Growing evidence suggests that plant–soil interactions have important implications for plant community composition. However, the role of phylogenetic relatedness in governing interactions between plants and soil biota is unclear, and more case studies are needed to help build a general picture of whether and how phylogeny might influence plant–soil interactions. In a recent study published in AoB PLANTS, Sweet and Burns performed a glasshouse experiment to test whether degree of phylogenetic relatedness between Aquilegia canadensis and six co-occurring heterospecifics affects A. canadensis biomass through soil legacy effects. They found that A. canadensis performed significantly better in distant relatives’ soils than in close relatives’ soils, and this effect disappeared with soil sterilization. The greater performance of A. canadensis in soils of more versus less distant relatives is consistent with a hypothesis of phylogenetically-constrained pathogen escape, a phenomenon expected to promote coexistence of phylogenetically distant species.
