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
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.
