Reproductive ecology of understory species in a tropical montane forest in Costa Rica

The reproductive ecology of nine hermaphroditic understory species in a tropical montane Quercus forest was studied at two sites (2300 and 2600 m elev.) in the Cordillera de Talamanca, Costa Rica. Flower life span, studied in six species, averaged 4.4 d. This is longer than flower life spans found in the Monteverde cloud forest (2.7 d) and comparable co flower life spans found for arctic and alpine species. We studied the breeding system in five species and found no self-incompatible species. Four species proved self-compatible, and three: of these showed autogamy. The main diurnal insect pollinator was the bumblebee Bombus ephippiatus. Natural fruit set was low (8-32%) in six species with few seeds per fruit, while two many-seeded species showed a high rare of fruit set (90 and 96%). The incidence of pre-dispersal seed predation was high; the percentage of seeds infested in four species ranged from 8 to 56 percent.