Portugal - Atlas do Ambiente III.6 - Zonas Fitogeográficas Predominantes

Summary

The Author shows that the three main Portuguese phytogeographical zones of continental Portugal are not correctly separated, as usually has been done, by the rivers Douro and Tagus. In the A. opinion, the northern zone is northernly delimited by the annual rainfall of 1250-1500 mm, and the central one runs till near the geo- logical Plistocenic and Pleiocenic formations in South Ribatejo, and on the northeast Alto Alentejo the Miocenic and granitic formations make a sharp boundary with the southern Silurian one. Each of these three phytogeographical zones are subdivided into secondary subzones according to the nature of the altitude, dryness index and geology. For each of these subzones, are reffered the more important and distinctive species.