Environmental variables affecting the density of ten forest species in the Northern Sierra of Oaxaca

Abstract

The characterization of the environmental conditions of forest species is important because it allows knowing part of their habitat; this information is useful for making decisions for an integral use of forests, including preventive measures that counteract habitat degradation or the risk of extinction of the plants. The main objective of this study was to identify the environmental variables that significantly affect the abundance of ten tree species growing in the temperate forests of Santiago Comaltepec, north of Oaxaca. Three analysis methods were used for this purpose: 1) principal component analysis, 2) non-parametric correlation coefficients, and 3) generalized linear models. A total of 23 climatic and physiographic variables were used: mainly records of average, minimum and maximum temperatures; rainfall during the summer, spring and winter, and rainfall during of the highest plant activity, as well as other attributes of each sampling plot including the slope, exposure and altitude. All the variables studied showed a significant correlation (p<0.001) with at least three species, several of them with correlation coefficients greater than 0.90. Of the ten species studied, three showed high sensitivity to temperature variables, mainly the minimum temperature, temperatures above 5 °C, and the aridity index; and three species showed high evidence of sensitivity to the precipitations registered in spring, in summer and in winter, and to the April-September precipitations.