Why Are Conifers Found in the Northern Regions?

The needle-like leaves that many conifers in cold regions possess allow them to shed water and snow effectively, which enhances their ability to survive in adverse conditions.

Conifers are found throughout the world in a variety of climates. These species are present in ecosystems ranging from southern California to northern Maine. Conifers are known for surviving in adverse conditions including extreme high and low temperatures, drought and strong winds. Many are fascinated by the broad range of climates in which conifers can survive.

The Northern Regions of the United States

The Northern Regions of the United States are composed of 16 wilderness areas, six National Wild Rivers and many extensive trail systems. These areas are covered by densely populated forests. The trees living in these forests are subject to very harsh conditions including high winds, low and below freezing temperature, as well as large amounts of precipitation. These trees have adapted to the harsh, cold environments in which they live and have many interesting traits that allow for their survival.

Leaves

In Northern regions, conifers are one of the only tree species that retains their leaves throughout the winter. Conifers have needle-like leaves that they keep for several years before they are shed. This is a contrast to trees that shed their leaves every fall. Conifer leaves are narrow and thin, which allow them to easily shed water and snow. There is also a waxy coating on the leaves that reduces the amount of water loss from the tree.

Dense Foliage

Conifers have dense foliage, which makes them more wind resistant and able to survive in Northern regions. These trees usually grow in large stands amongst other conifer trees. The trees that are on the perimeter of the stand are subject to the most wind damage while the trees on the inside of the stand are more protected. In some regions, the foliage is "flagged" in the direction facing away from the prevailing wind direction. This is a way that some scientists use to determine what direction wind travels during the harsh winter.

Seeds

Conifer trees are gymnosperms, which is a term used to describe trees that produce cone-bearing seeds. The cone protects the seeds from adverse conditions. The cones do not immediately open as soon as the cone has finished growing, which means that seeds are not immediately subject to the harsh elements found in colder climates.

Branches

The branches on conifers usually grow from the trunk of the tree at obtuse angles toward the ground. This allows the branches to shed snow more easily than the branches of trees that point horizontally outward from the trunk of the tree. Northern regions have colder temperatures and more precipitation, so this adaptation is especially important for conifer survival.

References

• University of Hawaii's Botany Department: Distribution and Diversity
• Northern Region: Welcome to the Northern Regions!
• Michigan Forests Forever Teachers Guide: Winter Adaptations of Trees