The cold, freezing, short days of winter in the Rocky Mountains are not the best time of year for most forms of life.  It is not easy to survive and all forms of life have different strategies for how to survive it.  Many animals migrate, hibernate or adapt.

But, what about those forms of life, such as trees, that can not simply leave the area or go underground into a nice, comfy den?  How do they survive the winter?

Trees main strategy to survive the winter is to go dormant.  This is like hibernation in animals.  For trees, dormancy is a period when they stop growing and are mainly resting.

Trees make some changes in order to give them a better chance at surviving the harsh, cold winter conditions while they are dormant.

 

LEAVES

During the winter, even though there is snow all around, the lack of liquid water is a major concern for trees.  Trees lose water through their leaves.  If a tree loses more water through its leaves than it is replaces through water being absorbed with its roots then it may die.

To keep this from happening, deciduous trees lose their leaves in the fall in order to prevent the loss of too much water during winter.  The broad leaves are great for photosynthesis during the summer when the tree is making energy.  But, in the fall those big leaves are a problem.  So, the tree simply gets rid of them in order to survive.

In contrast, needles on evergreen trees are small and do not lose very much water.  In addition to being small, the needles are covered in a waxy substance which also helps prevent losing too much water.  These differences allow evergreen trees to keep their needles all winter long.

ANTIFREEZE – CHANGE CELLS SO THEY WON’T FREEZE

A trees trunks, branches, and twigs are left aboveground all winter long with nothing over them to keep them protected.  They can’t simply grab a coat to keep them warm.  Instead they do something much more complicated to keep their cells from freezing.  I will try my best to explain it in a simple manner.

The first thing that trees do is to force the water out of their cells into the area between cells.  This way the water will not freeze inside the cells and kill them.  Rather the water freezes between the cells and creates a little bit of heat that warms up the cells.

While the water is moving out of the cells, the cells also are changing the liquid inside them from something that is mostly water to something that is made up of more sugars and acts like an anti-freeze.  Anti-freeze is a liquid that has a much lower freezing point than water.  This means that the cells can get much colder before they freeze and die.