ing bare ground areas.This becomes relevant in systems where the vegetation is distributed in patches surrounded by bare soil.However,whether roots of different species may be overlapping under bare ground areas is still controversial.The factors control-ling root responses when no plants appear to be directly influ-encing the gap among patches are still unclear.The aim of our study was to detect perennial grasses responses to an N enrich-ment pulse.Methods In a semi-arid steppe(Patagonia,Argentina),we buried root traps filled with sieved soil with and without N addition,under bare soil patches.Traps were harvested after 4 and 6 months.Trap neighbour-hoods(30 cm in diameter)included at least three of the dominant tussock species.After harvests,we identified species in the traps by root traits and quantified diversity,biomass and specific relative growth rates.Important Findings Bare ground areas show simultaneous root growth of different spe-cies.Diversity of perennial grass roots was higher with N addition than without it in the first harvest(4 months),but this difference disappeared in the second harvest(6 months).Root biomass was maximal after 6 months in N addition traps.Species preferred by herbivores(Bromus pictus and Poa ligularis)showed rapid growth and responses to N addition.Differences between harvests may be an indicative that N pulses interact with rising temperatures and soil water content as growing season progress.展开更多
The assemblages of myxomycetes associated with the three types of temperate grasslands(tall grass,mixed grass and short grass)found across the western central United States were examined by collecting samples for isol...The assemblages of myxomycetes associated with the three types of temperate grasslands(tall grass,mixed grass and short grass)found across the western central United States were examined by collecting samples for isolation of these organisms from nine study sites.Samples consisted of two types of ground litter,two types of aerial litter(dead but still attached plant parts)and dung.These were brought back to the laboratory and used to prepare a series of moist chamber cultures.These cultures yielded 1,301 collections of myxomycetes representing 59 species in 18 genera.Some collections could be identified only to genus and one in particular(Lepidoderma sp.)appears to be an undescribed taxon.Physarum spectabile was recorded for the first time in North America.Overall,only eight species(Badhamia melanospora,Didymium anellus,D.difforme,D.squamulosum,Perichaena depressa,Physarum cinereum,P.pusillum,and Stemonitis fusca)were recovered from all nine study sites and thus are considered to represent a core component of the myxomycete biota of temperate grasslands.展开更多
The ecosystem of the Three Gorges in the Yangtze River was changed into an artificial lake(reservoir)ecosystem after impoundment in June 2003.We surveyed the seasonal variation and spatial distribution of copepods fro...The ecosystem of the Three Gorges in the Yangtze River was changed into an artificial lake(reservoir)ecosystem after impoundment in June 2003.We surveyed the seasonal variation and spatial distribution of copepods from April 2004 to January 2005 in order to provide data for clarifying the successional pattern of the ecosystem.From Jiangjin to Maoping,eight copepod species were collected and classified into Calanoida(2),Harpacticoida(1),and Cyclopoida(5).Among them,Mesocyclops pehpeiensis,M.leuckarti and Sinocalanus dorrii had a relatively wide distribution.No distinct difference in species number was found among the sampling sites,but the species composition was different.Species composition,distribution and density of copepods showed significant seasonal variations.In addition,copepod density showed an obvious gradient with the distance from the reservoir dam:the nearer to the dam,the denser the copepods.展开更多
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.
文摘The original version of this article contains a mistake in font setting on p.350. The last part of Table 3 note, i.e. 'biomass…molluscs (Liang et al., 1995)' should belong to the paper body. Therefore, the last sentence
基金supported by the 2016 Special Scientific Research Project of Shaanxi Education Department(Grant No.16JK2129)
文摘The new urbanization is an important carrier of ecological civilization construction, and ecological old-age care is the concrete manifestation of the perfect combination of the two, the proper meaning of the new urbanization connotation and an inevitable trend of its development. Based on the analysis of the connotation and relationship between the new urbanization and ecological old-age care, together with the current situation and existing problems of the current nursing institutions and ecological old-age care in Xi'an area, this paper discusses the major issues that should be noticed when constructing the ecological old-age care community in Xi'an and three main construction modes.
