2.We grew ragwort (Jacobaea vulgaris) in field soil conditioned specifically by 10 plant species, belonging to three functional groups (grasses, forbs and legumes), in a multispecies mixture of the conditioned soils and in control (unconditioned) field soil. We measured plant biomass, concentrations of primary (amino acids) and secondary (pyrrolizidine alkaloids) metabolites in phloem exudates, and performance of the generalist aphid Brachycaudus cardui and the specialist Aphis jacobaeae.
3.We observed that plant species, via species-specific effects on soil fungal communities, exerted unique plant-soil effects on J. vulgaris biomass, amino acid concentrations in phloem exudates and aphid performance. The direction and magnitude of the species-specific PSF effects on aphid performance differed between both aphid species. PSF effects on soil fungal communities, plant biomass and A. jacobaeae performance also differed between grasses, forbs and legumes, with soil conditioning by forbs resulting in lowest plant biomass and aphid performance.
4.Synthesis. Our study provides novel evidence that plant-soil feedback (PSF) effects on above-ground plant-insect interactions are highly species-specific. Our results add a new dimension to the rapidly developing research fields of PSF and above-below-ground interactions, and highlights that these fields are tightly linked.
Kos, M. (Creator), Tuijl, M. A. B. (Creator), de Roo, J. (Creator), Mulder, P. P. J. (Creator) & Bezemer, T. M. (Creator), Dryad, 02 Apr 2015