Biogeographic Regionalization of the European North by Boundaries of Freshwater Copepoda Ranges

Biogeographic regionalization of the European North was performed based on the distribution of three orders of microscopic crustaceans (Copepoda). Biogeographic boundaries were drawn along the areas of crowding of complementary range boundaries of 29 species, subspecies, and forms of Harpacticoida; 14 species of Calanoida' and 11 species of Cyclopoida. Eleven biogeographic units (regions) were identified, the boundaries of which corresponded to the latitudinal and longitudinal boundaries of changes in climate type (subtype) and natural-climatic zones. An association was thus established between the composition of copepod taxocenoses and climatic factors, differing between the three orders. The orders were found to be significant as indicators for detecting the consequences of future climatic changes in the North.