Exploring Regional Biogeography of Abundant and Rare Bacteria in Soils With Long‐Read CycloneSEQ

Background Rare microbial communities represent an important component of biodiversity in soil ecosystems, co‐existing with abundant species to drive ecosystem multifunctionality and maintain its stable operation. However, knowledge remains limited regarding the geographical distribution patterns and potential driving factors of microorganisms, especially rare species, in soil ecosystems. Result Using the CycloneSEQ WT sequencing platform, we systematically investigated soil bacterial communities across 160 sampling sites in southern Jiangxi Province. Abundant and rare taxa exhibited significant compositional differences. Abundant taxa displayed stronger distance‐decay relationships and were primarily driven by climatic factors. In contrast, rare taxa demonstrated higher sensitivity to spatial factors, while the influence of soil pH was substantially stronger on rare taxa than on abundant taxa. While stochastic processes predominantly governed community assembly for both taxa, rare taxa showed greater susceptibility to homogeneous selection, whereas abundant taxa were more strongly influenced by variable selection and dispersal limitation. Network analysis indicated that abundant taxa formed tighter connections internally, while rare taxa established more extensive but looser interactions with other nodes in the network. Conclusions This study reveals different biogeographic patterns between abundant and rare bacterial taxa. Abundant taxa exhibited strong distance‐decay driven by environmental heterogeneity and dispersal limitation, whereas rare taxa showed weak distance‐decay governed by homogeneous selection, providing theoretical support for maintaining microbial diversity in agricultural soils.