Trees, Trees, Trees

Trees are living organisms that need nutrients, water, air, and sunlight to survive – just like us! Trees are all around us and they are the largest plants on the planet. Trees can live for a long time. They are perennial meaning they live for more than 2 years. Trees play important roles in their ecosystems and in people’s lives. Let’s learn all about trees!

 

 

Parts of a Tree

Trees come in all shapes and sizes! In general, trees share the same basic needs and the same basic parts that help them get what they need to survive, grow, and reproduce. Learn about the different parts of a tree below!

 

NPS / S. Lowe illustration

1. Roots – Roots anchor the tree to the ground. They are mostly underground in the soil where they absorb water and nutrients the tree needs to survive.
2. Trunk – The trunk is the main stem of the tree that connects the roots to the branches. It acts like a large pipe to transport water and nutrients from the roots to the branches and leaves.
3. Branches – Branches grow off the trunk of the tree and support leaf growth of the tree. They extend up and out so that leaves can access sunlight and make food via photosynthesis.
4. Leaves – Leaves grow off branches of the tree. They absorb energy from the sun and then through a process called photosynthesis make food for the tree. Leaves come in all shapes and sizes, depending on the species of tree.
5. Canopy – The canopy is the top part of the tree made up of leaves and branches. This part of the tree shades the roots and the trunk of the tree.
6. Fruit – Fruits grow off branches of trees alongside leaves. Fruits are sometimes edible and surround the seed(s) of the tree. Not all trees grow fruits that we are familiar with like apples and oranges, but they are an important part of reproduction to house and disperse (spread) seeds. One popular fruit tree in the C&O Canal NHP that you may not know is the paw paw tree.

To practice labelling the parts of a tree, check out the Parts of a Tree Worksheet.

 

NPS / S. Lowe illustration

Trees Throughout the 4 Seasons

As the seasons change, so do the leaves of deciduous trees!

Spring: In the spring, leaf buds appear and leaves begin to grow.


Summer: In the summer, leaves have fully grown in. They are green because chlorophyll in the leaves is green. Chlorophyll help leaves turn sunlight into energy.


Fall: As the weather gets colder and there is less sunlight in the fall, chlorophyll in the tree’s leaves starts to break down. The colors of other chemicals in the leaves become visible and the leaves change color. They begin to fall off the tree.


Winter: By winter, the tree has dropped all of its leaves and the branches are bare.


Investigate how leaves change color with the Trees in 4 Seasons Worksheet.

 

Life Cycle of a Tree

 

NPS / S. Lowe illustration

1. Seed: Trees start out small as just a single seed. When the seed germinates (begins to grow and develop) in the soil, it begins to sprout out shoots (roots) to anchor the little tree to the ground.
2. Seedling: The soil in the ground provides the tree with nutrients and water and before long a tiny leaf shoots out from the ground, and the tree begins developing as a seedling. Because of a lack of development and protection, seedlings have a high mortality rate. This means that many seedlings die from disease or from being eaten.
3. Sapling: The next stage in the cycle is the sapling (or the juvenile, young) stage. If the tree survived predation and disease, then it most likely has grown to be around 1-4 inches in diameter and is around the small size you would see at your local nursery. The tree is not yet mature enough to reproduce (create a new tree from a seed).
4. Mature Tree: The tree matures and will continue to grow. Each species of tree will grow to different heights and in different soil environments. Trees will flower during the proper season and produce fruit. Fruits contain seeds so that the tree can reproduce after dispersing (releasing) seeds back into the environment. This starts a new tree’s life cycle!
5. Snag: At the end of a tree’s life, its purpose is still not done. When a tree dies, it is called a snag. Snags provide shelters in hollows and holes for birds, bats, and other mammals. They are broken down by insects and fungi and used for food. Decaying wood returns nutrients back into the soil. These nutrients support new tree growth. This is the end of the tree’s life cycle!

 

Benefits Trees Provide

• Trees improve air quality by removing carbon dioxide from the atmosphere and storing carbon in their tissues. Trees also release oxygen back into the atmosphere, allowing humans and animals to breathe.
• Trees provide a habitat for many species and provide shade for people and animals.
• The leaves, seeds, and fruits of trees provide food for animals and people.
• Trees’ roots stabilize the soil, reduce erosion, and absorb stormwater runoff. This is a great service for the C&O Canal that helps prevent flooding and erosion of the towpath.

For more content about trees, application of tree knowledge through activities, and guidance on observing trees in the C&O Canal, check out the Trees, Trees, Trees self-facilitated field trip.