PROPERTIES AND EROSIONAL RESPONSE OF SOILS IN A DEGRADED ECOSYSTEM INCRETE (GREECE)

To study desertification processes relating to soil erosion, a climato logical and altitudinal gradient from south to north was selected in C rete (Greece) and four locations were selected along the gradient. At the locations precipitation ranged from 1400 mm/year at the highest lo cation to 400 mm/year at the lowest. All locations are affected by the actual land use: intensive grazing, small controlled fires, and aband oned agricultural terraces. Representative soil profiles were describe d in the field and analyzed in the laboratory, and rainfall simulation experiments in the field measured soil erosion over different soil su rfaces and land uses. Data on physical and chemical properties were ob tained from the soil profiles and soil hydrology, and erosion data wer e obtained from the rainfall simulation experiments. Soil aggregation was studied with samples taken from the soil in the rainfall simulatio n plots and special attention being paid to the aggregate size distrib ution and the water-stable microaggregation. The interaction between c limatological conditions and land use seems to be the main factor cont rolling soil erosion. This paper describes how the expected erosion al ong the gradient (from the most humid to the driest site) can be affec ted and disturbed by specific processes derived from land use.