Natural and Ecological Succession in an Urban Fragment of the Atlantic Forest in Pernambuco, Brazil

The development of studies on natural regeneration in fragments of the Atlantic Forest assists to evaluate the regenerative power of forests against natural and anthropic disturbances. So, the objective of the work was to analyze the structure of the regenerative component and ecological succession of arboreal species in an urban fragment of Atlantic Forest. The study was undertaken in Parque Estadual Dois Irmãos (PEDI), in Recife, Pernambuco, in which 10 subplots of 1 m x 25 m (25 m²) each was installed. As inclusion criterion, the regenerating individuals of arboreal species should have a height equal to or greater than one meter and circumference at the height of the chest (CAP 1.30 m) inferior to 15 cm. The individuals were classified as the ecological groups origin (native or exotic species) and were calculated via phytosociological parameters such as heights classes for regenerating individuals and diversity index. For data analysis Mata Nativa version 4.05 was used. The families that presented the highest number of species were: Myrtaceae and Fabaceae. It was observed that 15% of the species belong to the pioneer group, while 48% belonged to the initial secondary group, and 22% to the late secondary group. The distribution of individuals of the species Hirtella racemosa and Chamaecrista ensiformis in the different size and relative density classes allow us to affirm that these species act directly in the process of ecological succession. The fragment is in the initial secondary stage of succession.