Phenological study on Stryphnodendron adstringens (Mart.) Coville in a cerrado sensu stricto site in the Fazenda Água Limpa, Federal District, Brazil

Stryphnodendron adstringens, popularly known as barbatimão, is widely distributed in the cerrado bioma from Pará, in the Amazon region, to the Brazilian central plateau reaching the Southeast (Minas Gerais and São Paulo). Its bark and fruits countain taninn and have medicinal properties. Its nutritional requirements are low and it doesn't accumulate aluminium. Flowers are hermaphrodite and pollinated by small insects, especially bees. It is one of the main woody species found in the site studied. The objective of this paper is to analyse the phenological events of this species in an area of cerrado sensu stricto in the Fazenda Água Limpa (15°56'S and 47°46'W) from 1987 to 1991. Ten trees were observed from january/18/1987 to november/07/1991. The climate is Köppen Aw, with a well-marked seasonality. Phenological patterns were graphically analysed, by Kruskall-Wallis test at 5% and by Spearman Rank Correlation. Annual leaf change patterns were similar over the five-year period. All individuals flowered each year, except for two that did not flower in 1990, one year after an accidental burning. Flowering occurred between July to November with the peaks varying over the years. All individuals produced fruits until 1989 when they were aborted by the burning. No fruiting was observed in the following year and just half of the fruit production was observed in 1991. The phenological model is annual with flowering, fruiting, seed dispersal, peaks of senescence and leaf flushing occurring in the dry season. Fruits take about one year to ripe. Occasional dry season fires deeply affected the reproductive activities, especially fruiting.

Phenology; savanna; cerrado; fire; Stryphnodendron adstringens; Brazil