在北海道东部地区,由于冬季严寒,土壤结冻期长。这期间白三叶的匍匐茎,在冻土(土壤受冻凸起)壅埋下越冬,匍匐茎的细胞间隙结冻,处于结冻状态。虽然看起来受到冻害,但实际上由于冻害而枯死的植株几乎没有。Jones和Wejer观察了一年生苜蓿越冬时受冻害的形态变化,查明了植株枯死的原因,认为冻害不能直接使植株枯死,而是因苜蓿的根和根冠内部形态发生了 In the eastern part of Hokkaido, soil freezing period is long due to the winter cold. During this period white clover stolons, in the frozen soil (soil by the cold bulge) 壅 buried under winter, stolons interstitial freeze, frozen in the state. Although it seems to be frostbite, there are virtually no plants that have died of frost damage. Jones and Wejer observed annual morphological changes of annual alfalfa frost damage, identified the cause of the withered plants, that the frost damage can not directly plant dead, but because of alfalfa root and crown internal morphology occurred