Urban tree characterization in the downtown area of Hualahuises, Nuevo León

Abstract

Trees are an important resource in urban areas due to the environmental services they provide. The objective of this study was to evaluate the floristic composition, structure, and diversity of urban trees in the center of Hualahuises, Nuevo León. The urban trees of the public spaces in the center of Hualahuises were evaluated, covering the public squaresand sidewalks. Total height, normal diameter and crown diameter were measured for each tree. For each species, abundance, cover, and frequency were determined to obtain its Importance Value Index. Species richness was also determined using the Margalef index, Shannon's diversity index, and the number of effective species. 38 species of vascular plants distributed in 35 genera and 22 families were recorded. 63.20 % (25 species) are introduced and 36.85 % (21 species) are native. The most representative family was Fabaceae with four species. The graphs of diameter and height classes indicate the existence of a higher proportion of individuals with small diameters (d1.30<5 cm) and intermediate heights (h>3 m and <6 m). The plant community presents intermediate-high values of richness and high values of diversity of species compared to other urban green areas of northeastern Mexico. More than half (63 %) of the species are introduced, among which Fraxinus americana and Thuja occidentalis stand out for their Importance Value Index. The native species with the highest importance value was Quercus virginiana.