An outdoor microcosm experiment with water microbes

To test the relative importance of dispersal, habitat filtering, drift, and historical contingency in structuring local water bacterial communities, we conducted a new community assembly experiment and reciprocal transplant experiment using microcosms filled with sterile or non-sterile original water medium under outdoor conditions. We collected air particulate matter at the experiment site and nearby. The immigration rates were increased through adding air particulate matter to the microcosms. The composition and diversity of bacterial taxa in the waters were assessed using 16S rRNA gene amplicon sequencing on the 13th and 60th days after the onset of the experiment. We attempted to study whether immigration rate increase could lead to community structure change and species diversity rise, and the effect of immigration rate on environment filtering, the intensity of drift process and historical contingency in a community.