Fauna epiedáfica em áreas de diferentes tipos de uso do solo: avaliação quantitativa, qualitativa e suficiência amostral

Abstract

Soil is populated by thousands of organisms responsible for various ecosystem functions. Soil fauna is related to various soil processes, and presents 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 epiedaphic fauna distribution in different soil uses and at different seasons of the year in São Gabriel, RS, evaluating its use as a bioindicator of 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, soil temperature, soil water content and biomass/litter were also evaluated, to verify the influence that these attributes exert on the soil fauna. The abundance and diversity were evaluated, diversity, uniformity and similarity indexes in the areas were calculated. Sample sufficiency was also evaluated for the method used in the study. The results presented a large diversity of edaphic organisms. Collembola, Hymenoptera and Arina were the groups with greater abundance. Some groups have shown to be sensitive to changes in environmental variables, so it can be stated that the soil fauna has the potential to be used in evaluating soil quality. 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 results of sample sufficiency calculations showed that the number of samples used in the study can be considered sufficient to evaluate soil fauna for most areas and times evaluated.