Species‐specific soil legacy effects on ecosystem multifunctionality via regulating plant overyielding

Abstract Soil legacy effects and biodiversity play important roles in driving plant community dynamics and functioning. However, experimental evidence of the effects of soil legacy on ecosystem multifunctionality (maintaining multiple functions simultaneously) is lacking. We first conducted a mesocosm experiment in which three common species (grass, legume, and forb) were planted in monocultures and mixed cultures to produce soil legacies. Subsequently, soils were sampled to test the soil legacy effects on ecosystem multifunctionality in a greenhouse experiment. Our findings showed that plant‐mediated soil legacy effects were species‐specific and strongly influenced the productivity of subsequent plants or combinations. Specifically, plant‐specific soil legacies had considerable impacts on the magnitude and direction of diversity‐dependent overyielding effects. Such effects can compensate for non‐legume soil legacy effects and maintain overall productivity. Functional diversity and ecosystem multifunctionality were largely affected by soil legacy effects and were significantly positively correlated with functional group richness. Based on our results, plant‐specific soil legacy is an important factor limiting the development of plant community and ecosystem multifunctionality in the early stage of community construction. The rational use of the synergistic effects of plant‐specific soil legacy and functional group richness may be a key to ensure the successful establishment of vegetation and grassland management.