Arboriza??o ao longo de ruas - túneis verdes - em Porto Alegre, RS, Brasil: avalia??o quantitativa e qualitativa

摘要

This study aims to identify the tree species used along the streets named as green tunnels and to evaluate the conditions of this vegetation in those streets in Porto Alegre city, RS, due to the relevance of the presence of trees placed along streets and avenues in urban environments. The relationship between the size of the tree versus the condition of its trunk was investigated, aiming to estimate if there is a conflict between big trees and the aerial cable net. Qualitative and quantitative surveys of the vegetation were conducted in nine streets (five green tunnels and four control streets). We registered 760 individuals of 61 species of trees, 25 native and 36 exotic, grouped in 33 botanical families which corresponds to about 34% of the tree species registered for Porto Alegre. This result alerts to the necessity of the implantation of a more heterogeneous vegetation along the streets compound of native species. The green tunnels present less species and minor preserved individuals than the control streets. It can partially be explained by the higher of the trees present in the green tunnels. As an alternative to the bigger individuals and the aerial power cables conflict, we recommend the adoption of an aerial compact distribution networks for services distribution.