ACTIVITIES: 10 minutes walking time each way, 50 minutes for ecosystem activities

Transcription

1 1 GRADE FIVE FALL NATURE WALK A Forest Ecosystem Version 10/4/11 OBJECTIVES: Understand that a habitat is a place where an organism finds all the things it needs to survive: air, food, water, and protection. Review the concepts of producer, consumer, decomposer. Recognize that the forest ecosystem is a system of plants and animals interacting with each other and with the non-living environment. Give an example of a forest food chain that includes some organisms students observed. Make weather observations and think about how these might affect the forest ecosystem. PREPARATION: BBY coordinator should mark walk with surveyor s tape as necessary. BBY coordinator should gather materials. Check with teachers to borrow thermometers and compasses. Prepare tongue depressors. Forest ecosystem activities should last approximately 55 min. Travel to and from Chiesa property will take about 20 minutes total. MATERIALS: (for each leader): Plastic bag with: thermometer (provided by teacher) compass (provided by teacher) short length of surveyor s tape plastic cups 2 spoons several magnifiers bug box tongue depressors labeled: sun, producer, consumer, decomposer (for each student) Clipboard, pencil and worksheets to record their observations. ACTIVITIES: 10 minutes walking time each way, 50 minutes for ecosystem activities Walk over to Chiesa Farm Conservation Area. Record weather observations. Note plants and animals of field habitat. Observe and describe 2 or more producers, consumers, and decomposers. Record observations. Walk back to school. Play food chain game on the way.

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3 3 1. Introduction to Ecosystems. PRE-WALK INTRODUCTION TO BE LED BY THE TEACHER (or by arrangement, by a Big Backyard volunteer) Say: A system is a collection of objects that interact with each other in some way. For example, in Grade 4 you studied about the Solar System. The Solar System is a system consisting of the sun, planets, moons and comets, etc. The Sun interacts with the planets by providing heat and light to them. It also holds them in orbit with its gravitational force. Today we are going to talk about an ecosystem. How do you think an ecosystem is different from the Solar System? (Focus is on living things.) An ecosystem is a collection of plants, animals and nonliving materials that interact with each other in a given place. In Grade 3 you studied about food chains in which organisms were linked according to how they get food. There can be many food chains in an ecosystem. Ecosystems can be found in different places. An ecosystem can be found in a place as small as a hole in a tree or a small pond or in a place as big as a mountain or the Earth. Today we are going to look at the forest ecosystem near Fiske. But first we need to review a little vocabulary that describes how parts of the forest interact with each other. Then we will know how to label what we see on our ecosystem walk. 2. Review of vocabulary. NEEDS OF ALL LIVING THINGS food, air, water, protection, space PRODUCER Producers make their own food. Plants are producers. They use the energy of the sun to make their own food from water, and air (carbon dioxide). A green chemical in the leaf helps the leaf trap sunlight. The food made by the plant is a type of sugar (glucose). Plants use this food to get the energy they need to live and grow. There is a scientific name for this process. It is PHOTOSYNTHESIS. Take the word apart to see clues to the meaning. Photo relates to light. Synthesis means putting different things together.

4 4 CONSUMER Consumers cannot produce their own food, they must eat other consumers or producers to get the energy they need to live and grow. DECOMPOSER Decomposers are fungi, tiny organisms called bacteria, and animals that feed on dead plant or animal material. In this process they help dead plants and animals rot or break down. Decomposers allow basic nutrients contained in the plant or animal bodies to be released into the soil. These nutrients are then used by plants to start a new cycle of life. (Examples of decomposers include mushrooms, mold, earthworms, insects, and microscopic bacteria) Death and decomposition are an essential part of all life cycles on Earth. To enable successful birth and growth of young plants and animals, older organisms must die and decompose. This limits the competition for resources and provides a fresh source of essential nutrients for new generations of life. 3. Walk objectives: observing weather and parts of the forest ecosystem We will observe and record the weather on the day of the walk. We will discover parts of the forest ecosystem: consumers, producers, decomposers, and nonliving things. We will use what we remember from your previous Big Backyard walks (from kindergarten on) to understand how parts of the ecosystem work. We will think about how weather might affect parts of the ecosystem.

