Regeneração natural de espécies arbóreas no Horto do Viveiro Florestal do CSTR, UFCG, Patos PB.

Abstract

Natural Regeneration of tree species in the hortucultural forest of CSTR, UFCG, Patos-PB. The present study evaluated the floristic and phytosociological parameters of the natural regeneration of species in the nursery of the CSTR, UFCG. The Horto area presents 1.6 hectares, and to collect vegetation data, a forest inventory was carried out in 18 plots (5.0 mx 5.0 m) of the natural regeneration of tree species in the study area. All individuals with height equal to or greater than 0.5 meters and chest circumference <6.0 cm (CAP <6.0 cm) were included. The regenerants were divided into two height classes: C1 = height class 0.5 to 1.0 m and C2 = Height class above 1.0 m. In the structural survey of the regenerating individuals 212 individuals were sampled, belonging to four botanical families, 10 genera and 11 species. Of these five are exotic and six native. Shannon indices (H ') = 1.31 and IIEA (impact index of exotic species) confirm the low floristic density of the area and the invasion of exotic species compromising the structure of the area, proving that exotic species influenced these low results. Leucaena leucocephala, Prosopis juliflora, presented higher values of ecological importance, and natural regeneration. Regarding the natives, Mimosa tenuiflora was the one that stood out best in this parameter. The high density of the exotic species indicated that the anthropic actions such as the withdrawal of species, introduction of the cattle for a certain period, favored the Dispersal and establishment of these species. Both contributed 82.55% of the individuals sampled. The high percentage found for this parameter is justified by the wide distribution of this species in the studied area, which was in 72.22% of the total sampled plots, besides presenting the highest density.