Tree vegetation in an urban remnant: Lago da Paz forest, Dois Vizinhos, PR, Brazil

This study had the objective to analyze the floristic, structure and diversity of regeneration of a forest fragment located in the urban area of Dois Vizinhos, Paraná State. We used the census method and the traditional phytosociological descriptors as parameters of analysis, giving indications about the ecological value of the fragment. The results showed the occurrence of 231 individuals in 2,500 m² area, distributed in 35 species of 22 botanical families. The families with the highest number of species were Lauraceae and Myrtaceae, with three species each, followed by Boraginaceae, Euphorbiaceae, Fabaceae, Meliaceae, Myrsinaceae, Rosaceae and Sapindaceae with two species each. The others were represented by one species each. Among eight exotic species, four are potential invaders, such as Ligustrum lucidum (34.0%) and Dyospyrus kaki (13.6%) that presented high coverage value (CV) and dominance with more than 50% of the registered individuals. Most of the species belong to the initial stages of succession. In the regeneration, we found 20 species, with only tree exotics and, among them, only one invasive (L. lucidum). The occurrence of exotic invasive species in urban forest fragments requires attention of public managers to the necessity of silvicultural interventions to recover their floristic and original structure