Comparative analysis of runoff and sediment yield with a rainfall simulator after experimental fire

Changes produced in runoff and sediment levels before and after fire and du ring the revegetation process were examined using a rainfall simulator. The area was burned in an experimental fire, reaching temperatures from 35 deg rees to 563 degrees C. Then it was revegetated using different species comb inations. Fifteen permanent plots were established in the burnt area (4 tre atments and a control replicated three times). Simulated rainfall of 15 mm per 5 min was applied in each treatment. No significant differences were fo und in sediment yield and runoff between treatments, but greatest runoff wa s observed to occur immediately after the fire. A significant relationship was found between runoff and woody cover, and a decrease in runoff can be o bserved as cover increases. The relationship between sediment yields and ru noff rates was also positive. The low rates observed during rainfall simula tion are due to the effect of natural vegetation rather than revegetation t reatments. The high organic matter content also had an influence on the low rates of runoff and sediment.