Floristic analysis in a toposequence of the municipality of Serrinha dos Pintos - Rio Grande do Norte state/Análise florística em uma topossequência no município de Serrinha dos Pintos - Rio Grande do Norte

Aiming to contribute to the knowledge of the vegetation of the municipality of Serrinha dos Pintos, Rio Grande do Norte state, a floristic analysis was carried out along a toposequence. Three distinct areas were selected: Plateau (700 m to 720 m altitude), Slope area (410 m to 510 m altitude) and Depression (270 m to 310 m altitude), with allocation of 30 fixed plots of 10 mx 10 m, 10 plots in each area. All individuals with heights greater than or equal to 1 meter and circumference greater than 10 centimeters were sampled. In order to observe the richness and diversity of the study areas, the Shannon-Wiener Diversity Index (H') was calculated. In all, 821 individuals were collected, identified in 35 species and 19 families. The Plateau was the area with the highest diversity of species (21), the families Fabaceae (8 spp.) and Euphorbiaceae (3 spp.) were the most representative; (18 spp.), Slope Area had (18 spp.), also Fabaceae (8 spp.) and Euphorbiaceae (3 spp.) were the families with the highest richness and Depression was the area with the lowest diversity (14 spp.), including Fabaceae (5 spp.) and Euphorbiaceae (3 spp). The most representative species in the three areas were Croton blanchetianus (Marmeleiro), Cenostigma bracteosum (caatingueira) and Myracrodruon urundeuva (Aroeira). The Shannon-Wiener diversity index (H') observed for the Plateau area was 2.42, in Slope Area, it was 2.07 and in Depression, it was 1.91. It is emphasized that the greater the result, the greater the diversity of species in the area in question. Keywords: Caatinga (Scrub forest); Floristic composition; Diversity; Semi-arid Com o objetivo de contribuir para o conhecimento da vegetação do município de Serrinha dos Pintos-RN, foi realizada a análise florística ao longo de uma topossequência. Foram selecionadas três áreas distintas: Chapada (700 m a 720 m de altitude), Encosta (410 m a 510 m de altitude) e Depressão (270 m a 310 m de altitude), onde foram alocadas 30 parcelas fixas de 10 m x 10 m, sendo 10 parcelas em cada área. Foram amostrados todos os indivíduos com alturas superiores ou iguais a 1 metro e circunferência maior que 10 centímetros. Para observar a riqueza e diversidade das áreas de estudo, foi calculado o Índice de diversidade de Shannon-Wiener (H). Ao todo, foram coletados 821 indivíduos, identificados em 35 espécies e 19 famílias. A Chapada foi a área com maior diversidade de espécies (21), sendo Fabaceae (8 spp.) e Euphorbiaceae (3 spp.) as mais represent