The balance between hummingbird visitation rate and pollen deposition in rare and abundant plants.

Pollinator-mediated competition and facilitation are key to maintaining plant communities by allowing rare and abundant species to coexist. To understand the dynamics of these processes, we evaluated the effect of dense dependence on visitation rates and pollen tubes in hummingbird-pollinated plants. Furthermore, we calculate the functional similarity and contribution of rare and abundant plants in competition and facilitation. We identified negative dense-dependence on the visitation rate, but with no effect on pollen tubes. Functional similarity between rare and abundant plants did not vary in different contexts of facilitation and competition, with greater functional contribution by rare ones. Our results indicate the relevance of conspecific abundance as a predictor to infer interactions and patterns of functional diversity. The maintenance of both more similar and more extreme traits from rare species may be another way to guarantee their advantage in high heterospecific density.