Before revision: The species pool hypothesis highlights the effects of historical processes and past adaptation on contemporary patterns of species diversity . This hypothesis has been contentious because it is difficult to test. Herewe argue that a trait-based approach enables an effective test of this hypothesis where increasing mismatch between community mean trait values (the optimal trait strategy) and the mean of the species pool (representing historical legacy) decreases species diversity . We confirm this prediction using a simulation model and demonstrate its utility using experimental communities of annual plants . Using this case study, we show thatour hypothesis is more easily falsifiable than the classical species pool hypothesis and could be applied as a null hypothesis to any system.
After revision: The species pool hypothesis highlights the effects of historical processes and past adaptation on contemporary patterns of species diversity and trait distribution together against null expectations. We use a simulation model and demonstrate its utility using experimental communities of annual plants . Using this case study, we show thatour hypothesis is more easily falsifiable than the classical species pool hypothesis and could be applied as a null hypothesis to any system.