Compound changes in temperature and snow depth lead to asymmetric and nonlinear responses in landscape freeze-thaw

Cycles of freeze-thaw (FT) are among the key landscape processes in cold regions. Under current global warming, understanding the alterations in FT characteristics is of a great importance for advising land management strategies in northern latitudes. Using a generic statistical approach, we address the impacts of compound changes in air temperature and snow depth on FT responses across Quebec, a Canadian province similar to 2.5 times larger than France. Our findings show significant and complex responses of landscape FT to compound changes in temperature and snow depth. We note a vivid spatial divide between northern and southern regions and point to the asymmetric and nonlinear nature of the FT response. In general, the response of FT characteristics is amplified under compound warming compared to cooling conditions. In addition, FT responses include nonlinearity, meaning that compounding changes in temperature and snow depth have more severe impacts compared to the cumulative response of each individually. These asymmetric and nonlinear responses have important implications for the future environment and socio-economic management in a thawing Quebec and highlight the complexity of landscape responses to climatic changes in cold regions.

Automated summary

In cold regions, cycles of freeze-thaw are important landscape processes, and compound changes in air temperature and snow depth have significant and complex impacts on these processes. There are spatial differences in the responses between northern and southern regions, and the responses exhibit asymmetric and nonlinear characteristics. Furthermore, under compound warming conditions, the response of freeze-thaw characteristics is amplified compared to cooling conditions, and the impacts of compound changes are more severe than the cumulative response of each individually.