Temperature adaptations of terrestrial arthropods of the Yenisey Region of Siberia (Asian Ecological Transect)

Field studies and sampling of terrestrial invertebrates for ecophysiological experiments were undertaken in the summer of 1994 and 1995 in different geographic regions of the Asian Transect (Krasnoyarsk to Karaul) in Siberia. Two important parameters reflecting invertebrate temperature adaptations were investigated: individual thermopreferenda and supercooling point temperatures. The most noticeable differences in thermopreferenda were between tundra and boreal species. The former species prefer temperatures usually 2 to 3 ∞C lower than the latter. Northern tundra species exhibit no seasonal changes in thermopreferenda, whereas boreal species have seasonal changes in their thermopreferenda. The majority of the species (total of 27 species) investigated are freeze-intolerant and overwinter in a supercooled state. Some arthropods are freeze-tolerant: three species of millipedes (Lithobiomorpha), but only two (adult) beetles from the Carabidae and Staphylinidae. This feature enables such species to be widespread over much of the territory of the Transect. The experimental data suggest that there is no special “northern” variety of cold hardiness in the fauna.

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