Composition and ecology of vascular epiphyte communities along an altitudinal gradient in central Veracruz, Mexico

Abstract

Vascular epiphytes were studied in forests at altitudes from 720 to 2370 m on the Atlantic slope of central Veracruz, Mexico. The biomass of all trees of each species > 10 cm diameter at breast height within plots between 625 and 1500 m 2 was estimated. The number of species per plot ranged between 22 and 53, and biomass between 9 and 249 g dry weight/m 2 . The highest values, both of species and biomass, were found at an intermediate altitude (1430 m). Habitat diversity may contribute to epiphyte diversity in humid forests, but the importance of this effect could not be distinguished from the influence of climate. A remarkably high number of bromeliads and orchids grew in relatively dry forests at low altitudes. In wet upper montane forests, bromeliads were replaced by ferns, while orchids were numerous at all sites, except for a pine forest. The number of epiphytic species and their biomass on a tree of a given site were closely related to tree size. According to Canonical Correspondence Analysis, the factor determining the composition of the epiphytic vegetation of a tree was altitude and to some extent tree size, whereas tree species had practically no influence. The only trees which had an evidently negative effect on epiphytes were pines, which were particularly hostile to orchids and to a lesser degree to ferns, and Bursera simaruba, which generally had few epiphytes due to its smooth and defoliating bark.

How prevalent is crassulacean acid metabolism among vascular epiphytes?

“…Tremblay et al 1998;Flores-Palacios and Garcia 2001). Secondly, plant biomass may also differ by many orders of magnitude•^take, e.g., tiny twig orchids versus massive aroids or large tank bromeliads (Hietz and Hietz-Seifert 1995). Thus, if CAM were particularly common in small and/or rare epiphyte species, the importance of CAM within an epiphyte community will be quite different from what could be concluded from species numbers alone.…”

“…Clearly, knowledge of the proportion of species with CAM alone does not allow one to draw unambiguous conclusions on the prevalence of CAM in a given community. The traditional "species approach" may still be valid in large-scale comparisons between vastly differing forest types (Hietz and Hietz-Seifert 1995;Hietz et al 1999). In extreme cases, e.g.…”

“…Griffiths et al 1986;Hietz et al 1999), the much better development of epiphytes in montane forests should still lead to a substantial increase in CAM biomass. The only data set available to test this notion is that of Hietz and Hietz-Seifert (1995;and R Hietz, unpublished data). The CAM biomass of six epiphyte communities, studied along an altitudinal gradient (720-2,370 m a.s.l.)…”

Epífitos vasculares sobre espécimes de Ficus organensis isoladas no norte da planície costeira do Rio Grande do Sul: padrões de abundância e distribuição

“…Os resultados obtidos na análise da distribuição espacial dos epífitos vasculares nas figueiras estão de acordo com os resultados obtidos por outros autores (Johansson 1974;Bøgh 1992;Hietz & Hietz-Seifert 1995a;Freiberg 1996;Rudolph et al 1998;Nieder et al 1999), embora as metodologias utilizadas tenham sido diferentes. Os fustes são, normalmente, áreas que não favorecem a instalação de epífitos vasculares, devido principalmente à verticalidade do substrato (Bøgh 1992;Waechter 1992;Freiberg 1996), à ação do vento, à presença de animais (em especial, gado bovino) nas imediações das árvores e à pequena altura deste segmento nas árvores isoladas, mesmo considerando a presença, nas figueiras, de extensas raízes tabulares, o que aumenta a área disponível para a colonização pelos epífitos vasculares.…”

Diversity, vertical structure and floristic relationships of vascular epiphytes in an urban remnant of the Brazilian Atlantic Forest

“…Richness and geographic distribution -The most species-rich families in the MK (Bromeliaceae, Polypodiaceae, Araceae and Orchidaceae) share a common, similar status in several floristic and/ or ecological surveys conducted on different forest physiognomies, both in the Atlantic forest (Waechter 1992, Dittrich et al 1999, Kersten & Silva 2001, Kersten et al 2009, Menini Neto et al 2009a, Bianchi et al 2012, Alves & Menini Neto 2014, Barbosa et al 2014) and the Neotropical region (Catling & Lefkovitch 1989, Hietz & Hietz-Seifert 1995, Arévalo & Betancur 2004. These families are also the richest ones in terms of vascular epiphytes (Gentry & Dodson 1987, Benzing 1990, Zotz 2013.…”