Reproductive phenology and mating potential in a low density tree population of Couratari multiflora (Lecythidaceae) in central Amazonia

The reproductive phenology of a population of 39 adult trees of Couratari m ultiflora was studied in 'terra firme' forests located 90 km N of Manaus, A mazonas, Brazil. Trees of this species, found in low densities, were invent oried in a 400-ha plot in which only one tree greater than or equal to 20 c m DBH per 10 ha was encountered. This species flowers from January to June, with a peak in the mid-wet season (March), and fruits during the dry seaso n (May-September). Median distances between synchronized flowering trees we re 600 to 1000 m depending on the time of the flowering season. The number of synchronous flowering trees at each observation date in the 400-ha plot was 14 or 17.5 per 1 d, 13 (both) per 15 d, and three or 13 per 30 d, depen ding upon which of the two methods was used to evaluate synchrony. Fifty pe rcent of the flowering trees overlapped in flowering with six to seven othe r flowering trees growing within a radius of 1000 m during most of the annu al flowering period. Outcrossing rates were 100 % and the relatively long d istances between trees in flower at the same time, support the assumption t hat this species is pollinated by pollinators travelling distances as far a s 1000 m.