Frost cankers in poplar are freeze-killed areas of bark and wood around which woody calluses develop and form buris and frost ribs. Frost dieback is a freeze-killed segment of the stem at the base, tip, or mid-portion of a branch or leader. It may or may not enhance natural pruning or poplar branches depending on whether the basal parts are damaged or alive and able to form abscission layers. In addition to abscission, low temperature affects increment, growth patterns, and vigor of poplar. Tree become stunted from persistent leader dieback. Suckers, crooks, and sweeps also characterize many stands of poplar. These characteristics of frost damage in mature forest stands are valuable in assessing the hazard of frost if the stands are to be clear-cut and reforested. The effects of frost damage are controlled somewhat in amenity, parks, and recreational areas because pruning is necessary to prevent wind breakage of staghead and frost-cankered trees.
Zalasky, Harry. 1976. Frost damage in poplar on the prairies. The Forestry Chronicle. 52(2).