During the inventory of ant heaps of the group Formica rufa, performed in the years 1972–73 in the Wielkopolski National Park near Poznań, it was found that the vegetal cover composition, determining to a large extent phytosociologic associations, is likely not so important to ants as the dominant stand. First of all, the specific composition of trees determines not only the degree of the forest bottom shade, but also the specific composition of aphids, constituting an important link in trophic alliances, and, besides that, assuring the corresponding composition of food for ants in the form of phytophages.