Urban lake ecosystems are significant for social development,but currently we know little about the geographical distribution of algal community in urban lakes at a large-scale.In this study,we investigated the algal ...Urban lake ecosystems are significant for social development,but currently we know little about the geographical distribution of algal community in urban lakes at a large-scale.In this study,we investigated the algal community structure in different areas of urban lakes in China and evaluated the influence of water quality parameters and geographical location on the algal community.The results showed that obvious differences in water quality and algal communities were observed among urban lakes in different geographical areas.Chlorophyta was the dominant phylum,followed by cyanobacteria in all areas.The network analysis indicated that algal community composition in urban lakes of the western and southern area showed more variations than the eastern and northern areas,respectively.Redundancy analysis and structural equation model revealed that nutrients and p H were dominant environmental factors that affected the algal community,and they showed higher influence than that of iron,manganese and COD Mn concentration.Importantly,algal community and density exhibited longitude and latitude relationship.In general,these results provided an ecological insight into large-scale geographical distributions of algal community in urban lakes,thereby having potential applications for management of the lakes.展开更多
The research on the biological ecology of the Prydz Bay-Amery Ice Shelf in East Antarctica is inadequate under the increasing threat from climate change,especially for Antarctic fish and krill.The Dynamic Bioclimatic ...The research on the biological ecology of the Prydz Bay-Amery Ice Shelf in East Antarctica is inadequate under the increasing threat from climate change,especially for Antarctic fish and krill.The Dynamic Bioclimatic Envelope Model(DBEM)has been widely used in predicting the variation of species distribution and abundance in ocean and land under climate change;it can quantify the spatiotemporal changes of multi population under different climate emission scenarios by identifying the environmental preferences of species.The species richness and geographical pattern of six Antarctic representative species around Prydz Bay-Amery ice shelf were studied under RCP 8.5 and RCP 2.6 emission scenarios from 1970 to 2060 using Geophysical Fluid Dynamics Laboratory(GFDL),Institut Pierre Simon Laplace(IPSL),and Max Planck Institute(MPI)earth system models.The results showed that the species richness decreased as a whole,and the latitude gradient moved to the pole.The reason is that ocean warming,sea ice melting,and human activities accelerate the distribution changes of species biogeographical pattern,and the habitat range of krill,silverfish,and other organisms is gradually limited,which further leads to the change of species composition and the decrease of biomass.It is obvious that priority should be given to Prydz Bay-Amery ice shelf in the planning of Marine Protected Areas(MPAs)in East Antarctica.展开更多
Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the region.However,...Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the region.However,phylogenetic relationships of Cymbidium have not been well resolved,hampering investigations of species diversification and the biogeographical history of this genus.In this study,we construct a plastome phylogeny of 56 Cymbidium species,with four well-resolved major clades,which provides a framework for biogeographical and diversification rate analyses.Molecular dating and biogeographical analyses show that Cymbidium likely originated in the region spanning northern IndoBurma to the eastern Himalayas during the early Miocene(~21.10 Ma).It then rapidly diversified into four major clades in East Asia within approximately a million years during the middle Miocene.Cymbidium spp.migration to the adjacent regions(Borneo,Philippines,and Sulawesi)primarily occurred during the Pliocene-Pleistocene period.Our analyses indicate that the net diversification rate of Cymbidium has decreased since its origin,and is positively associated with changes in temperature and monsoon intensity.Favorable hydrothermal conditions brought by monsoon intensification in the early Miocene possibly contributed to the initial rapid diversification,after which the net diversification rate was reduced with the cooling climate after the middle Miocene.The transition from epiphytic to terrestrial habits may have enabled adaptation to cooler environments and colonization of northern niches,yet without a significant effect on diversification rates.This study provides new insights into how monsoon activity and temperature changes affected the diversification dynamics of plants in Southeast Asia.展开更多
Background:The regional species pool and local community assembly processes shape the biogeographic patterns of soil bacterial community diversity.However,how community assembly mechanisms regulate biogeographic patte...Background:The regional species pool and local community assembly processes shape the biogeographic patterns of soil bacterial community diversity.However,how community assembly mechanisms regulate biogeographic patterns in rare and abundant bacterial communities remains unclear.Methods:Soil samples of 16 grassland habitats across the Inner Mongolian Plateau and Qinghai-Tibet Plateau(QTP)transects were collected to investigate the variation ofβ-diversity in rare taxa(RT)and abundant taxa(AT).Highthroughput sequencing analysis of 16S rRNA gene amplicons was implemented on an Ilumina MiSeq platform.Results:Significant distance-decay relationships ofβ-diversity in RT and AT were observed at transect and habitat scales,and the turnover rate increased from desert to meadow steppe in both taxa.For variations ofβ-diversity along environmental gradient,the regional species pool had a limited effect on both taxa except RT in QTP.Deterministic processes,including homogeneous selection(85.1%-97.3%)and heterogenous