1. Feeding Relationships
Food Chains
Food Webs
Trophic Levels
10% Rule
Biomass

2. Food Chain
Food chain- A series of steps in an ecosystem in which organisms transfer energy by eating and by being eaten.
The sun is the original energy source for producers, but consumers rely on
carbohydrates and lipids for energy from the food they eat.

3. Food Webs Are a network of complex of feeding relationships.
A food web links all the food chains in an ecosystem together.

4. Trophic Levels
A trophic level is a step in a food chain or web is called a trophic level
Producers(1st level)
plants, trees, grass, algae
Consumers (2nd – 4th level)
Primary grasshopper
Secondary frog
Tertiary snake

5. Trophic Level
Add new trophic levels diagram

6. Trophic Levels
Each consumer depends on the trophic level below for energy
Autotroph
Organism that is able to capture energy from sunlight or chemicals and make their own food.
Ex. Plant and Algae
Heterotroph
Organism that obtains food by consuming other living things, also called a consumer.
Ex. Lion and human

7. Food Web Analysis
Are there any primary consumers that can also be a secondary consumer?
What would happen to the food web if –
The harvest mice where to die off in the area?
B) The algae died?
C) The grasshopper died?

8. Food Web
Food web Explains all of the feeding relationships at each trophic level in a community. A food web is more realistic than a food chain since most organisms feed on more that one organism.

9. Food Web Example Cooper’s Hawk Loggerhead Shrike American Kestrel
Grass & Seeds
Grasshopper
American Kestrel
Loggerhead Shrike
Cricket
Shrew
Sparrow
Deer Mouse
Cooper’s Hawk

10. Food Web Activity

11. 10% Rule
As energy is transferred from one trophic level to the next 90% of the energy is lost as heat to the environment Why do we call it the 10 % rule? Only 10% of the available energy is transferred to the next trophic level

12. New 10 % rule diagram so students can model their own

13. 10% Rule
Have the students create a diagram

14. Ecological Pyramids
Ecological pyramids – show the relationships in food chains and food webs
The bottom of the food pyramid represents the producers, the next level the herbivores, the next the 1st carnivore, and the next and/or top carnivore.
Carnivore
Herbivore
Producer

15. Ecological Pyramids
Ecologists recognize three different types of ecological pyramids:
energy pyramids
biomass pyramids
pyramids of numbers

16. Energy Pyramid
Energy Pyramid- Shows the relative amount of energy at each trophic level.

17. Energy Pyramid

18. Biomass Pyramid
Biomass- The total amount of living organic matter at each trophic level.

19. Biomass Pyramid

20. Pyramid of Numbers
Pyramid of numbers- Shows the relative number of individual organisms at each trophic level.

21. Pyramid of Numbers

22. What is Ecology?
Ecology- The study of organisms and how they interact with their environment. (includes both biotic and abiotic factors).

23. What is an Ecosystem?
Ecosystem- A collection of the organisms that live in a particular place together with their nonliving or physical environment.

24. Biotic & Abiotic Factors
Biotic factors – the biological influences
on an organism within an ecosystem,
the living cast of living characters.

25. Biotic v. Abiotic Factors
Abiotic factors – physical or non living factors
that influence an ecosystem.

26. Biotic or Abiotic?

27. Biotic or Abiotic?

28. Levels of Organization within an Ecosystem
The study of ecology ranges from the study of individual organisms to the study of the entire biosphere.
Species (Individual)
Population
Community
Ecosystem
Biome
Biosphere

29. Levels of Organization
A species is a group of organisms that can breed and produce fertile offspring. (ex: black bears)
2. A population is a group of individuals that belong to the same species and live in the same area (ex: all the black bears in Yellowstone Park)

30. Levels of Organization
A community is a group of different populations that live together in a defined area. Exp. lions and tigers and bears living in the same area
4. A ecosystem is a collection of all the organisms that live in a particular place, together with their physical environment

31. Levels of Organization
5. A biome is a group of ecosystems that have the same climate and dominant communities.
6. A biosphere is the parts of the earth in which life exists, including land, water, air and atmosphere.

32. Ecology: Levels of Organization

33. The Niche An organisms' niche is the full range of
physical and biological conditions in
which the organism lives and the way in
which it uses those conditions.

34. The Niche A organisms niche includes - the type of food it consumes
- how it obtains food
- physical conditions necessary to survive
- the organism's reproductive pattern

35. Niche v. Habitat An organisms habitat is where it lives.
An organisms niche is how it lives.

36. No two species can share the same niche in the same habitat.
Cape May Warbler
Feeds at the tips of branches
near the top of the tree
Bay-Breasted Warbler
Feeds in the middle
part of the tree
Yellow-Rumped Warbler
Feeds in the lower part of the tree and
at the bases of the middle branches
Spruce tree