Forest fires are one of the main environmental threats in Chile. Fires in this Mediterranean climate region frequently affect native forests and exotic plantations, including in several cases urban and rural settlements. Considering the scarcity of information regarding the fire response dynamics of tree species that are frequently affected by fires, this study aims to establish a flammability classification according to the evolution of the fire initiation risk presented by the most affected forest species in the Valparaíso region. Three exotic species, Eucalyptus globulus, Pinus radiata, and Acacia dealbata, and two native species, Cryptocarya alba and Quillaja saponaria, were studied. Flammability assays indicate that E. globulus, A. dealbata, and C. alba are extremely flammable, whereas P. radiata and Q. saponaria are flammable. Furthermore, E. globulus and A. dealbata have the highest heating values while Q. saponaria has the lowest values. The extreme flammability of E. globulus, A. dealbata, and C. alba indicates a high susceptibility to ignite. Furthermore, the high heat of combustion of E. globulus and A. dealbata can be associated with a high energy release, increasing the risk of fires spreading. In contrast, Q. saponaria has the lowest predisposition to ignite and capacity to release heat. Accordingly, this work shows that all studied tree species contain organic metabolites that are potentially flammable (sesquiterpenes, aliphatic hydrocarbons, alcohol esters, ketones, diterpenes, and triterpenes) and can be considered as drivers of flammability in vegetation. Finally, these preliminary results will aid in the construction of more resilient landscapes in the near future.

Mediterranean climate regions have become more vulnerable to fire due to the extreme weather conditions and numerous Eucalyptus globulus plantation areas. The aim of this study is to analyze the fire hazard related to E. globulus in a forest fire scenario, based on the contrast of thermochemical parameters and their relationship with chemical properties, considering the predominant exotic forest species (E. globulus, Pinus radiata, Acacia dealbata, and Acacia melanoxylon) present in the Valparaiso region, Chile. The results revealed that although all of the studied species were highly flammable, E. globulus was extremely flammable, as its leaves contain high concentrations of essential oils, monoterpenes, and sesquiterpenes, which can generate a flammable atmosphere due to their low flashpoint and the strong negative influence shown between the essential oils, volatile terpenes, and limonene concentration. Moreover, the heat of combustion of E. globulus was positively correlated with its high essential oil contents. Finally, all of the studied species had low flashpoints and high heating values; therefore, they are predisposed to ignite in the presence of a heat source, releasing high amounts of energy during combustion, which contributes to the risk of the formation and spread of canopy fires among these tree formations.

RELACIÓN ENTRE VARIABLES METEOROLÓGICAS E INCENDIOS FORESTALES EN LA PROVINCIA PINAR DEL RÍO, CUBA

DISEÑO DE UN ÍNDICE DE PELIGRO DE INCENDIO FORESTAL PARA LA PROVINCIA PINAR DEL RÍO, CUBA

TREE STRUCTURE IN THE FOREST OF PINDO MIRADOR BIOLOGICAL STATION, PASTAZA, ECUADOR

The database on fire statistics is useful tool for efficient planning of preventive suitable measures to each area. Base on that, it allows to establish the trend of occurrences of fires and their affectations, periods the day and year with increased risk for emergency and spreading; but also the causes of emergence, the forest and species to be damage. Likewise, it is possible to analyze the effectiveness of fire protection services. The present study aims to analyze through the database, the trend of forest fires dynamic in Pinar del Río using a series of 20 years since (1994-2013), to improve the prevention actions. The results have shown a total of 1,466 fires and 31,881.6 ha of burned areas during the last 20 years mainly at 14:00 to 17:00 hours of pine plantation.