selection(48.1%-64.2%),dominated the assembly of RT at both the transect and habitat scales.In contrast,the assembly of AT exhibited habitat specificity and was dominated by homogeneous selection(47.2%-80.6%),heterogenous selection(42.1%-54.2%),and dispersal limitation(41.8%)in different transects and habitats.Moreover,the local assembly processes of the AT community were more stochastic than those of the RT community.Mean annual precipitation(MAP)was the dominant driver of community assembly at the transect scale,with extreme MAP(<200 or>400 mm)resulting in more deterministic processes and a moderate level of MAP(200-400 mm)leading to more stochastic processes.However,the effects of geographical distance and soil properties on different grassland habitats cannot be ignored.Conclusions:Although both bacterial taxa exhibited significant distance-decay patterns,different assembly mechanisms shaped theβ-diversity of AT and RT communities in grassland soils.Our results suggested that MAP can mediate community assembly of soil bacteria on a large scale.展开更多
Aims Carbon(C),nitrogen(N)and phosphorus(P)stoichiometry strongly affect functions and nutrient cycling within ecosystems.However,the related researches in shrubs were very limited.In this study,we aimed to inves-tiga...Aims Carbon(C),nitrogen(N)and phosphorus(P)stoichiometry strongly affect functions and nutrient cycling within ecosystems.However,the related researches in shrubs were very limited.In this study,we aimed to inves-tigate leaf stoichiometry and its driving factors in shrubs,and whether stoichiometry significantly differs among closely related species.Methods We analyzed leaf C,N and P concentrations and their ratios in 32 species of Ericaceae from 161 sites across southern China.We examined the relationships of leaf stoichiometry with environmen-tal variables using linear regressions,and quantified the interactive and independent effects of climate,soil and species on foliar stoi-chiometry using general linear models(GLM).Important Findings The foliar C,N and P contents of Ericaceae were 484.66,14.44 and 1.06 mg g−1,respectively.Leaf C,N and P concentrations and their ratios in Ericaceae were significantly related with latitude and altitude,except the N:P insignificantly correlated with latitude.Climate(mean annual temperature and precipitation)and soil properties(soil C,N and P and bulk density)were significantly influenced element stoichiom-etry.The GLM analysis showed that soil exerted a greater direct effect on leaf stoichiometry than climate did,and climate affected leaf traits mainly via indirect ways.Further,soil properties had stronger influ-ences on leaf P than on leaf C and N.Among all independent factors examined,we found species accounted for the largest proportion of the variation in foliar stoichiometry.These results suggest that species can largely influence foliar stoichiometry,even at a lower taxonomic level.展开更多
基金the National Natural Science Foundation of China(No.51978561)the International Science and Technology Cooperation Program in Shaanxi Province(No.2018kw-011)Shaanxi Provincial Key Research and Development Projects(Nos.2019ZDLSF06-01 and 2019ZDLSF06-02).
文摘Urban lake ecosystems are significant for social development,but currently we know little about the geographical distribution of algal community in urban lakes at a large-scale.In this study,we investigated the algal community structure in different areas of urban lakes in China and evaluated the influence of water quality parameters and geographical location on the algal community.The results showed that obvious differences in water quality and algal communities were observed among urban lakes in different geographical areas.Chlorophyta was the dominant phylum,followed by cyanobacteria in all areas.The network analysis indicated that algal community composition in urban lakes of the western and southern area showed more variations than the eastern and northern areas,respectively.Redundancy analysis and structural equation model revealed that nutrients and p H were dominant environmental factors that affected the algal community,and they showed higher influence than that of iron,manganese and COD Mn concentration.Importantly,algal community and density exhibited longitude and latitude relationship.In general,these results provided an ecological insight into large-scale geographical distributions of algal community in urban lakes,thereby having potential applications for management of the lakes.
基金Supported by the National Natural Science Foundation of China(No.42176234)the Chinese Arctic and Antarctic Creative Program(No.JDB20210211)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.GML2019ZD0402)。
文摘The research on the biological ecology of the Prydz Bay-Amery Ice Shelf in East Antarctica is inadequate under the increasing threat from climate change,especially for Antarctic fish and krill.The Dynamic Bioclimatic Envelope Model(DBEM)has been widely used in predicting the variation of species distribution and abundance in ocean and land under climate change;it can quantify the spatiotemporal changes of multi population under different climate emission scenarios by identifying the environmental preferences of species.The species richness and geographical pattern of six Antarctic representative species around Prydz Bay-Amery ice shelf were studied under RCP 8.5 and RCP 2.6 emission scenarios from 1970 to 2060 using Geophysical Fluid Dynamics Laboratory(GFDL),Institut Pierre Simon Laplace(IPSL),and Max Planck Institute(MPI)earth system models.The results showed that the species richness decreased as a whole,and the latitude gradient moved to the pole.The reason is that ocean warming,sea ice melting,and human activities accelerate the distribution changes of species biogeographical pattern,and the habitat range of krill,silverfish,and other organisms is gradually limited,which further leads to the change of species composition and the decrease of biomass.It is obvious that priority should be given to Prydz Bay-Amery ice shelf in the planning of Marine Protected Areas(MPAs)in East Antarctica.
