Bacterial community variation. Overall the variation of bacterial community for each habitat was evaluated by the over-dispersion parameter theta (m ± sd) from the Dirichlet-multinomial model. Higher theta indicates higher variation and vice versa. The variation within a bacterial community was calculated at 1,000, 3,000, 6,000, and 9,000 read depths as shown by different colors. No significant difference was found in bacterial community variation at different read depths.
Zhou et al. Genome Biology 2013 14:R1 doi:10.1186/gb-2013-14-1-r1