Temporal carry-over effects in sequential plant–soil feedbacks

Plant-soil feedbacks (PSF) strongly influence plant performance. However, to what extent these PSF effects are persistent in the soil and how they are altered by species that subsequently condition the soil is unclear. Here we test how conspecific and heterospecific soil-conditioning effects interact across different soil-conditioning phases. We conducted a fully factorial glasshouse experiment where six plant species conditioned soils in two consecutive phases and measured the performance of Jacobaea vulgaris. The species that conditioned the soil during the second conditioning phase strongly determined the performance of J. vulgaris, but also the order and combination of species that conditioned the soil in the two phases accounted for a large part of the variance. For shoot biomass this interaction was the dominant variance component. We show that soil conditioning legacies carry-over and interact with the conditioning effects of succeeding plants. In the field, species replacements ...