Orchid's diversity at Tepequem's Tepuy, Roraima, Brazil

Abstract

The Orchidaceae family is one of the largest among the angiosperm, with more than 27000 species, 2,500 is endemic to Brazil, 871 species are found in the Brazilian Amazon. In the far north of Brazil, in the state of Roraima, is located the Tepequem Mountains, a Tepuy-mountain top with table shape-with relictual vegetation due to prolonged isolation. Historically, Tepequem was a site of diamond exploration, which caused changes in the landscape. However, with mining decay, ecotourism became the main economic activity. About 68% of Roraima's territory is composed of conservation areas and indigenous lands, and the Tepequem Mountain is the only Tepuy found outside the protected areas. Thus, this study aims to describe the orchid flora found at Tepequem's Tepuy, an area of ecological and economic importance for Roraima's ecotourism. The survey was carried out through expeditions between the years of 2013-2015. The species were photographed, harvested and taken to Embrapa Roraima for identification, exsiccate confection and/or cultivation. The exsiccatae were deposited at Roraima's Integrated Museum (Museu Integrado de Roraima-MIRR) and the Federal University of Roraima (Universidade Federal de Roraima-UFRR). Any orchid species deposited by other collectors was also considered. Thus, 20 genera and 34 species were registered at Tepequem. The genera with largest representation were the Epidendrum (7 spp.), Scaphyglottis (4 spp.) and Habenaria (3 spp.), with 70% of the other genera presenting one species only. 10% of Roraima's orchid's diversity is found at Tepequem. The diversity of habitats-forest, campina and savannah-found at Tepequem's Tepuy allows the Orchidaceae species diversity and the unique flora with low similarities to other floristic surveys.