Small‐scale observation on the effects of burrowing activities of ants on soil hydraulic processes

Abstract

SummaryAnts alter soil structure when making their nests and the fresh soil aggregates brought to the surface become available for erosion. However, the effects of burrowing activities of ants on soil hydrological processes are unclear. In this study, the effects of Tetramorium caespitum, Messor aciculatus and Camponotus japonicus nests on the preferential flow and soil surface hydrologic processes at a small scale were assessed on the Loess Plateau. Soil dyeing and rainfall simulation experiments were conducted to quantify the effects of ants' nests on runoff and water infiltration on slopes. The diameters of nest entrances for T. caespitum, M. aciculatus and C. japonicus were 0.19, 0.33 and 0.56 cm, respectively. The nests of M. aciculatus and C. japonicus promoted water infiltration, resulted in large soil water contents and decreased surface runoff. The turret‐like mounds around the nest entrances made by T. caespitum prevented the formation of soil preferential flow. The depths of dyeing in the soil with M. aciculatus and C. japonicus nests were 32.6 and 49.2 cm, respectively, which were significantly (P < 0.05) deeper than those in the soil with T. caespitum nests (10.0 cm) and no nest (10.3 cm). The unstable soil aggregates made by ants on the soil surface break down easily and encourage the loss of soil sediment. The results show that increasing the ant colonies, especially those with larger bodies, could be considered a strategy to increase water infiltration and soil water content in semiarid areas. In the meantime, the sediment loss cannot be neglected.Highlights This study evaluated the effects of hypogeal ants on soil erosion. The turret‐like mounds of T. caespitum prevent the formation of preferential flow. Ants with larger bodies made bigger nest entrances and resulted in more infiltration. The burrowing activities of ants exacerbate soil erosion.