Landscape Ecology vol. 3 no. 1 pp 3-18 (1989) SPB Academic Publishing bv, The Hague

The relationship between groundwater and landscape in representative areas of the Spanish plateaux is dis- cussed, with specialattention given tothe Douro River basin. The study focusseson the transference of water and matter that is conditioned by groundwater flow systems, and also on water bodies, wet meadows, marsh- es, saline soils under their influence. These factors are of great importance in semiarid areas. Using photointerpretation, interviews, vegetation plots, water samples from wells and springs and soil samples, and the results of data processing (principal component analysis, shared information) we find that hydrological processes are the main controlling factor in the ecological function and variation of uncultivated lowlands. These processes include the alternation of recharge and discharge areas, the geochemical evolution of groundwater and the independent flows of the regional system. The landscapes in recharge and discharge areas are compared, as well as the influence of the evolutionary stage of the groundwater in the latter areas (glycophyteor halophyte vegetation). After observing the ecologi- cal importance of these aquifer discharges systems, the causes of their accelerated transformation are analyzed