Abstract
Microbial communities are undergoing unprecedented dispersion and amalgamation across diverse ecosystems, thereby exerting profound and pervasive influences on microbial assemblages and ecosystem dynamics. This review delves into the phenomenon of community coalescence, offering an ecological overview that outlines its four-step process and elucidates the intrinsic interconnections in the context of community assembly. We examine pivotal mechanisms driving community coalescence, with a particular emphasis on elucidating the fates of both source and resident microbial communities and the consequential impacts on the ecosystem. Finally, we proffer recommendations to guide researchers in this rapidly evolving domain, facilitating deeper insights into the ecological ramifications of microbial community coalescence.