THE EFFECT OF FIRE ON SOIL MESOFAUNA - RE COLONIZATION OF BURNT AREAS

This work was conduced in a 4 ha plot, whose forest cover was felled a nd burned to form a pasture. The burning was not homogeneous, giving r ise to a patchwork of well burnt and unburnt areas. The soil fauna of these two types of areas was compared collecting 15 sampling units in each 1, 15, 30, 40, 60, 125, 145, 200, 270, 320 and 370 days after the burning. A metallic soil gauge with 25 cm2 was used to sample, and Be rlese-Tullgren funnels to extract the soil fauna. The results indicate that the population density of the fauna was drastically affected by the fire. In the burnt area the number of Oribatida (46.464 ind/m2) wa s less than the total number if other sub-orders of Acari (132.532 ind /m2), the density of Collembola (7.361 ind/m2) was inferior to the tot al number of other insects (22.460 ind/m2). An inverse situation was o bserved in the non-burnt area (Oribatida = 79.045 ind/m2; other Acari = 34.025 ind/m2 - Collembola = 17.2.76 ind/m2; other insects = 11.098 ind/m2).