Why Are There Conifer Trees in the Mountains?

conifer trees

Conifer trees covered in snow during winter in the Rocky Mountains.

Conifer trees are generally the most common trees at higher elevations.  There are number of ways they are adapted to survive in the mountains.

I enjoy hikes that take me to the tops of mountains. The hike usually starts low and climbs up into a conifer forest of pine trees or spruce and then gets above tree line to the alpine tundra.  Have you ever wondered why as you gain elevation in the Rocky Mountains there are more conifer trees than broadleaf trees, such as Maples?

Once again, as seems to be the answer to most questions about why the natural world is the way it is, the answer is survival.  Conifer trees, such as pine trees and other common trees of the Rockies, are adapted to survive higher up on mountains where broadleaf or deciduous trees can’t live.  You can learn all about the common trees of the Rockies and more with Jake’s Nature Guide: Rocky Mountains.

What are the challenges to surviving at higher elevations?

The higher up in elevation you go on a mountain the harsher the conditions are for survival.  The areas higher up on mountains are windier, colder, and receive more snow than places lower on the mountains or in valleys.  The weather also stays colder longer higher up in the mountains, which means there is a shorter growing season – the time when plants and trees can grow.

Conifer trees have the following advantages that help them survive in higher elevations on mountains:

pine tree needles, conifer trees

Lodgepole pine needles

NEEDLES NOT LEAVES

Conifer trees do not have leaves, but instead have needles. Similar to how you can tell what kind of tree it is by looking at the leaves, you can help identify an evergreen tree by the needles.   Different kinds of trees have different lengths and even shapes of needles.

One reason needles help trees survive at higher elevations is because they keep the tree from losing too much water through its leaves (Needles and leaves lose water from their leaves through tiny openings that open for photosynthesis to occur).  Needles are smaller than broad leaves so there is less surface area from which to lose water.  Needles also have a waxy covering that keeps in water.

In the wintertime there may be a lot of snow around, but there is actually not a lot of water around in a liquid form, which is what trees need to survive.  So, if a tree loses too much water it would die.

A second advantage of having needles at higher elevation is that trees do not have to grow new leaves in spring.  Growing new leaves every year takes a lot of energy for a tree.  In the mountains there is a much shorter growing season and all plants and trees need to take complete advantage of that small amount of time in order to survive.

One final advantage of needles is that they allow the tree to photosynthesize all year long.  This means that even in the middle of winter on a sunny day, and if there is enough water, they are able to create their own energy.  This gives them an extra advantage that helps them survive in the harsh mountain environment.

 

conifer trees or evergreen trees

Photo courtesy of Mike Kuhns

CONICAL SHAPE

Have you ever noticed that Christmas Trees and all conifer trees have a nice conical shape?  That shape is important because it keeps them from falling over in the winter from too much snow collecting on them.

Snow accumulates on branches and leaves or needles when it is snowing a lot.  The conical shape of conifers prevents as much accumulation as there would be on a wider shaped tree.  The conical shape of the tree also helps to get the snow to fall off the tree quickly.

FLEXIBLE

Winter can damage trees with too much snow accumulation on a tree causing it to break off and fall down.  In addition to the conical shape of conifers, some tree species, such as firs and spruces have another important feature that helps them survive – they are quite flexible.  This  allows them to bend as lots of snow accumulates and piles up on them.  This flexibility keeps them from breaking under heavy loads of snow and then their conical shape helps them shed the snow and they then return to their normal upright position.

You can learn more about the all aspects of the natural world of in the Rocky Mountains in Jake’s Nature Guide: Rocky Mountains.

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