The development of cold hardiness in coniferous species is, as in most woody species, under the control of the climatic environment that prevails where the trees are grown. Although there are interspecific differences in the capacity for cold hardening and a wide range of variation exists, it is likely that there is a generic process for the plants to cold harden and deharden. In this chapter we describe the seasonal changes in cold hardiness in conifer species and use this seasonality of hardening and dehardening as a basis to discuss the quantitative aspects of environmental control of the development and loss of cold hardiness. Finally, these quantitative relationships are the bases for development of predictive models of cold hardening and dehardening.
Greer, D. H., Leinonen, I., & Repo, T. (2001). Modelling Cold Hardiness Development and Loss in Conifers (pp. 437–460). https://doi.org/10.1007/978-94-015-9650-3_16