Investigation Name_________________________________

Bottling EcosystemsIf you look at a snapshot of an ecosystem you can see some of the plants, animals, and nonliving things that exist there. But ecosystems are places full of activity with many parts that change over time. How can you observe an ecosystem as it changes? By constructing a model you can see many kinds of change that take place on a much larger scale in an ecosystem. A good model should include both biotic (living) and abiotic (nonliving) components of the ecosystem to be studies. In this Investigation you will model some of the changes and interactions that occur in two ecosystems – an aquatic community and a terrestrial community.

Background Information:

Ecosystems exist in a delicate balance which has evolved over millions of years. Small changes can affect this balance. Cycles exist which restore nutrients to the systems. The water cycle, nitrogen cycle, and carbon cycle are three important ones. The success of plant and animal life depends on them. The atmosphere is in delicate balance. Too much C02 could increase atmospheric temperatures while a decrease in ozone levels may raise exposure to harmful UV rays. Change in weather patterns could change a normally high precipitation area into a low precipitation area. Industrial pollutants can cause acid rain. Plants and animals may be affected in unpredictable ways by these climactic changes.

Purpose of the Ecosystem lab:

To understand by observing the interdependency of biotic and abiotic factors in a given ecosystem.

To observe how an ecosystem changes over time based on limiting factors of the ecosystem. To observe and understand the law of “Conservation of Matter”. Matter is neither created nor

destroyed (Antoine Lavoisier 1743-94) and this application to the nitrogen, carbon, water, and phosphorus cycles.

Make predictions about changes over time. Think about natural selection, adaptations, and symbiotic relationships. How do these concepts add to the species’ survival over time? How does and ecosystem maintain homeostasis?

Trace energy flow (food web/chain) and understand the pyramid of energy flow in regard to the carrying capacity of specific biomes.

II - Creating an ecosystemIn order to create an enclosed ecosystem, various components need to be observed.1. Distinguish between biotic and abiotic factors

a. Biotic factors refer to ______________________________________________

Name three biotic factors necessary for the terrestrial chamber.

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Name three biotic factors necessary for the aquatic chamber.

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b. Abiotic factors refer to ______________________________________________

Name three or more abiotic factors necessary for the terrestrial chamber.____________________ _______________________ _________________________

Name three or more abiotic factors necessary for the aquatic chamber.____________________ _______________________ _________________________

c. An enclosed ecosystem is considered stable or self- sustaining if materials are cycled andthere is a flow of energy. List 4 material cycles necessary for ecosystem stability.

________________ ____________________ _________________ ________________

d. What is meant by limiting factors? Provide three examples of limiting factors pertinent toour self-sustaining ecosystem.

e. State the purpose of the Bottled Ecosystem experiment.

f. Explain or draw how water will cycle in your biome.

g. Explain or draw how carbon will cycle in your biome.

h. Explain or draw how nitrogen will cycle in your biome.

Bottle Ecosystem Procedure:

1. Remove and discard the labels from two 2 L plastic soda bottles. Using a marker, mark the bottles to be cut as shown in the diagram below. Then ask your teacher to check the lines and initial here___________.

2. Cut the bottles along the marked lines. Do not discard the tops of the bottles because they will be used later. Make a cover for each sampling hole by placing a 5 cm square piece of plastic cover each hole and attaching one side of the plastic square to the bottle with tape.

What purpose will the sampling holes serve?_________________________________________

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3. Using a nail, make a hole in the top of one bottle lid.4. Using a pin, make several holes in the top of bottle B near the neck.

What purpose will these small holes serve?_________________________________________

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5. Assemble the soda bottle pieces into a microscale ecosystem with an aquatic community (Section 1) and a terrestrial community (Section 2) as seen in the diagram.

6. To make section 1 place 3 cm of aquarium gravel in the base of bottle A and then fill with water to within 3 cm of the sampling hole. Use as much natural water stream or lake water as possible. Carefully place the Elodea, duckweed, algae, snails, and fish in the water.

Why did we include these organisms?___________________________________________

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7. To make section 2, run a piece of string through the cap with a hole in it and then tighten the cap onto bottle B. Invert bottle B, place it on top of section 1, making sure the string reaches the water in section 1. Tape the bottles together. Make sure the tape creates a complete seal between the two bottles.

What purpose will the string serve?_______________________

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8. Fill section 2 with about 3 cm of gravel and then about 5 cm of soil. Place several seeds in the soil, buried lightly. Then add some dead organic matter, a slice of potato or other vegetable, a worm, and any other decomposers or organisms you have.

Why did we include these components?______________________________________________

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9. How will you measure the “success” of your ecosystem? Consider the life and growth of the organisms. I will ask you each week to describe your ecosystem as successful or not. You will use these criteria to answer that question.

Summary Questions

1. How is your model ecosystem similar to a real ecosystem? How is it different?

2. As your model ecosystem changed over time, which organism increased in number, which remained the same, and which declined?

3. How did the abiotic parts of the ecosystem change over time?

4. Draw an example of the food web that existed in your ecosystem.

5. Was your ecosystem successful or unsuccessful? Explain in detail. Success depends on organisms surviving.

6. Did you enjoy this lab? If so, what was the best part? If not, what could make the lab better?

7. Rather than write a formal conclusion, what are three things that you learned (or expanded your previous knowledge about) from this experience?