Average α-diversity (Shannon diversity) for (a) 16S rRNA genes, and (b) KEGG functional genes derived from community mRNA transcripts. Error bars reflect one standard error. In order to make our results more comparable to a prior study of bacterial succession in the Avena rhizosphere, Shannon taxonomic diversity was calculated based on 16S rRNA genes [13]. The different letters represent significant differences measured by Tukey HSD analysis at the final timepoint. (c) The cumulative number of significant differentially upregulated decomposition CAZy (d-CAZy) genes relative to bulk soil, measured by DESeq (p < 0.05). Treatments are: rhizosphere + detritus (filled red circle, solid line), rhizosphere (hollow red circle, dashed line), bulk soil + detritus (filled blue square, solid line), and untreated bulk soil (hollow blue square, dashed line).