Introduction
The state of Piauí has extensive transition areas covered with ecotonal vegetation. The ecotones or transitional zones in the northeastern region of Brazil harbor rich anuran faunas (MATAVELLI et al., 2019). This diversity of contrasting environments from neighboring biomes likely allow the coexistence of high faunistic and floristic diversities that need to be studied further. Despite the increase in studies with amphibians from Piauí state, there is still a lack of studies in some locations, such as the Sete Cidades National Park (SCNP), a conservation unit created to protect the natural resources of an ecotonal region. Even after nearly 60 years of its creation, the distribution pattern of amphibians (or even a list of species) remains unknown. Thus, we provide a checklist of anuran species from the SCNP, comparing its richness with other protected areas in Caatinga and Cerrado biomes.
Material and methods
The SCNP is located in the northern region of the state of Piauí, northeastern Brazil (04°05’- 04°15’S and 41°30’- 41°45’W, WGS84 datum), a transitional area Cerrado-Caatinga, with formation of six different vegetation types. During the rainy periods of 2018 and 2019, we conducted anuran sampling using auditory census and active visual searches in different environments used by anurans within SCNP. Statistical analyses were used to evaluate the efficiency of anuran sampling methods and calculate the expected species richness using the nonparametric estimators. Besides, we compared the anuran species richness of the SCNP with other 28 protected areas distributed in Caatinga and Cerrado biomes using the Jaccard Similarity coefficient and calculated the Local Contribution to Beta Diversity - LCBD to evaluate the variation in species composition among different sites.
Results
We recorded 30 anuran species in the SCNP, distributed in six families: Bufonidae, Hylidae, Leptodactylidae, Microhylidae, Odontophrynidae, and Phyllomedusidae. The species accumulation curve presented a strong tendency towards stabilization, suggesting that the sampling effort was appropriate and the observed species richness represented about 88.8% to 95.2% of the species richness estimated. We observed low similarities in species composition between different protected areas compared, which was mainly determined by species turnover among areas, with formation of two clusters: one formed by the Caatinga biome protected areas and another by Cerrado biome protected areas.
The anurofauna of the SCNP was more similar to that recorded in Delta do Parnaíba Environmental Protected Area, in Ubajara National Park, and in Lençóis Maranhenses National Park, whereas anuran richness registered in Santuário do Caraça RPPN and Peti Environmental Station, both in state of Minas Gerais, were more distinct from our study. In this case, the geographical distance between the protected areas was able to explain the amphibian species composition dissimilarity in the areas investigated (r = 0.68, p = 0.001), where the further away are two areas more dissimilarity is their anuran composition.
Discussion
Of the 55 amphibian species recorded in the state of Piauí (ROBERTO et al., 2013), approximately 54% are found in the SCNP. This species richness was higher than other protected areas of the state, such as Uruçuí-Una Ecological Station (DAL VECHIO et al., 2013), Delta do Parnaíba Environmental Protection Area in the coastal zone of states of Piauí and Maranhão (ARAÚJO et al., 2018), Serra das Confusões National Park (DAL VECHIO et al. 2016), and Serra da Capivara National Park (CAVALCANTI et al., 2014). The greater number of species recorded here is probably caused by the influence of different phytogeographic elements (Cerrado-Caatinga), since ecotonal areas harbor high biodiversity, and the anurofauna in these environments presents species typical of each of these domains (DAL VECHIO et al., 2016).
We registered about 17% of the 181 species of anurans in Caatinga and Cerrado biomes protected areas. Although direct comparison of species composition might be difficult in some cases due to the use of different collection methods and sampling efforts, the SCNP is undeniably a key area of high biological diversity and important for anuran conservation and preservation. We present the first record Leptodactylus cf. mystaceus for northern Piauí increasing its geographical distribution by approximately 548 Km, northeast of Ribeiro Gonçalves (ROBERTO et al., 2013). Our results show that SCNP presents the highest anuran species richness in the state of Piauí and one of the two highest among all northeastern National Parks, increasing the knowledge of amphibian diversity in the Northeast region of Brazil.
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Kássio C. Araújo¹*, Etielle B. Andrade², Ana C. Brasileiro¹, Ronildo A. Benício³, Felipe P. Sena², Rayone A. Silva², Antonia Joyce S. Santos², Claylton A. Costa² & Robson W. Ávila²
¹Universidade Federal do Ceará, Centro de Ciências, Programa de Pós-Graduação em Ecologia e Recursos Naturais, Bloco 902, Campus do PICI, Av. Humberto Monte, s/n, 60455-760, Fortaleza, CE, Brasil. ¹Instituto Federal de Educação, Ciência e Tecnologia do Piauí, Grupo de Pesquisa em Biodiversidade e Biotecnologia do Centro-Norte Piauiense, Campus Pedro II, 64255-000, Pedro II, PI, Brasil. ¹Universidade Regional do Cariri, Laboratório de Herpetologia, Programa de Pós-Graduação em Diversidade Biológica e Recursos Naturais, 63105-000, Crato, CE, Brasil.
*Corresponding author: Kássio C. Araújo, e-mail: kassio.ufpi@gmail.com
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