Composição florística e estrutura de um fragmento de vegetação savânica sobre os tabuleiros pré-litorâneos na zona urbana de Fortaleza, Ceará.

Abstract

Urban growth promotes reduction in the vegetation cover, introduction of exotic species and has serious implications for biological conservation. In the urban area of Fortaleza, Ceará state, a vegetation fragment with savannic physiognomy (24 ha – 3º47’55”S and 38º29’10”W) was sampled for a floristic survey and had 1 ha subjected to a phytosociological inventory. The floristic list of the fragment, considered a priority area for municipal conservation, is showed here. Phytosociological data have also been sampled, providing more information about the savannas from the Brazilian’s Northeast coast. For the floristic list, species from all growth forms present in the fragment were collected. For the description of the structure of the vegetation, we assigned randomly eight transects with 5 × 250 m (1ha in total) in which the perimeters at ground level (PNS) and the total height of individual plants were measured for all woody plants with PNS greater than or equal to 9 cm. In the floristic survey we collected 151 species (138 indigenous and 13 exotic) and in the phytosociological study, 37 species (35 native). The density and basal coverage of the community were 1218 ind/ha and 7.34 m2 /ha, respectively. The average height and average diameter were respectively 2.53 ± 1.29 m and 6.68 ± 5.67 cm. Although our study site is geographically out of the Cerrado domain, it has structural variables compatible with the ones observed within the range of variations found in other Cerrado areas.