Critérios locais de seleção de plantas empregadas como fitocombustíveis : uma análise do comportamento humano de forrageio

Abstract

The use of plant resources as fuel is common in human populations, mainly in developing or underdeveloped countries located in tropical regions. Environmental factors, particular characteristics of the plants and cultural background are some important variables that have strong influence in how people select plants to be used as fuel, and also, might guide the local preference decisions. However, these variables have been analyzed separately in the current studies in ethnobiology, and the evaluation of wood quality is restricted to physical-quemical components. In this way, little is known about the influence of the wood quality and wood acquisition in the strategies developed by the collectors. This kind of interaction would indicate if the behavior of the collectors is guided by a cost-benefit reasoning adequate to the local demand. In this context, we formulated the following questions: 1) Which characteristics better explain the use and preference for fuelwood? 2) Is there a cost-benefit reasoning guiding the use and the preference of fuelwood? Considering the hypothesis, a) the most used species provide better cost-benefit ratio for the collectors. To test this hypothesis, we used as scenery the rural community of Carão located in northeastern of Brazil. The data were collected through semi-structured interviews with the head of each family (n=31), and also, through the scoring technique for the characteristics corresponding to the quality of the wood and the difficulty of acquiring the resources, in addition to performing multiple regressions with the information obtained to access the information regarding the selection criteria of the fuel plants. We verified that, in the context studied, the choices made in the process of selection of vegetal resources for the fuel use are not random, but directed to a set of characteristics that correspond to the best quality of the wood, associating cost and benefit variables for a better. However, the relationship cannot be associated with the TFO assumptions, as it does not present an influence of the energy expenditure in obtaining the resources. In this way, we show that the choices have a complexity, and that they are not random, so the best way to understand the factors behind the selection is through the relationship of the wood quality variables with the perceived availability.