Aiphanes - Habitat and Ecology

Habitat and Ecology

Aiphanes species are palms of the forest understorey and subcanopy. The most widely distributed species, A. horrida, occurs both in tropical dry forest and in more humid forest types, but there is a gap in its distribution which coincides with the wettest forests of the upper Amazon Basin. Two other species, A. minima and A. eggersii, are also found in drier environments; A. eggersii is found in areas receiving as little as 500 mm (20 in) of precipitation annually. The remaining species are found in montane forests at high elevations or in wet—often very wet—lowland forests, including areas receiving as much as 9,000 mm (350 in) of annual precipitation.

Records of visits by pollinators exist for only a few species, but most of these suggest that the species are pollinated by insects. Flowers of A. chiribogensis produce small quantities of nectar, but lack a scent. Fruit flies (Drosophilidae), fungus gnats (Mycetophilidae, Sciaridae), midges (Cecidomyiidae, Ceratopogonidae) and micromoths (Lepidoptera) were recorded visiting these flowers, but bees and hover flies were not. Aiphanes eggersii was thought to be pollinated by bees and possibly by wind. Fruit flies (Drosophilidae), hover flies (Syrphidae), biting midges (Ceratopogonidae) and leaf beetles (Chrysomelidae) were recorded visiting the flowers of A. erinacea, but bees were not. Aiphanes horrida was reportly pollinated by wind, bees (Meliponidae), weevils (Curculionidae) and bugs (Hemiptera). Flies and weevils were observed on the flowers of A. simplex.

The fruit of A. horrida is rich in vitamins and energy and likely to be eaten by many animals. Oilbirds are reported to eat its fruit and disperse its seeds. Squirrels are also reported to consume the fruit, despite the spiny nature of the tree. The fruit, flowers and seeds of A. minima are consumed by the vulnerable Saint Vincent Amazon (Amazona guildingii) and is also considered a potentially important food species for the critically endangered Puerto Rican Amazon (Amazona vittata).

Several species show clumped distributions. Dispersal limitation has been invoked to explain the clumped distribution of adults and limited recruitment of seedlings in both A. erinacea in Ecuador and A. minima in Puerto Rico. Similarly, the rarity of A. lindeniana and A. simplex in Colombian forests may be linked to limited seed production and the limited effectiveness of seed dispersal by avian and mammalian frugivores.