Background:
In this unit students will learn that every living thing is affected by both other living things and nonliving things in its environment. These organisms, in turn, affect their environment. The place where these living and nonliving things affect and depend on each other is called an ecosystem. Many different ecosystems are contained in the biosphere- the region on which living things on the earth are found. Ecosystems can be very small and "man-made", such as a terrarium in a classroom, or a natural unit such as a forest. In any case, they are always a "web of life."

"Within any ecosystem there is a one-way flow of energy through living things and a cycling of nonliving materials" (Silver Burdett & Ginn. Teacher's Ed., p.125a). The flow of energy is explained by the food chain which begins with the producers, then the consumers, and finally ends with the decomposers. This food chain can be expanded into a food web (or web of life) where the connections and interrelations between many food chains can be shown. The cycling of nonliving materials includes the water cycle and the carbon-dioxide cycle.

The following lessons are part of an environmental unit based on the Silver Burdett & Ginn textbook Unit 4 Ecosystems and Ranger Rick's The Web of Life big book and teaching guide. They allow the students to learn about the interrelations between living and nonliving things and the focus on the many food chains and life cycles that are continuously taking place. Each lesson will begin with the lesson objectives.

Lesson 1: Forests

1. complete an information sheet after finding the information through research
2. complete a mural of a coniferous forest or a deciduous forest (may have items collected from a nearby forest attached)
3. know the difference between a coniferous forest and a deciduous forest

Time- 2 hours

Materials:
various books on forest, habitat worksheet, large paper for murals, construction paper in various "forest" colors, paints, markers, and/or crayons, tape or glue, items from a nearby forest: twigs, leaves, soil, etc.

Teaching outline:
Ask students to collect items from a nearby forest ahead of time and to bring in at least one book each on forests. Collect books on forests ahead of time if there are not enough books in the classroom library. Set up an area with supplies for the project.

Procedure:

1. Tap Prior Knowledge
   Ask students if they can describe a forest. List on the board the words they use to describe a forest. Begin making a web with the commonalities between forests in the middle and any description for a particular forest around the middle in groups. Is there just one type of forest? If not, what are the different kinds of forests? Explain that there are different types of forests and that they will be specifically looking at two kinds: coniferous and deciduous.

2. Hands-on activity
   If possible, arrange students into groups of four. Place books on forests in an accessible location for all the groups. Each students receives two habitat worksheets: one for coniferous forests and one for deciduous forests. Groups are given time to research and fill in the information they discover. (Note: although the research is done in groups, each child completes his/her own worksheets.)

   Once the information is found and the worksheets completed by all members of the group, preparation for the murals may begin. Each group is to design and complete two murals. Half of the group is to make a mural of a coniferous forest and the other half is to make a mural of a deciduous forest. The students in each group decide who works on which mural and how each mural is to be completed. Students may use the art form they enjoy most (painting, coloring, pasting, etc.)

Teacher notes:
It is important to et up ahead of time so that no learning time is wasted in the classroom. Circulate among the groups making sure that the students stay on-task and help mediate any dispute that may arise among group members.

Assessment:
Upon completion of the lesson the students will have researched coniferous and deciduous forests, completed a habitat worksheet on each type of forest and participated in the planning and completion of a forest mural.

Extension Activities:

1. Read books set in the forest or connected to forest life.
2. Create a poem on forest life.

Food Webs
Lesson 2

Objectives:
The students will:
listen to a reading of The Web of Life
participate in a class discussion on the relationship between living things in a food chain and food web
create a food chain found in a deciduous forest
create a food web with classmates using their food chain.

Time allotment: 60-90 minutes

Materials:
a piece of scratch paper or each child, pencil, big book The Web of Life, construction paper, coloring supplies, yarn or string. scissors, tape or glue

Teaching outline:
Set up table with art supplies and clear bulletin for food webs

Procedure:

1. Tap prior knowledge
   Ask students if they know what a food chain is. Have them give some examples. Try to get them o use the words producer, consumer, and decomposer. Ask them what oder they think these things go in. Extend this discussion to food webs. what is a web? What does a web look like? What do you think a food web could be?
   
