Biogeography of the Antilles based on a parsimony analysis of orchid distributions

Abstract

Aim We obtain biogeographical patterns based on the distributions of shared orchid species of the Caribbean. These patterns are used to define biogeographical zones. We then analyse the concordance between the distributional patterns with ecological and physical features of the islands. Location We use orchid species recorded on 49 islands of the Greater, Lesser, and southern Antilles, and the Bahamas. Three continental areas are included: Florida (North America), the Yucatan (Central America), and the Guianas (South America). Methods We use a parsimonious analysis of species distributions that produces the best arrangements of shared taxa among areas. The analysis uses 356 shared orchid species of the 863 species recorded for studied areas. The methodology has been used to infer historical relationships among areas but we interpret the results as static or ecological patterns of biogeographical affinities. Results Two kinds of island groupings are revealed. (1) Groups with common geology and geomorphology: the Bahama Archipelago, the Virgin Islands, the Cayman Islands and the southern Dutch Antilles. (2) An aggregation of distant islands with a heterogeneous geology but a common physiography: the Greater Antilles/Trinidad/Lesser Antilles/Margarita‐Tobago. The Guianas are linked with the Greater Antilles, while the Yucatan and Florida are linked to the Bahamas. Main conclusions Groupings of islands are congruent with their gross ecological features either from similar geomorphology or common physiography. The strong affinity among islands considerably distant among each other is explained by the high vagility of dust‐seeded orchids. Then, floristic affinities seem determined by ecological characteristics of islands rather than by dispersal barriers. We predict that other plant groups with dust‐like diaspores and animals with good vagility should show comparable biogeographic patterns. Parsimony analysis of distributions (PAD) is an alternative methodology to multivariate analysis to compare biotas, and a graphic complement to quantitative methods producing numerical values.

Large‐scale diversity patterns of vascular epiphytes in Neotropical montane rain forests

“…, 1994, Hietz & Hietz‐Seifert, 1995). Trejo‐Torres & Ackermann (2001) have shown that the overlap in the Orchid inventories of distanced Caribbean islands was high, when the physiographic and ecological conditions allowed the species presence. In contrast, even neighbouring islands had a small floristic overlap if their physiognomy was different.…”

Vagility: The Neglected Component in Historical Biogeography

“…It has been shown that ecological traits determining the vagility potential of species can affect their distributions (e.g., Doyen and Tschinkel 1974;Lomolino 1983;Shine 1987;Trejo-Torres and Ackerman 2001). Here I use a scenario of two islands to describe possible modes of evolution of geographic ranges and discuss the central role of vagility.…”

Riqueza e endemismo de espécies de Baptistonia (Orchidaceae), no Brasil

“…Muitas vezes, as OGUs são quadrículas (Morrone 1994). O mesmo foi utilizado em várias espécies animais e vegetais (Posadas & Miranda-Esquivel 1999, Trejjo-Torres & Ackerman 2001, Garcia-Barros et al 2002, Morrone & Escalante 2002, Rovito et al 2004. Craw (1988) sugeriu utilizar áreas de endemismo predeterminadas e Silva & Oren (1996) escolheram áreas interfluviais.…”