A Student Produced Field Guide to Neighborhood Trees

This activity is designed to increase students' knowledge of trees, improve scientific observation skills, use field research techniques, includes application of learned skills, and requires critical thinking.

Key Concepts:
1. Dichotomous keys can be used to systematically organize and retrieve information.
2. Detailed observations are a vital part of scientific work.

Key Terms students may not be familiar with:
Dichotomous key, field guide, coniferous, deciduous, species, population, community.

I plan on starting this project the first day of school with my seventh graders. I plan on doing the project early for a few reasons. One is that the trees are more easily identifiable when they still have leaves. Another is that in most classes they are hit with rules and the like for the first few days. It will also force them to think critically and work together from the first day on, setting the tone for the year.

Materials:

Tree Identification Field Guides
Notebooks / Journals
Crayons for Leaf Rubbings

1. I think it is important to engage the students before something new is started. To do this, I may engage them by telling them that we may need to make a field guide of the neighborhood trees. It may be interesting to shock them by doing this the first day of class in the fall when they aren't quite sure of what is going on.
2. Have the students make general observations of the trees around the school. In small groups have them brainstorm a list of characteristics that can be used to distinguish different types of trees. After an appropriate amount of time have the students report back to the large group. The instructor may want to record the characteristics the different groups came up with.
3. Day Two. Discuss, show examples of, and have the students draw different characteristics and terminology required to study and identify trees.
a. Important terminology
- Species, population, community, ecosystem
- Coniferous, deciduous
- Single, clustered, scaly needles
- Simple, compound leaves
- Alternate, opposite
b. Other possible useful terminology
- Margin, notch, lobe, sinus, toothed, double toothed, blunt toothed, fine toothed, sharp toothed, entire margin, leaf base, asymmetrical leaf base, petiole, stipule, bud, bud scar, etc.
4. Day Three. Assign students trees on or near the school campus. I would probably do this in pairs. (It may be useful to create a generalized form for recording the information below.)
a. Have the group use as many "scientific" words they learned the previous day to describe the leaves of the tree.
b. Also include detailed descriptions of:
- General tree shape and size
- Bark
- Flower, fruit, or cone
c. Make a rubbing of the leaf if applicable.
d. Using a tree I.D. book, identify the tree species. Record both the common and scientific name. Confirm tree species with instructor. (I prefer not to teach the kids how to use the tree I.D. books or dichotomous keys at this point.)
5. Day Four. Have students make a page (or two) for a class field guide of neighborhood trees. The format of the page could include the above information. It could be expanded to include digital pictures or drawings of the tree, leaves, bark, twigs, buds, fruit, cones, flowers, etc. It may be useful to have the students stick to an agreed upon format. Each student should print six copies of their page.
6. Day Five. Teach the students how to use and create a dichotomous key. Start off by having the students use a simple dichotomous key like the one attached. (Alien dichotomous key from Nature Connections). The students could then create their own dichotomous key of familiar objects such as shoes, sports teams, video games, etc.
7. Day Six and Seven. Divide the class into six groups (or to what fits your needs). Each group will receive a copy of a page from the field guide. The group will then design a dichotomous key to help a person identify the trees found in the field guide. The small group will need to defend their key to other small groups, the instructor, and then finally to the large group. The class will decide which key to use in their final product. You could compare their key to ones used in tree I.D. books.
8. The instructor or the students can then put together the field guide by combining the dichotomous key with the individual pages made by the students. The final field guide can be used to show parents, displayed, or used by the students for tree identification. Rubric that can be used for summative assessment. I created this rubric at Rubistar, an online source that offers rubric templates. I recommend checking it out if you haven't already. ( 7kB Aug24 07) A worksheet on dichotomous keys from Nature Connections website. (Acrobat (PDF) 84kB Aug24 07)

Previously, I would have individual students collect and identify leaves. I really wanted to include inquiry and cooperation into the unit. In the past we have also measured trees, as well as determine their age using an increment borer. I could modify the lesson to allow for this as well.

The time line I followed is approximate, so it may take longer. Some students may lag behind and need more time or assistance.

Normal safety precautions should be followed as you would whenever students are taken outside. My concern is usually with crossing streets, or bee sting allergies.

A diagnostic assessment could be done at the beginning of the activity to see what the students' previous knowledge is.

Attached rubric used for summative assessment.

7.1.A.2 -Scientific models
6.1.B.3 - International units
7.1.B.4 - Scientific principles
8.1.B.1 - Systematic observations
7.IV.B.1 - Tissues, organs, organ systems
7.IV.B.2 - Homeostasis
7.IV.B.4 - Dichotomous Keys
7.IV.B.5 - Kingdom identification
7.IV.C.2 - Populations