基金supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB31000000)The 14th Five-Year Plan of the Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences (XTBG-1450101)+3 种基金the Science and Technology Basic Resources Investigation Program of China (2021FY100200)the Key Basic Research Program of Yunnan Province,China (202101BC070003)the Yunnan Revitalization Talent Support Program"Young Talent"and"Innovation Team"ProjectsEcological and Environmental Conservation Program from the Department of Ecology and Environment of Yunnan Province。
文摘Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the region.However,phylogenetic relationships of Cymbidium have not been well resolved,hampering investigations of species diversification and the biogeographical history of this genus.In this study,we construct a plastome phylogeny of 56 Cymbidium species,with four well-resolved major clades,which provides a framework for biogeographical and diversification rate analyses.Molecular dating and biogeographical analyses show that Cymbidium likely originated in the region spanning northern IndoBurma to the eastern Himalayas during the early Miocene(~21.10 Ma).It then rapidly diversified into four major clades in East Asia within approximately a million years during the middle Miocene.Cymbidium spp.migration to the adjacent regions(Borneo,Philippines,and Sulawesi)primarily occurred during the Pliocene-Pleistocene period.Our analyses indicate that the net diversification rate of Cymbidium has decreased since its origin,and is positively associated with changes in temperature and monsoon intensity.Favorable hydrothermal conditions brought by monsoon intensification in the early Miocene possibly contributed to the initial rapid diversification,after which the net diversification rate was reduced with the cooling climate after the middle Miocene.The transition from epiphytic to terrestrial habits may have enabled adaptation to cooler environments and colonization of northern niches,yet without a significant effect on diversification rates.This study provides new insights into how monsoon activity and temperature changes affected the diversification dynamics of plants in Southeast Asia.
基金National Natural Science Foundation of China,Grant/Award Numbers:32271619,32192461。
文摘Background:The regional species pool and local community assembly processes shape the biogeographic patterns of soil bacterial community diversity.However,how community assembly mechanisms regulate biogeographic patterns in rare and abundant bacterial communities remains unclear.Methods:Soil samples of 16 grassland habitats across the Inner Mongolian Plateau and Qinghai-Tibet Plateau(QTP)transects were collected to investigate the variation ofβ-diversity in rare taxa(RT)and abundant taxa(AT).Highthroughput sequencing analysis of 16S rRNA gene amplicons was implemented on an Ilumina MiSeq platform.Results:Significant distance-decay relationships ofβ-diversity in RT and AT were observed at transect and habitat scales,and the turnover rate increased from desert to meadow steppe in both taxa.For variations ofβ-diversity along environmental gradient,the regional species pool had a limited effect on both taxa except RT in QTP.Deterministic processes,including homogeneous selection(85.1%-97.3%)and heterogenous selection(48.1%-64.2%),dominated the assembly of RT at both the transect and habitat scales.In contrast,the assembly of AT exhibited habitat specificity and was dominated by homogeneous selection(47.2%-80.6%),heterogenous selection(42.1%-54.2%),and dispersal limitation(41.8%)in different transects and habitats.Moreover,the local assembly processes of the AT community were more stochastic than those of the RT community.Mean annual precipitation(MAP)was the dominant driver of community assembly at the transect scale,with extreme MAP(<200 or>400 mm)resulting in more deterministic processes and a moderate level of MAP(200-400 mm)leading to more stochastic processes.However,the effects of geographical distance and soil properties on different grassland habitats cannot be ignored.Conclusions:Although both bacterial taxa exhibited significant distance-decay patterns,different assembly mechanisms shaped theβ-diversity of AT and RT communities in grassland soils.Our results suggested that MAP can mediate community assembly of soil bacteria on a large scale.
基金This work was supported by the‘Strategic Priority Research Program-Climate Change:Carbon Budget and Related Issues’of the Chinese Academy of Sciences(#XDA05050300).
文摘Aims Carbon(C),nitrogen(N)and phosphorus(P)stoichiometry strongly affect functions and nutrient cycling within ecosystems.However,the related researches in shrubs were very limited.In this study,we aimed to inves-tigate leaf stoichiometry and its driving factors in shrubs,and whether stoichiometry significantly differs among closely related species.Methods We analyzed leaf C,N and P concentrations and their ratios in 32 species of Ericaceae from 161 sites across southern China.We examined the relationships of leaf stoichiometry with environmen-tal variables using linear regressions,and quantified the interactive and independent effects of climate,soil and species on foliar stoi-chiometry using general linear models(GLM).Important Findings The foliar C,N and P contents of Ericaceae were 484.66,14.44 and 1.06 mg g−1,respectively.Leaf C,N and P concentrations and their ratios in Ericaceae were significantly related with latitude and altitude,except the N:P insignificantly correlated with latitude.Climate(mean annual temperature and precipitation)and soil properties(soil C,N and P and bulk density)were significantly influenced element stoichiom-etry.The GLM analysis showed that soil exerted a greater direct effect on leaf stoichiometry than climate did,and climate affected leaf traits mainly via indirect ways.Further,soil properties had stronger influ-ences on leaf P than on leaf C and N.Among all independent factors examined,we found species accounted for the largest proportion of the variation in foliar stoichiometry.These results suggest that species can largely influence foliar stoichiometry,even at a lower taxonomic level.