2. Share with neighbor
   Each child writes down on the scratch paper what he/she thinks a food web is and hands it to his/her neighbor.
   Read the big book The Web of Life to the class, discussing the information. Point out important infpration words they need to know.
   Have students check each other's paper with food chain definition to see if anyone had the correct answer or was on the right track with his/her thinking.
   
3. Hands-on activity:
   After the book is read and discussed, have each students make a food chain found in a deciduous forest by drawing each step on a separate piece of construction paper and connecting them in the correct order with string. each food chain should have at least four steps. Try to direct students so that do not all have the same food chain.
   Once each student has completed the food chain, place them in groups (4-6 students) and have them combine their food chains to create a food web. Check to make sure the webs are accurate. If the webs are accurate, assign a spot on the bulletin board and allow the group to attach the web on the board.

Assessment:
Upon completion of the lesson the student will have:

1. listened to a reading of The Web of Life
   
2. participated in a discussion on food chains and food webs
   
3. completed an individual food chain
   
4. completed a group food web

Extension Activities:
Read Food Chains, Food Webs by Patricia Lauber to the class
Have students create chains or webs for other habitats. Chains could look like the russion nesting dolls. (See book by Lauber for examples.)

Leaves, Leaves, Leaves
Lesson 3:

Objectives:
The student will:

1. predict results of a simple experiment
   
2. observe the importance of the sun on plants
   
3. become familiar with the process of photosynthesis
   
4. learn that plants are producers

Time allotment: 45-60 minutes (part 1) and 30-45 minutes (part 2)

Materials:
one houseplant for each group, four one-inch squares of construction paper for each plant, paper clips, math/science journals

Teaching outline:
Purchase one plant for each group (4-6 students) if none are available in the classroom or have students bring in plants ahead of time. Bring out construction paper for squares.

Procedure:

1. Tap prior knowledge
   Review participants in food chain. Discuss which role plants take in the food chain. How do plants make food, which is energy? Have students write their thoughts in their journal.
   
2. Share with neighbor
   Place students in groups and have them share and discuss their thoughts. They can adjust or make changes if they wish to do so after discussing the topic in their group.
   
3. Hands-on activity
   Give each group a plan. Explain that in a few moments they will have someone go get some construction paper and cut out four one-inch squares from that paper. Someone else from the group will go and get four paper clips. Finally, another person(s) will attach the four square pieces of paper with the paper clips to four separate leaves on the plant. Place the plant in the sun. The students are to predict in their journal what they think will happen to the portion of the leaves under the paper.
   After a week, remove the squares. Have the students examine the leaves. After examining the leaves the students are to answer the following questions in their journals:
   
   1. What happened? Be specific. (Light colored patches developed in the areas that did not receive sunlight.)
      
   2. Why did that happen to the covered leaves? (Leaves stop making chlorophyll and do not carry on photosynthesis in the absence of sunlight.)
      
   3. What would happen if none of the leaves could get any sunlight? (The plant would die.)
      
   4. Why do you think that trees in a forest grow tall and their branches spread out wide? (to enable leaves to reach the sunlight)

Teacher notes:
Make sure plants are placed in a sunny area or the experiment may not work as well.

Lesson Assessment:
Upon completion of the lesson students will have:

1. predicted the results of a simple experiment
   
2. completed a simple experiment and recorded the results
   
3. become familiar with photosynthesis
   
4. learned that plants are producers and the first in the food chain

Extension activities:
Try the experiment with transparent and translucent coverings for the leaves to see if their is a difference.

Adopt a Tree
Lesson 4

Objectives:
The student will explore trees outdoors; select a tree to study; observe the tree and record the results on the worksheet.

Time Allotment: 45-60 minutes

Materials:
pencil, worksheet, tree book (field guide), measuring tape, magnifying glass, small garden shovel, white paper, crayons, tape, camera (optional)

Teacher Outline:

1. Run off copies of the worksheet
   
2. Place all the materials in easy to carry containers
   
3. Select an area close to the school with a variety of trees.

Procedure:
1. Hands-on activity
Divide class into groups of 2-4 students. Distribute a worksheet to each student and a container with the materials to each group. Take the class outdoors and have each group select a tree to "adopt" and study. Go over the worksheet and ask if their are any questions. Circulate among the groups to answer any question.

