Relative abundance values in heavy fractions (density greater or
equal to 1.725 g/mL) for the top 10 $^{15}$N "responders" (putative
diazotrophs, see results for selection criteria of top 10) at each
incubation day. Each point is a relative abundance value for the indicated
OTU in a CsCl gradient fraction SSU rRNA gene collection. See
Table~\ref*{tab:LTP_blast} for BLAST results against the LTP database (release
115). Point area is proportional to CsCl gradient fraction density, and color
signifies control (red) or labeled (blue) treatment.
