Discussion
Overall, our results support the idea that soil microorganisms are drivers of PSF: they influence plant growth in a species-specific way (Fig. 1, 2) and they respond, to some extent, to plant community structure (Fig. 3). However, we show that contrary to expectations, the main microbial drivers of PSF were not pathogens. We also show that contrary to other studies arguing that microbial α-diversity is a major driver of various ecosystem functions and plant performance (e.g., Delgado-Baquerizo et al. , 2016; Wagg et al. , 2014), here plant growth response was much more tied to the presence of specific microorganisms (Fig. 2), rather than to community-level properties such as richness or diversity (Table 1).