As early as 1874, the French scientist P^re A. David introduced to science a new bird species, Trochalopteron milnei, described as： ＂Ressemblant au T.formosum du Setchouan, mais ayant le dessus de la tete couleur de...As early as 1874, the French scientist P^re A. David introduced to science a new bird species, Trochalopteron milnei, described as： ＂Ressemblant au T.formosum du Setchouan, mais ayant le dessus de la tete couleur de cannelle ou d＇amadou, et la r6gion parotique blanche＂ （David, 1874）. The bird skin that P^re David collected, and so far deposited in Museum National d＇Histoire Naturelle in Paris, was from ＂Koaten of W Fo-kien＂, in the current Chinese romanization system, Koaten is spelt as Guadun and Fo-kien spelt as Fujian.展开更多
A universal method of molecular dating that can be applied to all families and genera regardless of their fossil records, or lack thereof, is highly desirable. A possible method for eudicots is to use a large phylogen...A universal method of molecular dating that can be applied to all families and genera regardless of their fossil records, or lack thereof, is highly desirable. A possible method for eudicots is to use a large phylogeny calibrated using deep fossils including tricolpate pollen as a fixed （124 mya） calibration point. This method was used to calculate node ages within three species-poor disjunct basal eudicot genera, Caulophyllum, Podophyllum and Pachysandra, and sensitivity of these ages to effects such as taxon sampling were then quantified. By deleting from one to three accessions related to each genus in 112 different combinations, a confidence range describing variation due only to taxon sampling was generated. Ranges for Caulophyllum, Podophyllum and Pachysandra were 8.4-10.6, 7.6-20.0, and 17.6-25.0 mya, respectively. However, the confidence ranges calculated using bootstrapping were much wider, at 3-19, 0-32 and 11-32 mya, respectively. Furthermore, deleting 10 adjacent taxa had a large effect in Pachysandra only, indicating that undersampling effects are significant among Buxales. Changes to sampling density in neighboring clades, or to the position of the fixed fossil calibration point had small to negligible effects. Non-parametric rate smoothing was more sensitive to taxon sampling effects than was penalized likelihood. The wide range for Podophyllum, compared to the other two genera, was probably due to a high degree of rate heterogeneity within this genus. Confidence ranges calculated by this method could be narrowed by sampling more individuals within the genus of interest, and by sequencing multiple DNA regions from all species in the phylogeny.展开更多
The phylogenetic relationships of species are fundamental to any biological investigation, including all evolutionary studies. Accurate inferences of sister group relationships provide the researcher with an historica...The phylogenetic relationships of species are fundamental to any biological investigation, including all evolutionary studies. Accurate inferences of sister group relationships provide the researcher with an historical framework within which the attributes or geographic origin of species (or supraspecific groups) evolved. Taken out of this phylogenetic context, interpretations of evolutionary processes or origins, geographic distributions, or speciation rates and mechanisms, are subject to nothing less than a biological experiment without controls. Cypriniformes is the most diverse clade of freshwater fishes with estimates of diversity of nearly 3,500 species. These fishes display an amazing array of morphological, ecological, behavioral, and geographic diversity and offer a tremendous opportunity to enhance our understanding of the biotic and abiotic factors associated with diversification and adaptation to environments. Given the nearly global distribution of these fishes, they serve as an important model group for a plethora of biological investigations, including indicator species for future cli-matic changes. The occurrence of the zebrafish, Danio rerio, in this order makes this clade a critical component in understanding and predicting the relationship between mutagenesis and phenotypic expressions in vertebrates, including humans. With the tremendous diversity in Cypriniformes, our understanding of their phylogenetic relationships has not proceeded at an acceptable rate, despite a plethora of morphological and more recent mo-lecular studies. Most studies are pre-Hennigian in origin or include relatively small numbers of taxa. Given that analyses of small numbers of taxa for molecular characters can be compromised by peculiarities of long-branch attraction and nodal-density effect, it is critical that significant progress in our understanding of the relationships of these important fishes occurs with increasing sampling