Reproductive phenology of epiphytes in Monteverde, Costa Rica

Abstract

Phenology of plants, or the timing of life cycle events, is important for understanding plant ecology, forest dynamics, and plant-animal interactions. In tropical forests, studies that document epiphyte reproductive phenology are relatively few because of the challenges of tracking plants that live in the canopy. Phenological patterns for 279 individuals of 7 epiphyte species were examined across 12 months in a tropical montane forest in Monteverde, Costa Rica. Epiphytes were located in one of two common tree species, Ficus tuerckheimii (Moraceae) or Ocotea tonduzii (Lauraceae). Flowering and fruiting (i.e., when ripe or unripe fruit is present on the plant) of study plants was recorded on monthly intervals, and phenology was examined as a function of the season at the study site (i.e., wet, transition, or dry season), and pollinator syndrome (bird-, or insect-pollinated) and seed dispersal syndrome (bird-, bat-, or wind-dispersed) of each plant. Though some epiphyte species flowered and fruited throughout the year, the majority showed significant seasonality in phenological events. Based on circular statistics, the timing of mean flowering of different epiphyte species varied, however, timing of mean fruiting for most species tended to occur during the wet season. Insect-and bird-pollinated species had peak flowering during the dry season and late wet season, respectively. Bird-dispersed fruits were present each month of the year with peaks from February to October and again in December. Wind-dispersed fruits were observed eight months of the year with a peak in the early wet season. The timing of epiphyte flowering coincided with flowering of large trees in the area. Epiphyte fruiting, however, is distinct from large tree fruiting. Our results demonstrate the seasonal nature of flowering and fruiting in individual epiphyte species while also highlighted the asynchronous nature of phenological events amongst the epiphyte community. Rev. Biol. Trop. 63 (4): 1119-1126. Epub 2015 December 01.

Vascular Epiphytes: The Ugly Duckling of Phenological Studies

“…It was not until 1975, in his article Phenological behavior of habitat and habitat classes on Barro Colorado Island, where Croat analyzed the phenological patterns of 41 epiphyte species. This resistance to incorporate epiphytes in phenological studies persists to this day, much of it related to the logistical challenge involved in monitoring individuals that grow on trees, often at heights over 40 m off the ground (Sheldon and Nadkarni, 2015).…”

“…It has been hypothesized that competition between species for pollinators can be reduced by avoiding the overlap of their flowering periods ("Hypothesis of the shared pollinator"; Wright and Calderon, 1995), but this has barely been explored when it comes to vascular epiphytes. A study that stands out in this respect is the one by Sheldon and Nadkarni (2015) where they looked at the floral phenology of a community of vascular epiphytes in a tropical forest. Although they did not directly evaluate the competition for pollinators, they found asynchrony in the flowering periods among epiphyte groups that shared a common kind of pollinator.…”

La precipitación está asociada con la fenología de Rodriguezia granadensis (Lindl.) Rchb. f. en Fusagasugá, Cundinamarca

“…La fenología, se refiere a los cambios visibles en el desarrollo biológico y se explica en términos de "estadios" o "fenofases" (Meier, 1997;Tang et al 2016). Los estudios que documentan la fenología de las especies epífitas son relativamente pocos, debido a la complejidad para el seguimiento de las plantas que viven en el dosel de los árboles (Sheldon & Nadkarni, 2015).…”

Flowering phenology of Catopsis compacta (Bromeliaceae), a dioecious epiphyte in an oak forest

“…Overall, the flowering periods of epiphytes are annual and continuous, lasting for 3-4 months (Sheldon & Nadkarni 2015). For dioecious epiphytes, the two known phenological studies reported an annual flowering pattern of about 8 months that was possibly induced by pollinator behavior, precipitation and solar radiation (Zimmerman et al 1989, Trejos-Hernández 2015.…”

“…The reproductive phenology of epiphytes, plants that grow on other plants without feeding directly from them, is linked to the presence of pollinators (Ackerman 1986, Zimmerman et al 1989, Jaramillo & Cavelier 1998, Sheldon & Nadkarni 2015 and to precipitation (Sahagun-Godinez 1996, Sheldon & Nadkarni 2015. Overall, the flowering periods of epiphytes are annual and continuous, lasting for 3-4 months (Sheldon & Nadkarni 2015).…”