5 5 1. Recording the weather. NATURE WALK: TO BE LED BY BIG BACKYARD VOLUNTEER Get into groups. Have students tuck for ticks tuck pant legs under sox. Start walking toward Adams St. Ask: How can we describe the weather today? What can we observe or measure? (clouds, temperature, wind, etc.) Ask the children to estimate the air temperature and write that number down in the appropriate space on their worksheet. Then have a volunteer hold the thermometer in the air about 1 meter above the ground. Be sure the glass bulb is not in direct sunlight. Allow a minute or two before reading the liquid level. Record actual temperature. Record other weather information. See student sheet. o Cloud cover and type. Use the cloud chart below to match what children see with the name of clouds. They may also sketch or use descriptive phrases for clouds. o Wind strength and direction. Use the surveyor s tape and compass. o Precipitation from: 2. Looking for evidence of producers, consumers and decomposers. a. Walking to the forest.

6 6 Carefully cross Adams St. and enter the Chiesa Farm field by the worn trail. As you walk through the field, ask students to notice the types of plants. How tall are they? Do they have flowers? Seeds? Are there trees in the field? Look and listen for animals crickets and grasshoppers, butterflies, and birds. Ask: What do these living things need in order to survive here? (Air, water, food, and protection) This is a FIELD HABITAT. A habitat is a place where a living thing has all that it needs to live and grow. (Optional) Play the ecosystem game with the cards from: Have students walk in a line. Give each child a card, but don t let others see what it is. Lead the group and as you walk, have students take turns trying to guess what is on the card with questions answered by yes or no. Good questions: Are you living or non-living? Are you a producer? Are you an insect? Do you walk on 4 feet? Continue walking through the second field. Compare the mowed and unmowed part of the field. Are there lots of dead leaves visible? (No) Mushrooms? (No) b. Exploring the forest. Introduction Stand under the tall trees as you enter the third area and ask students to look into the woods. Ask: How is this habitat different from the fields? (Temperature, type of plants and animals, sounds, etc.) Say: This is a FOREST HABITAT. Today we are searching for evidence that this forest is system called an ECOSYSTEM. We will be looking for living things that make their own food. What are these called? (Plants/producers) We will be looking for non-living things that help a plant to make food what are some of these? (Air, water, soil nutrients; green chemical in leaves that helps to capture sunlight) We will be looking for living things that eat living plants. What are these called? (Animals/consumers) And we will be looking for living things that get their food from dead plants and animals. What are these called? (Decomposers) POISON IVY ID: Before we start, it is important to know how to keep the living things in this area safe. This is conservation area, so we will not be harming any of the living things here on our visit. How about us? The biggest problem for us humans in this area is poison ivy. There is a LOT of it here. Ask: What does poison ivy look like? (3 leaves) Sometimes poison ivy is shiny, sometimes it s dull; sometimes it s green, sometimes its red; sometimes it grows on the ground, sometimes it climbs up a tree. BUT IT ALWAYS HAS 3 LEAVES and NEVER has thorns. Use a stick to point to several plants and check to see that your group can identify poison ivy. Of course if you are not sure about a plant, it s best to avoid touching it. Though the middle of the trail is clear of poison ivy, the plant

7 7 is found along the edges of the trail and in the woods. Insist that children stay behind you and on the trail unless you indicate an area for exploration without poison ivy. Everyone s job is to look for and stay away from poison ivy! c. Looking for producers Remind students to stay on the worn paths unless you tell them otherwise. Ask: Do you see producers here? (Yes, lots of trees, shrubs, ferns, moss) What do you see that tells you that they are producers? (green color) Indicate trees with low branches growing along the edge of the trail, plants growing close to the ground and shrubs in between. Give students a few minutes to answer the following two questions: How many different producers can you find? Remember that a producer is an organism that has green parts and makes its own food. Can you find a producer that is being/has been eaten by an animal? Gather the group to share findings. Provide students with an opportunity to draw two producers. Invite them to include one that shows evidence of being eaten. oak maple hickory d. Looking for consumers Take students to an area with low oak branches. If students have not noticed holes in tree leaves, invite them to find a leaf with holes. Ask: What could make these holes? Have them look on the underside of the leaves to see if they can find out who is making the holes. (Animals that eat plants probably insects, but often they are no longer on the leaves) Winter moth caterpillars (see illustration, left) have made many of these holes. These caterpillars dropped from the trees in July and made cocoons in the soil. Next winter the adults will emerge and fly around on warmish days. Of course there are many other insects and other animals that eat oak leaves. Are there any types of leaves that don t seem to be eaten? Point to an oak leaf with sections that have a lacy appearance where the green part is missing. Oak leaf skeletonizer caterpillars are insects that are like kids who just eat the frosting in an Oreo cookie and leave the chocolate cookie. They just eat the green and leave the veins and top layer of the leaf. This leaf layer looks like waxed paper. Eventually the caterpillars become moths.

