Floristic inventory of a zone of ecological tension in the Atlantic Forest of Northeastern Brazil

Abstract The Serra de Itabaiana National Park, Sergipe, is situated in a transition area between Atlantic Forest and the Caatinga and is considered by the Ministério do Meio Ambiente to be extremely important for the conservation of the Atlantic Forest flora. The paucity of floristic information from Sergipe state and areas of ecological tension motivated this floristic survey in the only National Park in the state. Botanical collections were made from 2006 to 2009, in six expedictions, by means of random walking. A total of 552 species distributed in 99 families of angiosperms and one gymnosperm were found. Of the species collected, 187 occurred in shrubby-herbaceous, 304 in shrubby, and 247 in arborescent physiognomy, with 23 common to all physiognomies. Leguminosae (41 spp.), Cyperaceae (40 spp.), Poaceae (38 spp.), Orchidaceae (30 spp.), Euphorbiaceae (27 spp.), Rubiaceae (24 spp.), Melastomataceae (21 spp.) and Bromeliaceae (20 spp.) were the richest families. The study revealed the presence of species in common with the Caatinga, Cerrado, Seasonal Forest, campo rupestre, restinga, tabuleiro and areas of ecological tension, corroborating floristically the classification of the locality as an area of ecological tension and reasserting its importance for the conservation of biodiversity