基金supported by the Sāo Paulo Research Foundation(FAPESP)postdoctoral fellowship grants 2018-05970-1 and 2019-11901-5。
文摘Niche partitioning is a widespread ecological strategy within trophic guilds,ensuring the coexistence of sympatric species by reducing interspecific competition.Stable isotope analysis of carbon and nitrogen and isotopic niche metrics(width and overlap)are used as a proxy to investigate niche partitioning among species of a guild.In our study,we investigated if niche partitioning was an ecological mechanism contributing to the coexistence of granivorous birds from the same geographic region along time,employing an isotopic approach.We sampled and isotopically analyzed(δ^(13)C andδ^(15)N values)wing feathers from 58 specimens of granivorous birds collected between 1900 and 1966 in southeastern Brazil.We grouped birds according to the main habitat type used by them(forest:Cyanoloxia brissonii,Leptotila and Leptotila verreauxi;and grassland:Columbina squammata and Sicalis flaveola).We used the Isotopic Richness(IRic)metric to measure the isotopic niche width and the Isotopic Similarity(ISim)and Isotopic Nestedness(INes)metrics to measure the niche overlap between groups and species.The results of low isotopic niche overlap suggest that common granivorous birds had a clear niche partitioning in southeastern Brazil in the late past,especially through foraging in distinct habitat types(forest and grassland;ISim=0.1,INes=0.2).Niche overlaps in almost all species-by-species comparisons were low(ISim≤0.3,INes≤0.4),except between C.brissonii and L.verreauxi(ISim=0.6,INes=1.0).These results suggest that these birds,belonging to the same trophic guild,coexisted through niche and resource partitioning.Despite being considered a plastic trophic guild,the isotopic niche partitioning among granivorous birds indicates that each of these species uses a set of specific resources and habitats.This raises an ecological concern about the homogenization of landscapes across the Neotropics,oversimplifying food resources and habitats to granivorous birds.
基金supported by a Special Talent Recruitment grant from Guangxi University to EGa Chinese Government Scholarship to KRG。
文摘Background:Mixed-species flocks(MSFs)have been well sampled in the South Asia,but there has been as yet surprisingly little work on MSFs of Nepal,despite a diverse and well-studied avifauna.We surveyed MSFs in two forest types in and around the Important Bird Area of Chitwan National Park in Nepal,between 150 and 800 m a.s.l.,to provide a first description of the composition of MSFs in this area.We also aimed to understand which species should be considered‘nuclear species',important to forming MSFs or leading them forward.Results:In total,we collected records on 222 MSFs that included 100 species,and 6097 individuals.The MSFs were similar to worldwide patterns in being dominated by leaf-gleaning,non-terrestrial insectivores.However,the MSFs were more dominated by canopy species than usual,and did not have a clear gregarious,understory leading species.Rather drongos(Family Dicruridae)and minivets(Family Campephagidae,Genus Pericrocotus)acted as leaders,and a cluster analysis of composition showed one group of large body size MSFs particularly characterized by the presence of the Greater Racket-tailed Drongo(Dicrurus paradiseus).Conclusions:Drongos are known to provide both costs and benefits to other flock participants:they are aggressive birds that can steal food,and manipulate other species with their vocalizations,but at the same time they are‘sentinel species'that produce information about predation risk other species can use.This study demonstrates that drongos can be considered nuclear species for some types of MSFs,despite the potential costs of their presence.MSFs led by sentinel species thus may form in Asia,as well as in the Neotropics.
文摘Aims The aim of this article is 3-fold.First,we present an updated version of a published megaphylogeny of vascular plants that can be used in studies of plant ecology and biogeography.second,we develop a tool that can be used by botanists and plant ecologists to generate phylogenetic hypotheses in three scenarios.Third,we use a set of regional assemblages of angiosperm trees in North america as a model system to evaluate the effect of differences in phylogenies generated using the three scenarios on the quantification of phylogenetic properties and the relationship between measures of phylogenetic properties and environment.Methods The taxonomy and nomenclature of plant species in the megaphy-logeny were standardized according to The Plant list(version 1.1).a tool for generating phylogenies was created using the r language.The robustness of derived phylogenies was evaluated using correlation and regression analyses.Important Findingsan updated megaphylogeny of vascular plants(PhytoPhylo)and a tool for reconstructing phylogenies of seed plants(s.Phylomaker)were generated.our study shows that phylogenies generated by s.Phylomaker using the PhytoPhylo megaphylogeny as a backbone are nearly as good as phylogeny resolved at the species level when using derived phylogenies to quantify phylogenetic properties(e.g.phylogenetic diversity and phylogenetic relatedness)of biological assemblages,and that s.Phylomaker-generated phylogenies are robust for studies of community ecology and biogeography,par-ticularly those seeking for patterns of phylogenetic properties along environmental gradients.
