Seed dormancy is a feature of plant life history found in every biome from deserts to tropical forests. Moreover, plants that occur in these environments exhibit the same range of dormancy types – physical, physiological, and morphological, as well as quiescence (non-dormancy). For the most part, ecologists have considered these dormancy types to represent functionally equivalent mechanisms that prevent seeds from germinating in unfavourable conditions, yet dormancy type also strongly influences seed persistence and seed interactions with soil microbial communities. In lowland tropical forest in Panama we have used long-term seed burial experiments to show that dormancy type is related to seed defence investment representing dormancy-defence syndromes. Additionally, we find a high degree of host-specificity in the interactions between seeds and soil fungi, consistent with density-dependent processes that maintain forest diversity. Finally, seed inoculation experiments reveal the existence of functional specificity, reflecting both positive and negative outcomes of infection of different species by the same soil fungi.