1. E N E R G Y Flow Through Ecosystems

2. E n e r g y !
At the core of every organism’s interaction with the environment, is its need for ENERGY to power the processes of life
The flow of ENERGY through an ecosystem is one of the most important factors that determines the capacity to sustain life
Sunlight is the main ENERGY source for life on earth

3. Ecosystems
Ecosystems = includes both the living components plus the non-living components of an environment

4. What does a chain look like?

5. Draw a food chain using these organisms:
(just the words, not the pics)
Big Leaf
Maple
Millipede
Salamander
Sharp
Shinned
Hawk H
Garter
Snake

6. Does yours look like this?
Sharp
Shinned
Hawk
Big Leaf
Maple
Millipede
Salamander
Garter
Snake
Today’s objective:
Using a food web to illustrate and analyze how energy flows through an ecosystem.

7. A food chain is:
a series of steps in which organisms transfer energy by eating and being eaten
grass → mouse → snake → hawk
Which of the above are nodes? Edges?
(nodes = parts of the system edges = interactions)

8. Nodes = the components - sun, grass, mouse, snake, hawk
Edges = direction of energy flow –
the arrows →

9. It’s ALL about ENERGY
Arrows show direction of ENERGY flow: NOT direction of eating:
Grass
Cow
Cow
Grass

10. Food Web
Insert the following organisms into your diagram to convert your food chain to a food web:
Shrew
Banana
Slug
Club
Moss
Bullfrog

11. Food Web = a set of interconnected food chains in an ecosystem.
Shrew
Food WEB
Food CHAIN
Sharp
Shinned
Hawk
Big Leaf
Maple
Garter
Snake
Millipede
Salamander
Banana
Slug
Club
Moss
Bullfrog

12. How does a food web differ from a food chain? Is a food web a network?
Shrew
Food WEB
Food CHAIN
Sharp
Shinned
Hawk
Big Leaf
Maple
Garter
Snake
Millipede
Salamander
Banana
Slug
Club
Moss
Bullfrog
How does a food web differ from a food chain?
Is a food web a network?

13. Everyone plays a specific role in the food chain of life and we classify organisms by their energy intake…. Producers & Consumers

14. Producers (also known as autotrophs)
Producers = get their energy from the sun
Place a star next to all the organisms that are producers / autotrophs in your food WEB

15. Did you get it right?
Big Leaf
Maple
Club
Moss

16. Consumers (also known as heterotrophs):
Consumers = hunt, gather, and store food because they cannot make their own
Herbivores = eat ONLY plants
Ex. cows, caterpillars, deer
Carnivores = eat ONLY meat
Ex. snakes, dogs, owls
Omnivores = eat BOTH plants & animals
Ex. humans, bears, crows
Detritivores = eat dead matter
Ex. earthworms, snails, crabs
Decomposers = break down organic matter
Ex. bacteria, fungi

17. Movement of E N E R G Y What happens to the energy in an ecosystem?
Energy flows through an ecosystem in one direction
sun → producers → consumers

18. Soooooooooooo,
In a food web, what is the difference between a consumer and a producer?
If all the shrews in our food web died, could this cause a change in the hawk population? Explain

19. Biotic & Abiotic Factors
Biotic Factors = the living factors of an ecosystem
Plants, animals, bacteria
Abiotic Factors = the non-living factors of an ecosystem
Sunlight, water, temperature, rocks, soil

20. Abiotic, Biotic, & Nodes…
Add the following ABIOTIC (non-living) NODE to your network
Sunlight
Make a key for your network to identify both types of NODES (abiotic and biotic) and your edges
Then, complete the assessment 