Download Species Interact in Five Major Ways Most Species Compete with

Endangered species: Southern Sea Otter
MILLER/SPOOLMAN
ESSENTIALS OF ECOLOGY
6TH
Chapter 5
Biodiversity, Species Interactions, and Population Control
Fig. 5-1a, p. 104
Species Interact in Five Major Ways
Most Species Compete with One Another for Certain Resources
• Interspecific competition
• For limited resources
• Predation
• Ecological niche for exploiting resources
• Parasitism
• Some niches overlap
• Mutualism
• Commensalism
Some Species Evolve Ways to Share Resources
Resource Partitioning Among Warblers
• Resource partitioning
• Using only parts of resource
g
• Using at different times
• Using in different ways
Fig. 5-2, p. 106
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Predator‐Prey Relationships
Specialist Species of Honeycreepers Fig. 5-3, p. 107
Fig. 5-4, p. 107
Most Consumer Species Feed on Live Organisms of Other Species (2)
• Prey may avoid capture by
1. Run, swim, fly
2. Protection: shells, bark, thorns
3 Camouflage
3.
4. Chemical warfare
5. Warning coloration
6. Mimicry
7. Deceptive looks
8. Deceptive behavior
(a) Span worm
Fig. 5-5a, p. 109
(b) Wandering leaf insect
(c) Bombardier beetle
Fig. 5-5b, p. 109
Fig. 5-5c, p. 109
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(d) Foul-tasting monarch butterfly
(e) Poison dart frog
Fig. 5-5d, p. 109
Fig. 5-5e, p. 109
(g) Hind wings of Io moth resemble
eyes of a much larger animal.
(f) Viceroy butterfly mimics monarch
butterfly
Fig. 5-5f, p. 109
Fig. 5-5g, p. 109
Science Focus: Threats to Kelp Forests
• Kelp forests: biologically diverse marine habitat
• Major threats to kelp forests
1 Sea urchins
1.
Sea urchins
2. Pollution from water run‐off
3. Global warming
(h) When touched, snake
caterpillar changes shape to look
like head of snake.
Fig. 5-5h, p. 109
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Purple Sea Urchin
Predator and Prey Interactions Can Drive Each Other’s Evolution
• Intense natural selection pressures between predator and prey populations
• Coevolution
• Interact over a long period of time
• Bats and moths: echolocation of bats and sensitive hearing of moths
Fig. 5-A, p. 108
Coevolution: A Langohrfledermaus Bat Hunting a Moth
Parasitism: Trout with Blood‐Sucking Sea Lamprey
Fig. 5-6, p. 110
Fig. 5-7, p. 110
Mutualism: Oxpeckers Clean Rhinoceros; Anemones Protect and Feed Clownfish Mutualism: Hummingbird and Flower Fig. 5-8, p. 110
Fig. 5-9, p. 111
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Commensalism: Bromiliad Roots on Tree Trunk Without Harming Tree
Most Populations Live Together in Clumps or Patches (1)
• Population distribution 1. Clumping
2. Uniform dispersion
3. Random dispersion
p
Fig. 5-10, p. 111
Population of Snow Geese
Generalized Dispersion Patterns
Fig. 5-11, p. 112
Populations Can Grow, Shrink, or Remain Stable (1)
• Population size governed by
•
•
•
•
Births
Deaths
Immigration
g
Emigration
Fig. 5-12, p. 112
Populations Can Grow, Shrink, or Remain Stable (2)
• Age structure
• Pre‐reproductive age
• Reproductive age
• Post‐reproductive age
p
g
• Population change =
(births + immigration) – (deaths + emigration)
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Trout Tolerance of Temperature
No Population Can Grow Indefinitely: J‐Curves and S‐Curves (1)
• Size of populations controlled by limiting factors:
•
•
•
•
•
Light
Water
Space
Nutrients
Exposure to too many competitors, predators or infectious diseases
Fig. 5-13, p. 113
No Population Can Grow Indefinitely: J‐Curves and S‐Curves (2)
• Environmental resistance No Population Can Grow Indefinitely: J‐Curves and S‐Curves (3)
• Exponential growth
• All factors that act to limit the growth of a population
• Carrying capacity (K)
Carrying capacity (K)
• Starts slowly, then accelerates to carrying capacity when meets environmental resistance
• Logistic growth
• Maximum population a given habitat can sustain
• Decreased population growth rate as population size reaches carrying capacity
Logistic Growth of Sheep in Tasmania
Science Focus: Why Do California’s Sea Otters Face an Uncertain Future?
• Low biotic potential
• Prey for orcas
• Cat parasites
• Thorny‐headed worms
• Toxic algae blooms
• PCBs and other toxins
• Oil spills
Fig. 5-15, p. 115
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Population Size of Southern Sea Otters Off the Coast of So. California (U.S.)
Case Study: Exploding White‐Tailed Deer Population in the U.S.
• 1900: deer habitat destruction and uncontrolled hunting
• 1920s–1930s: laws to protect the deer
• Current population explosion for deer
• Spread Lyme disease
• Deer‐vehicle accidents
• Eating garden plants and shrubs
• Ways to control the deer population
Fig. 5-B, p. 114
Mature Male White‐Tailed Deer
When a Population Exceeds Its Habitat’s Carrying Capacity, Its Population Can Crash
• A population exceeds the area’s carrying capacity
• Reproductive time lag may lead to overshoot
• Population crash
Population crash
• Damage may reduce area’s carrying capacity
Fig. 5-16, p. 115
Exponential Growth, Overshoot, and Population Crash of a Reindeer
Species Have Different Reproductive Patterns (2)
• Other species
•
•
•
•
•
•
•
Reproduce later in life
Small number of offspring with long life spans
Young offspring grow inside mother
g
p gg
Long time to maturity
Protected by parents, and potentially groups
Humans
Elephants Fig. 5-17, p. 116
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Under Some Circumstances Population Density Affects Population Size
• Stable
• Density‐dependent population controls
•
•
•
•
Several Different Types of Population Change Occur in Nature
Predation
Parasitism
Infectious disease
Competition for resources
• Irruptive
• Population surge, followed by crash
• Cyclic fluctuations, boom‐and‐bust cycles
• Top‐down population regulation
• Bottom‐up population regulation • Irregular Population Cycles for the Snowshoe Hare and Canada Lynx
Communities and Ecosystems Change over Time: Ecological Succession
• Natural ecological restoration
• Primary succession
• Secondary succession
Fig. 5-18, p. 118
Some Ecosystems Start from Scratch: Primary Succession
Primary Ecological Succession
• No soil in a terrestrial system
• No bottom sediment in an aquatic system
• Takes hundreds to thousands of years
• Need to build up soils/sediments to provide necessary nutrients
Fig. 5-19, p. 119
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Natural Ecological Restoration of Disturbed Land
Fig. 5-20, p. 120
Secondary Ecological Succession in Yellowstone Following the 1998 Fire
Fig. 5-21, p. 120
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