Phenology of Pentaclethra macroloba (Willd.) Kuntze (Fabaceae): hyperdominant tree of the Amazonian estuary.

Pentaclethra macroloba (pracaxizeiro) is a hyperdominant species of the Amazon estuary floodplain. The oil extracted from its seeds has medicinal properties. The effect of the polymodal flood cycle on the phenology of tree, including the pracaxizeiro, from Amazonian estuary is little known. The hypothesis that the flood pulse is the main factor that directs the phenological processes of the pracaxizeiro was tested. Reproductive and vegetative phenophases of 30 pracaxizeiro were monitored fortnight from September/2017 to September/2018, in the Environmental Protection Area of Fazendinha, Macapá, Brazil. Phenophases were correlated with maximum temperature (°C), precipitation (mm) and flood level (cm), using the Spearman correlation. There was positive correlation with temperature between flower buds (rs = 0.57) and flowers in anthesis (rs = 0.63), already with precipitation (buds: rs = -0.50, anthesis: rs = -0.53) and floods (buds: rs = -0.65, anthesis: rs = -0.69) correlations were negative. The correlation was positive between immature fruit with temperature (rs = 0.73) and negative with precipitation (rs = -0.64) and flood (rs = -0.57). Fruit ripening (rainfall: rs = 0.38, flood: rs = 0.50) and seed dispersal (rainfall: rs = 0.76, flood: rs = 0.81) occur in the rainy season and peak flood Amazon river. Leaf production and fall have low correlation with the abiotic variables tested. Flourish in the dry season prevents loss of floral resources due to torrential rains of the Amazon and maximizes pollination by insects. The flood pulse, together with precipitation, acts as a trigger in fruit ripening and seed dispersal.Edição especial dos resumos do IUFRO World Congress, 25., 2019, Curitiba