Figure 2 . General bacterial alpha diversity patterns. Boxplot of alpha diversity indices, including community richness (Ace and Chao) and diversity (Shannon and Simpson). Microbial alpha diversity in the soil samples from different forest types (a), different depths (b), and different slope positions (c). NA, C. oleifera new afforestation; GLF, G. jasminoides in a low-yielding C. oleifera forest; LF, low-yielding C. oleifera forest; GNA, G. jasminoidesin C. oleifera new afforestation. Twenty, soil layer at 0–20 cm depth; Forty, soil layer at 20–40 cm depth; Sixty, soil layer at 40–60 cm depth. OUT, operational taxonomic unit; ACE, abundance-based coverage estimator. The data are represented as a box-and-whisker plot representing median values with interquartile ranges. Different colors indicate different sampling campaigns and sampling locations (depth and slope positon n = 9forest type n = 12; *P < 0.05, **P < 0.01, [Student’s t -test for estimator]).