of species to mitigate these potential problems. The recent Cypriniformes Tree of Life initiative is an effort to achieve this goal with morphological and molecular (mitochondrial and nuclear) data. In this early synthesis of our understanding of the phylogenetic relationships of these fishes, all types of data have contributed historically to improving our understanding, but not all analyses are complementary in taxon sampling, thus precluding direct understanding of the impact of taxon sampling on achieving accurate phylogenetic inferences. However, recent molecular studies do provide some insight and in some instances taxon sampling can be implicated as a variable that can influence sister group relationships. Other instances may also exist but without inclusion of more taxa for both mitochondrial and nuclear genes, one cannot distinguish between inferences being dictated by taxon sampling or the origins of the molecular data.展开更多
Appropriate and extensive taxon sampling is one of the most important determinants of accurate phylogenetic estimation. In addition, accuracy of inferences about evolutionary processes obtained from phyloge-netic anal...Appropriate and extensive taxon sampling is one of the most important determinants of accurate phylogenetic estimation. In addition, accuracy of inferences about evolutionary processes obtained from phyloge-netic analyses is improved significantly by thorough taxon sampling efforts. Many recent efforts to improve phylogenetic estimates have focused instead on increasing sequence length or the number of overall characters in the analysis, and this often does have a beneficial effect on the accuracy of phylogenetic analyses. However, phylogenetic analyses of few taxa (but each represented by many characters) can be subject to strong systematic biases, which in turn produce high measures of repeatability (such as bootstrap proportions) in support of incor-rect or misleading phylogenetic results. Thus, it is important for phylogeneticists to consider both the sampling of taxa, as well as the sampling of characters, in designing phylogenetic studies. Taxon sampling also improves estimates of evolutionary parameters derived from phylogenetic trees, and is thus important for improved applica-tions of phylogenetic analyses. Analysis of sensitivity to taxon inclusion, the possible effects of long-branch attraction, and sensitivity of parameter estimation for model-based methods should be a part of any careful and thorough phylogenetic analysis. Furthermore, recent improvements in phylogenetic algorithms and in computa-tional power have removed many constraints on analyzing large, thoroughly sampled data sets. Thorough taxon sampling is thus one of the most practical ways to improve the accuracy of phylogenetic estimates, as well as the accuracy of biological inferences that are based on these phylogenetic trees.展开更多
Epimedii Herba is a commonly used traditional Chinese herbal medicine.Five Epimedium species are included in Chinese Pharmacopoeia and most species of Epimedium are used as Epimedii Herba in practical application.Howe...Epimedii Herba is a commonly used traditional Chinese herbal medicine.Five Epimedium species are included in Chinese Pharmacopoeia and most species of Epimedium are used as Epimedii Herba in practical application.However,as the largest herbaceous genus of the Berberidaceae,Epimedium has many taxonomic controversies which hinder the effective use of Epimedii Herba.This paper reviewed the taxonomic research related to Epimedium,including taxonomic history,taxonomic values of morphological characters,species and distribution,infra-genera taxonomic system and the taxonomic research of Chinese Epimedium.For instance,we recognized Epimedium wushanense and clarified that the species,as described in Flora Reipublicae Popularis Sinicae and Flora of China,actually includes four Epimedium species similar in leaflet shape.In general,it was recognized here that Epimedium comprises 62 species,of which 52 species are distributed in China.For Chinese Epimedium species with the most taxonomic problems,the taxonomic research on the taxa was reviewed and the newest species key was proposed along with proposals for those taxonomic problems needing further resolution.This review is of great implication for the identification,exploration and utilization of Epimedii Herba.展开更多
