Purpose, preferences and fuel value index of trees used for firewood in El Ocote Biosphere Reserve, Chiapas, Mexico.

Firewood is the main source of energy in rural communities of emerging economies. Rural people develop different strategies to select and use the available species. Analysis of the firewood consumption and its relation to the wood-energetic properties was performed in four rural villages in the El Ocote Biosphere Reserve. The relationship between the preferential use of species for firewood and wood properties (moisture, ash, volatile content and specific wood density) of 39 species was analyzed using a combination of interviews and laboratory analysis. Fuel value index (FVI) was used to rank species and compare them with a preference index obtained by 76 interviews. People recognized seven characteristics that define the choice of a species for firewood (the kind of flame, the length of the flame, the amount and duration of coal, the type of smoke produced, the ease of ignition, the flavor given to food, and the quantity of ash left). Preference criteria do not match with the FVI. Six of the preferred species have low FVI values (<60.0), 29 species have intermediate (60–300) while only four species showed the highest FVI values (>300). We conclude that the FVI is not related to the preference of the species used by people within the reserve. Availability, proximity to home and feasibility may influence the choice of species used for firewood. [ABSTRACT FROM AUTHOR]