Tree Families

Nathaniel Cornelius- nsc27@zips.uakron.edu

Nick Lewis- nal55@zips.uakron.edu

Background Information

Ohio Learning Standards

Activity

Assessments

Supply List

Materials, Resources, and Books

Visuals for Assessment

Background Information

Knowledge of evolution, biodiversity, and speciation
Basic knowledge of tree characteristics

Ohio's State Tree

The Buckeye Tree (Aesculus glabra) is the official state tree of Ohio
It is used for the mascot of The Ohio State University

Ohio's Largest Tree

This American Sycamore (Platanus occidentalis) is the largest recorded tree in Ohio to date
It is 88 feet tall (more than 15 people tall)
It is estimated to be over 200 years ol

The World's Oldest Tree

The oldest tree recorded is this tree called Methuselah which was 4,852 years old
There is supposedly another tree that is over 5,000 years old that is in an undisclosed location in order to protect the tree

How do we know how old these trees are?

You can count the number of rings on a tree to roughly estimate the age of a tree
Each ring of the tree represents one year of growth for the tree
- Larger spaces between rings represent rainy years
- Smaller spaces represent dry years

Why are leaves important?

They give trees energy!
The process of photosynthesis converts carbon dioxide, sunlight, water, and minerals into glucose which provides energy for the tree.
In return the tree releases oxygen into the air, allowing humans like us to breathe!

Ohio Learning Standards

B.E.2: Speciation: Biological classification expanded to molecular evidence

Classification systems are frameworks, developed by scientists, for describing the diversity of organisms; indicating the degree of relatedness among organisms. Recent molecular sequence data generally support earlier hypotheses regarding lineages of organisms based upon morphological comparisons. Both morphological and molecular comparisons can be used to describe patterns of biodiversity (cladograms present hypotheses to explain descent from a common ancestor with modification). The concept of descent from a common ancestor with modification provides a natural explanation for the diversity of life on Earth as partially represented in the fossil record and in the similarities of existing species.

Activity

To begin the activity, direct students to head out into the woods for about 5 minutes and ask them to find a leaf (try to find a unique one that other people haven't found) from the ground (making sure to remind them not to pull live leaves off of trees).
Give the students 30 seconds to examine their leaves using hand magnifying glasses, directing them to think of a few noticeable characteristics.
Post four signs around the room, one which says "My leaf has needles", one which says "My leaf has lobes", one which says "My leaf are long and skinny" and one which says "My leaf is round and oval shaped".
Instruct your students to stand by the sign that they think best fits their leaf.
Give the students 1 minute to share their leaf with the other students at the station. Have them focus on what is similar and what is different between the leaves. (If a student is alone at a station then the instructor should listen to the student talk about their leaf and ask questions which make them think about it)
Debrief with the students, discussing how leaves are a great indicator of relatedness among trees (you can use the idea of a family to help the students understand the concept).
Finally, to assess the students' understanding of what they have been taught, disperse printed copies of the 12 leaves found on this page to each student and ask them to group the leaves that they think are part of the same "tree family" (can alternatively be completed in teams)
After we are done with the leaves, we will press them in a large textbook and leave them for a few days and students will be allowed to laminate them or leaf rubbings to use for crafts

Assessments

Summative assessment based on successfully characterizing and classifying leaves within their families.
Disperse printed copies of the 12 leaves found on this page to each student and ask them to group the leaves that they think are part of the same "tree family" (can alternatively be completed in teams)