Although soil nematode diversity has been used as an indicator of habitat characteristics and environmental change,the diversity of entire soil nematode communities has not been comprehensively evaluated at different ...Although soil nematode diversity has been used as an indicator of habitat characteristics and environmental change,the diversity of entire soil nematode communities has not been comprehensively evaluated at different taxonomic levels,or for different functional groups,or at a fine taxonomic level within functional groups.In this study,two taxonomic diversity indices,the Shannon-Wiener index(H′)and Simpson index(l),were used to evaluate the following:1)nematode diversity at different taxonomic levels for the whole community,2)nematode diversity of different functional groups,and 3)nematode generic diversity of functional groups in the following four land-use types:forage land,cropland,secondary forest,and grassshrubland.The results showed that significant differences in nematode diversity among landuse types were detected by assessment at the order level but not at the family or genus level.The results also showed that significant differences in nematode diversity were better revealed by assessment of trophic groups rather than cp groups.The generic diversities(H′)of omnivorous nematodes and cp3 nematodes also significantly differed among land-use types.Our results indicate that diversity at a high taxonomic level(i.e.,order)may be a more useful indicator than diversity at a low taxonomic level(i.e.,family or genus)of differences among land-use types.In addition,the functional group diversity(i.e.,trophic group,cp group,and the combination of these two groups)for the whole community and the taxonomic diversity within functional groups were useful indicators of differences among land-use types.展开更多
Microbial communities inhabiting river ecosystems play crucial roles in global biogeochemical cycling and pollution attenuation.Spatial variations in local microbial assemblages are important for detailed understandin...Microbial communities inhabiting river ecosystems play crucial roles in global biogeochemical cycling and pollution attenuation.Spatial variations in local microbial assemblages are important for detailed understanding of community assembly and developing robust biodiversity sampling strategies.Here,we intensely analyzed twenty water samples collected from a one-meter spaced transect from the near-shore to the near-center in the Meramec River in eastern Missouri,USA and examined the microbial community composition with 16S rRNA gene amplicon sequencing.Riverine microbiomes across the transect exhibited extremely high similarity,with Pearson’s correlation coefficients above 0.9 for all pairwise community composition comparisons.However,despite the high similarity,PERMANOVA revealed significant spatial differences between near-shore and nearcenter communities(p=0.001).Sloan’s neutral model simulations revealed that within-transect community composition variation was largely explained by demographic stochasticity(R^(2)=0.89).Despite being primarily explained by neutral processes,LefSe analyses also revealed taxa from ten families of which relative abundances differed directionally from the bank to the river center,indicating an additional role of environmental filtering.Notably,the local variations within a river transect can have profound impacts on the documentation of alpha diversity.Taxon-accumulation curves indicated that even twenty samples did not fully saturate the sampling effort at the genus level,yet four,six and seven samples were able to capture 80%of the phylum-level,family-level,and genus-level diversity,respectively.This study for the first time reveals hyperlocal variations in riverine microbiomes and their assembly mechanisms,demanding attention to more robust sampling strategies for documenting microbial diversity in riverine systems.展开更多
A new monotypic genus in the Boletaceae,Borofutus,typified by B.dhakanus,is described using morphological and molecular evidence.This is a putatively ectomycorrhizal fungus associated with Shorea robusta.Borofutus is ...A new monotypic genus in the Boletaceae,Borofutus,typified by B.dhakanus,is described using morphological and molecular evidence.This is a putatively ectomycorrhizal fungus associated with Shorea robusta.Borofutus is characterized by the combination of the following characters:basidiomata small to medium-sized;pileus grayish brown to cocoa brown;hymenophore subdecurrent,cream then golden brown,with broad,nearly hexagonal pores;basidiospores purple to purplish red in H2O,ornamented with irregular to regular shallow pits;cystidia lageniform,thick-walled.Borofutus is sister to Spongiforma in molecular phylogenetic analyses using DNA nucleotide sequences of single or multiple loci.A description,line drawings,phylogenetic placement and comparison with allied taxa are presented herein.展开更多
The known species in the genus Clemelis Robineau-Desvoidy,1863 from China are reviewed and one new species from Shanxi,C.xuei sp.nov.,is described and illustrated.Clemelis jingentaoi,Zhang&Hao,2019 is a synonym of...The known species in the genus Clemelis Robineau-Desvoidy,1863 from China are reviewed and one new species from Shanxi,C.xuei sp.nov.,is described and illustrated.Clemelis jingentaoi,Zhang&Hao,2019 is a synonym of Austrophorocera hirsute(Mesnil,1946),syn.nov.A key to the two Chinese species is provided.展开更多
