Plant-soil feedbacks in multispecies communities: Extension of theory and an empirical test to explain tree diversity patterns in eastern deciduous forests

Explaining the large numbers of species that coexist within communities is a long-standing challenge in biology. Ecological theory suggests that coexistence requires negative frequency-dependent feedbacks to prevent exclusion of the least fit species. For plant communities, empirical evidence of negative frequency-dependence is rapidly accumulating and increasingly identified as a potential driver of species coexistence and diversity patterns. Until now, however, connecting these empirical findings with ecological theory has been hampered by the corresponding theoretical framework of frequency-dependent feedback not being developed beyond a small number of interacting species.