Ecological assessment of two urban areas with strong anthropogenic influence Vladimir Stolzenberg Torres, Felipe Todeschini, Mariana Freitas Farias

Abstract

This study presents aspects relating to diversity, uniformity and species richness, within two fragments of the urban forest of Porto Alegre, RS. As results found, it follows that diversity showed a small variation according to the Shannon indices: 2.23370 to 2.85944; Brillouin: 2.05334 to 2.69756; Jentsch mixing quotient: 0.05863 to 0.21925; Margalef's wealth: 4.62189 to 7.64656; Menhinick wealth: 2.56074 to 2.99822; Pielou uniformity: 0.78866 to 0.80540; Sheldon uniformity: 0.42565 to 0.46672; Heip uniformity: 0.41130 to 0.43865; Hill’s uniformity: 0.70717 to 0.83782; and Hill’s Uniformity modified by Alatalo: 0.68191 to 0.81836. When analyzing the floristic similarity between the fragments, using the Sorensen quotient, an index variation of the order of 0.52174 was obtained. The results found reinforce the relevance of studies carried out in urban fragments, having made it possible to demonstrate that levels of anthropogenic disturbance interfere with the process of landscape evolution, which determines the change in the composition and diversity of the location. Therefore, the greatest complexity, when it occurs, is due to mere accident, or human whim, with no prior planning that intentionally leads to this condition being evident.