Environment and Natural Resources Research; Vol. 2, No. 3; 2012 ISSN 1927-0488 E-ISSN 1927-0496 Published by Canadian Center of Science and Education 115 Floristic Composition, Species Richness and Diversity of Campo Rupestre Vegetation from the Itacolomi State Park, Minas Gerais, Brazil Markus Gastauer 1, 2 , Maria Cristina Teixeira Braga Messias 3 & João Augusto Alves Meira Neto 1, 2 1 Laboratory of Plant Ecology, Department of Plant Biology, Federal University of Viçosa, Viçosa, Minas Gerais, Brazil 2 Center of Environmental Sciences Floresta-Escola, City of Waters, Frutal, Minas Gerais, Brazil 3 Department of Biodiversity, Evolution and Environment, Federal University of Ouro Preto, Ouro Preto, Minas Gerais, Brazil Correspondence: João Augusto Alves Meira Neto, Laboratory of Plant Ecology, Federal University of Viçosa, Viçosa, Brazil. Tel: 55-313-899-1955. E-mail: j.meira@ufv.br Received: May 11, 2012 Accepted: June 11, 2012 Online Published: September 1, 2012 doi:10.5539/enrr.v2n3p115 URL: http://dx.doi.org/10.5539/enrr.v2n3p115 Abstract Nevertheless campos rupestres are considered species rich and diverse vegetation formations, phytosociological surveys from the Itacolomi State Park, Minas Gerais, Brazil, are lacking in scientific literature. To close this gap, we compared floristic composition, species richness and diversity from two sites, Lagoa Seca and Calais, both situated within the park. Calais is moderately impacted by extensive pasture, fire, and settling activities. Both surveys contained 15 plots of 10 x 10 m, cardinality of each species was estimated. Beside species richness, the indexes of Shannon-Wiener, Fisher’s α, the community richness estimator Jackknife 1 and the numbers of endemic, endangered and invasive species were compared. With 107 species, the moderately impacted Calais showed higher species richness than Lagoa Seca (76 species). The indices of Shannon-Wiener and Fisher’s α, the community richness estimator, as well as point diversity and spatial turnover derived from the species-area relationship (SAR) indicated higher diversity for Calais. From Lagoa Seca, 30% of all species are endemic to the Atlantic Rainforest or to Cerrado, and four species are endangered, not any species found in Lagoa Seca is described as an invasive one. On the other hand, 23 species found in Calais are invasive species, only one from all 107 species is endangered. Only 19% of all species found in Calais are endemic. Nevertheless species richness and diversity differ between both study sites, they are exceptionally high compared to similar vegetation formations from further regions. This justifies the declaration of the park as a local hotspot of biodiversity. Furthermore, our results show that species richness or diversity measures are inappropriate criteria to evaluate the intactness of campo rupestre vegetation. More weight should be put on criteria like numbers of invasive, endemic or endangered species. Keywords: endemism, endangered species, invasive species, conservation, species-area relationship, species richness 1. Introduction In the Brazilian Mountain Ranges, tropical forests and savannahs are displaced by rocky outcrop vegetation types above certain altitudes (usually 900 m, Scolforo & Carvalho, 2006). These azonal rock fields are species rich ecosystems containing many endemics (Caiafa &Silva, 2005; Conceição & Giulietti, 2002; Giulietti, Menezes, Pirani, Meguro, & Wanderley, 1987; Jacobi, Carmo, & Vincent, 2008; Messias, Leite, Meira Neto, & Kozovits, 2011; Pirani, Giuletti, Mello-Silva, & Meguro, 1994; Romero & Nakajima, 1999). Although endangered due to the intensification of grazing, fire clearing, continued urbanization, dispersion of invasive plant species, collection of endangered (medical) plants, mining activities and nutrient input from industry and traffic (Pirani, Mello-Silva, & Giuletti, 2003), still little is known about species composition and diversity of these ecosystems (Almeida, 2008; Messias et al., 2011; Mourão & Stehmann, 2007). In Brazil, different types of rocky outcrop vegetation can be distinguished, although this differentiation is not unambiguous (Alves & Kolbeck, 2010). We adapt the Alves and Kolbeck (2010) system, where campo de