LAUSR

ABSTRACT Here, we propose the modern soil map as a source for creating spatial context for agent-based modelling of the historical expansion and dispersal of ground squirrel species. On the basis of this soil map, we produced a lithologic map of the near-surface layers of the Quaternary cover. Units of this new lithologic map (i.e. certain kinds of substrate) were assessed in context of preferability by certain ground squirrel species. Then, these (basic) preference rates were modified for the case of valley slopes (positive impact of valley slopes) and for the case of loess-and-soil accumulation (also positive impact). The hypothesis of the positive impact of loess and soil accumulation is supported by following facts: range shrinking of Spermophilus species in the Holocene; stability of the range boundary between Spermophilus pygmaeus and Spermophilus suslicus in the Middle and Late Pleistocene and the ability of the Pleistocene ecosystems to support high animal biomass even during cold epochs.