Figure 2.

Temporal distribution of ammonia-oxidizing archaea (AOA) (solid lines, circles) and ammonia-oxidizing bacteria (AOB) (broken lines, squares), amoA gene abundances, and the archaeal percentage of the total amoA genes (broken line, triangles), all determined in three different layers in the water column of Lake Lucerne. In the left panels the DNA gene abundances are shown, on the right the cDNA abundances. Periods of mixing of the water layers are depicted by grey rectangles. Gene abundances were obtained by taking the average of three replicated qPCR analyses. Standard deviations of the replicates are indicated by error bars.