Unit 1 - Structural Units & Functions

Lesson 1: Classifying Trees


The tree is the defining organism within a forest. In fact, forests are classified based on predominant tree type.

There are different ways to identify or classify trees, such as deciduous, conifer, broadleaf, or needle-like.

The most common way of classifying trees is by dividing them into their biological classes — Angiosperms or Gymnosperms.


  • Gymnosperms are trees that have naked seeds: their seeds are not enclosed in fruit.

  • The most common gymnosperms are the coniferous trees, also known as conifers, softwoods, needle-leaved trees, or evergreens. Familiar examples include pine, spruce, and fir.

  • Gymnosperms usually keep their leaves or needles all year.

  • Most of the forests in Canada are dominated by this type of tree.

Click here to watch a video on gymnosperms. After watching the video try the quiz to test your knowledge.




  • Angiosperms are trees that produce flowers that, produce seeds surrounded by fruit.

  • Angiosperms are also known as broad-leaved trees. A broad-leaved tree has wide leaves and is typically deciduous, although there are exceptions to this (see textbox).

  • Oaks, poplars, birches, and maples are familiar examples of deciduous, broad-leaved trees that can be found in Canadian forests.

  • Angiosperms have leaves that usually change color and shed their leaves in the fall.

Click here to watch a video on angiosperms.  Then try the quiz to test your knowledge.






When categorizing trees, there are exceptions to the rules.
For example, even though larch trees are gymnosperms, they drop their leaves/needles each autumn. Holly is an angiosperm (broad leaf tree) which keeps it's leaves all year round.
In tropical rain forests, for example, many broad-leaved trees are evergreen, which means they keep their leaves all year.