View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Repositorio da Producao Cientifica e Intelectual da Unicamp 269 Vol.50, n. 2 : pp.269-277, March 2007 ISSN 1516-8913 Printed in Brazil BRAZILIAN ARCHIVES OF BIOLOGY AND TECHNOLOGY AN INTERNATIONAL JOURNAL The Vascular Flora of the Cerrado in Emas National Park (Central Brazil): a Savanna Flora Summarized Marco Antônio Batalha 1* and Fernando Roberto Martins 2 1Departamento de Botânica; Universidade Federal de São Carlos; [email protected]; C. P. 676; 13565-905; São Carlos - SP - Brasil. 2Departamento de Botânica; Instituto de Biologia; Universidade Estadual de Campinas; [email protected]; C. P. 6109; 13083-970; Campinas - SP - Brasil ABSTRACT The Brazilian cerrado may be divided in two main phytogeographic sectors: one characterized by Piptocarpha rotundifolia , in which the Emas National Park (ENP) is located, and other characterized by Curatella americana. We carried out a floristic survey in ENP, which allowed an assessment of the taxonomic composition, taxa size, and similarity with other sites for the ENP’s vascular flora. We compared the ENP’s flora with southeastern outlying cerrado sites, also in the Piptocarpha sector, and with general floristic patterns in the cerrado vegetation. The distribution of species per family in ENP was significantly different from that obtained for each component of the general cerrado flora. The herbaceous component was characterized by an overproportion of Myrtaceae and an underproportion of Orchidaceae and Lythraceae; and the woody component, by an overproportion of Myrtaceae and Nyctaginaceae. When compared with outlying cerrado sites, the ENP was quite distinct, not only at species level, but also at family level. Key words: Cerrado, floristics, phytogeography, principal component analysis, savanna INTRODUCTION high richness, high degree of endemism, and current conservation status (Fonseca et al., 2000). The Cerrado Domain is the second largest The cerrado vascular flora has an herbaceous and a Brazilian phytogeographic province, occupying woody component, which are antagonistic because originally 23% of Brazil’s land area (Ratter et al., both are heliophilous (Coutinho, 1990). Castro et 1997). As its name implies, in the Cerrado al. (1999) and Ratter et al. (2003) compiled many Domain, the cerrado vegetation prevails. The floristic and quantitative surveys and listed 973 cerrado vegetation has several structural and and 951 species, respectively, identified for the physiognomic types, from grasslands to tall cerrado woody component. Based on taxonomic woodlands, but most of its physiognomies fit the revisions, floristic surveys, and visits to herbaria, definition of tropical savannas (Sarmiento, 1983). Batalha (2001) listed 2,856 species in the cerrado The cerrado core area covers the Brazilian Central herbaceous component. Plateau, and outlying areas occur, for example, in Castro (1994) recognized two major sectors in the the southeastern São Paulo State (Ratter et al., whole Brazilian cerrado area, separated by an 1997). The cerrado was included among the imaginary line from northeast to southwest hotspots for conservation in the world due to its crossing roughly the center of the Central * Author for correspondence Brazilian Archives of Biology and Technology 270 Batalha, M. A. and Martins, F. R. Brazilian Plateau. The sector south of this line is with general floristic patterns in the cerrado indicated by the presence of Piptocarpha vegetation. Both ENP and the southeastern rotundifolia (Less.) Baker (Asteraceae), while the outlying sites are in the Piptocarpha rotundifolia sector north of this line, by the presence of sector; whereas ENP is located in the northwestern Curatella americana L. (Dilleniaceae) (Fig. 1). extreme of this sector, the outlying sites are Ratter et al. (1996; 2003) recognized six and seven located in its southeastern extreme. We tried to phytogeographic groups, respectively, for the answer the following questions: Is the distribution cerrado woody flora but did not discuss the of species per family in the woody and herbaceous occurrence of P. rotundifolia and C. americana as components in ENP different from those found by a major division of the cerrado phytogeographic Castro et al. (1999) and Batalha (2001) for the sectors. whole cerrado? If so, which families characterize The Emas National Park (ENP) is located in the the ENP’s woody and herbaceous components? Is cerrado core region and is one of the largest and there any species amongst the most constant most important reserves representing this woody species in cerrado sites (Ratter et al., 1996; vegetation type (Fonseca et al., 2000). Recently, 2003) that does not occur in ENP? Are there ENP was included by Unesco (2001) in the World woody species in ENP’s flora that should be Natural Heritage List as one of the most important included in the checklist elaborated by Castro et al. sites containing flora, fauna, and key habitats that (1999)? Within the P. rotundifolia sector, are the characterize the cerrado. We carried