Biologia reprodutiva de Psychotria suterella Muell. Arg. (Rubiaceae) e a abordagem de escalas ecológicas para a fenologia de floração e frutificação

Abstract

(Reproductive biology of Psychotria suterella (Rubiaceae) and the approach of ecological scales for flowering and fruiting phenology). Foraging behavior of pollinators and seed dispersers is related to resource heterogeneity in the environment, making it important to know the spatio-temporal variation of resources in order to understand the mutualistic relationships established between plants and animals. Psychotria suterella flowered from January to April, months with highest annual rainfall, and exhibited high synchronism among the populations in the landscape studied. The flowering pattern found on the category of individuals corresponds to that one found in populations and landscape categories. Fructification occurred all year long, with greater availability of mature fruits in May and December; and synchronism was lower in this phenophase than in flowering. Only intermorph pollinations produced fruits and seeds, indicating that this plant species relies on pollen vectors for sexual reproduction. Since there is no evidence of pollen limitation, we consider that differences in fructification among populations could be related to abiotic factors. The overlap between flowering pattern of Psychotria suterella and Bombus brasiliensis foraging activicty, the fact that B. brasiliensis is the most important pollinator of this plant species, as well as the importance of P. suterella for this bee diet, suggest that selective pressures could be acting between these species, underlying this mutualistic interaction.