Classroom Happenings - Dendrology: The Study of Trees

On a recent chilly morning, Grade 7 Science Teacher Andrew Reeder and a group of young explorers trekked down to the woods behind the Bryan Innovation Lab to gather data about some of the trees on Steward’s campus. This semester, Mr. Reeder’s students are learning about dendrology – the study of trees – through the use of scientific tools, data analysis, and critical thinking. 

“The dendrology unit helps students learn that trees contain much more complexity than meets the eye,” said Mr. Reeder. Behind the Bryan Lab, students practiced gathering scientific data using an increment borer – a forestry tool used to extract a thin, pencil-sized core sample from a tree. One by one, the students gave it a try, quickly realizing how difficult it can be to bore into a tree. 

Students collected cores from a variety of tree species, including white oak, shortleaf pine, eastern red cedar, and sweetgum. Using the cores collected, students calculated the age of the different trees by counting the annual growth rings, which appear as alternating light and dark bands. They also measured the width of each growth ring after learning that a wider ring indicates more rainfall during that spring and summer.

Maggie LaRoach ’31 and her classmates teamed up to collect core samples from an oak tree and a maple tree. 

“Using the increment borer was so interesting!” said Maggie. “We each took a turn to twist it in and use its metal scoop to collect a sample. We twisted it two complete turns to get the perfect sample.”

Maggie’s classmate Henry Watrous ’31 was surprised to learn that “only three inches of the wood inside of a tree trunk is alive. The rest is technically dead.” He added, “Being outside in nature during class is great because we always do cool things. I learned that trees are more important to us than some people think.”

“Students learned that removing a small core from a tree does not injure it,” said Mr. Reeder. The seventh graders also discovered that even the largest trees on campus are less than 100 years old, and that pine trees produce the clearest ring pattern. They were fascinated to learn that trees contain transport cells (the xylem and phloem), which carry water and sugar through a tree with what Mr. Reeder described as “more negative pressure than man-made machines can create.” 

Maggie said, “What I found most interesting about trees was that they have cores that can tell you information about their year of growth.” After studying dendrology, she noted, “Now that I’ve learned there’s a whole process that goes on inside the tree, I think of trees as one of nature’s best inventions. I will remember this experience forever.” 

In the coming weeks, Mr. Reeder’s students will use a tangent height gauge (a handheld device used to measure the height of objects by using simple trigonometry) to measure the height of several trees of their choice, including the tallest tree they see. 

“This is a great way for students to practice gathering and recording accurate scientific data using a variety of field tools — the same tools and techniques that forestry and ecology professionals use,” said Mr. Reeder.

Lessons that include being in nature “provoke students to examine and question the world around them with greater wonder and creativity,” noted Mr. Reeder. “Outdoor lessons remove the barrier between classroom learning and the real world. Being outside, breathing in the brisk air, and exploring the life of trees is a great way to connect with our schoolwide theme of nature. Students feel freer to move around and ask questions when learning outdoors. As they learn more about the natural world, they feel more connected to it and become better stewards of our shared environment.”