Soil fauna under eucalypt stands of different ages in the Savanna of Piauí
The reforestation with eucalyptus has increased significantly in the Brazilian Savanah and it can promote changes on soil biological properties, mainly soil fauna. Thus, the aim of this study was to evaluate the composition of soil fauna in areas with Eucalyptus plantations of different ages compared with native savanna. The study was conducted in Eucalytptus plantations aged one, two, three and four years and area with native forest was taken as reference. Soil fauna was collected in the dry and rainy season to evaluate the number of individuals from different taxonomic groups, richness, uniformity and diversity. The highest number of soil fauna was found in eucalyptus plantations with one year old at both seasons. However, the richness did not differ between seasons. In areas where with eucalyptus plantations with one and two years old showed 90% of individuals represented by Coleoptera and Formicidae, which contributed for decreasing in fauna uniformity. The implantation of Eucalyptus early reduced the diversity and uniformity of soil fauna; however, there was a recovery of this biological attribute after two years of reforestation.