We compared two sympatric species of Psychotria (P. brasiliensis and P. nuda), regarding phenology and spatial distribution. The phenological events were associated with abiotic factors (rainfall, temperature and photoperiod) and biotic factors (pollinators and frugivores). We carried out the study between August/1998 and July/1999 in an undisturbed area of the Atlantic Forest at Ilha Grande, Rio de Janeiro. We made phenological observations and also recorded the species visiting the flowers and eating the fruits of both plant species. The production of new leaves occurred from November/1998 to May/1999 for both species. There was a positive correlation between photoperiod, rainfall and temperature (climatological means) and leafing period. The flowering period was between March and June for P. nuda and, April and July for P. brasiliensis. Psychotria nuda was visited mainly by males of an species of hummingbird, Thalurania glaucopis (Trochilidae) (47,2%; n=682), while P. brasiliensis was visited by females (85,1%; n=1869) of this hummingbird species. Both species flowered in the same period, used the same pollinator, but may not compete for this resource, thus we rejected the "shared-pollinator" hypothesis. The fruiting period ocurred all year round for P. nuda and P. brasiliensis. Lipaugus lanioides, was the most frequent frugivore in P. brasiliensis. Psychotria nuda and P. brasiliensis had clumped distribution, apparently due to vegetative reproduction, mostly by P. nuda. This study suggests that both species of Psychotria are important resources for Atlantic Rain Forest bird species.
Psychotria; phenology; spatial distribution; Atlantic Forest; Brazil
