Relationship between ant activity and microaggregate stability

Environmental changes may cause soil degradation, which in turn affects soil biota. Ants play a key role in soil engineering. Therefore, their effects on soil systems have been extensively studied. However, we identified an important gap in the literature regarding the effect of ant bioturbation on microaggregate stability (<0.250 mm). This study was conducted in a fragmented landscape with a strong urban-rural interface in Southern Brazil. A total of 128 ant mounds and four soil profiles 0−100 cm (22 control samples) were tested for readily dispersible clay (RDC). RDC was determined using the turbidimeter method (NTU). Considering the control samples (121.0 NTU) and ant mound aggregates (48.6 NTU), the microaggregates collected from ant mounds exhibited substantially lower readily dispersible clay than control soils. Mean turbidity was approximately 2.5-fold lower in mound-derived samples. Because soil source depth and other potentially confounding factors were not experimentally controlled, this result should be interpreted as an association that warrants mechanistic investigation.