Vegetatio 75: 73-80, 1988 © Kluwer Academic Publishers, Dordrecht - Printed in the Netherlands 73 Long-term vegetation changes on the stabilized dunes of Dofiana National Park (SW Spain) Manuel Granados Corona, Angel Martin Vicente & Francisco Garcia Novo Department of Ecology, University of Sevilla, Ap. 1095, 41080 Sevilla, Spain Accepted 10.3.1988 Keywords: Coastal dune, Human impact, Mediterranean forest, Mediterranean scrub Abstract Changes in the vegetation of stabilized sand dunes of Dofiana National Park in the last four centuries have been analysed, combining ecological and historical sources of information. Quantitative vegetation data have been obtained from 5 inventories of a 15 km long transect, consisting of 34 points where nearby woody plants have been recorded. Inventories were taken in 1636, 1647, 1652, 1682 and 1859. The analysis of these data, combined with climatic and management information on the area, reveals that until 1636 a mediterranean forest dominated by Quercus suber, existed; it was used as a game preserve. From 1636 to 1682 vegetation underwent profound changes with a marked drop in trees and mature scrub. The vegetation was replaced by a pioneer scrub species. This rapid change was brought about by the introduc- tion of cattle and pigs, timber and cork exploitation, and the use of prescribed fire. The climatic crisis that arose circa 1700 led to erosion of the sandy soils, which made the vegetation change irreversibly. Livestock pressure hampered natural forest regeneration until 1737 when Pinuspinea plantations started. From then on- wards little change in vegetation is known to have occurred. It is suggested that the main steps of change in Dofiana vegetation history may have occurred in many other areas of the Mediterranean Basin. Nomenclature: follows Tutin et aL (1964-1980), Flora Europaea. Introduction The Dofiana National Park (Reserve of the Bi- osphere of the MaB Program; 50720 ha) is situated on the SW coast of Spain between 3707 ' and 36°48'N and 6°12 ' and 6°34'W. The climate is of a mediterranean subhumid type with some atlantic influence. According to Gaussen (1949) it can be classified as thermo-mediterranean. Average rain- fall is 620 mm with less than 75 mm from May to September. The average daily mean temperature is 9.3 °C during the coldest months (January and De- cember). The summer temperature is high with a daily mean of 23.9 °C for July, the warmest month. Due to their origin as fixed holocene sand dunes, the stabilized sands have an undulating topography (Vanney & Menanteau 1985). The presence of a hanging water table along with the permeability of the sandy substrate, makes higher zones markedly arid in summer, while depressions are humid with occasional flooding in winter. The present vegetation is dominated by mediterra- nean scrub, the floristic composition of which close- ly follows local topography. On higher places an