out a floristic southeastern outlying cerrado sites (Mantovani and survey in the cerrado of ENP (Batalha and Martins, 1993; Batalha et al., 1997; Batalha and Martins, 2002), which allowed an assessment of Mantovani, 2000) more similar among themselves the taxonomic composition, taxa size, and than to a core cerrado site, such as ENP? When similarity with other sites for the ENP’s vascular compared with these southeastern outlying cerrado flora. sites, which families characterize the ENP and The aim of this study was to compare the ENP’s which families characterize the outlying sites? flora with southeastern outlying cerrado sites and Figure 1 – Cerrado region and its two sectors, the Curatella americana and Piptocarpha rotundifolia sectors, with approximate locations of the Emas National Park (ENP) and southeastern sites (after Castro, 1994, modified). Brazilian Archives of Biology and Technology The Vascular Flora of the Cerrado in Emas National Park (Central Brazil) 271 MATERIAL AND METHODS that is, families and genera with only one species in a given flora. The ENP is located in the Brazilian Central For both components of the cerrado flora, we Plateau, in the cerrado core region, southwestern computed the frequency distribution of species per Goiás State (17 °49’-18 °28’S, 52 °39’-53 °10’W). family. We compared ENP with outlying cerrado The park was created in 1961 with 132,941 ha. sites in which both herbaceous and woody Regional climate is humid tropical, with wet components were sampled: Mojiguaçu (Mantovani summer and dry winter, and classified as Aw and Martins, 1993), Pirassununga (Batalha et al., following Köppen (1931). Annual rainfall varies 1997), and Santa Rita do Passa Quatro (Batalha from 1,200 to 2,000 mm, concentrated from and Mantovani, 2000), all located in the October to March, and mean annual temperature southeastern São Paulo State. We calculated the lies around 24.6 °C (Ramos-Neto and Pivello, similarity values among these four sites with 2000). Three quarters of ENP consist of flat Sørensen index (Magurran, 1988). tableland 820-888 m a.s.l., and the remaining area To determine which families characterize each consists of hilly terrains 720-820 m a.s.l. site, we used the Principal Component Analysis The cerrado in ENP has almost all physiognomies (PCA) (Jongman et al., 1995). In this case, we found in this vegetation type, from campo limpo (a included only those families with at least ten grassland) to cerrado sensu stricto (a woodland). species in one of the sites. Including only the In the reserve, open cerrado physiognomies – richest families in the PCA reduces bias in the campo limpo , campo sujo (a shrub savanna), and analysis (Gauch, 1982). If we had included all the campo cerrado (a savanna woodland) – prevail families, our matrix would have many zeros and and cover 68.1% of the total area, especially on the low values, which could mask the patterns we flat tablelands (Ramos-Neto and Pivello, 2000). were interested in. Thus, selecting the ten richest The more closed cerrado sensu stricto covers families comprises most of the species and reduces 25.1% of the reserve, mainly on the hilly terrain. bias in the analyses. Data were standardized and Other vegetation types, such as floodplain centralized before the analysis (Jongman et al., grassland (4.9% of the total area) and riparian or 1995). seasonal semideciduous forests (1.2%), also exist To compare the distribution of woody species per within the park. Roads, firebreaks, and physical family in ENP and in the whole cerrado, we installations occupy the remaining 0.7%. reclassified the checklist compiled by Castro et al. We carried out a floristic survey in all cerrado (1999) according to Judd et al.’s (2002) system. physiognomies occurring within the reserve, from We considered only those species identified with November 1998 to October 1999, in monthly field confidence, that is, those species identified trips. In each one of them, the sampling effort dubiously (aff. or cf.) or only to genus or family varied from 50 to 60 hours. We identified the level were not included in our analysis. We collected material to species level by comparing it selected the ten richest families of each flora to to lodged vouchers and consulting taxonomic carry out the comparison. Even if one of the references. The identified specimens were then richest families in a flora was not among the sent to taxonomists for confirmation. The voucher richest families in the other, it was included in the material was lodged mainly in the São Paulo State analysis. For example, Euphorbiaceae, which was Botanical Institute herbarium. one of the richest families in the woody We classified the species in families according to component of the cerrado as a whole but not in the system proposed by Judd et al. (2002) and in ENP, was included in the analysis. Floristic life-forms following Raunkiaer’s (1934) system surveys in the cerrado have shown that its flora is adapted by Mueller-Dombois and Ellenberg characterized by few families with a great number (1974).