EFFECTS OF FIRE AND OF CLEARING IN A MEDITERRANEAN QUERCUS-ILEX WOODLAND - AN EXPERIMENTAL APPROACH

The object of the study is to compare the importance of soil and nutrient losses from plots in an ever green oak (Quercus ilex) woodland under different environmental conditions; namely under undisturbed forest and at sites that had been clear felled and burnt under controlled conditions. At each site, the plots were instrumented with 10 Gerlach troughs located at the footslope of each plot, and with 12 troughs in the upper part of the burned plot inserted at regular intervals from the water divide. Raingauges were subsequently added and data on rainfall intensity collected at a nearby station. Results indicate that burning has a significant effect with respect to runoff and nutrient and sediment losses. The impact of clear-felling is much less. Sediment transport on the slope is not only caused by surface runoff but by other agents of erosion as well.