Biodiversity distribution patterns are a basic and long-standing but crucial aspect of ecology research.These patterns form the primary source of data used to develop biodiversity protection practices,especially in mo...Biodiversity distribution patterns are a basic and long-standing but crucial aspect of ecology research.These patterns form the primary source of data used to develop biodiversity protection practices,especially in mountain ecosystems.Shrubs comprise one of the main types of vegetation on the Qinghai–Tibetan Plateau,where they serve vital ecological functions.In this study,we used a community phylogenetic approach to examine the distribution patterns of shrub communities along the longitudinal and latitudinal gradients on the northeastern Qinghai–Tibetan Plateau.We observed significant latitudinal trends in both the phylogenetic diversity(PD)and net relatedness index(NRI)values of shrub communities,such that the former decreased and the latter increased with increasing latitude.However,no significant PD,NRI and nearest taxon index(NTI)distribution patterns were observed along a longitudinal gradient.A further analysis revealed that the combination of temperature-related and precipitation-related climate variables most strongly affected the PD,NRI and NTI values of shrub communities,indicating that the latitudinal patterns in the PD,NRI and NTI of a shrub community may be determined mainly by interactions with these climate factors.展开更多
Coastal marshes are transitional areas between terrestrial and aquatic ecosystems.They are sensitive to climate change and anthropogenic activities.In recent decades,the reclamation of coastal marshes has greatly incr...Coastal marshes are transitional areas between terrestrial and aquatic ecosystems.They are sensitive to climate change and anthropogenic activities.In recent decades,the reclamation of coastal marshes has greatly increased,and its effects on microbial communities in coastal marshes have been studied with great interest.Most of these studies have explained the short-term spatiotemporal variation in soil microbial community dynamics.However,the impact of reclamation on the community composition and assembly processes of functional microbes(e.g.,ammonia-oxidizing prokaryotes)is often ignored.In this study,using quantitative polymerase chain reaction and the Ion S5™XL sequencing platform,we investigated the spatiotemporal dynamics,assembly processes,and diversity patterns of ammonia-oxidizing prokaryotes in 1000-year-old reclaimed coastal salt marshes.The taxonomic and phylogenetic diversity and composition of ammonia oxidizers showed apparent spatiotemporal variations with soil reclamation.Phylogenetic null modelling-based analysis showed that across all sites,the archaeal ammonia-oxidizing community was assembled by a deterministic process(84.71%),and deterministic processes were also dominant(55.2%)for ammonia-oxidizing bacterial communities except for communities at 60 years of reclamation.The assembly process and nitrification activity in reclaimed soils were positively correlated.The abundance of the amoA gene and changes in ammonia-oxidizing archaeal and bacterial diversities significantly affected the nitrification activity in reclaimed soils.These findings suggest that long-term coastal salt marsh reclamation affects nitrification by modulating the activities of ammonia-oxidizing microorganisms and regulating their community structures and assembly processes.These results provide a better understanding of the effects of long-term land reclamation on soil nitrogen-cycling microbial communities.展开更多
为探索研究尺度、零模型与群落谱系结构的关系,在小秦岭自然保护区建立1 hm^2样地,运用约束型、非约束型零模型分别从10、20、25 m 3个研究尺度上分析群落谱系结构,结果表明:(1)非约束型模型下,谱系结构聚集;约束型模型下,10、20 m尺度...为探索研究尺度、零模型与群落谱系结构的关系,在小秦岭自然保护区建立1 hm^2样地,运用约束型、非约束型零模型分别从10、20、25 m 3个研究尺度上分析群落谱系结构,结果表明:(1)非约束型模型下,谱系结构聚集;约束型模型下,10、20 m尺度上,谱系聚集,25 m尺度上谱系分散。对比发现,随研究尺度增大,谱系聚集程度降低,趋于分散,可能是由于环境异质性对物种分布的影响程度降低,密度制约作用增强所致。(2)空间因子对谱系结构的影响远远大于地形因子,随研究尺度增加,空间因子及地形因子的解释量逐渐增大。地形的不同营造了不同的空间差异,二者密切相关。因此,空间因子是影响谱系结构形成的直接因素,而地形因子是间接因素。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 p...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
基金funded jointly by the Natural Science Foundation of Qinghai Province(2019-ZJ-910)the International Communication and Cooperation Project of Qinghai Province(2019-HZ-807)+1 种基金the National Program on Basic Work Project of China(2015FY11030001)the Qinghai Province High-level Innovative Talents Program
文摘Biodiversity distribution patterns are a basic and long-standing but crucial aspect of ecology research.These patterns form the primary source of data used to develop biodiversity protection practices,especially in mountain ecosystems.Shrubs comprise one of the main types of vegetation on the Qinghai–Tibetan Plateau,where they serve vital ecological functions.In this study,we used a community phylogenetic approach to examine the distribution patterns of shrub communities along the longitudinal and latitudinal gradients on the northeastern Qinghai–Tibetan Plateau.We observed significant latitudinal trends in both the phylogenetic diversity(PD)and net relatedness index(NRI)values of shrub communities,such that the former decreased and the latter increased with increasing latitude.However,no significant PD,NRI and nearest taxon index(NTI)distribution patterns were observed along a longitudinal gradient.A further analysis revealed that the combination of temperature-related and precipitation-related climate variables most strongly affected the PD,NRI and NTI values of shrub communities,indicating that the latitudinal patterns in the PD,NRI and NTI of a shrub community may be determined mainly by interactions with these climate factors.
基金financially supported by the Ningbo Science and Technology Bureau,China (Nos.2021S018 and 2022Z169)the National Natural Science Foundation of China (No.42077026)
文摘Coastal marshes are transitional areas between terrestrial and aquatic ecosystems.They are sensitive to climate change and anthropogenic activities.In recent decades,the reclamation of coastal marshes has greatly increased,and its effects on microbial communities in coastal marshes have been studied with great interest.Most of these studies have explained the short-term spatiotemporal variation in soil microbial community dynamics.However,the impact of reclamation on the community composition and assembly processes of functional microbes(e.g.,ammonia-oxidizing prokaryotes)is often ignored.In this study,using quantitative polymerase chain reaction and the Ion S5™XL sequencing platform,we investigated the spatiotemporal dynamics,assembly processes,and diversity patterns of ammonia-oxidizing prokaryotes in 1000-year-old reclaimed coastal salt marshes.The taxonomic and phylogenetic diversity and composition of ammonia oxidizers showed apparent spatiotemporal variations with soil reclamation.Phylogenetic null modelling-based analysis showed that across all sites,the archaeal ammonia-oxidizing community was assembled by a deterministic process(84.71%),and deterministic processes were also dominant(55.2%)for ammonia-oxidizing bacterial communities except for communities at 60 years of reclamation.The assembly process and nitrification activity in reclaimed soils were positively correlated.The abundance of the amoA gene and changes in ammonia-oxidizing archaeal and bacterial diversities significantly affected the nitrification activity in reclaimed soils.These findings suggest that long-term coastal salt marsh reclamation affects nitrification by modulating the activities of ammonia-oxidizing microorganisms and regulating their community structures and assembly processes.These results provide a better understanding of the effects of long-term land reclamation on soil nitrogen-cycling microbial communities.
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.
