Seasonal dynamics and interactions among Baltic Sea prokaryoticand eukaryotic plankton assemblages

One of the main goals of microbial ecology is to identify the mechanismsthat regulate patterns in community structure at temporal scalescompatible with populations’ turnover times across complete seasonalcycles. Here, we examined high-frequency temporal dynamics of marineplankton from a sampling effort covering 2011-2013, roughly twice weekly,comprising 144 samples. Bacterial and eukaryotic communities wereprofiled by 16S and 18S high-throughput sequencing, respectively.Interestingly, we found that no combination of the measured environmentalparameters could predict a significant proportion of the variation inpopulation dynamics of bacterioplankton, and even less so for eukaryoticplankton. Large differences in physicochemical conditions and communitycomposition typical of temperate climates mean that different regimes canquickly succeed each other over the year, with the relative importance ofdifferent drivers changing equally rapidly. Nevertheless, our approachrevealed interesting recurrent co-occurrence patterns across distinctenvironmental changes. Hence, we could make abundance predictions formore than half of the most frequent OTUs based on interactions with otherOTUs. These results suggests that a complex set of biotic interactions arecontributing to temporal patterns among planktonic assemblages despiterapid changes in environmental conditions.
QC 20160504