Most alpine plants are faced with low temperature extremes at some point in their lives. There are a number of ways that a plant can survive these extremes. Plants can avoid exposure to low temperature by using different forms of seasonal phenology, morphology, or by variable growth form preference. They can also avoid the freezing of their exposed tissues by increasing the amount of solutes in their tissues, known as freezing-point depression. Another, somewhat similar, method plants may use to avoid freezing is supercooling, which prevents ice crystallization within plant tissues. These methods are only sufficient when temperature is only moderately cold. In the alpine zone, temperatures are often low enough that these methods are not sufficient.[8] When plants need a more permanent solution, they can develop freeze tolerance. Plants can also dehydrate their cells by moving water into intercellular spaces. This causes ice formation outside of the cell where ice crystals will not cause damage. When all of these strategies fail to prevent frost damage, alpine plants often have the capacity to repair or replace the organs damaged. As it is often difficult to prevent damage, many alpine plants depend on the replacement of their organs.[9] They help make this possible by placing their meristems below ground, where temperatures are generally warmer.[8]