The effect of Lasius niger (Hymenoptera, Formicidae) ant nest on selected soil chemical properties

The set of chemical properties: total, available and watersoluble P, total C, available K, Na, Ca and pH in H2O and KCl were studied in 64 nests of Lasius niger and in surrounding soils (control). Ant nests were located in wide range of soil conditions. Additionally, spatial distribution of those parameters was studied in three nests. The pooled average values for all investigated soil parameters, except that of Ca and C were significantly higher in the nests than in surrounding soil. At the same time, chemical properties of the nest were effected by chemical properties of surrounding soil; pH value in the nests increased in comparison to control in acidic soils but the opposite was true in alkaline soil. Content of available P in the nest was higher than in surrounding soil. As the content of available P in surrounding soil increased the enrichment of the nest (increase of available P in nest in comparison with control) was higher. Adjacent soils with low available Ca and total C supported nests that were higher in these elements while surrounding soil with higher Ca ans C supported nests that were lower in these elements. The changes in chemical properties were more pronounced in the aboveground than in the belowground part of the nest. The results indicates that the main processes taking part in chemical changes of soil in the ant nests are soil mixing due to excavation of deeper soil layers, enrichment of substrate by ants (by rest of food, excreta etc.) and interactions of nest chemistry with other physical, chemical and microbial parameters in the nest.