[Effects of freeze-thaw cycles on soil arthropod in the permafrost region of the Great Hing'an Mountains, Northeast China].

A laboratory experiment was conducted to investigate the impacts of freeze-thaw intensity (-5-5 ℃, -10-5 ℃) and frequency (1, 5, 10, 15 times) on the community structure of soil arthropod in permafrost zone, Great Hing'an Mountains with the 5 ℃ as control. A total of 4198 individuals of soil arthropod were extracted, belonging to 4 classes, 9 orders, 24 families and 33 genera. The results showed that the number of individuals and groups of soil arthropod decreased significantly in the treatment with high frost intensity (-10-5 ℃), while the individuals of some taxa increased in the treatment with low frost intensity (-5-5 ℃) after the first freeze-thaw incubation. The group number, Margalef index and Shannon index decreased with the increases of freeze-thaw cycling times in low frost intensity treatment, while did not change regularly in high frost intensity treatment. Larva stage was a kind of survival strategy for arthropod to resist low temperature stress, with Acari showing stronger cold tolerance. Different responses of soil arthropod to freeze-thaw cycles, synergistic effect among species and soil environment were factors affecting the structure of soil arthropod community. This study could provide scientific data and theoretical basis for the research and conservation of soil arthropod diversity in the permafrost zone in mid-high latitudes.