Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional biota.The Qinghai-Tibet Plateau(QTP)harbors a...Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional biota.The Qinghai-Tibet Plateau(QTP)harbors an exceptionally diverse flora,however,a phylogenetic perspective has rarely been used to investigate its beta diversity and floristic regions.In this study,we used a phylogenetic approach to identify patterns of beta diversity and quantitatively delimit floristic regions on the Qinghai-Tibet Plateau.We also examined the relationships between multifaceted beta diversity,geographical distance,and climatic difference,and evaluated the relative importance of various factors(i.e.,climate,topography and history)in shaping patterns of beta diversity.Sørensen dissimilarity indices indicated that patterns of species turnover among sites dominated the QTP.We also found that patterns of both taxonomic and phylogenetic beta diversity were significantly related to geographical distance and climatic difference.The environmental factors that contributed most to these patterns of beta diversity include annual precipitation,mean annual temperature,climatic gradients and climatic instability.Hierarchical dendrograms of dissimilarity and non-metric multidimensional scaling ordination based on phylogenetic beta diversity data identified ten floristic subregions in the QTP.Our results suggest that the contemporary environment and historical climate changes have filtered species composition among sites and eventually determined beta diversity patterns of plants in the QTP.展开更多
The significance of microbes for ecosystem functioning is well known;however,within a single system,the relative contributions of keystone and rare taxa to soil microbial functions are less well quantified,as are thei...The significance of microbes for ecosystem functioning is well known;however,within a single system,the relative contributions of keystone and rare taxa to soil microbial functions are less well quantified,as are their shared or unique responses to abiotic conditions.Furthermore,their associations with tree community composition in natural forest ecosystems are not well understood.In this study,a total of 1287 soil samples were collected from a 20-ha subtropical forest plot and analyzed using high-throughput sequencing.Based on co-occurrence network analyses,we conducted a comparison of the associations between keystone and rare taxa with the structure,functions and stability of soil microbial communities.Additionally,we examined their associations with tree community composition.Results showed that keystone taxa made a significantly greater contribution than rare taxa in all comparisons of microbial functions and stability.Keystone taxa had direct effects on microbial community structure and also mediated indirect effects of abiotic conditions.Neither effect was evident for rare taxa.The importance of keystone taxa also extended to aboveground composition,where tree community composition was more closely associated with keystone taxa than with rare taxa.While it may still be premature to establish causality,our study represents one of the initial attempts to compare the relative importance of keystone and rare microbial taxa in forest soils.These findings offer the potential to improve natural forest ecosystem functioning and tree diversity through the manipulation of a small number of keystone soil microbial taxa,as has been demonstrated in agroecosystems.展开更多
基金This study was funded by the National Natural Science Foundation of China(grant no.31901212)Talent Start-up Foundation of Guangzhou University(grant no.RP2020079).
文摘Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional biota.The Qinghai-Tibet Plateau(QTP)harbors an exceptionally diverse flora,however,a phylogenetic perspective has rarely been used to investigate its beta diversity and floristic regions.In this study,we used a phylogenetic approach to identify patterns of beta diversity and quantitatively delimit floristic regions on the Qinghai-Tibet Plateau.We also examined the relationships between multifaceted beta diversity,geographical distance,and climatic difference,and evaluated the relative importance of various factors(i.e.,climate,topography and history)in shaping patterns of beta diversity.Sørensen dissimilarity indices indicated that patterns of species turnover among sites dominated the QTP.We also found that patterns of both taxonomic and phylogenetic beta diversity were significantly related to geographical distance and climatic difference.The environmental factors that contributed most to these patterns of beta diversity include annual precipitation,mean annual temperature,climatic gradients and climatic instability.Hierarchical dendrograms of dissimilarity and non-metric multidimensional scaling ordination based on phylogenetic beta diversity data identified ten floristic subregions in the QTP.Our results suggest that the contemporary environment and historical climate changes have filtered species composition among sites and eventually determined beta diversity patterns of plants in the QTP.
基金supported by the National Natural Science Foundation of China 470(32071645 and 32471613)the Research Project of Baishanzu National Park(2022JBGS04 and 2023JBGS06)the Fundamental Research Funds for the Central Universities of China and the Natural Sciences and Engineering Research Council of Canada.
文摘The significance of microbes for ecosystem functioning is well known;however,within a single system,the relative contributions of keystone and rare taxa to soil microbial functions are less well quantified,as are their shared or unique responses to abiotic conditions.Furthermore,their associations with tree community composition in natural forest ecosystems are not well understood.In this study,a total of 1287 soil samples were collected from a 20-ha subtropical forest plot and analyzed using high-throughput sequencing.Based on co-occurrence network analyses,we conducted a comparison of the associations between keystone and rare taxa with the structure,functions and stability of soil microbial communities.Additionally,we examined their associations with tree community composition.Results showed that keystone taxa made a significantly greater contribution than rare taxa in all comparisons of microbial functions and stability.Keystone taxa had direct effects on microbial community structure and also mediated indirect effects of abiotic conditions.Neither effect was evident for rare taxa.The importance of keystone taxa also extended to aboveground composition,where tree community composition was more closely associated with keystone taxa than with rare taxa.While it may still be premature to establish causality,our study represents one of the initial attempts to compare the relative importance of keystone and rare microbial taxa in forest soils.These findings offer the potential to improve natural forest ecosystem functioning and tree diversity through the manipulation of a small number of keystone soil microbial taxa,as has been demonstrated in agroecosystems.
