The study of native palms is important for its great value economic and in maintenance of communities of several species of vertebrates and invertebrates that feed on their fruits, seeds and leaves. The efficiency in the production of palm fruits is directly related to the presence of pollinating insects, especially beetles, bees and flies. The palm Mauritia flexuosa, commonly known as buriti, is the most abundant species in Brazil and is also called the "tree of life" because it is 100% usable. This study aimed to contribute to the knowledge of the pollination ecology of buriti in Restinga, in the municipality of Barreirinhas, Maranhão, Brazil. Therefore, we obtained data on reproductive phenology, floral biology, breeding system, and flower visitors. For phenological monitoring 25 individuals of each sex were selected, which were observed from August/2009 to October/2012. The stages of a flower and fruit were related to climatic variables through correlation Speaman. The process of anthesis and floral longevity was observed during peak flowering species, verifying the pollen viability, stigmatic receptivity, the regions emitting scent and occurrence of thermogenesis. Tests of cross-pollination and apomixis were made to check the reproductive system. The transport of pollen grains by wind was observed through glass slides greased with vaseline which have remained hanging near the pistillate inflorescences for 24 hours. The floral visitors were collected by bagging inflorescences of 20 of each sex and were classified according to the frequency and behavior. The buriti presented annual, synchronous and seasonal phenological pattern with flowering from August to November and peak fruit falling in September, which corresponds to the dry season, differing from that of the Amazon, where these phenological events occurred in rainy season. This difference can be explained by the greater availability of water in the region, which makes the buriti not necessarily depend on the rains to flowering. This was evidenced by the significant negative correlation of phenophases with precipitation and relative humidity. A strong solar irradiation and water availability in the environment contributed to the success in flowering and fruiting of buriti. In addition, biotic factors may have influenced the phenology, whose reproductive strategy adopted appears to be synchronization of flowering and fruiting with the activity of pollinators and seed dispersers. Thus the species warrants its reproduction in an optimal period for seed germination and seedling establishment. The reproductive system of buriti is xenogamic. The set of floral traits, combined with the abundance of pollen and the strong odor suggests that the buriti has as its main strategy pollination cantharophly, but the wind has a great importance in pollination. Besides presenting a mixed pollination (ambophily), flowers buriti attracted a wide variety of visitors, whose wealth was higher than those observed in the the Amazon.
|
