2.1. Wood selection
Wood species selection for the combustion experiments was
based on the abundance of forest tree species in Portugal (AFN,
2005). Maritime pine (Pinus pinaster) and eucalyptus (Eucalyptus
globulus) currently account for more than 40% of the Portuguese
forest and are prevalent in the northern half of the country. Cork
oak (Quercus suber) and holm oak (Quercus rotundifolia), cover,
respectively, 21% and 13% of forested land in Portugal, and are
prevalent in the South. Other deciduous oaks, such as the pyrenean
oak (Quercus pyrenaica), were once the dominant species in the
northern lands but now represent 4% of the country’s forest cover,
with a patchy distribution. All these species are native to Portugal,
except eucalyptus, which is native to Australia, and is widely
planted for use as a feedstock to the pulp and paper industry. Tree
species used in the combustion experiments are listed in Table 1,
together with their scientific names, wood type, land cover and
moisture content (as used in the experiments