Risk indices corresponding to the forest biomass in the hill area of Galicia were determined. The use of these indices allows the design of risk index maps, very useful for the prevention of, and effective fight against, forest fires. These parameters are complemented with chemical analyses based on the elementary composition, concentration of heavy metals, humidity percentage, ash left in the bomb after combustion, and moisture content. The energy maps of the studied area are also shown. These maps are a necessary reference when evaluating the energy xyloenergy - of the area for its sensible economic exploitation. Other parameters of interest such as the bioclimatic characteristics of the area and the biological properties of each forest species were also studied. The different parameters were measured using, as main equipment, a bomb calorimeter in an oxygen atmosphere, an epiradiator, an elementary analysis equipment and an atomic absorption spectrophotometer.