Portugal - Atlas do Ambiente II.3 - Carta de Distribuição de Carvalhos e Castanheiros

Summary

The present chart of the distribution of oak woodlands and chestnut groves was based on elements collected from the «Preparation Chart» for the Agricul- ture and Forestry Chart in the scale 1:250 000, worked out by the Agrarian Survey and Land-Use Planning Service, now a National Center. This Service, in 1965, had already published a chart of the distribution of the chestnut groves in the scale 1:500 000. The criteria followed for this chart of the Atlas are defined, the various woodlands of the species being represented, namely the pure woodlands, the mixed woodlands (dominant or dominated), and the scattered ones, mention being ma- de of the smallest areas mapped. The morphological characterization of the different oak species (Quercus ro- bur, Q. pyrenaica, Q. faginea, Q. canariensis, Q. coccifera and Q. lusitanica) and their hybrids is briefty made. The pronounced polymorphism of these spe- cies is mentioned to distinguish subspecies (or races), varieties and forms. Their chorological distribution in Portugal is shown, together with orogra- phical, ecological, bioclimatological and pedological information. The natural arboreal oak formations in their nearly primordial or primor- dial state, the oak woodlands, are of a rare occurrence today or limited to small woods, windbreaks and hedges. Under the phytosociological viewpoint, such natural arboreal formations, namely those in the northern and montane zones, affiliate themselves to the class Querco-Fagetea, the order Querc