Figure legends
Figure 1 Schematic depiction of the experimental design. The study combined a PSF experiment and a plant diversity-productivity relationship experiment. In the soil conditioning phase (Phase I), plant communities with a range of species richness levels grew in homogeneous soils, and soil microbial communities were trained by the plant communities. In the response phase (Phase II), newly established plant communities grew with soil inoculums which the same plant communities conditioned.
Figure 2 (a) RDA analysis showing how plant species richness and soil moisture content influenced species compositions of soil bacterial and fungal communities in Phase I. SR, plant species richness; SMC, soil moisture content. Effects of plant diversity and soil moisture treatments on (b) bacterial diversity, (c) fungal diversity, (d) AMF OTU richness, (e) AMF relative abundance, (f) fungal pathogen OTU richness and (g) fungal pathogen relative abundance. Means and SE are given. Solid lines indicate significant correlations between plant species richness and microbial variables (P < 0.05).
Figure 3 Plant diversity-productivity relationships in the (a) Phase I and (b) II under different soil moisture treatments. The solid lines indicate fitted lines for plant diversity-productivity relationships, and the grey areas indicate the 95% confidence intervals. The dashed line indicates an insignificant correlation (P > 0.05). Letter codes indicate Phase I-Phase II soil moisture treatments: A-A = Ambient-Ambient; A-D = Ambient-Drought; D-A = Drought-Ambient; D-D = Drought-Drought.
Figure 4 Net biodiversity, complementarity and selection effects at different species richness levels in Phases I (a, b, c) and II (d, e, f). Means and SE are given. Letter codes indicate Phase I-Phase II soil moisture treatments: A-A = Ambient-Ambient; D-A = Drought-Ambient; A-D = Ambient-Drought; D-D = Drought-Drought.