Download Ch 40 Communities

Chapter 40
• Community Interactions
Copyright © 2005 Pearson Prentice Hall, Inc.
Importance of Community Interactions
Effects of Competition
Among Species
• Ecological Niche: Place & Role of
Each Species in Its Ecosystem
• Adaptations Reduce the Overlap of
Ecological Niches Among Coexisting
Species
– Competitive exclusion
– Resource partitioning
Copyright © 2005 Pearson Prentice Hall, Inc.
(F40.1 p. 821)
(F40.2 p. 821)
population
density
Competitive Exclusion
grown in
separate flasks
grown in the
same flask
days
P. aurelia
P. caudatum
60
Resource Partitioning
foraging height (feet)
Cape May
warbler
40
Blackburnian
warbler
blackthroated
green warbler
20
bay-breasted
warbler
myrtle
warbler
0
Effects of Competition
Among Species
• Competition Helps Control Population
Size and Distribution
– Keystone species
830)
Copyright © 2005 Pearson Prentice Hall, Inc.
(F40.13 p.
Keystone
Species:
Removal
dramatically
alters the
community
Results of Interactions Between
Predators and Their Prey
• Forms of predation
(F40.3 p. 822)
• Predator–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 resembling specific objects (F40.5 p.
824)
• Camouflage assists predators
Copyright © 2005 Pearson Prentice Hall, Inc.
(F40.6 p. 824)
Results of Interactions Between
Predators and Their Prey?
– Bright Colors Often Warn of Danger
• 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
• Startle coloration
Copyright © 2005 Pearson Prentice Hall, Inc.
(F40.9 p. 826)
(F 40.10 p. 827)
Results of Interactions Between
Predators and Their Prey
– Some Predators and Prey Engage in
Chemical Warfare
– Plants and Herbivores Have Coevolutionary
Adaptations
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Symbiosis
• Parasitism Harms, but Does Not
Immediately Kill, the Host
• In 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
Secondary
– Primary Succession Can Begin on Bare Rock
• Primary succession
(F40.15 p. 832)
– An Abandoned Farm Will Undergo Secondary
Succession
• Secondary succession
Copyright © 2005 Pearson Prentice Hall, Inc.
(F40.16 p. 833)
lichens and moss
on bare rock
0
bluebell, yarrow
blueberry,
juniper
time (years)
jack pine, black spruce, balsam fir,
paper birch,
aspen
white spruce,
climax forest
1000
plowed
field
0
ragweed,
crabgrass
and other
grasses
asters,
Virginia pine,
blackberry
goldenrod,
tulip poplar,
broom sedge
sweet gum
grass
time (years)
oak-hickory climax
forest
200
Succession: Change In Community
Interactions Over Time
• Succession Also Occurs in Ponds and
Lakes
– Succession in a small freshwater pond
(F40.17 p. 833)
– Exotic species
Copyright © 2005 Pearson Prentice Hall, Inc.
(FE40.2 p. 834)
Succession: Change In Community
Interactions Over Time
• Succession Culminates in the Climax
Community
• Some Ecosystems Are Maintained in
a Subclimax State
– Color variants of “walking sticks” prefer
different plants
(F40.18 p. 836)
Copyright © 2005 Pearson Prentice Hall, Inc.