Post-fire evaluation of a mixed Pinus-Quercus forest in Zaragoza, Nuevo León

Abstract

Fire has been a driver of biodiversity, succession, and vegetation dynamics by promoting a wide range of adaptive responses to particulars fire regimes. The objective of this study was to estimate the recovery of the vegetation and determine if the fire had a significant influence on the richness, diversity and distribution of the species, after 21 years of its impact. Forty 20 x 20 m plots were sampled, equally distributed in areas with fire, northeast (NE) and southwest (SW) exposure, and without fire, NE and SW exposure, vegetation was evaluated, and physical variables were estimated. The Importance Value Index was determined. An ANOVA was performed to compare richness and diversity and a multivariate analysis to determine the most relevant factors in the distribution of the species. In the burned areas, Quercus intricata was more important and Pinus cembroides in the areas without fire. ANOVA showed a significant difference (P≤ 0.05) in richness and diversity, and Tukey's test showed that the burned area with SO exposure presented greater richness than the rest of the evaluated areas. The most relevant factors in the distribution of the species were fire, altitude and exposure. The opening of the canopy generates favorable conditions for some shrubby species that are oppressed by the trees.