Lesson Six: Patterns in the Trees

Lesson 1 Lesson 2 Lesson 3 Lesson 4 Lesson 5 Lesson 6 Lesson 7 Lesson 8

Teacher Information:

First Nations People across Canada have always had a special relationship with the environment and animals. An excellent example is the way in which Aboriginal Peoples on the Plains utilized every part of the buffalo, letting little go to waste. First Nations cultures have a deep respect for the earth, often referring to it as Mother Earth. They also recognize that everything in nature is connected. This concept is often referred to as the “circle of life.” Plants, animals, and the environment are interdependent, working with one another in creating the ecosystem and becoming a part of the food chain. The earth feeds the plants and animals that in turn feed the people. When someone died, their body would feed the plants and animals. First Nations had to be aware of everything happening to the land, in the air and in the water in order to live successfully off of what Mother Nature provided. Aboriginal People were excellent observers, demonstrated for instance by their recognition that certain animal behaviors signaled changes in the weather.

The history of a tree is written in rings. Trees tell us how old they are, how the weather was each year and when they survived fire. The tree preserves a record of every branch and every wound throughout its life.

Dendrochronology is the study and interpretation of treering patterns.

Tree trunks grow bigger each year when the cambium adds a new layer of wood over the old layers. The cambium produces large cells in the spring and smaller cells during the summer. In many trees the early cells are light in color and later cells are dark in color. Since the trunk of a tree is round, the result is a pattern that appears as rings. We call these annual rings or tree rings. Since trees generally produce one ring for each year of growth, you can find the age of a tree by counting its rings.

The presence of covered-over wounds provides information about previous fires, insect or disease attacks, and when and where branches grew. If your tree once got hit by a lawn mower and its bark torn, there is a record of it in your tree. Careful inspection reveals the age of the tree when each of these events occurred.

Note the Above three paragraphs and the following diagram are from: www.na.fs.fed.us/.../ treeguidehtm/chapter4.htm

For this lesson you will need to gather a sample of a variety of different tree species. Cut a sample from each that will demonstrate a different number of tree rings.

You will also need to photocopy the above diagram to distribute to your students.

Main Lesson:

Discuss with students how Aboriginal Peoples have always respected and appreciated all that nature and the environment has to offer. Trees played a very important role in the lives of Aboriginal Peoples as they used them for shelter (tipi poles), for ground transportation (dog travois and Red River Cart), water transportation (canoes), and for everyday basic needs such as cooking and eating utensils.

Distribute the above diagram to the students and discuss the importance of tree rings. Break students into each group and give each group at least two samples of tree rings. Students will verbally discuss with one another the patterns that they notice on each individual tree sample. They will then compare the two (or more) samples. Students will then record their observations on a chart. Students will count the number of tree rings to determine the age of the tree samples. This should be followed by comparing the two (or more) tree ring samples. Students will then create and label a diagram that is representative of one of their tree samples.

Note: this exercise can also apply to tree leaves as well. Students may collect a variety of tree leaves from the school grounds and analyze the patterns that are present amongst the leaves.