Teacher notes:
Keep an eye on all students to make sure they are on task and safe especially if you are near a busy street. Make sure containers with the materials are complete and ready to go.

Lesson Assessment:
Upon completion of the lesson students will have selected a tree to "adopt" and completed the worksheet while studying the adopted tree.

Find the Insects
Lesson 5

Objectives:
The student will:

1. learn that insects are consumers
   
2. make and use a "beater tray"
   
3. discover some insects that live in a tree

Time allotment: 45-60

Materials:
large cardboard carton, white paper, insect guide book, pencil

Teacher outline:
Collect enough insect guide books and large cardboard cartons for all the groups

Procedure:

1. Tap prior knowledge
   Ask students to describe an insect. Discuss what makes an insect. What kind of insect live in trees.
   
2. Hands-on activity
   Divide students into groups of 2-3 students. Before going outside, have each group make a "beater tray out of the large cardboard cartons using the following directions:
   
   1. Cut the sides of the cartons so that they are only about three-inches high.
      
   2. Line the inside of the cartons with white paper.
      After the trays are made go outside and find a tree. Place the tray under the tree and gently shake a branch. Look for insects that fell into the tray. Draw pictures of the insects, record which tree they came from, and any information about the insect (physical features, behavior, etc.) Use the insect guide book to identify the insects found and learn more about them. Discuss how the tree they came from helped the insect survive. When the activity is over, return the insects to their home.

Assessment:
Upon completion of the lesson students will have made a beater tray, learned that insects are consumers, and discovered which insects live in the trees near the school.

What Lives on a Fallen Tree?
Lesson 6

Objectives:
The students will:

1. study the community on a rotting log
   
2. collect sow bugs
   
3. complete a simple experiment
   
4. listen to The Magic School Bus Meets the Rot Squad by Joanna Cole
   
5. learn that many decomposers call a rotting log their home

Time allotment: 60-90 minutes Materials:
rotting log, clear plastic box with holes in the cover, large plastic tray, soil, water, math/science journal

Teaching outline:
Find a rotting log that can be observed, making sure there are no wasp nests or other hazards.

Procedure:

1. Tap prior knowledge
   What is a habitat? Is a rotting log a habitat? Why or why not? What kinds of things do you expect to find in a rotting log?
   
2. Hands-on activity
   Go outdoors and locate a rotting log. Carefully explore the log. Have students look for plants growing on or near the log, insects and animals. Are there any signs that this is the home of any creatures such as spider webs, holes, eggs, etc.? Peel away some bark and dig in the rotting wood. What happens? Lift the log (or part of the log) and look underneath. Have any parts of the log already turned into soil? Students are to record the steps they complete and record (includes drawings) what they observe.
   While looking for insects/animals, students are to collect about six sow bugs and place them in the clear plastic box with holes. These bugs are decomposers commonly found on rotting wood. They are dark in color, with flat, oval bodies divided into segments. Place the container in a cool, shady area and observe how they behave for about a week. Record the observations.
   For a separate experiment, place about an inch of soil in the bottom of the large plastic container. Sprinkle water on only half the soil to make it damp; leave the other half dry. Take some of the sow bugs and place them in the middle of the tray. Have students record their observations. Which side do the sow bugs prefer? (the damp side) After the experiments are completed return to the rotting log and release the sow bugs back into their habitat.

Teacher notes:
Make sure you locate and check out any rotting logs before taking the children. The logs should be free of any type of wasp nest or other hazard.

Assessment:
Upon completion of the lesson students will have:

1. studied the community of a rotting log and recorded her/his observations
   
2. collected sow bugs
   
3. collected sow bugs
   
4. completed a simple experiment with the sow bugs
   
5. listened to The Magic School Bus Meets the Rot Squad by Joanna Cole
   
6. learn that many decomposers call a rotting log their home

Extension activities: Create a class farm of other decomposers such as worms.