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

Copyright © 2005 Pearson Prentice Hall, Inc.

Chapter 40Chapter 40

• Community InteractionsCommunity Interactions

Importance of Community Interactions

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Effects of Competition Effects of Competition Among SpeciesAmong Species

• Ecological Niche: Place & Role Ecological Niche: Place & Role of Each Species in Its Ecosystemof Each Species in Its Ecosystem

• Adaptations Reduce the Overlap Adaptations Reduce the Overlap of Ecological Niches Among of Ecological Niches Among Coexisting SpeciesCoexisting Species– Competitive exclusionCompetitive exclusion (F40.1 p. 821)(F40.1 p. 821) – Resource partitioning Resource partitioning (F40.2 p. 821)(F40.2 p. 821)

P. aurelia

P. caudatum

grown in separate flasks

grown in the same flask

days

population density

Competitive Exclusion

Blackburnianwarbler

Cape Maywarbler

black-throatedgreen warbler

bay-breastedwarbler

myrtlewarbler

fora

ging

hei

ght

(fee

t)

0

20

40

60

Resource Partitioning

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Effects of Competition Effects of Competition Among SpeciesAmong Species

• Competition Helps Control Competition Helps Control Population Size and DistributionPopulation Size and Distribution– Keystone species Keystone species (F40.13 p. (F40.13 p.

830)830)

Keystone Species:Removal dramatically alters the community

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Results of Interactions Between Results of Interactions Between Predators and Their PreyPredators and Their Prey

• Forms of predationForms of predation (F40.3 p. 822)(F40.3 p. 822)

• Predator–Prey Interactions Shape Predator–Prey Interactions Shape Evolutionary AdaptationsEvolutionary Adaptations– Warning coloration Warning coloration (F40.7 p. (F40.7 p.

825)825)

– Warning mimicry Warning mimicry (F40.8 p. 825)(F40.8 p. 825)

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Results of Interactions Between Results of Interactions Between Predators and Their PreyPredators and Their Prey

– Some Predators and Prey Have Evolved Some Predators and Prey Have Evolved Counteracting BehaviorsCounteracting Behaviors

– Camouflage Conceals Both Predators and Camouflage Conceals Both Predators and Their PreyTheir Prey• Camouflage by blending in Camouflage by blending in (F40.4 p. 823)(F40.4 p. 823) • Camouflage by resembling specific objects Camouflage by resembling specific objects

(F40.5 p. 824)(F40.5 p. 824) • Camouflage assists predators Camouflage assists predators (F40.6 p. 824)(F40.6 p. 824)

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Results of Interactions Between Results of Interactions Between Predators and Their Prey?Predators and Their Prey?

– Bright Colors Often Warn of DangerBright Colors Often Warn of Danger• Chemical warfare (F40.11 p. 827)Chemical warfare (F40.11 p. 827)

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Results of Interactions Between Results of Interactions Between Predators and Their PreyPredators and Their Prey

– Some Organisms Gain Protection Through Some Organisms Gain Protection Through MimicryMimicry• Visual and behavioral mimicry Visual and behavioral mimicry

(F40.9 p. 826)(F40.9 p. 826) • Startle coloration Startle coloration (F 40.10 p. 827)(F 40.10 p. 827)

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Results of Interactions Between Results of Interactions Between Predators and Their PreyPredators and Their Prey

– Some Predators and Prey Engage in Some Predators and Prey Engage in Chemical WarfareChemical Warfare

– Plants and Herbivores Have Plants and Herbivores Have Coevolutionary AdaptationsCoevolutionary Adaptations

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SymbiosisSymbiosis

• Parasitism Harms, but Does Not Parasitism Harms, but Does Not Immediately Kill, the HostImmediately Kill, the Host

• In Mutualistic Interactions, Both In Mutualistic Interactions, Both Species BenefitSpecies Benefit– Mutualism Mutualism (F40.12 p. (F40.12 p.

828)828)

– A mutualistic relationship A mutualistic relationship (FE40.1 p. 829) (FE40.1 p. 829)

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Succession: Change In Community Succession: Change In Community Interactions Over TimeInteractions Over Time

• Major Forms of Succession: Primary and Major Forms of Succession: Primary and SecondarySecondary– Primary Succession Can Begin on Bare RockPrimary Succession Can Begin on Bare Rock

• Primary succession Primary succession (F40.15 p. 832)(F40.15 p. 832) – An Abandoned Farm Will Undergo An Abandoned Farm Will Undergo

Secondary SuccessionSecondary Succession• Secondary succession Secondary succession (F40.16 p. 833)(F40.16 p. 833)

0 1000time (years)

lichens and mosson bare rock

bluebell, yarrow balsam fir,paper birch,white spruce,climax forest

blueberry,juniper

jack pine, black spruce,aspen

0time (years)

200

plowedfield

ragweed,crabgrassand othergrasses

asters,goldenrod,broom sedgegrass

blackberry Virginia pine,tulip poplar,sweet gum

oak-hickory climaxforest

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Succession: Change In Community Succession: Change In Community Interactions Over TimeInteractions Over Time

• Succession Also Occurs in Ponds Succession Also Occurs in Ponds and Lakesand Lakes– Succession in a small freshwater pond Succession in a small freshwater pond

(F40.17 p. 833)(F40.17 p. 833) – Exotic species Exotic species (FE40.2 p. 834)(FE40.2 p. 834)

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Succession: Change In Community Succession: Change In Community Interactions Over TimeInteractions Over Time

• Succession Culminates in the Succession Culminates in the Climax CommunityClimax Community

• Some Ecosystems Are Maintained Some Ecosystems Are Maintained in a Subclimax Statein a Subclimax State– Color variants of “walking sticks” prefer Color variants of “walking sticks” prefer

different plants different plants (F40.18 p. 836)(F40.18 p. 836)