Natural Regeneration in Urban Fragment of Atlantic Forest, Pernambuco, Brazil

Abstract

Aims: Evaluate the phytosociological structure of natural regeneration, the ecological group and the species dispersion syndrome in an urban fragment of the Atlantic Forest, Pernambuco, Brazil.
 Study Design: Systematic sampling.
 Place and Duration of Study: Immaculate Catholic College Conceição do Recife (FICR), in the municipality of Recife, PE, in August 2019.
 Methodology: In the survey, 10 plots of 5 m x 5 m were sampled, and all living individuals with height ≥ 1 m and circumference at 1.30 m from the soil were sampled < 15 cm. The structure of natural regeneration was analyzed based on phytosociological parameters and distribution of individuals in height classes. Species diversity was estimated using the Shannon diversity and Pielou equability indices.
 Results: We sampled 236 individuals, belonging to 26 species. The estimated density and dominance were 9,940 ind.ha-1 and 5.27 m2.ha-1, respectively. The families with the highest species richness were Fabaceae, Myrtaceae and Bignoniaceae. The species that stood out when considering density, frequency, dominance, importance value and natural regeneration were Protium heptaphyllum, Eschweilera ovata, Casearia javitensis, Brosimum guianense, Handroanthus sp.1, Xylopia frutescens, Thyrsodium spruceanum and Myrciaria ferruginea, being considered well adapted, showing efficiency in the development and establishment of new individuals. The Elaeis guineensis it was also among those that stood out the most, and it was necessary to monitor and control, because it is an invasive alien species. The indices of Shannon diversity and Pielou equability were 2.56 nats.ind.-1 and 0.76, respectively. In the area, the initial secondary species with zoochoric dispersal syndrome predominated. The distribution of the number of individuals for height classes occurred in the following order: C3 > C1 > C2.
 Conclusion: The area is in the intermediate stage of ecological succession, with moderate species richness. It is necessary to monitor the area, aiming at the control of the species Elaeis guineensis and native species with low natural regeneration.