Conclusions
Our results illustrated that plant-soil feedbacks critically influenced plant diversity-productivity relationships, likely through the dilution effects of species-specific pathogens in more diverse communities. We also found that past drought can result in a soil microbial legacy that can have subsequent impacts on plant diversity-productivity relationships. Drying-rewetting scenarios can strengthen complementary effects while weakening selection effects. Our results highlight the importance of soil microbial communities in driving plant diversity effects on ecosystem functioning, and that changes to future rainfall patterns can have direct and long-lasting effects on biodiversity-ecosystem functioning relationships through soil legacies created by past rainfall patterns and which interacts with plant diversity and subsequent rainfall.