Ammonia-oxidizing archaea(AOA)are important in converting ammonia into nitrate in soils.While many aspects of their community structure have been studied,the relative importance of stochastic versus deterministic proc...Ammonia-oxidizing archaea(AOA)are important in converting ammonia into nitrate in soils.While many aspects of their community structure have been studied,the relative importance of stochastic versus deterministic processes has poorly been understood.We compared AOA communities across the North China Plain,targeting the amoA gene.A phylogenetic null modelling approach was used to calculate the beta nearest taxon index to quantify the influence of stochastic and deterministic processes.We found that spatial distance between samples predicted the perceived processes involved in community structuring,with stochastic processes dominating at local scales.At greater distances,stochasticity became weaker.However,soil pH,which was also the strongest determinant of AOA community,was a much stronger predictor of community structuring,leaving the distance effect redundant as an explanation of community structuring processes.The communities of AOA differing by less than 1 pH unit differed mainly stochastically in terms of operational taxonomic unit composition.At larger pH differences,deterministic processes based on heterogeneous selection between clades became increasingly dominant.It appears that AOA community composition is largely determined by the environment.However,very similar pH environments are the exception.In environments with very close pH values,stochastic effects dominantly cause differences in community composition,whether spatially near or far.展开更多
A new species of Gesneriaceae,Primulina titan,is described and photographed from northern Guangxi,China.It resembles P.hunanensis,but can be distinguished by combined morphological characters of leaf,bract,corolla,sta...A new species of Gesneriaceae,Primulina titan,is described and photographed from northern Guangxi,China.It resembles P.hunanensis,but can be distinguished by combined morphological characters of leaf,bract,corolla,stamen and pistil.We found only one population with approx.800 mature individuals at the type locality.This species is provisionally assessed as vulnerable[VU D1]using IUCN criteria.展开更多
文摘As early as 1874, the French scientist P^re A. David introduced to science a new bird species, Trochalopteron milnei, described as： ＂Ressemblant au T.formosum du Setchouan, mais ayant le dessus de la tete couleur de cannelle ou d＇amadou, et la r6gion parotique blanche＂ （David, 1874）. The bird skin that P^re David collected, and so far deposited in Museum National d＇Histoire Naturelle in Paris, was from ＂Koaten of W Fo-kien＂, in the current Chinese romanization system, Koaten is spelt as Guadun and Fo-kien spelt as Fujian.
基金NERC (fellowship NE/B500658/1) for the financial support that made this work possible
文摘A universal method of molecular dating that can be applied to all families and genera regardless of their fossil records, or lack thereof, is highly desirable. A possible method for eudicots is to use a large phylogeny calibrated using deep fossils including tricolpate pollen as a fixed （124 mya） calibration point. This method was used to calculate node ages within three species-poor disjunct basal eudicot genera, Caulophyllum, Podophyllum and Pachysandra, and sensitivity of these ages to effects such as taxon sampling were then quantified. By deleting from one to three accessions related to each genus in 112 different combinations, a confidence range describing variation due only to taxon sampling was generated. Ranges for Caulophyllum, Podophyllum and Pachysandra were 8.4-10.6, 7.6-20.0, and 17.6-25.0 mya, respectively. However, the confidence ranges calculated using bootstrapping were much wider, at 3-19, 0-32 and 11-32 mya, respectively. Furthermore, deleting 10 adjacent taxa had a large effect in Pachysandra only, indicating that undersampling effects are significant among Buxales. Changes to sampling density in neighboring clades, or to the position of the fixed fossil calibration point had small to negligible effects. Non-parametric rate smoothing was more sensitive to taxon sampling effects than was penalized likelihood. The wide range for Podophyllum, compared to the other two genera, was probably due to a high degree of rate heterogeneity within this genus. Confidence ranges calculated by this method could be narrowed by sampling more individuals within the genus of interest, and by sequencing multiple DNA regions from all species in the phylogeny.
