Fauna de abelhas (Hymenoptera, Apoidea) nos campos rupestres da cadeia do espinhaço e biogeografia de espécies endêmicas em formações campestres altimontanas do centro-leste do Brasil

Abstract

Bee fauna (Hymenoptera, Apoidea) in the campos rupestres of the Espinhaço range and biogeography of bee species endemic to mountaintop grasslands of central-east Brazil. The aim of this work is the comprehensive knowledge of the richness, composition and geographical distribution of the bee fauna of the campos rupestres (quartzite rocky grasslands) on the Espinhaço range, and to investigate the endemic elements in mountaintop grasslands and the historical relationships among the central-east Brazilian highlands, based on the geographical distribution of these elements. Bees were sampled in the campos rupestres of the Espinhaço range between October 2004 and May 2006 and, in the mountaintop grasslands of the Mantiqueira (Itatiaia e Ibitipoca), Canastra and Caparaó ranges and on the Veadeiros plateau, between October 2006 and April 2007. Additional data were also obtained from secondary sources, through the compiling of field and literature records and and to data associated to specimens in taxonomic collections. More than 500 species were recorded for the Espinhaço range, from where two new species were described. Parsimony Analysis of Endemicity (PAE) was employed to detect the biogeographycal relationships among 10 high-altitude (> 1,000 m elevation) geographic areas and in an additional biogeographic unit composed of the subtropical/temperate regions of South America., based on the presence or absence of 29 species in the investigated areas. Two equally parsimonious area cladograms were obtained (63 steps, consistency index of 0.46 and retention index of 0.55), recognizing the same two major clades. The first included the southeasternmost massifs (immerse in the Atlantic Forest Domain), and the subtropical/temperate regions of South America, and the second one, included the northwesternmost massifs (immerse in the Cerrado domain). The biogeography units partially support the hipothesis of gradual isolation of massifs in accordance to a North-South regional heating, after the last glaciation event.