Changes in heat values and in flammability with the seasons of the year for the different species which make up the woodland map of two zones, Sada (coastal area) and Santiago (hillside and plateau area), situated in La Coruna (Galicia, Spain), are reported These data were evaluated as a help for fighting forest fires, which have been very frequent in this region during the last decade. The species studied are the most abundant in the areas: Eucalyptus globulus Labill., Pinus pinaster Aiton, Ulex europaeus L., Rubus fructicosus L., Pteridium aquilinum L., Sarothamnus scoparius (L.) Link, Quercus robur L., Castanea sativa Miller and Acer pseudoplatanus L. The calorific were measured by static bomb calorimetry. data were complemented with flammability determinations and completed with chemical analyses of the different species. Copyright (C) 1996 Elsevier Science Ltd.