Connecting microbial communities: The dispersal of taxa as a major factor shaping aquatic bacterioplankton assemblages
Clara Ruiz-González, Institut de Ciències del Mar (ICM-CSIC), Barcelona, Spain
Bacteria are major players in marine and inland waters, but how variations in taxonomic composition impact their role in ecosystems remains unclear. This is partly because bacterial communities harbour thousands of taxa with very different lifestyles, persistence and dispersal capacities. Although the advent of sequencing technologies has fostered our understanding of the processes and factors shaping bacterial assemblages, there are still limitations among microbial ecology studies: e.g., most research is ecosystem-specific, neglecting the dispersal of microbes across different habitats or local communities. During the past years we have explored the biogeography of bacteria considering this potential connectivity among communities, unveiling a major role of microbial dispersal in fresh- and marine waters: We have shown that boreal lakes and rivers are strongly influenced by the transport of taxa from the surrounding terrestrial landscape, and that deep ocean communities seem largely structured by the sinking of surface microbes attached to particles. In addition, by modelling the spatial distribution of individual bacterial taxa, we have identified specific behaviours within aquatic prokaryotes, which can in turn be used to understand underlying processes linked to local selection or passive dispersal, or how environmental fluctuations regulate the relative abundances of generalist and specialist taxa across communities.