Plant Ecology and Evolution 148(2): 229-236, doi: 10.5091/plecevo.2015.983
Theoretical predictions of plant-pollinator interactions in sympatric species of Psychotria (Rubiaceae) in Cerrado of Brazil
expand article infoJosé N. Mesquita-Neto, Carlos M. Silva-Neto, Edivani V. Franceschinelli
Open Access
Background and aims – In highly seasonal habitats, sympatric species are often constrained to flower simultaneously. Many sympatric species of Psychotria have similar floral traits, are pollinated by bees, moths, butterflies and flies and flower at the same time of year. This genus provides an opportunity to analyse the relationships between sympatric congeneric plants and pollinators. Interactions between potentially sympatric Psychotria species and their pollinators were surveyed to assess the occurrence of sharing, specialisation, or generalisation of pollinators and plants in the system. Methods – A dataset compiled from studies of pollination biology of this genus was used to investigate aspects of interactions with shared pollinators and flowering overlap. These data were used to draw a bipartite graph and analyse the interaction network and degree of niche overlap. Key results – In total, the dataset included eight species of potentially co-occurring Psychotria species, which interacted with 24 species of pollinators. The most generalised plant in the network was Psychotria trichophoroides . The pollinators with the highest number of links, and therefore the most important for the network, belonged to orders Hymenoptera and Lepidoptera. Pollinators were shared among Psychotria species, thus pollination niches did overlap ( = 0.20, P random ≥ observed = 0.04), and plants of this genus depended on pollinators that were generalists among them. Conclusion – The peak of overlap in flowering phenology, when all of the species may potentially co-flower, coincided with the Cerrado rainy season. Since all Psychotria species occurred in sympatry, overlapped in flowering phenology, and had asymmetric interactions with floral visitors, it is possible that pollination facilitation is present in this system.