1. Principles of Ecology
TSW identify the levels of classification within ecology and differentiate between food chains and food webs

2. What is ecology?
The study of the interactions of organisms with one another and with their physical surroundings

3. Levels of Organization (Broadest to most specific)
Biosphere
Biome
Ecosystem
Community
Population
Individual

4. 6. Biosphere
Contains the part of the earth in which ALL life exists (including land, air, water, and atmosphere)

5. 5. Biome
A group of ecosystems that have the same climate and similar dominant communities
Can you think of any biomes?

6. 4. Ecosystem
A collection of all of the organisms that live in a particular place, together with their nonliving, or physical environment

7. 3. Community All the populations of organisms living in a defined area
Can be one inch of soil or and entire forest

8. 2. Population
A group of individuals that belong to the SAME SPECIES and live in the same area

9. 1. Individual
One organism of a particular species

10. What keeps populations from growing without end?
Limiting interactions
Density-dependent
Density-independent

11. Density-dependent Factor
Factor that depends directly on the size of a population
Examples:
Disease (esp. parasitism)
Predation
Competition for space and resources
Crowding and stress

12. Density- independent Factor
Limiting factor that affects all populations in a similar way, regardless of population size
Examples:
Temperature and climate changes
Natural disasters
Chemical pollutants

13. Simple Interactions
Food chain: a series of steps in which organisms transfer energy by eating or being eaten

14. Trophic Levels
Producers: Organisms that make their own food from inorganic sources
1º consumer: aka Herbivores, get food/energy by feeding DIRECTLY on producers
2º consumer: Feed on 1º consumers

15. Ecological Pyramids
Diagram showing the relative amounts of energy/matter contained within each trophic level in a food chain/food web

16. 3 Types of Pyramids
Energy: Lose actual energy as you move up the pyramid
Biomass: Most mass is found at the bottom of the pyramid
Numbers: Most individuals are found at the bottom of the pyramid

17. Rule of 10
Only about 10% of the energy available within one trophic level is transferred to organisms at the next level

19. Food Web
When the feeding relationships among the various organisms in an ecosystem form a network of complex interactions
Link all food chains together