A vegetação sobre o afloramento rochoso no Morro da Pioneira, Serra da Jibóia: fisionomia, estrutura e diversidade

Abstract

Studies on rocky outcrops at the top of the Atlantic Forest in Bahia have not yet been carried out, being essential, since this type of vegetation has a great ecological importance, in addition to occurring frequently in the Brazilian landscape. The rocky outcrop studied is located in Morro da Pioneira, Serra da Jibóia, a mountain massif that has an important remnant of Atlantic Forest. This vegetation is recognized as an important target to be considered in future studies, due to its importance for the conservation of mountain biodiversity in Brazil. The physiognomy was described using Raunkiaer's life form classification system, and its unfolding, the biological spectrum. To assess the structure of this community, the rank scale method was used, bearing in mind the specificities of this type of vegetation, especially its fragility presented before the impacting activities observed in other methods. To assess the diversity of the community under study, the following were used: the Shannon-Wiener diversity index (H'), and the Pielou evenness index (J'). As for physiognomy, the biological spectrum shows a high frequency of camephytes (46.88%), followed by phanerophytes (25%), hemicryptophytes (21.88%) and geophytes (6.25%). The camephytic phytoclimate is common at high altitudes subjected to cold climates. Thirty-two species were found in the outcrop, distributed in thirty genera and sixteen families. Vellozia sp. nova was the most frequent species (25.69%), followed by Epidendrum secundum (14.68%), Tibouchina tomentulosa (11.47%), Mandevilla tenuifolia (8.72%) and Alcantharea imperialis (7.34%). . The most important species for the community was Vellozia sp. nova followed by Alcantharea imperialis, Tibouchina tomentulosa and Epidendrum secundum. The calculated Shannon-Wiener diversity index was H' = 2.601. The calculated Pielou equability was J' = 0.750.