Avaliação da vegetação das praças da cidade de Patos, Paraíba.

Abstract

Due to the importance of green areas in improving environmental quality, which preserve values and bring benefits to human populations, this work aimed to diagnose the current situation of the vegetation present in the squares of the city of Patos-PB, in order to obtain subsidies that can reveal whether the vegetation cover present in the squares is sufficient and is in satisfactory conditions. To analyze the vegetation, a census was taken in 37 squares in the city of Patos-PB. The sampled individuals were classified by botanical family, genus, species, common name and origin. Diversity was calculated by the Shannon-Wienner Diversity Index and Pielou's Equability Index. Similarity among the squares was done by Jaccard's similarity index. Dendrometric variables were estimated: diameter at breast height (DBH), measured at 1.30 m from the ground surface, total height and crown diameter. The phytosociological parameters of density (absolute and relative), frequency (absolute and relative) and dominance (absolute and relative) were calculated. Based on the phytosanitary aspects, the individuals were classified as good, satisfactory and poor. The Green Area Index, Vegetation Cover and Vegetation Cover Percentage were calculated for the squares. The squares in the city of Patos are, in general, in a good state of conservation, with most trees and shrubs in satisfactory and good phytosanitary conditions. The most present botanical family was Fabaceae and the dominant species was Azadirachta indica A.Juss. The native species Tabebuia aurea, Sarcomphalus joazeiro, Cenostigma pluviosum and Peltophorum dubium were considered examples of large-sized natives that can be used in the afforestation of squares and Handroanthus impetiginosus did not have large-sized individuals, but proved to be adapting to this form of planting. The percentage of vegetation cover in the squares was considered satisfactory, mainly due to the existence of squares with small areas, which ended up overestimating this variable. The green area index for the squares of the city of Patos-PB per inhabitant was 0.58 m2 /inhabitant, which is well below what is recommended by the Brazilian Society of Urban Afforestation. This reinforces the need to create new green areas and urban arborization plans that meet the reality of the city.