1. Community ecology
AP Biology Chapter 53

2. Community
An assemblage of populations of various species living close enough for potential interactions

3. Species Diversity Species richness: Relative abundance:
Total amount of species in a community
Relative abundance:
Total amount of one species in a community

4. Competitive Exclusion Principle
Direct interspecific competition will always lead to the extinction of one species
One species will have a slight competitive edge in surviving and reproducing

5. Ecological Niche
Every species survives and reproduces utilizing a range of chemical and biological conditions

6. Species Interactions

7. Types of Interactions Interspecific Interactions
Interactions with other species
Intraspecific Interactions
Interactions within one species

8. Predation (+/-)

9. Evolution of Coloration
Cryptic: animal blends in to surroundings
Aposematic: animal is brightly colored (warning)

10. Evolution of Coloration
Batesian mimicry: smaller species is harmless
Mullerian mimicry: both species are harmful

11. Herbivory (+/-)

12. Parasitism (+/-)

13. Mutualism (+/+)

14. Commensalism (+/0)

15. Food Chain
A linear relationship that illustrates how energy flows in an ecosystem.

16. Food Web
A collection of interconnecting food chains

17. Keystone Species Organism with a pivotal role in an ecosystem
The removal of a keystone species results in the collapse of the ecosystem
Ex: sea otter (Enhydra lutris)

19. Disturbance
An event that changes a the dynamics of a community

20. Primary Succession Formation of a community in a place without soil
Volcanoes
Landslides
Flooding

21. Primary Succession Pioneer species arrive that do not need soil
Ex: photosynthetic prokaryotes & windblown spores

22. Primary Succession Pioneer species decompose into organic matter
Rocks erode into minerals forming soil

23. Primary Succession
Simple plants like mosses and ferns grow in soil

24. Primary Succession
Grasses and wildflowers replace seedless plants

25. Primary Succession
Over time, forests replace prairies

26. Primary Succession
Animals have a substantial habitat

27. Secondary Succession Soil already present Faster than 1º succession
Different pioneer species
Ex: fires

29. Climax Community
A stable group of plants and animals that is the end result of the succession process
Does not always mean forest
Grasses in prairies
Cacti in deserts