Copyright © 2005 Pearson Prentice Hall, Inc. Chapter 40 Community InteractionsCommunity Interactions

Importance of Community Interactions

Copyright © 2005 Pearson Prentice Hall, Inc. Effects of Competition Among Species Ecological Niche: Place & Role of Each Species in Its EcosystemEcological Niche: Place & Role of Each Species in Its Ecosystem Adaptations Reduce the Overlap of Ecological Niches Among Coexisting SpeciesAdaptations Reduce the Overlap of Ecological Niches Among Coexisting Species –Competitive exclusion (F40.1 p. 821) –Resource partitioning (F40.2 p. 821)

P. aurelia P. caudatum grown in separate flasks grown in the same flask days population density Competitive Exclusion

Blackburnian warbler Cape May warbler black- throated green warbler bay-breasted warbler myrtle warbler foraging height (feet) Resource Partitioning

Copyright © 2005 Pearson Prentice Hall, Inc. Effects of Competition Among Species Competition Helps Control Population Size and DistributionCompetition Helps Control Population Size and Distribution –Keystone species (F40.13 p. 830)

Keystone Species: Removal dramatically alters the community

Copyright © 2005 Pearson Prentice Hall, Inc. Results of Interactions Between Predators and Their Prey Forms of predation (F40.3 p. 822)Forms of predation (F40.3 p. 822) Predator–Prey Interactions Shape Evolutionary AdaptationsPredator–Prey Interactions Shape Evolutionary Adaptations –Warning coloration (F40.7 p. 825) –Warning mimicry (F40.8 p. 825)

Copyright © 2005 Pearson Prentice Hall, Inc. Results of Interactions Between Predators and Their Prey –Some Predators and Prey Have Evolved Counteracting Behaviors –Camouflage Conceals Both Predators and Their Prey Camouflage by blending in (F40.4 p. 823)Camouflage by blending in (F40.4 p. 823) Camouflage by resembling specific objects (F40.5 p. 824)Camouflage by resembling specific objects (F40.5 p. 824) Camouflage assists predators (F40.6 p. 824)Camouflage assists predators (F40.6 p. 824)

Copyright © 2005 Pearson Prentice Hall, Inc. Results of Interactions Between Predators and Their Prey? –Bright Colors Often Warn of Danger Chemical warfare (F40.11 p. 827)Chemical warfare (F40.11 p. 827)

Copyright © 2005 Pearson Prentice Hall, Inc. Results of Interactions Between Predators and Their Prey –Some Organisms Gain Protection Through Mimicry Visual and behavioral mimicry (F40.9 p. 826)Visual and behavioral mimicry (F40.9 p. 826) Startle coloration (F p. 827)Startle coloration (F p. 827)

Copyright © 2005 Pearson Prentice Hall, Inc. Results of Interactions Between Predators and Their Prey –Some Predators and Prey Engage in Chemical Warfare –Plants and Herbivores Have Coevolutionary Adaptations

Copyright © 2005 Pearson Prentice Hall, Inc. Symbiosis Parasitism Harms, but Does Not Immediately Kill, the HostParasitism Harms, but Does Not Immediately Kill, the Host In Mutualistic Interactions, Both Species BenefitIn Mutualistic Interactions, Both Species Benefit –Mutualism (F40.12 p. 828) –A mutualistic relationship (FE40.1 p. 829)

Copyright © 2005 Pearson Prentice Hall, Inc. Succession: Change In Community Interactions Over Time Major Forms of Succession: Primary and SecondaryMajor Forms of Succession: Primary and Secondary –Primary Succession Can Begin on Bare Rock Primary succession (F40.15 p. 832)Primary succession (F40.15 p. 832) –An Abandoned Farm Will Undergo Secondary Succession Secondary succession (F40.16 p. 833)Secondary succession (F40.16 p. 833)

01000 time (years) lichens and moss on bare rock bluebell, yarrow balsam fir, paper birch, white spruce, climax forest blueberry, juniper jack pine, black spruce, aspen

0 time (years) 200 plowed field ragweed, crabgrass and other grasses asters, goldenrod, broom sedge grass blackberry Virginia pine, tulip poplar, sweet gum oak-hickory climax forest

Copyright © 2005 Pearson Prentice Hall, Inc. Succession: Change In Community Interactions Over Time Succession Also Occurs in Ponds and LakesSuccession Also Occurs in Ponds and Lakes –Succession in a small freshwater pond (F40.17 p. 833) –Exotic species (FE40.2 p. 834)

Copyright © 2005 Pearson Prentice Hall, Inc. Succession: Change In Community Interactions Over Time Succession Culminates in the Climax CommunitySuccession Culminates in the Climax Community Some Ecosystems Are Maintained in a Subclimax StateSome Ecosystems Are Maintained in a Subclimax State –Color variants of “walking sticks” prefer different plants (F40.18 p. 836)