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

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.

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).

Chapter 20 Predation, continued Predator Adaptations 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.

Chapter 20 Predation, continued Adaptations in Animal Prey 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.

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

Chapter 20 Competition Competitive Exclusion Section 1 Species Interactions Chapter 20 Competition Competitive Exclusion Competition may cause competitive exclusion, the elimination of one species in a community.

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

Competition, continued Section 1 Species Interactions 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.

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

Warbler Foraging Zones Section 1 Species Interactions Chapter 20 Warbler Foraging Zones

Chapter 20 Symbiosis Parasitism Section 1 Species Interactions Chapter 20 Symbiosis Parasitism In parasitism, one species (the parasite) feeds on, but does not always kill, another species (the host).

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

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

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.

Chapter 20 Species Richness 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.

Species Richness, continued 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.

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

Species Richness, continued 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.

Successional Changes in Communities 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.

Successional Changes in Communities, continued 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.

Successional Changes in Communities, continued 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.

The Complexity of Succession 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.

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

Ecological Succession Section 2 Patterns in Communities Chapter 20 Ecological Succession

Chapter 20 Multiple Choice Standardized Test Prep Multiple Choice 1. A certain tropical tree has a fruit that is eaten by only one species of bats. As the bat digests the fruit, the seeds are made ready to sprout. When the bat excretes the wastes of the fruit, it drops seeds in new locations. Which of the following is the correct term for the relationship between the bat and the tree? A. predation B. mutualism C. competition D. commensalism

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued 1. A certain tropical tree has a fruit that is eaten by only one species of bats. As the bat digests the fruit, the seeds are made ready to sprout. When the bat excretes the wastes of the fruit, it drops seeds in new locations. Which of the following is the correct term for the relationship between the bat and the tree? A. predation B. mutualism C. competition D. commensalism

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued 2. Which of the following is a parasite? F. a lion hunting a zebra G. a deer grazing on grass H. a tick sucking blood from a dog J. a snake swallowing a bird’s egg

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued 2. Which of the following is a parasite? F. a lion hunting a zebra G. a deer grazing on grass H. a tick sucking blood from a dog J. a snake swallowing a bird’s egg

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued 3. Three species of birds forage for insects in the same tree. However, each species tends to forage in different parts of the tree. This pattern of foraging is best explained as an adaptation to which of the following relationships? A. predation B. mutualism C. competition D. commensalism

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued 3. Three species of birds forage for insects in the same tree. However, each species tends to forage in different parts of the tree. This pattern of foraging is best explained as an adaptation to which of the following relationships? A. predation B. mutualism C. competition D. commensalism

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued Use the map below to answer question 4. The map shows two islands.

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued 4. What can you infer about the number of species on each of these islands? F. Island A has more species. G. Island B has more species. H. Island A and Island B will have the same number of species. J. Both islands will have fewer species than islands that are located farther north.

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued 4. What can you infer about the number of species on each of these islands? F. Island A has more species. G. Island B has more species. H. Island A and Island B will have the same number of species. J. Both islands will have fewer species than islands that are located farther north.

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued Complete the following analogy: 5. predator : prey :: herbivore : A. carnivore B. plant C. parasite D. predation

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued Complete the following analogy: 5. predator : prey :: herbivore : A. carnivore B. plant C. parasite D. predation

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued Use the graph below to answer question 6. The shading in the graph indicates the frequency with which a certain bird species obtains prey, by prey size and location.

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued 6. Which of the following statements is best supported by this graph? F. Most often, the bird eats insects. G. Most often, the bird nests above ground. H. Most often, the bird finds prey at ground level. J. Most often, the bird eats prey that is between 3 and 5 mm long.

Multiple Choice, continued Chapter 20 Standardized Test Prep Multiple Choice, continued 6. Which of the following statements is best supported by this graph? F. Most often, the bird eats insects. G. Most often, the bird nests above ground. H. Most often, the bird finds prey at ground level. J. Most often, the bird eats prey that is between 3 and 5 mm long.

Chapter 20 Short Response Standardized Test Prep Short Response Some plants produce chemicals that are irritating or poisonous to some animals. Explain the role of these adaptations in an ecological community.

Short Response, continued Chapter 20 Standardized Test Prep Short Response, continued Some plants produce chemicals that are irritating or poisonous to some animals. Explain the role of these adaptations in an ecological community. Answer: Secondary compounds are defensive chemicals synthesized by plants to prevent plants from being eaten. Strychnine and nicotine are two examples.

Chapter 20 Extended Response Standardized Test Prep Extended Response Base your answers to parts A & B on the information below. The gradual, sequential change in species in an area is called ecological succession. Part A Describe the stages of primary succession. Part B Compare primary succession and secondary succession.

Extended Response, continued Chapter 20 Standardized Test Prep Extended Response, continued Answer: Part A Primary succession starts with the exposure of bare land. Lichens colonize the rock. Decaying lichens as well as minerals from the rock lead to soil formation. Soil leads to colonization by pioneer species, such as moss and weeds. Large plants, such as shrubs and trees, replace pioneer species. Various trees become dominant, and succession ends with a mature forest. Part B Primary succession occurs when bare rock is exposed by geological events, such as island formation or glacier retreat. Secondary succession occurs after a disturbance clears away an existing community, but the soil remains intact.