文摘The phylogenetic relationships of species are fundamental to any biological investigation, including all evolutionary studies. Accurate inferences of sister group relationships provide the researcher with an historical framework within which the attributes or geographic origin of species (or supraspecific groups) evolved. Taken out of this phylogenetic context, interpretations of evolutionary processes or origins, geographic distributions, or speciation rates and mechanisms, are subject to nothing less than a biological experiment without controls. Cypriniformes is the most diverse clade of freshwater fishes with estimates of diversity of nearly 3,500 species. These fishes display an amazing array of morphological, ecological, behavioral, and geographic diversity and offer a tremendous opportunity to enhance our understanding of the biotic and abiotic factors associated with diversification and adaptation to environments. Given the nearly global distribution of these fishes, they serve as an important model group for a plethora of biological investigations, including indicator species for future cli-matic changes. The occurrence of the zebrafish, Danio rerio, in this order makes this clade a critical component in understanding and predicting the relationship between mutagenesis and phenotypic expressions in vertebrates, including humans. With the tremendous diversity in Cypriniformes, our understanding of their phylogenetic relationships has not proceeded at an acceptable rate, despite a plethora of morphological and more recent mo-lecular studies. Most studies are pre-Hennigian in origin or include relatively small numbers of taxa. Given that analyses of small numbers of taxa for molecular characters can be compromised by peculiarities of long-branch attraction and nodal-density effect, it is critical that significant progress in our understanding of the relationships of these important fishes occurs with increasing sampling of species to mitigate these potential problems. The recent Cypriniformes Tree of Life initiative is an effort to achieve this goal with morphological and molecular (mitochondrial and nuclear) data. In this early synthesis of our understanding of the phylogenetic relationships of these fishes, all types of data have contributed historically to improving our understanding, but not all analyses are complementary in taxon sampling, thus precluding direct understanding of the impact of taxon sampling on achieving accurate phylogenetic inferences. However, recent molecular studies do provide some insight and in some instances taxon sampling can be implicated as a variable that can influence sister group relationships. Other instances may also exist but without inclusion of more taxa for both mitochondrial and nuclear genes, one cannot distinguish between inferences being dictated by taxon sampling or the origins of the molecular data.
文摘Appropriate and extensive taxon sampling is one of the most important determinants of accurate phylogenetic estimation. In addition, accuracy of inferences about evolutionary processes obtained from phyloge-netic analyses is improved significantly by thorough taxon sampling efforts. Many recent efforts to improve phylogenetic estimates have focused instead on increasing sequence length or the number of overall characters in the analysis, and this often does have a beneficial effect on the accuracy of phylogenetic analyses. However, phylogenetic analyses of few taxa (but each represented by many characters) can be subject to strong systematic biases, which in turn produce high measures of repeatability (such as bootstrap proportions) in support of incor-rect or misleading phylogenetic results. Thus, it is important for phylogeneticists to consider both the sampling of taxa, as well as the sampling of characters, in designing phylogenetic studies. Taxon sampling also improves estimates of evolutionary parameters derived from phylogenetic trees, and is thus important for improved applica-tions of phylogenetic analyses. Analysis of sensitivity to taxon inclusion, the possible effects of long-branch attraction, and sensitivity of parameter estimation for model-based methods should be a part of any careful and thorough phylogenetic analysis. Furthermore, recent improvements in phylogenetic algorithms and in computa-tional power have removed many constraints on analyzing large, thoroughly sampled data sets. Thorough taxon sampling is thus one of the most practical ways to improve the accuracy of phylogenetic estimates, as well as the accuracy of biological inferences that are based on these phylogenetic trees.
