1. From the Sun, Through an Ecosystem, Into Heat
Energy Flow
From the Sun, Through an Ecosystem, Into Heat

2. Autotrophs / Producers
Auto = Self-made
example: Automatic, Automobile
Troph = Eater / Food
Example: trophy (prizes in competitions used to be food!)
So, AUTOTROPHS make their own food. They produce their own food.
How?
Photosynthesis!!!!

3. Heterotrophs / Consumers
Hetero = different Troph = food
Heterotrophs CANNOT make their own food, so they must eat other organism. They consume other animals.
Heterotrophs are ALL organisms that eat other organisms
They are herbivores, carnivores, omnivores, and detrivores. ALL of these animals cannot make their own food, and must eat other organisms (including plants) FOR food!

4. Decomposers
DECOMPOSERS are heterotrophs that eat dead things and in the process return nutrients to the soil.
DECOMPOSERS are always DETRIVORES
Detrivore specifies that they eat dead things
Decomposer specifies that they break down dead things and return nutrients to the soil
What are some examples of DECOMPOSERS?

5. DECOMPOSERS Bacteria Fungi Flies Maggots Hyenas Dung Beetles Worms
Mold

6. Primary, Secondary, Tertiary
Primary Consumers eat Autotrophs (plants)
Secondary Consumers eat Primary Consumers
Tertiary Consumers eat Secondary Consumers

7. Pop Questions Are all consumers meat-eaters?
NO! Herbivores are consumers too
Are carnivores ever primary consumers?
NO! But, omnivores can be
Are herbivores always primary consumers?
YES!

8. Trophic Levels Each step in the chain represents a TROPHIC LEVEL
A trophic level is an feeding step in the passage of energy and materials through an ecosystem

10. Energy Flow Energy enters the ecosystem as Sunlight
Sunlight is the One + Only + Ultimate energy source
It is turned into food by autotroph (plants)
However, plants only capture 1% of total sun / energy
Plants use this energy to grow, to reproduce, to move (a little), and to keep themselves alive
Overall, plants use 90% of energy this way!
So, only 10% of energy is passed on to the next trophic level (whatever eats the plant)

11. 10% Rule
At every level, 90% of the energy received from food is used to keep the organism alive.
For example, a zebra who eats grass only gets 10% of the energy from grass that the grass got from the sun.
Then, the lion who eat the zebra only gets 10% of the energy from the zebra that the zebra got from the grass.
This makes sense! THE ZEBRA USES ENERGY RUNNING AWAY FROM THE LION!!

13. Energy Pyramid

14. Pop Question!

15. The same holds true with Biomass
Biomass: Total amount of living tissue within a given trophic level (I am ___ lbs of human biomass)
Just like an energy pyramid, BIOMASS decreases as you go up trophic levels.
And, the 10% Rule applies!
Energy is mass!

16. So, how much grass does it take you to survive?
Meat Eater:
Vegetarian:
Human  Cow  Grass  Sun
150lbs x 10 (cow) x 10 (grass)
15,000 lbs
Human  Vegetables  Sun
150lbs x 10 (veggies)
1500 lbs
It’s better for the earth to be a vegetarian. Except…
You may not be getting enough PROTEIN!

18. Ok, let’s see how we’re doing
First, put a P (producer) or a C (consumer) next to the animals
Now, put a O (omnivore), H (herbivore), or C (carnivore) next to the animals too.
Now draw an energy pyramid (up to Tertiary Consumer) using any of those animals.