Figure 2.

Number of operational taxonomic units (OTUs) observed in relation to different restriction enzyme/fluorescent label combinations. Boxes give median with upper line representing 75th percentile and lower line 25th percentile; whiskers extend to the most extreme data points with range not more than 1.5 times the interquartile range from the box. Number of OTU is a measure for "bacterial richness". a) elevated carbon dioxide in comparison to ambient levels; b) three different plant diversity levels.