Abstract
Dominant taxa often emerge during microbial succession. It is not always clear what makes a taxon dominant, and dispersal ability may be an overlooked mechanism promoting dominance late in succession. We investigated mechanisms leading to dominance of the yeast Candida pseudoglaebosa in the model carnivorous pitcher plant (Sarracenia purpurea) microbial metacommunity. C. pseudoglaebosa was the dominant taxon in the metacommunity, but not every individual pitcher community, throughout succession. Its frequency in the metacommunity increased between early and late-successional stages, and it was not replaced by other taxa. Despite its dominance, C. pseudoglaebosa was not a superior competitor. Instead, it was a superior disperser: it arrived in pitchers earlier, and dispersed into more pitchers, than other taxa. We attribute the continuous dominance of C. pseudoglaebosa in S. purpurea pitchers to its dispersal ability and the spatial structure of the metacommunity. Dispersal ability influences dominance throughout microbial succession.