The epiphyte communities of a montane rain forest in the Andes of Venezuela: patterns in the distribution of the flora

Abstract

The dependent flora was surveyed on 20 trees at a 1.5-ha site in montane rain forest at 2600 m altitude in western Venezuela. Vascular species were recorded over the whole site and totalled 120 epiphytes, 21 climbers, 3 hemiepiphytes, 5 nomadic vines and 6 mistletoes. Non-vascular species were recorded within 95 sample plots and totalled 22 mosses, 66 liverworts and 46 macrolichens. The angiosperm species were restricted in geographical range to the Neotropics; 22.1% were endemic to Venezuela. Pteridophyte and bryophyte species were largely restricted to the Neotropics but few were endemic. Macrolichen species were mostly pantropical or cosmopolitan; only 9.6% were restricted to the Neotropics and none was endemic. Canonical Correspondence Analysis found the environmental variables most closely correlated with variation in community composition to be height above ground and a horizontal gradient reflecting differences in forest structure. The epiphytic vegetation was classified using Two-way Indicator Species Analysis into a Syrrhopodon gaudichaudii–Elaphoglossum hoffmannii group of lower trunks, an Omphalanthus filiformis–Maxillaria miniata group of intermediate levels and an Usnea–Parmotrema group of upper crowns. Diversity increased with height above ground; non-vascular diversity was greatest in upper crowns whereas vascular diversity was greatest at intermediate levels. Similarity levels were low among sample plots of the same community, whereas between-tree and between-stand similarities were relatively high.

Floristic composition and community structure of epiphytic angiosperms in a terra firme forest in central Amazonia

“…Orchidaceae was recorded as the third most diverse family and ranked in fourth position in terms of FIV, a result that contradicts expectations and contrasts with the standard of most of the epiphytic flora inventories in Neotropical regions, since it is often cited in the first position Kelly et al 2004;Kuper et al 2004;Kromer et al 2005;Zotz & Schultz 2008). In the subtropical forests of Brazil, Orchidacae is also cited as the most diverse family (Alves et al 2008;Neto et al 2009;Kersten 2010;Blum et al 2011).…”

“…Despite the presence of common accidental epiphytes belonging to various families in the inventories of epiphytic flora, there are few studies that quantify and report the occurrence of species in this taxon (Barthlott et al 2001;Arévalo & Betancur 2004;Kelly et al 2004;Zotz & Schultz 2008), be those specimens behaving as epiphytes, hemiepiphytes, accidental epiphytes or facultative epiphytes. Furthermore, in many regions, it is uncommon for members of this family to present epiphytism.…”

“…Many studies conducted in the Neotropics mention that the canopy is the area of greatest epiphytic richness and abundance (Rudolph et al 1998;Kelly et al 2004;Schuettpelz & Trapnell 2006;Pos & Sleegers 2010). According to these authors, the high species richness in the canopy can be attributed to the greater diversity of substrates for attachment (bifurcations and different lighting conditions in the branches).…”

The vascular epiphytes of a lowland forest in Panama—species composition and spatial structure

“…Vascular epiphytes frequently represent the most species-rich life form in tropical forests (Benzing 1990;Gentry and Dodson 1987). Although their contribution to local species richness is generally greater in montane forests (Kelly et al 2004), they still account for at least 10-20% of all vascular species in most lowland forests (Baislev et al 1998;Benavides et al 2005;Bordenave et al 1998;Croat 1978;Whitmore et al 1985).…”

Ecogeografía del género Sticta (Ascomycota liquenizados: Lobariaceae) en Colombia

“…Estudios filogené-ticos recientes sugieren que el paradigma que muchas especies tienen distribución pantropical (Galloway, 1979;Lücking, 2003;HerreraCampos et al, 2004;Feuerer & Hawksworth, 2007;Aptroot & Iqbal, 2011) es incorrecto y que la mayoría tienen rangos de distribución bien definidos (Molina, Crespo, Blanco, Lumbsch & Hawksworth, 2004;Tehler, Irestedt, Wedin & Ertz, 2010;Del Prado et al, 2006;Moncada, 2012;Moncada, Lücking & Suárez, 2013), aumentando la posibilidad de que especies sean endémicas e incrementando el valor potencial de sus recursos genéticos y bioquímicos. Existen pocos estudios cuantitativos sobre la ecología de líquenes tropicales, y a menudo aplican una taxonomía superficial que no refleja conceptos apropiados que permitan delimitar especies o excluyen grupos taxonómicamente difíciles (Kelly et al, 2004;Holz & Gradstein, 2005;Boonpragop & Polyiam, 2007;Dyer & Letourneau, 2007). Entre las excepciones están los estudios de los líquenes foliícolas de Costa Rica por Lücking (1998aLücking ( , 1999a, los líquenes corticícolas de los llanos de Venezuela Komposch y Hafellner (2000, 2003, los líquenes del sur de Brasil (Martins, 2006) y los microlíquenes corticícolas del nordeste de Brasil (Cáceres, Lücking & Rambold, 2007.…”