The following suggestions are designed to make students more aware of the variety, value and requirements of trees, especially in the city.
A. Kinds of trees
A tree is identified by how it differs from other trees. Look for each of the following and find out what kind of tree each is:
- Three kinds of trees with simple leaves.
- One kind of tree with compound leaves.
- One kind of tree which will have colorful leaves.
- Two kinds of trees which will have edible fruits or nuts.
- Two kinds of trees with smooth edges on the leaves.
- One kind of tree which does not lose its leaves.
- One kind of tree with opposite leaf arrangement.
B. Injuries to trees
One of the requirements for trees to grow in the city is protection from injury. Look for trees that are sick or injured and try to decide what caused the injury. Examples might be:
- Construction equipment
- Lawn mowers, string trimmers
- Carving initials in bark
- Utility cutting or topping
- Trampling of soil
- Crowding by house or sidewalk
- Insects or disease
Suggest ways that such injury can be prevented: For example, use mulch around trees, avoid overhead wires when planting, don't carve on trees, use care in mowing around trees, etc.
C. Rate of growth
A cottonwood tree may grow to a height of 12 feet in one year. It may take an oak six years to reach this height. Try to find out when various trees in the neighborhood were planted. Measure the height and diameter to see which kind grows faster. How does location affect the rate of growth? How much did the twigs grow this year? Last year? How is growth rate of a tree affected by soil, moisture, sunlight, care?
D. Uses for living trees
Look for different uses of trees and which types of trees might be best for each use. These might include:
- Hedges for privacy
- Support birdhouses
- Swings or hammocks
- Tree houses
- Noise suppression
- Fruits and nuts
- Erosion control
- Wood for future use
Decide which types of trees are best for each use.
E. Uses of wood products
Look for different ways wood is being used. These might include:
- Utility poles
- Lawn furniture
- Railroad ties
- Truck beds
- Tool handles
- Baseball bats
F. Types of wood
Each kind of tree produces a different type of wood. Differences may be in hardness, weight, strength, workability, color, grain, etc. Examine several wooden objects. Try to determine what kind of wood each is made of. Why was this particular type chosen for this particular job? Is this the best wood for the job? If not, then why was this wood used? Could some material other than wood have been used? If so, would it have been as attractive? Would it have cost the same?
G. Temperature control
One of the greatest values of trees in cities is the shade they produce. With a thermometer, find the temperature under a good shade tree and out in the open sunlight. Bury the bulb of the thermometer one inch underground in each place and read the temperature after five minutes. What difference do you notice in the soil under the tree and in the open? What difference do you notice in the types of plants which grow in each place? Why do these differences exist? How else do trees act as "air conditioners?"
H. Trees needed
In any city there are areas which would be improved by the planting of a few trees. Look for these areas near the school and describe what kinds should be planted, how they should be arranged, and the purposes for the trees. Such places might include:
- Parking lots needing shade.
- Playgrounds needing windbreaks or shade.
- Houses needing privacy.
- Factories or streets needing noise suppression.
--adapted from " Teacher's Guide for Arbor Day" Missouri Department of Conservation