1. Flow of Energy in an Ecosystem
2.2

2. Food Chains v. Food Webs
Food chain- a SIMPLE model that shows how energy flows through an ecosystem.
Ex- carrots-> Rabbit-> fox-> Mountain lion
Food web- more complex and realistic model that shows how energy flows through an ecosystem.
Ex- A rabbit eats carrots and grain and corn.
A fox eats rabbits and chipmunks and salmon.
A mountain lion eats foxes and rabbits and salmon.

3. Which is which?

4. Who is in a food web/chain?
Autotroph- an organism that collects energy from sunlight or other inorganic substances in order to PRODUCE THEIR OWN FOOD. Also known as producers. (auto means to do something yourself)
Ex: all plants are autotrophs due to their chloroplasts.
Heterotroph- An organism that gets its energy by CONSUMING OTHER ORGANISMS. Also known as consumers.
Ex: humans, anything that physically eats.

6. Who is in a food web/chain?
Type of Heterotrophs
Herbivore- any heterotroph that strictly eats plants.
Ex: Cows, rabbits, grasshoppers, etc.
Carnivore- any heterotroph that eats other heterotrophs.
Ex: wolves, lions, tigers, etc.
Omnivore- any heterotroph that eats both plants AND other heterotrophs.
Ex: Most humans, bears, mockingbirds.

7. Who is in a food web/chain?
Detrivore- an organism that eats fragments of dead matter in the ecosystem, either plans or animal remains and returns nutrients to the enviornment.
Ex: Worms, maggots, etc.
Similar to Detrivores are decomposers which include fungi and bacteria. They are different from detrivores due to their release of digestive enzymes.

8. How do we organize food webs/chains?
Trophic level- each step in a food web or food chain, usually represented with an energy pyramid.
Autotrophs make up the first level in an energy pyramid, preceeded by the detrivores in their enviornment.
Heterotrophs make up the rest of an energy pyramid.
Energy Pyramid

9. How do we organize food webs/chains?
Another way or organizing the flow of energy is by a Biomass Pyramid.
Bio-Life
Mass- Amount of matter.
A Biomass pyramid tracks how much living matter is left over at the end of every trophic level.

10. Key Points
There are different ways to track the flow of energy through an ecosystem.
Autotrophs make their own food.
Heterotrophs eat other heterotrophs for their food.
There are different types of heterotrophs.