The effect of fire on soil mesofauna: recolonization of burnt areas

Abstract

This work was conduced in a 4 ha plot, whose forest cover was felled and bumed to form a pasture. The burning was not homogeneous, giving rise 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 Berlese-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 burnit area the number of Oribatida (46.464 ind/m²) was less than the total number if other sub-orders of Acari (132.532 ind/m²); the density of Collembola (7.361 jnd/m²) was inferior to the total number of other insects (22.460 ind/m²). An inverse situation was observed 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).