基金supported by the National Natural Science Foundation of China (32071675,31670346)Biological Resources Programme,Chinese Academy of Sciences(KFJ-BRP-007-16)+4 种基金the Application Foundation Frontier Project of Wuhan Science and Technology Bureau (2019020701011435)the National Science and Technology Infrastructure program of China-compilation of Ex Situ Cultivated Flora of Botanical Garden (2015FY210100)the Key Scientific Research Talents Project of Wuhan Botanical Garden,Chinese Academy of Sciences (Y855281A05)Key Area R&D Project of Guangdong Province (2020B020221001)Guangdong Provincial Special Fund For Modern Agriculture Industry Technology Innovation Teams,China (2020KJ148)
文摘Epimedii Herba is a commonly used traditional Chinese herbal medicine.Five Epimedium species are included in Chinese Pharmacopoeia and most species of Epimedium are used as Epimedii Herba in practical application.However,as the largest herbaceous genus of the Berberidaceae,Epimedium has many taxonomic controversies which hinder the effective use of Epimedii Herba.This paper reviewed the taxonomic research related to Epimedium,including taxonomic history,taxonomic values of morphological characters,species and distribution,infra-genera taxonomic system and the taxonomic research of Chinese Epimedium.For instance,we recognized Epimedium wushanense and clarified that the species,as described in Flora Reipublicae Popularis Sinicae and Flora of China,actually includes four Epimedium species similar in leaflet shape.In general,it was recognized here that Epimedium comprises 62 species,of which 52 species are distributed in China.For Chinese Epimedium species with the most taxonomic problems,the taxonomic research on the taxa was reviewed and the newest species key was proposed along with proposals for those taxonomic problems needing further resolution.This review is of great implication for the identification,exploration and utilization of Epimedii Herba.
基金supported by the National Natural Science Foundation of China(41877055)the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2016YFC0502400)+2 种基金the Guangxi Natural Science Foundation Program(2018GXNSFAA281008)the Foundation for Young Scholars in Western China of CAS given to Jie Zhaothe Youth Innovation Team Project of ISA,CAS(2017QNCXTD_ZJ).
文摘Although soil nematode diversity has been used as an indicator of habitat characteristics and environmental change,the diversity of entire soil nematode communities has not been comprehensively evaluated at different taxonomic levels,or for different functional groups,or at a fine taxonomic level within functional groups.In this study,two taxonomic diversity indices,the Shannon-Wiener index(H′)and Simpson index(l),were used to evaluate the following:1)nematode diversity at different taxonomic levels for the whole community,2)nematode diversity of different functional groups,and 3)nematode generic diversity of functional groups in the following four land-use types:forage land,cropland,secondary forest,and grassshrubland.The results showed that significant differences in nematode diversity among landuse types were detected by assessment at the order level but not at the family or genus level.The results also showed that significant differences in nematode diversity were better revealed by assessment of trophic groups rather than cp groups.The generic diversities(H′)of omnivorous nematodes and cp3 nematodes also significantly differed among land-use types.Our results indicate that diversity at a high taxonomic level(i.e.,order)may be a more useful indicator than diversity at a low taxonomic level(i.e.,family or genus)of differences among land-use types.In addition,the functional group diversity(i.e.,trophic group,cp group,and the combination of these two groups)for the whole community and the taxonomic diversity within functional groups were useful indicators of differences among land-use types.
文摘Microbial communities inhabiting river ecosystems play crucial roles in global biogeochemical cycling and pollution attenuation.Spatial variations in local microbial assemblages are important for detailed understanding of community assembly and developing robust biodiversity sampling strategies.Here,we intensely analyzed twenty water samples collected from a one-meter spaced transect from the near-shore to the near-center in the Meramec River in eastern Missouri,USA and examined the microbial community composition with 16S rRNA gene amplicon sequencing.Riverine microbiomes across the transect exhibited extremely high similarity,with Pearson’s correlation coefficients above 0.9 for all pairwise community composition comparisons.However,despite the high similarity,PERMANOVA revealed significant spatial differences between near-shore and nearcenter communities(p=0.001).Sloan’s neutral model simulations revealed that within-transect community composition variation was largely explained by demographic stochasticity(R^(2)=0.89).Despite being primarily explained by neutral processes,LefSe analyses also revealed taxa from ten families of which relative abundances differed directionally from the bank to the river center,indicating an additional role of environmental filtering.Notably,the local variations within a river transect can have profound impacts on the documentation of alpha diversity.Taxon-accumulation curves indicated that even twenty samples did not fully saturate the sampling effort at the genus level,yet four,six and seven samples were able to capture 80%of the phylum-level,family-level,and genus-level diversity,respectively.This study for the first time reveals hyperlocal variations in riverine microbiomes and their assembly mechanisms,demanding attention to more robust sampling strategies for documenting microbial diversity in riverine systems.
