Avaliações energéticas de espécies florestais nativas plantadas na região do Médio Paranapanema, SP

Abstract

The use of renewable sources of energy is a worldwide trend and is being increasingly widespread, mainly for environmental and economic reasons. Biomass has become one of the most commonly used renewable sources of energy in the last years. Many of the biomass fuels used today comes in the form of wood products and others sources. In Brazil, woody biomass has great expression in the country's energy supply, 12,5% of the total (BRASIL, 2008). However, the growing demand for such application requires the expansion of forest plantations for sustained production. Meanwhile, the forest plantations should be targeted by productivity of forests and the characteristics of wood during energy use to reach high yields. The Brazilian species are, relatively, little known in terms of energy uses, since most of the plantations are traditionally carried out with species of the genus Pine and Eucalyptus. This study aimed to bring about qualitative and quantitative characteristics of Brazilian forest species, as well as a study about the influence of age on the characteristics of wood energy uses, in order, to provide subsidies for the selection of species with vocation for this purpose. The research was conducted from recovery plantations in the region of Assis, Brazil. In such areas, the Forest Institute of the State of Sao Paulo developed tissues for quantification of biomass production and carbon (MELO et al., 2008) and, in addition, this study was conducted, aiming to offer new data and information for this important segment. In the first study, 12 species from 6 to 8 years were evaluated, on the energy production and properties of wood related to this purpose. The second assessment compared the characteristics of two species of wood in two distinct age groups, 6 and 8 years and 36 and 37 years. Based on the results it was concluded that: a) None of the species studied showed limitations on its woods’ characteristics, related to energy use; b) The decisive factor on the selection of species for planting was the production of biomass; c) Related with the last point, four species present more potential for energy use, namely: Enteroplobium contortisiliquum, Anadenanthera macrocarpa, Cytharexyllum myrianthum and Acacia polyphyla d) In the second study, conducted on the Anadenanthera falcata and Myracrodruon urundeuva, there was the influence of age in all properties of the woods, for both species analyzed. e) Considering the last species mentioned, it was found that the density, the heating value, the carbon fixed, the extractives content and the lignin content were positively associated with age, while the volatile materials content and ash showed negative influence of the effect of age.