Edaphic Fauna Diversity and its Relationship with Soil and Vegetation Attributes in a Toposequence Under Natural Grasslands in the Pampa Biome – South Brazil

Abstract

The edaphic fauna is fundamental to the natural processes that occur in soils, such as nutrient cycling. Despite its importance, studies on this topic in the Pampa Biome are still scarce. The objective was to investigate the influence of edaphic organisms on the dynamics of soil, organic matter and pasture attributes, in toposequence under natural grasslands in the Pampa Biome. For that, in ten different points of the landscape, in different seasons (spring-summer-autumn-winter), chemical, physical-chemical and biological soil attributes, bromatological vegetation attributes and sampling of edaphic fauna using traps of fall, making taxonomic identification of the edaphic groups found, after calculating the Shannon-Weaver diversity index and the Simpson index. The data were submitted to exploratory multivariate analysis of principal components (PCA). The lower slope positions showed better levels of natural fertility, with abundance of collembola in these positions. There was a negative correlation between collembola and arachnids, indicating a predatory relationship. The physical-chemical and vegetational attributes had a higher influence on the edaphic organisms dynamics than the different seasons. However, the Hymenopteras showed a strong correlation with the summer, being predominant in some points, in that season. One can perceive the complexity of the dynamics of edaphic organisms in the different conditions found. Due to the importance of these organisms and natural grasslands for the provision of ecosystem services, the preservation of the same becomes essential.

Keywords: Soil organic matter - Soil Biomass - Natural Grasslands - Bromatology - Soil Fauna