基金supported by the Funds for International Cooperation and Exchange of the National Natural Science Foundation of China(No.31210103919)the National Basic Research Program of China(No.2009CB522300)the Hundred Talents Program of the Chinese Academy of Sciences,and the Ministry of Science and Technology of China(2008FY110300)。
文摘A new monotypic genus in the Boletaceae,Borofutus,typified by B.dhakanus,is described using morphological and molecular evidence.This is a putatively ectomycorrhizal fungus associated with Shorea robusta.Borofutus is characterized by the combination of the following characters:basidiomata small to medium-sized;pileus grayish brown to cocoa brown;hymenophore subdecurrent,cream then golden brown,with broad,nearly hexagonal pores;basidiospores purple to purplish red in H2O,ornamented with irregular to regular shallow pits;cystidia lageniform,thick-walled.Borofutus is sister to Spongiforma in molecular phylogenetic analyses using DNA nucleotide sequences of single or multiple loci.A description,line drawings,phylogenetic placement and comparison with allied taxa are presented herein.
基金supported by the Science&Technology Fundamental Resources Investigation Program(2023FY100302)the National Natural Science Foundation of China(32470459+1 种基金31272279)the Natural Science Foundation of Liaoning Province(2022-BS-332).
文摘The known species in the genus Clemelis Robineau-Desvoidy,1863 from China are reviewed and one new species from Shanxi,C.xuei sp.nov.,is described and illustrated.Clemelis jingentaoi,Zhang&Hao,2019 is a synonym of Austrophorocera hirsute(Mesnil,1946),syn.nov.A key to the two Chinese species is provided.
文摘Ammonia-oxidizing archaea(AOA)are important in converting ammonia into nitrate in soils.While many aspects of their community structure have been studied,the relative importance of stochastic versus deterministic processes has poorly been understood.We compared AOA communities across the North China Plain,targeting the amoA gene.A phylogenetic null modelling approach was used to calculate the beta nearest taxon index to quantify the influence of stochastic and deterministic processes.We found that spatial distance between samples predicted the perceived processes involved in community structuring,with stochastic processes dominating at local scales.At greater distances,stochasticity became weaker.However,soil pH,which was also the strongest determinant of AOA community,was a much stronger predictor of community structuring,leaving the distance effect redundant as an explanation of community structuring processes.The communities of AOA differing by less than 1 pH unit differed mainly stochastically in terms of operational taxonomic unit composition.At larger pH differences,deterministic processes based on heterogeneous selection between clades became increasingly dominant.It appears that AOA community composition is largely determined by the environment.However,very similar pH environments are the exception.In environments with very close pH values,stochastic effects dominantly cause differences in community composition,whether spatially near or far.
基金STS Program of the Chinese Academy of Sciences(KFJ-3W-No1-22)Guangxi Natural Science Foundation(2017GXNSFAA198006)+4 种基金National Natural Science Foundation(31860047)Foundation of Guangxi Key Laboratory of Plant Conservation and Restoration Ecology in Karst Terrain(19-050-6)Guilin Science&Technology Foundation(20180107-6)the Basal Research Fund of GXIB(Guizhiye20009)21st Talent project of“Ten-Hundred-Thousand”in Guangxi and the Key Science&Technology Research and Development Project of Guangxi(Guike AB16380053).
文摘A new species of Gesneriaceae,Primulina titan,is described and photographed from northern Guangxi,China.It resembles P.hunanensis,but can be distinguished by combined morphological characters of leaf,bract,corolla,stamen and pistil.We found only one population with approx.800 mature individuals at the type locality.This species is provisionally assessed as vulnerable[VU D1]using IUCN criteria.
