Does the severity of a forest fire modify the composition, diversity and structure of temperate forests in Jalisco?

Abstract

Introduction: Forest fires are natural disturbances that influence structure, dynamics, performance, composition and diversity of species. Objective: To compare composition, structure and diversity of temperate forest vegetation affected by different levels of severity of a forest fire in Jalisco. Materials and methods: Composition, horizontal structure, importance value index (IVI), diameter class, diversity indexes of Shannon, Simpson, Margalef richness and Bray-Curtis similarity were evaluated in three regions (Bosque La Primavera and Sierra de Tapalpa and Sierra de Quila) of temperate forest with three levels of severity (no fire, moderate and extreme). Results: Twelve species from six families were recorded. Pinaceae and Fagaceae were the most dominant. Dominance ranged from 0.2 to 50 m2∙ha-1 in moderate and extreme severity sites. Pinus devoniana recorded the highest IVI (71 %) in Sierra de Tapalpa. The highest number of trees was recorded in diameter class ≤30 cm. Diversity and richness indices showed significant differences (P < 0.05) for Sierra de Tapalpa and Sierra de Quila and among fire levels; the highest indices were recorded in sites of moderate severity. Tree composition similarity between regions was low (<33 %). Conclusions: Moderate severity of forest fire favored composition, structure and diversity of vegetation in temperate forests of Jalisco, indicating that the level of severity influences resilience of forest ecosystem communities.