1. The Biosphere
Chapter 3

2. What is Ecology?

3. Ecology
The study of the interactions among organisms and between organisms their environment.

4. Biosphere
All parts of the Earth where life can exist (land, water and air).

5. Biotic vs. Abiotic Biotic: the living factors in an ecosystem
Abiotic: the nonliving factors in an ecosystem

6. Levels of Organization
Ecosystem: interactions among the community and abiotic factors
Community: group of interacting populations
Population: group of one species living in the same place at the same time

7. Energy, Producers, and Consumers

8. Autotrophs An organism that can make its own food.
Use photosynthesis or chemosynthesis.
Also called producers.

9. Heterotrophs • An organism that has to get its food from others.
• Also called consumers.

10. Types of Heterotrophs Herbivores: eat only plants
Carnivores: eat only meat
Omnivores: eat both plants and meat
Detritovores: break down dead material; decomposers
Scavengers: eat dead animals

11. Energy Flow in Ecosystems

12. Feeding Relationships
• Food chains: less complex
• Food webs: show all eating relationships in an ecosystem. BETTER!

13. Trophic Levels • Each step in a food chain.
• As you move up trophic levels, 90% of the energy is lost.

14. Ecological Pyramids
• Energy Pyramid
(kCal)

15. Cycles of Matter

16. The Water Cycle

17. Nutrient Chemicals an organism needs to sustain life. Carbon Nitrogen
Phosphorous

18. Carbon Cycle

19. Nitrogen Cycle

20. Phosphorous Cycle

21. Ecosystems & Communities
Chapter 4

22. Niches & Community Interactions

23. Niche Everything an organism does to survive.
All physical and biological conditions.
What it eats, where it lives (habitat), how it avoids predators, etc.

24. Competition
Occurs when two organisms want the same resource at the same time.
Competitive Exclusion Principle: No two species can occupy the same niche at the same time.

25. Predation
An interaction where one organism captures and feeds on another organism.
Predator: the “killer”
Prey: the “killed”

26. Keystone Species
A species that exerts strong control on the structure of a community so that changes to its population causes dramatic changes
Ex: sea otters, honeybees

27. Symbiosis Any relationship in which two species live closely together.
Mutualism: both species benefit
Ex: bees and flowers
Commensalism: one species benefits while the other is not affected
Ex: barnacles on a whale
Parasitism: one species benefits, while the other is harmed
Ex: tapeworms- YUK!
Examples of Symbiosis