Data from: Species coexistence through simultaneous fluctuation-dependent mechanisms

Understanding the origins and maintenance of biodiversity remains one of
biology's grand challenges. From theory and observational evidence we
know that variability in environmental conditions through time is likely
critical to the coexistence of competing species. Nevertheless, strong
experimental tests of fluctuation-driven coexistence are rare, and have
typically focused on just one of two potential mechanisms, the temporal
storage effect, to the neglect of the theoretically equally plausible
mechanism known as relatively nonlinearity of competition. We combined
experiments and simulations in a system of nectar yeasts to quantify the
relative contribution of the two mechanisms to coexistence. Resource
competition models parameterized from single-species assays predicted the
outcomes of mixed-culture competition experiments with 83% accuracy. Model
simulations revealed that both mechanisms have measurable effects on
coexistence, and relative nonlinearity can be equal or greater in
magnitude to the temporal storage effect. In addition, we show that their
effect on coexistence can be both antagonistic and complementary. These
results falsify the common assumption that relative nonlinearity is of
negligible importance, and in doing so reveal the importance of testing
coexistence mechanisms in combination.