How does the microbial rare biosphere coexist with dominant species?

Description

Our planet teems with microorganisms, which often present a skewed abundance distribution in a local community, with relatively few dominant species co-existing alongside a high number of rare species, i.e. the microbial rare biosphere. Recent studies have demonstrated that rare taxa not only serve as limitless reservoirs of genetic and functional diversity but also perform a disproportionate level of functions. However, most of our current knowledge of microbial community is based on dominant species; relatively little is known about the ecological mechanisms mediating the structure of rare biosphere, i.e. speciation, dispersal, selection, and drift. To fill this gap, we investigated which processes contribute to the soil microbial rare biosphere persistence and dynamics across space and time on the salt mash chronosequence located on the island of Schiermonnikoog, the Netherlands. Using high-throughput 16 cDNA sequencing, we observed that the species composition of rare biosphere was different from that of dominant biosphere. In the rare biosphere, most species were permanently rare, whereas only a small fraction of the rare biosphere was conditionally rare and transiently rare. To further explore which mechanisms contribute the observed pattern, we disentangled the ecological processes by combining phylogenetic community structure with ecological null model analysis. We found that homogenizing selection was the predominant ecological process contributing to the variation of the rare biosphere structure, suggesting that most rare species persist in low abundance due to their special life-history strategies or ecological trade-offs. Together, these results elucidated how the highly diverse microbial rare biosphere is assembled, which will promote a better understanding of the main processes underpinning the huge diversity found in microbial communities.

Periode	13-feb.-2019
Evenementstitel	Netherlands Annual Ecology Meeting 2019
Evenementstype	Conference
Conferentienummer	12
Organisator	Netherlands Ecological Research Network (NERN)
Locatie	Lunteren, NetherlandsToon op kaart
Mate van erkenning	National