文摘Aims Our aims were 3-fold:(i)to determine whether global change has altered the composition and structure of the plant community found in the sessile oak forests on the NE Iberian Peninsula over the last decades,(ii)to establish whether the decline in forest exploitation activities that has taken place since the mid-20th century has had any effect on the forests and(iii)to ascertain whether there is any evidence of impact from climate warming.Methods We assess changes in the plant community by comparing a cur-rent survey of sessile oak forest with a historical data set obtained from previous regional studies dating from 1962 to 1977.We ana-lyse the regional changes in the community in terms of biodiversity variables,species composition and plant traits.Furthermore,plants traits such as plant life forms and chorological groups are used to discern any effects from land-use changes and climate warming on the plant community.Important Findingsthere has been a loss of diversity in the community and,in the hottest region,there is also a loss of species richness.the composition of the community suggests that,although significant changes have taken place over recent decades,these changes differ between regions as a result of the low impact global change has had in the western regions.For instance,while the tree canopy cover in the western sessile oak forests remains stable,the eastern sessile oak forests are still recovering from the former exploitation that led to a loss of their rich and abundant herbaceous stratum.In fact,the recovery process in the catalan Pre-coastal Range has constituted an increase in the Euro-Siberian plants typical to this community.Moreover,in the eastern forests,there is evidence that climate warming has impacted the thermophilization of the sessile oak forests found on the coastal Range.
文摘As one of the last remaining naturally grazed ecosystems on Earth,the Serengeti National Park is an ideal location to study the influence of migratory mammals on the structure of microbial communities and the factors that generate biogeography of soil microbes.Furthermore,volcanic inputs generate environmental gradients that may also structure microbial communities.We studied 16S rRNA amplicons in a 13-year herbivore removal experiment to examine the influence of grazing and environmental gradients on the natural distribution of soil microbes.Removal of mammalian herbivores shifted microbial community structure,with 31 taxa that were significant indicator taxa of the ungrazed treatment and three taxa that were indicators of the grazed treatment.The abundance of many taxa were correlated with soil texture,phosphorus,iron,calcium and rainfall,and the evenness of taxa within samples was also correlated with these variables.Bayesian general linear mixed effects models with single predictors of multiple,highly correlated variables of beta diversity were consistent with a significant,but weak(2%),effect of grazing,and stronger effects of phosphorus(14%).Beta diversity of microbial communities was greater in grazed than in ungrazed plots;suggesting that the impacts of grazing on community assembly of microbes results from deterministic environmental filtering caused by the influence of herbivores on plant communities and soil properties rather than stochastic dispersal via herds of large mammals.These herbivore effects are superimposed on deterministic environmental filtering by natural soil and precipitation gradients across the Serengeti.
文摘Aims Conduct a quantitative,but rapid,regional-level assessment of the alpine flora across northwest Yunnan(NWY)to provide a broadbased understanding of local and regional patterns of the composition,diversity and health of alpine ecosystems across NWY.Methods A stratified random sampling design was employed to select sites across the different mountain ranges of NWY.Vegetation was sampled by stratifying each site by the three major alpine vegetation community types:meadow,dwarf shrub and scree.Two 50-m transects were randomly located within each community type at each sampling site with 101-m^(2) subplots systematically placed along each transect.Environmental variables were recorded at each transect.Multivariate analyses were used to classify the major plant community assemblages and link community patterns to environmental and habitat variables.Important Findings Forb species richness varied from 19 to 105 species per site(21 sites total)with an average of 59 species per site(60 m^(2) sampled per site).Most species were patchily distributed with narrow distributions and/or small population sizes;over half the species occurred at only one or two sites.Distinct species assemblages were identified in the meadow vegetation that was strongly aggregated by geographic location suggesting the presence of distinct phytogeographic zones of the meadow alpine flora.Elevation and geographic location were the dominant environmental gradients underlying the variations in species composition.Jaccard’s coefficient of similarity averaged only 10%among sites indicating there was little similarity in the alpine flora across the region.The alpine vegetation is highly heterogeneous across the complex landscape of the Hengduan Mountains of NWY.Conservation strategies need to take into account the large geographic differences in the flora to maximize protection of biodiversity.
基金the National Natural Science Foundation of China(Nos.91851104,41703074 and 41901135)the National Key Research and Development Program of China(No.2017YFA0605203)the Natural Science Foundation of Fujian Province of China(No.2019J02016)。
文摘The global decline of freshwater biodiversity caused by climate change and human activities are supposed to disrupt ecosystem services related to water quality and alter the structure and function of aquatic communities across space and time,yet the effects of the combination of these factors on plankton community ecosystem has received relatively little attention.This study aimed to explore the impacts of disturbances(e.g.human activity,temperature,precipitation,and water level)on phytoplankton community structure(i.e.community evenness and community composition)and function(i.e.resource use efficiency)in four subtropical reservoirs over 7 years from 2010 to 2016.Our results showed that community turnover(measured as community dissimilarity)was positively related to disturbance frequency,but no significant correlation was found between phytoplankton biodiversity(i.e.evenness)and disturbance frequency.Phytoplankton resource use efficiency(RUE=phytoplankton biomass/total phosphorus)was increased with a higher frequency of disturbance with an exception of cyanobacteria.The RUE of Cyanobacteria and diatoms showed significantly negative correlations with their community evenness,while the RUE of Chlorophyta exhibited a positive correlation with their community turnover.We suggest that multiple environmental disturbances may play crucial roles in shaping the structure and functioning of plankton communities in subtropical reservoirs,and mechanism of this process can provide key information for freshwater uses,management and conservation.
