The significance of fire intensity in creating local patchiness in the Chilean matorral

The hypothesis that high and low intensity human-made fires can produce eco logically different effects in the Chilean matorral is examined. We compare d the abundance of naturally established seedlings under shrubs burned by l ow and high intensity tires on five north and five south facing slopes. On south facing slopes, we found 54 shrubs burned by law intensity fires and o nly 4 shrubs burned by high intensity fires. In contrast, north facing slop es had approximately the same number of shrubs burned by low and high fire intensity fires (24 versus 19, respectively). We only found seedlings under shrubs burned by low intensity fires and most of them were of A Muehlenbec kia hastulata and Trevoa trinervis. Also viable seeds were only found under shrubs burned by low intensity fires. Results indicate that fire intensity can be an important factor determining species distribution patterns in th e matorral.