The analysis of a large number of chronobiological observations (heliospheric modulations, cosmophysical factors, weak low-frequency electromagnetic influences, etc.) allows us to make a conclusion about the possibility of direct and indirect exogenous (relative to the biosphere) modulations of biological processes in avroral and arctic zones. A nonequivalence of various seasons for the performance of introduction experiments was established. It was shown that the intensive fluctuations of environmental conditions are very important for the survival of living forms introduced into subarctic regions.