Tree density and shading in green areas of residential blocks in Palmas, Tocantins

Abstract

Urban green spaces are among the most efficient alternatives to mitigate the effects of pollution and heat islands present in the urban environment, the more densely wooded, the more effective in reducing temperature, increasing humidity and removing pollutants. Palmas, capital of the state of Tocantins, was created in 1989, it was planned with differentiated solutions where each residential block would have a percentage of non-edifying green area and sport and leisure in order to promote thermal comfort and social interaction, however, the first stages of the construction of the city were marked by a broad process of deforestation and a change in the functionality of these green spaces. In the present study, we used spatial indices to assess the tree cover of green areas in residential blocks and whether this would be sufficient to influence local thermal comfort. Information on the size of green areas, composition and frequency of species and canopy diameter was obtained to calculate the tree density indices-ADI and shading-ISA. The reduced dominance reflects a high diversity of species characteristic of natural environments, and the low values of the spatial indexes indicate tree insufficiency in most green areas, corroborating our hypothesis that the promotion of local thermal comfort would not be achieved in all residential blocks.