Vegetation and environmental change from late Bronze Age to the Roman period in north-west Portugal is reconstructed on the basis of charcoal analyses. The site was occupied by people of the Castrejo culture, i.e. an Iron Age culture that developed in the north-west Iberian peninsula. The pattern of exploitation of natural wood resources by local populations during this period appears to be similar during the three phases of occupation. The frequencies of light-demanding plant species, mostly Leguminosae, testify to considerable destruction and degeneration of the climax woodlands. The preference of particular wood for specific uses, such as roofing, is discussed and the Holocene history of selected trees within the wider region is considered.