Microbial α-diversity poorly predicts plant growth
Even if microbial α-diversity has been suggested to drive crucial ecosystem functions including plant productivity and diversity (van der Heijden et al. , 1998; Delgado-Baquerizo et al. , 2016; Laforest-Lapointe et al. , 2017), here we found that microbial richness and Shannon’s diversity are poor predictors of PSF. Plants responded to specific OTUs (Fig. 2), or groups of microorganisms (Table 1), but not to community diversity per se. This, however, does not completely rule out microbial α-diversity as a potentially important component of PSF. If there exists concurrent variation in (1) the impact of different plants on microbial diversity and (2) the response of these different plants to such diversity, then non-neutral PSF are to be expected. We found poor evidence for the latter in our study (Table 1).