1. Principles of Ecology
Objectives: 1. Explain the difference between abiotic and biotic factors. 2. Describe the levels of biological organization 3. Differentiate between an organisms habitat and its niche.

2. Vocabulary
Ecology Biosphere Biotic factor Abiotic factor Population Biological Community Ecosystem
Biome
Habitat
Niche
Predation
Symbiosis
Mutualism
Commensalism
Parasitism

3. Ecology
Ecology: the study of relationships between living organism, and their interaction with their environments.
Biosphere: The portion of the earth that supports life.

4. Biotic and Abiotic Factors
Biotic Factors: The living factors in an organism’s environment.
Abiotic Factors: The non-living factors in an organism’s environment.

6. Levels of Organization in ecology
Organisms Population Biological community Ec osystem Biome Bioshpere

7. organism
The lowest level of ecological classification is the single organism.
(Example: one single fish)

8. Population
A population is all the individuals of a single species that share the same geographic location at the same time.
(example: a school of fish)

9. Biological Community
Community: A group of interacting populations that occupy the same geographic area at the same time.

10. Ecosystem
Ecosystem: includes a community and all the abiotic factors that effect it.

11. Biome
Biome: a large group of ecosystems that share the same climate and have similar types of communities.
(Example: a marine biome)

12. Habitat and Niche Habitat: the area where an organism lives.
Niche: the role or position that an organism has in it’s environment. (it’s job).

13. Community Interactions

14. Community Interactions
Competition: occurs when more than one organism uses a resource at the same time.
Competition for food, water, space, light, and mates.
Predation: The act of one organism consuming another organism for food.

15. Community Relationships Continued
Symbiotic relationship: A close relationship that exists when two or more species live together.

16. Three types of Symbiotic Relationships
Mutualism: when the two or more organisms both benefit from the relationship.
Commensalism: a relationship when one organism benefits and the other organisms is neither helped nor harmed.
Parasitism: a relationship when one organism benefits at the expense of another organism.