Analysis of the edaphic fauna in different soil uses in the pampa biome

Abstract

The soil is populated by thousands of organisms which are responsible for various ecosystem functions. Among these organisms, those belonging to the soil fauna stand out and present a great sensitivity, responding to modifications in the environment, and may be regarded as a good soil quality bioindicator. This work aimed to characterize the edaphic fauna distribution in different soil uses and at different seasons of the year in São Gabriel, RS state, evaluating its use as a bio-indicator of the soil quality. Soil fauna evaluations were conducted in three areas of different soil uses: native forest, native pasture and ryegrass/soybean, in two distinct seasons (winter and summer). During the samples, the soil temperature, the soil water content and the biomass/litter were also evaluated, to verify the influence that these attributes exert on the soil fauna. The abundance and diversity were evaluated as well as the diversity, uniformity and similarity indexes in the areas were calculated. The results presented a large diversity of edaphic organisms. Collembola, Hymenoptera and Acarina were the groups with greater abundance. Some groups have shown to be sensitive to changes in environmental variables. The area with greater diversity and greater uniformity was the native forest, while the ryegrass/soybean had the least diversity and uniformity. The most similar areas were the native forest and the native pasture in the winter evaluations. The soil fauna presents potential to be used as a soil quality bioindicator.