Nutrient & Energy Flow

2.2

I. Producers vs. ConsumersA. Producers / Autotrophs-

Organisms that can make their own food/sugars.1. Plants are autotrophs & some bacteria 2. Use light energy, carbon dioxide and water to create sugar and give off oxygen

Sun + CO2 + H2O => C6H12O6 + O2(This is the equation for photosynthesis)

I. Producers vs. ConsumersB. Types of Heterotrophs

(obtain their food)1. Herbivore- Eats only plants2. Carnivore- Eats only other animals3. Scavenger- Eats only other animals that have already died4. Omnivore- Eats both plants and other animals

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I. Producers vs. Consumers5. Decomposer- Break down complex compounds of dead organisms and release nutrients

a. Usually bacteria or fungi

b. Important for completing the cycle of nutrients

c. Used in landfills to speed the rate that wastes get broken down

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II. Trophic LevelsA. “Troph” = Food/Energy

1. Explain auto”troph” and hetero”troph”

B. Trophic Levels represent the different steps in a food chain or web.1. Shows how energy is transferred

II. Trophic Levels

“Tertiary Consumers”Click Here

2nd – Order Heterotroph

Autotroph

1st - Order Heterotroph

3rd – OrderHeterotroph

PRODUC

ER

CARNIV

ORE

CARNIV

ORE

HERBIV

ORE

III. Food Chain vs. Food WebA. Energy and other nutrients

that are eaten flow from one organism to the next.

B. Food Chain- Simple model that shows how matter and energy move through an ecosystem (one organism to the next)

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III. Food Chain vs. Food Web

1. Autotroph -> Heterotroph -> Decomposer

2. Ex: Berries (autotroph) are eaten by a mouse (heterotroph) who dies and decays (decomposer)

3. Some energy is lost as heat at each level

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III. Food Chain vs. Food WebC. Food Web- Model of ALL

possible feeding relationships in a community.

1. More complex than food chains (more realistic, too!)

a. See pg. 43 for picture

2. Most organisms do not rely on just one food source

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III. Food Chain vs. Food WebGo outside…

1. Write down one example of a simple food chain that you

see.

2. Write down one example of a food web that you see.

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Energy Pipeline Demonstration

(Takes entire class period)

(Sept. 18, 2008: Lead by guest speaker from Game &

Parks)

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IV. Ecological PyramidsA. Ecological pyramids show

amounts at each trophic level.1. See pg. 44for Energy, Numbers and Biomass Pyramids. 2. Notice: the number at each level sometimes goes up, sometimes it goes down.

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IV. Ecological PyramidsB. Test Practice: Study this

ecological pyramid. There will be questions on the next slides.

Grasshopper

Small Bird

Snake

Large

Bird

IV. Ecological Pyramids1. Which animal will eat the largest numbers of its prey?

The small bird will eat many grasshoppers

Grasshopper

Small Bird

Snake

Large BirdHint: What has more calories, steak or salad?

IV. Ecological Pyramids2. Which level will have the highest concentration of pesticide particles in the digestive tract? Explain.

The large bird is highest. The concentration will increase at each level because each animal below eats many of the pesticide-infested animals.

V. CyclesA. Law of Conservation of

Mass: Matter is neither created or destroyed.

1. Therefore it must be RECYCLED or we would run out!

2. Matter includes water, carbon, nitrogen, phosphorus, etc.

Not true of energy…It is

created by the sun and is

destroyed all the time!

V. CyclesB. Explain the Water Cycle Below

V. Cycles

Feel like doing some theatre? As a class, read the “Water Cycle Play” script for another look at

how water is recycled.

(Time Permitting)

V. CyclesC.Explain the Carbon Cycle below

V. Cycles1. Remember that all living things

have carbon. We call this “organic.”

2. The “global warming” is caused by raising levels of carbon (CO2) let off by industry?

a. For an “other assignment” research the question, “Is global warming really caused by humans?”

V. CyclesD. Nitrogen Fixation- Converting

nitrogen gas in the atmosphere to ammonium (nitrogen) compounds in the soil for plant growth

1. Taken up by roots

2. This is done by bacteria in the soil or on the roots

a) Ex: soy beans, alfalfa

3. See pg. 48 to study diagram

V. CyclesE. Denitrification- Converting dead

organisms into nitrogen gas in the air

1. Done by decomposers

VI. Limiting FactorsA. Limiting Factor- Any thing that

limits the number of individuals in a population1. Can be living (biotic)

a. Amount of grass available for cattle to graze2. Can be non-living (abiotic)

a. Amount of rain affects how much grass can grow

VI. Limiting Factors3. Common Limiting Factors

a. Food & Waterb. Spacec. Shelterd. Moisturee. Temperature

VI. Limiting Factors

Play “Oh Deer” to simulate and graph how limiting

factors affect populations

(Time permitting—Takes at least 30 minutes)

VI. Limiting FactorsB. Carrying Capacity- The

largest number of individuals of one species that the ecosystem can support.1. Carrying capacity exists because of limiting factors!

VI. Limiting Factors2. What can we do to INCREASE carrying capacity?

a. Plant treesb. Waste lessc. Use biotechnology to

increase food supplyd. Health Care/Medicine

ReviewWhat’s the difference between an autotroph and heterotroph?

List the 5 kinds of heterotrophs.

Give an example of a producer, 1st, 2nd, and 3rd order heterotroph.

ReviewGive another name for the top consumer in a food chain.

What is the difference between a food chain and food web?

Why are cycles important on earth?

ReviewIs energy recycled?

Define nitrogen fixation.

List three limiting factors in an ecosystem.

If there are a lot of limiting factors will the carrying capacity be high or low?