Quantas espécies de plantas vasculares existem em um hotspot local de biodiversidade no sudeste do Brasil?

Abstract

Scientific information about the distribution of species richness and diversity is necessary for full comprehension of our evolutionary heritage forming a powerful tool for the development of nature conservation strategies. The aim of this article was to estimate the vascular plant species richness of the campos rupestres from the Itacolomi State Park (ISP) in order to verify the park´s classification as a local hotspot of biodiversity and to outline the status quo of knowledge about biodiversity in the region. For that, the species richness of two phytosociological surveys of 0.15 ha each were extrapolated using (a) the species-area relationship fitted by the power and the logarithmic model as well as (b) the taxon ratio model. The taxon ratio model estimates total vascular plant species richness to 1109 species using seven different taxa. Extrapolations of different fittings of the species-area relationships calculate the complete park's richness to values between 241 and 386 (logarithmic model), and 3346 to 10421 (power model). These extrapolations are far beyond realistic: the logarithmic model underestimates the park´s species richness, because more than 520 vascular plant species have already been registered in the park. On the other hand, it is not plausible that one-fourth or more of all species registered so far in the Atlantic Tropical Forest Biome occur in the ISP as indicated by the extrapolation with the power model. The most realistic estimation was achieved by the taxon ratio model. Although confidence intervals are large, the species richness estimated by this method legitimates the classification of the ISP as a local hotspot of biodiversity, but this value also outlines the lack of knowledge about biodiversity in this region and the urgent need for more taxonomical and ecological research.Key words: campos rupestres, species-area relationship, taxon ratios, Espinhaço Mountain Range. ResumoInformação científica sobre a distribuição de riqueza e diversidade de espécies é necessária para a compreensão plena da nossa herança evolutiva formando uma ferramenta poderosa para o desenvolvimento de estratégias de conservação de natureza. O objetivo deste trabalho constituiu-se em estimar a riqueza de plantas vasculares nos campos rupestres do Parque Estadual do Itacolomi (PEI) para justificar a sua classificação como um hotspot local de biodiversidade e para delinear o status quo do conhecimento sobre a biodiversidade na região. Para isso, o número de espécies encontradas em dois levantamentos fitossociológicos de 0,15 ha cada foi extrapolado usando (a) a relação espécie-área ajustada pelo modelo de potência e pelo modelo logarítmico bem como (b) o modelo de relação de táxons. O modelo de relação de táxons estimou a riqueza total para 1.109 espécies usando sete diferentes táxons. Extrapolações de diferentes modelos da relação espécie-área estimaram a riqueza 133Neotropical Biology and Conservation How many vascular plant species are there in a local hotspot of biodiversity in Southeastern Brazil?...

Vascular plant community composition from the campos rupestres of the Itacolomi State Park, Brazil

“…In a recent census, which included this survey, 520 species had already been recorded for the ISP, but the magnitude of the total species richness of vascular plants is estimated to be between 880 and 1340 species (Gastauer and Meira Neto 2013). Habernaria itaculumia (Orchidaceae, Batista et al 2004) and Chamaecrista dentata (Fabaceae, Dutra et al 2008) are species endemic to the park.…”

“…Due to the characteristic mosaic of different physiognomies of campo rupestre vegetation and the seasonal semideciduous Atlantic forest (Peron 1989, Gastauer and Meira Neto 2013), the park contains a diverse flora with many endemics (Batista et al 2004, Dutra et al 2008, Dutra et al 2009). …”

“…Although campos rupestres contain a high degree of endemic species, little data are available for this endangered ecosystem (Gastauer and Meira Neto 2013). The aim of this data paper is the distribution of a data set containing species lists from two campo rupestre communities from the ISP along with a list of soil parameters to increase knowledge of the actual distribution of campo rupestre species.…”