Biodiversity and spatial distribution of epiphytic ferns on Alsophila setosa Kaulf. (Cyatheaceae) caudices in Rio Grande do Sul, Brazil

Abstract

The extractive exploitation of the tree fern Alsophila setosa Kaulf. alters forest formations and diminishes the availability of micro-habitat for epiphytes. A survey of epiphytic fern communities on A. setosa at 16 study sites in different forest formations in the State of Rio Grande do Sul, Brazil, documented the occurrence of 31 species representing 16 genera and six families. The greatest richness of species occurred in Polypodiaceae (39%) and in the genus Asplenium L. (22%). Habitual holoepiphyte was the predominant ecological category, representing 61% of the species. Similarity analysis demonstrated heterogeneity in the composition of the epiphytic ferns at the study sites and indicated that the vegetation type is not the main factor for floristic difference. The lowest total specific richness (5) was recorded for the seasonal deciduous forest site. The majority of the sites presented similar averages of phorophyte height and epiphyte richness per caudex. In 25% of the sites the height of the host plants presented significant correlation with specific richness. Considering that the majority of the epiphytes are habitual and that some of them occur exclusively or preferentially on tree ferns, the maintenance of these host plants in the vegetation is essential for the conservation of epiphytic species.Keywords: composition, species richness, epiphytism, tree fern, conservation. (5) foi registrada em sítio de floresta estacional decidual. A maioria dos sítios apresentou médias similares de altura dos forófitos e de riqueza de epífitos por cáudice. Em 25% dos sítios, a altura das plantas hospedeiras apresentou correlação significativa com riqueza específica. Considerando que a maioria dos epífitos é habitual e que alguns deles ocorrem exclusivamente ou preferencialmente sobre samambaias arborescentes, a manutenção dessas plantas hospedeiras, na vegetação, é essencial para a conservação de espécies epifíticas.Palavras-chave: composição, riqueza de espécies, epifitismo, samambaia arborescente, conservação.

Epiphytic ferns in swamp forest remnants of the coastal plain of southern Brazil: latitudinal effects on the plant community

“…was similar to the 31 species found by Schmitt & Windisch (2010) on 160 individuals of Alsophila setosa in different forest types in Rio Grande do Sul. In a forest with Araucaria in Rio Grande do Sul, Schmitt et al (2005) sampled 40 tree ferns of Dicksonia sellowiana Hook.…”

“…October-December 2016 2016). Among the seven works that focused on epiphytism of seedless vascular plants (ferns and lycophytes), four were carried out exclusively with tree ferns (Schmitt et al 2005;Fraga et al 2008;Schmitt & Windisch 2010;Schneider & Schmitt 2011) while the other studies included all types of phorophytes (Labiak & Prado 1998;Barros et al 2014;Quevedo et al 2014).…”

Abiotic environmental conditions for germination and development of gametophytes of Cyathea phalerata Mart. (Cyatheaceae)

“…Arborescent ferns play an important role in tropical forests and, in particular, due to its long and erect caudices, they provide a habitat for many epiphytic species (Schmitt & Windisch 2010;Schneider & Schmitt 2011). However, these plants are targets of extractive exploitation, particularly in the South of Brazil, which has a negative impact on the availability of microhabitats for epiphytes that preferentially or exclusively occur on their caudices (Schmitt & Windisch 2005).…”

Distribution patterns of ferns and lycophytes in the Coastal Region of the state of Rio Grande do Sul, Brazil

“…The presence of a center of diversity and endemism of ferns and lycophytes in the Atlantic Forest of southeastern Brazil (Tryon 1972), is relevant for the diversity of southern Brazil, including the Coastal Region of the state of Rio Grande do Sul. This diversity within Rio Grande do Sul is represented by approximately 397 species (Sehnem 1977), mainly known from regional surveys (Mondin & Silveira 1989;Bueno & Senna 1992;Senna & Waechter 1997;Athayde-Filho & Windisch 2006;Schmitt et al 2006;Lehn et al 2009;Santos & Windisch 2008Schmitt & Goetz 2010Becker et al 2013;Silva et al 2013;Gonzatti et al 2014a;Gonzatti et al 2014b;Mallmann & Schmitt 2014), phytogeographic and palynological reviews (Sehnem 1977;Lorscheitter et al 1998;1999;2001;, and research on ecology, phenology and development (Schmitt & Windisch 2010;Schneider & Schmitt 2011;Schmitt & Windisch 2012;Rocha et al 2013;Neumann et al 2014;Quevedo et al 2014; among others).…”