1. Mono Lake: an Alkaline Lake Ecosystem
7th Grade Ecosystem Unit
March, 2009

2. Pictures of Ecosystems
Identify your Ecosystem: what is its name?
Why is this an Ecosystem?
Discuss and write a response to the overarching question: “How are all parts of an ecosystem interrelated?”

3. Where is Mono Lake? See CD-ROM for maps
Best way to learn about ecosystem is to visit it, but a field trip to California is not feasible, so we’re going to watch a 20 minute video instead…
Take notes during video
Fill our worksheet “Thinking about Mono Lake” after video

4. March 13: Quickwrite in Pairs:
Give 4 examples of interactions between abiotic and biotic components in an ecosystem? 1) 2) 3) 4)

5. Ecosystem Defined
An Ecosystem includes all of the organisms in a defined space, the physical environment the organisms live in, and the interactions that go on among the organisms and that environment.

6. Feeding Relationship FLY SPIDER
One way organisms in Mono Lake ecosystem interact with each other is by EATING each other. This is called a feeding relationship.
FLY
SPIDER

7. Mono Lake Organism Cards
Group work
Mission: Organize the cards, picture side up. Show all feeding relationships with arrows. Every organism should be used at least once.
Remember Arrow Direction

8. Draw and explain one feeding relationship in the Monolake Ecosystem
March 19: Quickwrite
Draw and explain one feeding relationship in the Monolake Ecosystem

10. Video Permission Slips?
For next week, after PSSA’s

11. Food Chain
Food Chain: The path that food takes from one organism to another organism.
In an ecosystem, many organisms survive by eating other organisms. The benefits of the food eaten by one organism can then move to another organism and another, as each one is eaten.
Show example on chalkboard.

12. Food Web Food web: A diagram that shows all the feeding relationships.
Many of the organisms in your feeding relationship projects are connected with more than one arrow. When you connect all the organisms with arrows, the arrows cross each other in a complex way.

13. Producers
Which organisms in the food web do not eat any other organisms?
How can they survive without eating?
Organisms that make their own food are producers. Producers produce the food that is used in an ecosystem.
algae
In Mono Lake, _____ are the producers.

14. Consumers
Producers make their own food, but animals, like brine shrimp and gulls, don’t make their own food. How do animals get their food?
Organisms that eat other organisms are called Consumers. Consumers get their food from the bodies of other organisms.

15. Primary, Secondary, Tertiary… Consumers
Primary (first level) consumers: Animals that eat Producers.
Secondary (second level) consumers: Animals that eat primary consumers.
Tertiary (third level) consumers: animals that eat secondary consumers.
Fourth level consumers: animals that eat tertiary consumers, etc. etc.

16. Decomposers
Some organisms are never eaten by consumers, but instead die natural deaths. Dead organisms are broken down and consumed by microorganisms called Decomposers.
Organisms like fungi and bacteria are decomposers.
Everything that is not eaten by a consumer is eventually eaten by decomposers.

17. Trophic Levels We call these different levels “trophic levels”
Producers
Consumers
Decomposers

18. Back to our Mono Lake Food Webs…
Reorganize your Mono Lake organism cards to show the levels of organisms in the ecosystem.
Put Producers at the bottom, Primary Consumers at the next level, etc.
How can you show Decomposers interacting with every level?

19. March 20
What happens to food chains and food webs when different environmental changes and changes in ecosystems caused by man occur?

20. What happens?
In groups, discuss and answer the following 4 questions. Post your answers on the chart paper. Try to come up with at least 2 answers to each question.
Be ready to discuss.

21. What would happen to our Food Web…
If a chemical poisoned and killed all the algae in the Mono Lake Ecosystem?
If there were heavy rains which caused the lake to decrease in salt concentration (salinity), consequently poisoning the brine shrimp?
If several of the species of birds were killed by a new predator?
If the coyotes became a problem and were hunted to extinction?

22. PESTS
What are pests?
How do pests impact our food chains and food webs?
What is pest management?
How do we manage the pests known as Tenebrio molitor (our mealworm and beetle p e t s) s

23. Make a table in science journals
Animal
Is a pest when…
Is not a pest when…
Mealworms
In your food storage
Kept as pets in science classroom
dog
Tears up house
Well trained

24. March 24: What is ‘Accountable Talk’?
Why do you think it is called “Accountable”?
What does it look like/ sound like?

25. Accountable Talk Game Rules
Each group member gets a colored marble or bead. The group gets one bucket.
Have a conversation on the given topic. It is a discussion, using Accountable Talk.
Place your marble/bead into the bucket each time you make a contribution to the discussion, including responses to others as well as new points.

26. What is a Pest?
Pests, as defined by National Park Service policy, are living organisms that interfere with the purpose or management objective of a specific site within a park, or that jeopardize human health or safety.

27. What is Integrated Pest Management or IPM?
IPM is a science-based, decision making process that coordinates knowledge of pest biology, the environment and available technology to prevent unacceptable levels of pest damage, by cost-effective means, while posing the least possible risk to people, resources and the environment.

28. Overarching Question Re-visited
How are all parts of an ecosystem interrelated?
Go back to how you answered this last week. What new concepts or things have you learned since then about ecosystem interactions?

29. Next Steps? Assessment after PSSA
Pg. 21 “Response Sheet: Mono Lake”
Mid-Summative Exam 3-4 (Food webs)
Apply what we know about food webs to the question of Energy in an Ecosystem. Think about how we get our energy.