8 8 Look for galls on oak trees. These are swellings either on the branch or on the leaves. Some insect mothers inject chemicals into the plant along with their eggs. These chemicals cause the plant to swell and this results in a protective room for the young insect to grow in. The galls marked with surveyor s tape show that another animal has tried to open the gall to eat the baby insect. Ask: What animal might do this? (A bird most likely) Look for any other consumers. You may see insects, chipmunks, birds, or squirrels. Most likely you will only see/hear signs of consumers, not the animals themselves. These include: holes in leaves or nuts, missing green material in leaves, rolled leaves, unusual bumps (galls), chewed twigs or nuts (look for tooth marks), holes in tree trunks or in the ground, tracks, silk webs (from caterpillars or spiders), scat (droppings), ant hills, bird calls, or nests. Ask students to draw two consumers, either ones they have seen or ones for which they have found evidence (signs). Ask them to make a note if they have seen or can guess what the consumer is/has been eating. e. Looking for decomposers Find a place with a lot of leaves on the ground, but no poison ivy. Ask: Do you rake leaves at your house? Have you ever raked them into a big pile? No one ever rakes the leaves in this forest. Why aren t the trees buried in a big pile of leaves? What do you think? Let s find out by looking at leaves. Can you find a leaf that fell this fall? Can you find a leaf that you think fell a year ago? Where is it? How is it different than the newly fallen leaf? (Smaller pieces, softer) Find a stick to dig with. Keep digging. How do the leaves change as you get deeper? (Leaves have decomposed more) Keep digging until you hit soil. Put a pinch of soil in your hand. How is soil different than leaves? (Texture, color, and composition changes) Look closely at some soil with a magnifier. What is in soil? (Roots, bits of dead leaves, gritty minerals, water) Any animals here? Have them record what they observed on #4 on the student sheet. Be sure to put soil and leaves back the way they were. Look for mushrooms. The part you see above the ground is only a portion of this organism. Fungi, such as mushrooms, mildew, mold and toadstools are not plants. They don't have green coloring (chlorophyll), so they can't make their own food. Mushrooms release chemicals that decompose (rot) dead plants and animals. Fungi absorb food from the organisms they are decomposing! Fungi change this decaying material into simple nutrients that plants need for new growth. If there were no decomposers, plants would run out of nutrients and could not grow. What would happen to animals then? (Animals would also die) Take time to choose and draw a mushroom. Find a rotten log. (BE SURE THERE IS NO POISON IVY IN THE AREA YOU ARE EXPLORING) Invite students to feel and describe the outside of the log. Most likely it will be

9 9 soft and damp. Get a cup and plastic spoon or fork and ask a student to hold these. Have students gather on the side of the log away from you, prepared to look quickly at what is under the log. Lift the log, and, if possible, roll the log toward you. Ask for observations. If you are lucky, you may see small animals scurrying under or on the log (sow bugs, worms, millipedes, slugs, beetles, etc.). If possible, have the student carefully catch one of these creatures with the spoon and put it in the cup or bug box. Pass the cup around with a magnifier. These are animals that also help to decompose the dead tree. You may also see thread-like light colored structures under the log. These are to fungi (mushrooms) what roots are to a plant. Notice how damp it is under the log. You can also try to lift some rocks. Be sure to return logs and rocks to their original position. After all, these are roofs to a whole world of living things. Provide time for students to draw another decomposer. 3. Walk back to school. Leader goes first as the group returns. Wrap up. Take out the throat sticks (sun, producer, consumer, decomposer). Tell students that they will use what they saw on the walk to show parts of the forest ecosystem. Ask: What do producers need to make food? (Air, water, sunlight). Are these things living or non-living? (Non-living) Give the student who responded the Sun stick and have him/her move to the head of the line. Say: Producers use sunlight to make their own food. Give an example of a producer that we saw. Choose one where there was evidence that an animal ate it. Give a second student the producer stick and have her/him get in line behind the Sun. Ask: Who ate this producer? Provide the consumer stick to a third student and have them get in line behind the producer. Ask: Can we make a longer food chain? Is there another forest animal that might eat this one? What if this last animal dies? Can you name a decomposer that can recycle the nutrients in the dead stuff? Give the decomposer stick to a 5 th student and have him/her stand behind the last consumer. Say: This decomposer helps to release nutrients from the dead stuff. These nutrients are needed by plants in order to live and grow.. Have the decomposer link up with the plant (producer) to show that plants continually need new supplies of nutrients in order to grow. While you walk, you can start over with new plants and animals.

