Figure captions
Fig. 1 The effect of (a) leaf- and (b) soil-microbial inoculation on plant productivity. Plant biomass was fitted in a linear mixed-effect model as a function of plant diversity, soil, leaf inoculation and their interactions with plant community composition taken as a random term. From the model the marginal means of plant biomass were extracted and contrasted between microbial treatments (see Table S3 for the statistics, *p < 0.05; **p < 0.01; ***p < 0.001). The mean value and standard error of plant biomass were shown.
Fig. 2 The relationships between plant diversity and biomass for different microbial inoculation treatments. A linear mixed-effect model was fitted to predict plant biomass as a function of plant diversity, leaf and soil inoculation and their interactions with plant composition taken as a random effect. The slopes of plant diversity-biomass relationships were extracted from the model and compared among microbe treatments using Tukey’s HSD, with different letter labels in the box indicating significant difference in the diversity-biomass slopes. Standard errors of plant biomass were shown. We only present high-concentration leaf microbial inoculum since low-concentration inoculum has no effect on plant productivity (See Method).
Fig. 3 The net biodiversity effect (a), complementarity (b) and selection effect(c) of plant biomass across microbial inoculation treatments. The difference of biodiversity effect between groups was tested using Tukey’s HSD. Groups with different letter labels above the boxes have significantly different biodiversity effect at p<0.05.
Fig. 4 The phylum-level taxonomic composition of (a) fungi and (b) bacteria in microbial samples. Non-inoculated and inoculated soils were collected at the end of the experiment, with L.0, L.1 and L.2 represent non-leaf microbe treatment, low- and high-concentration leaf microbe treatments respectively. Leaf and soil inoculum as well as background soil were collected at the beginning of the experiment, representing the leaf and soil microbial communities collected in the field and the background soil substrate used in the study.
Fig. 5 Distance-based redundancy analysis indicating the variation in (a) bacterial and (b) fungal soil community composition across microbial inoculation treatments and plant diversity. Arrows represent the effect of plant diversity, soil inoculation (Soil), low-concentration leaf inoculation (Leaf1) and high-concentration leaf inoculation (Leaf2) on microbial community composition, with significant relationships indicated by asterisks (see Table S4 for the statistics, *p < 0.05; **p < 0.01; ***p < 0.001).