Data for: Spatial structure within root systems moderates stability of Arbuscular Mycorrhizal mutualism and plant-soil feedbacks

The persistence of mutualisms is paradoxical, as there are fitness incentives for exploitation.  This is particularly true for plant-microbe mutualisms like arbuscular mycorrhizae (AM), which are promiscuously horizontally-transmitted.  Preferential allocation by hosts to the best mutualist can stabilize horizontal mutualisms, however, preferential allocation is imperfect, with its fidelity likely depending upon the spatial structure of symbionts in plant roots.  In this study, we tested AM mutualisms’ dependence on two dimensions of spatial structure: the initial spatial association of fungi and the ease of fungal dispersal, through three complementary experiments. We found that fitness of the beneficial AM fungus increased when fungi were initially separate, while initial spatial mixing benefited the fitness of the non-beneficial fungus. These effects were strongest when dispersal was limited, and hosts could discriminate.  Additionally, we found that changes in AM fungal proportional..., , An updated version of this dataset has been published. Please visit this link: https://doi.org/10.5061/dryad.s1rn8pk8z