Diversity and structure of tree species in rural localities of Hualahuises, Mexico

Abstract

In this study, the proportion of native vs. introduced tree species in urban forests of six rural areas of Hualahuises, Nuevo León (Northeast Mexico) was evaluated. For the analysis of variance, the proportions test was used with a confidence level of 0.95 through the prop.test command in R. 252 individuals of 32 species distributed in 29 genera and 19 families were recorded. The Fabaceae family was the largest represented with seven species. Of the 32 species, 19 are native (59.37 %) and 13 introduced (40.63 %). Based upon their origin, 77.79 % of the individuals are native and 22.21 % introduced. Regarding their dimensions, the percentage differences are greater: the native ones represent 91.69 % of the basimetric area, 92.36 % of the crown area, 92.22 % of the assumed crown area and 96.78 % of crown volume, while the non-natives present values lower than 9.00 %. At the species level, those with the highest structural values were Prosopis laevigata followed by Vachellia farnesiana and Ebenopsis ebano. The three species are native belonging to the Fabaceae family and together they represent 44.05 % of the abundance and 63.71 % of the Urban Importance Value Index. According to the analysis of variance, the native species turned out to have higher values of richness, basal area, and crown area than the introduced species in the assessed localities.