1. Community Ecology Chapter 20 Table of Contents Section 1 Species Interactions Section 2 Patterns in Communities

2. Section 1 Species Interactions Chapter 20 Objectives Identify two types of predator adaptations and two types of prey adaptations. Identify possible causes and results of interspecific competition. Compare parasitism, mutualism, and commensalism, and give one example of each.

3. Section 1 Species Interactions Chapter 20 Predation Predation is an interaction in which one organism (the predator) captures and eats all or part of another individual organism (the prey).

4. Section 1 Species Interactions Chapter 20 Predation, continued Predator Adaptations –Predators have adaptations to efficiently capture prey, whereas prey species have adaptations to avoid capture.

5. Section 1 Species Interactions Chapter 20 Predation, continued Adaptations in Animal Prey –Mimicry is an adaptation in which a species gains an advantage by resembling another species or object.

6. Section 1 Species Interactions Chapter 20 Predation, continued Adaptations in Plant Prey –Many plants produce secondary compounds as a chemical defense.

7. Chapter 20 Click below to watch the Visual Concept. Competition Section 1 Species Interactions

8. Chapter 20 Competition Competitive Exclusion –Competition may cause competitive exclusion, the elimination of one species in a community.

9. Chapter 20 Effect of Competition on Two Species of Barnacles Section 1 Species Interactions

10. Chapter 20 Competition, continued Character Displacement –Competition may drive the evolution of niche differences among competitors. This evolution of differences in a characteristic due to competition is called character displacement.

11. Section 1 Species Interactions Chapter 20 Competition, continued Resource Partitioning –Differential resource use to avoid competition is called resource partitioning.

12. Chapter 20 Warbler Foraging Zones Section 1 Species Interactions

13. Chapter 20 Symbiosis Parasitism –In parasitism, one species (the parasite) feeds on, but does not always kill, another species (the host).

14. Section 1 Species Interactions Chapter 20 Symbiosis, continued Mutualism –In mutualism, both interacting species benefit.

15. Section 1 Species Interactions Chapter 20 Symbiosis, continued Commensalism –In commensalism, one species benefits, and the other is not affected.

16. Section 2 Patterns in Communities Chapter 20 Objectives Describe the factors that affect species richness in a community. Explain how disturbances affect community stability. Distinguish between types of succession, and explain why succession may not be predictable.

17. Section 2 Patterns in Communities Chapter 20 Species Richness Species richness is the number of species in a community. Species evenness is the relative abundance of each species.

18. Section 2 Patterns in Communities Chapter 20 Species Richness, continued Latitude and Species Richness –In general, species richness is greatest near the equator, and larger areas support more species.

19. Section 2 Patterns in Communities Chapter 20 Species Richness, continued Species Interactions and Species Richness –Species interactions such as predation can promote species richness.

20. Section 2 Patterns in Communities Chapter 20 Species Richness, continued Community Stability and Species Richness –Disturbances can alter a community by eliminating or removing organisms or altering resource availability. –Species richness may improve a community’s stability. –Areas of low species richness may be less stable in the event of an ecological disturbance.

21. Section 2 Patterns in Communities Chapter 20 Successional Changes in Communities Ecological succession is a change in the species composition of a community over time.

22. Section 2 Patterns in Communities Chapter 20 Successional Changes in Communities, continued Primary Succession –Primary succession is the assembly of a community on newly created habitat. –Primary succession occurs in areas that have been recently exposed to the elements and lack soil.

23. Section 2 Patterns in Communities Chapter 20 Successional Changes in Communities, continued Secondary Succession –Secondary succession is the change in an existing community following a disturbance. –Secondary succession occurs in areas where the original ecosystem has been cleared by a disturbance.

24. Section 2 Patterns in Communities Chapter 20 The Complexity of Succession The traditional description of succession is that the community proceeds through a predictable series of stages until it reaches a stable end point, called the climax community. Primary succession typically proceeds from lichens and mosses to a climax community. Secondary succession typically proceeds from weeds to a climax community.

25. Chapter 20 Ecological Succession at Glacier Bay Section 2 Patterns in Communities