Ecologia reprodutiva de espécies simpátricas de Qualea (Vochisiaceae) no Cerrado

Abstract

Congenerous species have several similar reproductive characteristics and can compete for the services provided by pollinators if they are present in the same area. This competition can negatively influence the rate of pollination, fertilization and formation of fruits and seeds, harming both species. In this way, we compared the reproductive ecology of two similar and sympatric species, Qualea multiflora and Q. parviflora (Vochysiaceae), investigating whether there is competition for pollinators and what are the possible strategies presented to compete or escape this dispute. In an area of ​​restricted savanna in an ecological reserve in Uberlândia, Minas Gerais, Brazil, we evaluated (1) reproductive phenology, by observing peaks in the activity of phenophases; (2) floral biology, quantifying parameters related to inflorescences (eg number of inflorescences per individual, length, number of buds), floral structures (eg petal length, petal width, fillet length), and pollen data and ova; (3) floral phenology, observing from floral anthesis to the fall of structures, determining the intensity of the odor released and the volume and concentration of nectar sugar; (4) the reproductive system based on pollination tests; and (5) floral visitors, who were observed, quantified and classified according to their role in the plant. There was no overlap of blooms. Qualea multiflora produced less inflorescences per individual than Q. parviflora. Structurally the flowers were similar, but Q. multiflora had larger flowers. The species presented distinct floral antense, but with similar resources: pollen and nectar. Both have a self-incompatible reproductive system. They are visited by different visitor communities, but they share the same pollinator guild. We conclude that due to the floral similarities, Qualea multiflora and Q. parviflora share the pollinator community. However, competition for pollination services is avoided since the species have sequential blooms and there was no overlapping of the peak peaks of floral activity.