Rapid induction of the heat hardening response in an Arctic insect

The ability to cope with increasing and more variable temperatures, due to predicted climate changes, through plastic and/or evolutionary responses will be crucial for the persistence of Arctic species. Here, we investigate plasticity of heat tolerance of the Greenlandic seed bug Nysius groenlandicus, which inhabits areas with widely fluctuating temperatures. We test the heat tolerance and hardening capacity (plasticity) of N. groenlandicus using both static (heat knock down time, HKDT) and dynamic (critical thermal maximum, CT max ) assays. We find that N. groenlandicus is able to tolerate short-term exposure to temperatures up to almost 50°C and that it can quickly increase heat resistance following heat hardening. Furthermore, we find that this hardening response is reversible within hours after hardening. These findings contrast with common observations from temperate and tropical insects and suggest high thermal plasticity in some Arctic insects which enables them to cope with extreme temperature variability in their habitats.

Research on Elastocoast Revetments Frost Heave Adaptability Model Test

Elastocoast revetments frost heave adaptability model test was carried out. Conclusions: (1) Elastocoast revetments can increase heat resistance and decrease the energy transfer. So the frozen depth and amount of frost heaving could be reduced. (2) This structure has deformation characteristics with temperature, and has a deformation at the test beginning. (3) The freezing rate under revetments is slow and the water supply is sufficient, because of which the amount of frost heaving will occur at one third of side slopes of canal, and the bottom of canal take the second place. (4) Consolidation settlement occurred after freeze-thaw cycling. And the revetments have a trend of becoming gentle slope. It indicates that Elastocoast revetments can commendably adapt to frost heave deformation. (5) The freeze-thaw durability is influenced by water content and the dosage of Elastocoast. The capability to resisting freeze-thaw denudation is better with the water content reduce and the material dosage increase.