Database for meta-analysis of herbivore impacts on plant-soil feedbacks

We conducted a meta-analysis to test for an interaction between plant-soil feedbacks and herbivory, including effects on the magnitude and direction of feedbacks, herbivore consumption and herbivore growth. We identified 197 studies to address herbivore impacts on plant-soil feedbacks and 189 studies to address plant-soil impacts on herbivores. We calculated Hedge’s D values to assess three questions: 1) What is the plant-soil feedback value of plants exposed to herbivory or no herbivory? 2) What is the growth or biomass of herbivores feeding on plants exposed to home or away soils in plant-soil feedback studies? 3) How much plant tissue is consumed by herbivores on plants grown in home or away soils? We found an overall significant weak negative effect of herbivory on plant-soil feedbacks that varied by plant functional type. In legumes herbivory drove plant-soil feedbacks from positive to negative, but herbivory on forbs further decreased negative feedbacks. Herbivore consumption was generally greater on plants grown in away soils. However, herbivore consumption was greater in home soils conditioned by legumes but lower in home soils conditioned by forbs. Therefore plant functional type determines the impact of conditioned soil on feedbacks, and herbivore consumption explains these results for legumes but not forbs.