No abstract

Vertical stratification and host preference by vascular epiphytes in a Chiapas, Mexico, cloud forest. The high diversity of vascular epiphytes in neotropical montane forest has been explained as the result of vertical stratification of the forest and specific relationships between epiphytes and their hosts trees at local scales. In a lower montane cloud forest, we studied the vertical stratification and host preferences of vascular epiphytes in a 0.0625 ha plot where 41 trees ≥ of 10 cm DBH were sampled during 12 months in 2001 and 2002. We found 43 epiphyte species growing on 15 tree genera. We tested for vertical strata and host preferences using 19 epiphyte taxa. We found strong evidence that epiphytes divided the canopy, but those epiphyte species dispersed by animals were generalists with respect to hosts and vertical strata. Wind dispersed epiphytes were vertically stratified, with a higher richness in the lowest tree strata. On average the epiphytes preferred 3.5 host species, suggesting low host preference. Two host species, Ardisia and Quercus, were avoided by the majority of the epiphyte species. Our results show that epiphytes divided the canopy horizontally and were stratified vertically, suggesting that host identity could be important determining the abundance of colonizing sites for epiphytes.

No abstract

Vascular epiphytes are a diverse and conspicuous component of biodiversity in tropical and subtropical forests. Yet, the patterns and drivers of epiphyte assemblages are poorly studied in comparison with soil-rooted plants. Current knowledge about diversity patterns of epiphytes mainly stems from local studies or floristic inventories, but this information has not yet been integrated to allow a better understanding of large-scale distribution patterns. EpIG-DB, the first database on epiphyte assemblages at the continental scale, resulted from an exhaustive compilation of published and unpublished inventory data from the Neotropics. The current version of EpIG-DB consists of 463,196 individual epiphytes from 3,005 species, which were collected from a total of 18,148 relevés (host trees and 'understory' plots). EpIG-DB reports the occurrence of 'true' epiphytes, hemiepiphytes and nomadic vines, including information on their cover, abundance, frequency and biomass. Most records (97%) correspond to sampled host trees, 76% of them aggregated in forest plots. The data is stored in a TURBOVEG database using the most up-to-date checklist of vascular epiphytes. A total of 18 additional fields were created for the standardization of associated data commonly used in epiphyte ecology (e.g. by considering different sampling methods). EpIG-DB currently covers six major biomes across the whole latitudinal range of epiphytes in the Neotropics but welcomes data globally. This novel database provides, for the first time, unique biodiversity data on epiphytes for the Neotropics and unified guidelines for future collection of epiphyte data. EpIG-DB will allow exploration of new ways to study the community ecology and biogeography of vascular epiphytes. K E Y W O R D S biodiversity, community ecology, database, forest plot, hemiepiphytes, Neotropics, nomadic vines, taxonomic diversity, vascular epiphytes, vegetation relevé 520 |

Resumen: Se realizó un listado florístico para el Cerro Quetzal (Polígono III) y zonas adyacentes de la Reserva de la Biosfera El Triunfo, Chiapas, México. Se integró una base de datos con 1,513 registros, incluye 140 familias, 432 géneros, 795 especies y 24 categorías infraespecíficas. El total de las especies registradas en este trabajo representa 9% de la flora conocida para Chiapas y aproximadamente un 26.5% de la flora estimada para El Triunfo. El número de especies es similar a las encontradas en los polígonos I y II (751 y 791 especies, respectivamente) y mayor al cerro Cebú (polígono V) (502 especies). Los tipos de vegetación presentes en el cerro Quetzal son: bosque de coníferas, bosque mesófilo de montaña, bosque tropical perennifolio, bosque tropical subcaducifolio y vegetación ruderal. El tipo de vegetación más importante por el número de especies y mejor recolectado es el bosque mesófilo de montaña. Este listado presenta novedades, como una especie nueva del género Ceratozamia (Zamiaceae) y una de Sterculia (Sterculiaceae), además de dos registros nuevos para Chiapas, una de la familia Araceae (Monstera dubia) y otra de la familia Fabaceae (Albizia carbonaria). Palabras clave: bases de datos, conservación, diversidad florística, Sierra Madre de Chiapas.Abstract: A floristic checklist was made for Mt. Quetzal (Polygon III) and adjacent areas at the Triunfo Biosphere Reserve, Chiapas, Mexico. A database of 1,513 specimens was created comprising 140 families, 432 genera, 795 species, and 24 infraspecies. The total number of species recorded in this study represented about 9% of the estimated flora of Chiapas and nearly 26.5% of the estimated flora for The Triunfo region. The number of species is also similar to that recorded for polygons I and II (751 and 791 respectively) but higher than Mt. Cebú (Polygon V) (502 species). The vegetation communities determined in the Mt. Quetzal were: conifers forest, cloud forest, tropical rain forest, subdeciduous tropical forest, and ruderal vegetation. The vegetation type more important based on the number of species and the best recollected was the cloud forest. This checklist also included novel taxa: a new species of Ceratozamia (Zamiaceae) and a new species of Sterculia (Sterculiaceae) and the presence Monstera dubia (Araceae) and Albizia carbonaria (Fabaceae) unrecorded for Chiapas.