10 10 POST-WALK CURRICULUM INTEGRATION OPPORTUNITIES: TO BE CHOSEN AND LED BY THE TEACHER 1. Say: Today we explored a forest ecosystem. What are some parts of this ecosystem? (Use notes from the walk.) Their answers should include examples of producers, consumers, decomposers and non-living things. If not, prompt them to include these things. An ecosystem is not a place, but a group of living organisms and non-living things (air, water, soil) that interact together in a given area. 2. Ask: How do you think the forest ecosystem is similar to the ecosystem of Granny Pond? (All energy comes from the sun; some organisms produce food; others eat producers or other consumers.) Ask: How do you think it is different? (Type of animals and plants, sources of water, and air.) 3. Say: What do you think might happen to the Chiesa Farm Conservation Area if a family of foxes moves in, and has many pups? What if many of the tree leaves are eaten by winter moth caterpillars? How do you think that affect our forest ecosystem? Any logical explanation on how this affects the food chain is acceptable. Stress that ecosystems are interdependent--all the parts are dependent on each other. Other what ifs. : What is happening to the ecosystems in. (use current events such as: oil spills, hurricanes, droughts, floods, or fires.) Possible Scenario: Fire burns woods. Many trees, now dead, fall down. Decomposers start decaying dead wood, since fire generally can t kill off all these organisms. Seeds (brought by wind or animals, or that are buried) sprout in rich soil. Because more sunlight gets to the forest floor, new plants grow quickly. Animals come to eat new plants, or to eat fruit from new plants. Eventually trees grow again, providing homes and shelters for large animals. Lead them to the conclusion that fire (or flood, or any other weather assault) can disrupt an ecosystem and move it out of balance. However, usually the ecosystem adjusts and finds a new balance. 4. Science Notebook question: Describe a time when the weather is very different from today. Tell how you think the forest ecosystem might be affected? Explain your answer. 5. Visit: Journey North: Follow an animal as the seasons change, or plant an International Tulip Garden. 6. Ecosystem game (includes game cards used on walk):

11 11 Name: Teacher: Weather: Outside Temperature: Estimated ºF Actual ºF Cloud cover (circle one) : No clouds Partly cloudy Mostly or completely cloudy Type of clouds (circle one) : Cumulus Other (describe) Stratus Cirrus Wind (circle one): No wind Slight breeze Strong gusts Wind direction (direction wind is coming FROM): Forest Ecosystem CAUTION: POISON IVY!!!!! 1. Draw two PRODUCERS. One should show evidence that part of it has been eaten. If you know the name of the producer, include that in your drawing and point out any interesting features.

12 12 2. Draw and describe two CONSUMERS. For some, you may only have evidence for the consumer, and not have actually seen it. If this is the case, draw the consumer you think is eating the plant and describe the evidence or animal sign that makes you think this. If you know the name of the consumer, include that in your drawing and point out any interesting features.

13 13 Notes: 3. Draw and describe two DECOMPOSERS. If you know the name of the consumer, include that in your drawing and point out any interesting features.

14 14 4. a. Describe the soil that you found. What are the ingredients in this soil? b. List two other NON LIVING things that are important to the living things in the forest ecosystem. Tell why they are important and where you found them Think about how the producers, consumers and decomposers might be connected as part of a system in the forest. Back at school, show your ideas by drawing a food chain here.