基金Estonian Science Foundation grants PSG136,PRG632,PUT1170the University of Tartu(PLTOM20903)the European Regional Development Fund(Centre of Excellence EcolChange).
文摘The cryptic lifestyle of most fungi necessitates molecular identification of the guild in environmental studies.Over the past decades,rapid development and affordability of molecular tools have tremendously improved insights of the fungal diversity in all ecosystems and habitats.Yet,in spite of the progress of molecular methods,knowledge about functional properties of the fungal taxa is vague and interpretation of environmental studies in an ecologically meaningful manner remains challenging.In order to facilitate functional assignments and ecological interpretation of environmental studies we introduce a user friendly traits and character database FungalTraits operating at genus and species hypothesis levels.Combining the information from previous efforts such as FUNGuild and FunFun together with involvement of expert knowledge,we reannotated 10,210 and 151 fungal and Stramenopila genera,respectively.This resulted in a stand-alone spreadsheet dataset covering 17 lifestyle related traits of fungal and Stramenopila genera,designed for rapid functional assignments of environmental stud-ies.In order to assign the trait states to fungal species hypotheses,the scientific community of experts manually categorised and assigned available trait information to 697,413 fungal ITS sequences.On the basis of those sequences we were able to summarise trait and host information into 92,623 fungal species hypotheses at 1%dissimilarity threshold.
基金Funding was provided by grants from FONCyT(PICT 00462)Universidad de Buenos Aires Ciencia y Técnica(UBACyT G0032)to MR Aguiar.
文摘Aims In arid communities,it has been proposed that individual plants can extend their roots beyond their canopy exploring neighbour-ing bare ground areas.This becomes relevant in systems where the vegetation is distributed in patches surrounded by bare soil.However,whether roots of different species may be overlapping under bare ground areas is still controversial.The factors control-ling root responses when no plants appear to be directly influ-encing the gap among patches are still unclear.The aim of our study was to detect perennial grasses responses to an N enrich-ment pulse.Methods In a semi-arid steppe(Patagonia,Argentina),we buried root traps filled with sieved soil with and without N addition,under bare soil patches.Traps were harvested after 4 and 6 months.Trap neighbour-hoods(30 cm in diameter)included at least three of the dominant tussock species.After harvests,we identified species in the traps by root traits and quantified diversity,biomass and specific relative growth rates.Important Findings Bare ground areas show simultaneous root growth of different spe-cies.Diversity of perennial grass roots was higher with N addition than without it in the first harvest(4 months),but this difference disappeared in the second harvest(6 months).Root biomass was maximal after 6 months in N addition traps.Species preferred by herbivores(Bromus pictus and Poa ligularis)showed rapid growth and responses to N addition.Differences between harvests may be an indicative that N pulses interact with rising temperatures and soil water content as growing season progress.
基金supported in part by grants from the National Science Foundation,the Prairie Biotic Research Inc.and the Wyoming Native Plant Society.
文摘The assemblages of myxomycetes associated with the three types of temperate grasslands(tall grass,mixed grass and short grass)found across the western central United States were examined by collecting samples for isolation of these organisms from nine study sites.Samples consisted of two types of ground litter,two types of aerial litter(dead but still attached plant parts)and dung.These were brought back to the laboratory and used to prepare a series of moist chamber cultures.These cultures yielded 1,301 collections of myxomycetes representing 59 species in 18 genera.Some collections could be identified only to genus and one in particular(Lepidoderma sp.)appears to be an undescribed taxon.Physarum spectabile was recorded for the first time in North America.Overall,only eight species(Badhamia melanospora,Didymium anellus,D.difforme,D.squamulosum,Perichaena depressa,Physarum cinereum,P.pusillum,and Stemonitis fusca)were recovered from all nine study sites and thus are considered to represent a core component of the myxomycete biota of temperate grasslands.
文摘The ecosystem of the Three Gorges in the Yangtze River was changed into an artificial lake(reservoir)ecosystem after impoundment in June 2003.We surveyed the seasonal variation and spatial distribution of copepods from April 2004 to January 2005 in order to provide data for clarifying the successional pattern of the ecosystem.From Jiangjin to Maoping,eight copepod species were collected and classified into Calanoida(2),Harpacticoida(1),and Cyclopoida(5).Among them,Mesocyclops pehpeiensis,M.leuckarti and Sinocalanus dorrii had a relatively wide distribution.No distinct difference in species number was found among the sampling sites,but the species composition was different.Species composition,distribution and density of copepods showed significant seasonal variations.In addition,copepod density showed an obvious gradient with the distance from the reservoir dam:the nearer to the dam,the denser the copepods.
