community and population ecology
Download
Skip this Video
Download Presentation
Community and Population Ecology

Loading in 2 Seconds...

play fullscreen
1 / 88

Community and Population Ecology - PowerPoint PPT Presentation


  • 426 Views
  • Uploaded on

Community and Population Ecology. Chapter 6. Core Case Study: American Alligator. Highly adaptable Only natural predator is humans 1967 – endangered species list Successful environmental comeback Keystone species. American Alligator. Fig. 6-1, p. 105.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Community and Population Ecology' - LeeJohn


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
core case study american alligator
Core Case Study: American Alligator
  • Highly adaptable
  • Only natural predator is humans
  • 1967 – endangered species list
  • Successful environmental comeback
  • Keystone species
american alligator
American Alligator

Fig. 6-1, p. 105

6 1 how does species diversity affect the sustainability of a community
6-1 How Does Species Diversity Affect the Sustainability of a Community?
  • Concept 6-1 Species diversity is a major component of biodiversity and tends to increase the sustainability of communities and ecosystems.
species diversity
Species Diversity
  • Species richness combined with species evenness
  • Niche structure
  • Varies with geographic location
  • Species richness declines towards poles
sustainability and environmental change
Sustainability and Environmental Change
  • Inertia or persistence
  • Constancy
  • Resilience
science focus community sustainability
Science Focus: Community Sustainability
  • No certain definition of sustainability
  • Do communities need high inertia and high resilience?
  • Communities may have one but not the other
  • Equilibrium is rare
richness and sustainability
Richness and Sustainability
  • Hypotheses
    • Does a community with high species richness have greater sustainability and productivity?
    • Is a species-rich community better able to recover from a disturbance?
  • Research suggests “yes” to both
6 2 what roles do species play in a community
6-2 What Roles Do Species Play in a Community?
  • Concept 6-2 Based on certain ecological roles they play in communities, species are described as native, nonnative, indicator, keystone, or foundation species.
ecological niche
Ecological Niche
  • Species occupy unique niches
  • Native species
  • Nonnative species
    • Spread in new, suitable niches
indicator species
Indicator Species
  • Early warning system
  • Birds
  • Butterflies
  • Amphibians
case study why are amphibians vanishing 1
Case Study: Why Are Amphibians Vanishing? (1)
  • Habitat loss and fragmentation
  • Prolonged drought
  • Pollution
  • Ultraviolet radiation
  • Parasites
case study why are amphibians vanishing 2
Case Study: Why Are Amphibians Vanishing? (2)
  • Viral and fungal diseases
  • Climate change
  • Overhunting
  • Nonnative predators and competition
  • Why we should care
slide15
Adult frog

(3 years)

Young frog

Tadpole

develops

into frog

Sperm

Sexual

reproduction

Tadpole

Eggs

Fertilized egg

development

Egg hatches

Organ formation

Fig. 6-2, p. 109

keystone species
Keystone Species
  • Significant role in their food web
  • Elimination may alter structure, function of community
  • Pollinators
  • Top predators
foundation species
Foundation Species
  • Create habitats and ecosystems
  • Beavers
  • Elephants
  • Seed dispersers
science focus why should we protect sharks
Science Focus: Why Should WeProtect Sharks?
  • Remove injured, sick animals
  • Many are gentle giants
  • Provide potential insight into cures for human diseases
  • Keystone species
6 3 how do species interact
6-3 How Do Species Interact?
  • Concept 6-3A Five basic species interactions – competition, predation, parasitism, mutualism, and commensalism – affect the resource use and population sizes of the species in a community.
  • Concept 6-3B Some species develop adaptations that allow them to reduce or avoid competition for resources with other species.
interspecific competition
Interspecific Competition
  • No two species can share vital limited resources for long
  • Resolved by:
    • Migration
    • Shift in feeding habits or behavior
    • Population drop
    • Extinction
  • Intense competition leads to resource partitioning
slide23
Blakburnian Warbler

Black-throated Green Warbler

Cape May Warbler

Bay-breasted Warbler

Yellow-rumped Warbler

Fig. 6-4, p. 112

predation
Predation
  • Predator-prey relationship
  • Predators and prey both benefit – individual vs. population
  • Predator strategies
  • Prey strategies
slide27
(a) Span worm

(b) Wandering leaf insect

Fig. 6-5ab, p. 113

slide29
(c) Bombardier beetle

(d) Foul-tasting monarch butterfly

Fig. 6-5cd, p. 113

slide31
(e) Poison dart frog

(f) Viceroy butterfly mimics

monarch butterfly

Fig. 6-5ef, p. 113

slide33
(h) When touched,

snake caterpillar changes

shape to look like head of snake.

(g) Hind wings of Io moth

resemble eyes of a much

larger animal.

Fig. 6-5gh, p. 113

parasitism
Parasitism
  • Live in or on the host
  • Parasite benefits, host harmed
  • Parasites promote biodiversity
mutualism
Mutualism
  • Everybody benefit by unintentional exploitation
  • Nutrition and protection
  • Gut inhabitant mutualism
slide37
(a) Oxpeckers and black rhinoceros

(b) Clownfish and sea anemone

(c) Mycorrhizal fungi on juniper seedlings in normal soil

(d) Lack of mycorrhizal fungi on juniper seedlings in sterilized soil

Fig. 6-6, p. 114

commensalism
Commensalism
  • Benefits one with little impact on other
6 4 how do communities respond to changing environmental conditions
6-4 How Do Communities Respond to Changing Environmental Conditions?
  • Concept 6-4A The structure and species composition of communities change in response to changing environmental conditions through a process called ecological succession.
  • Concept 6-4B According to the precautionary principle, we should take measures to prevent or reduce harm to human health and natural systems even if some possible cause-and-effect relationships have not been fully established scientifically.
ecological succession
Ecological Succession
  • Primary succession
  • Secondary succession
  • Disturbances create new conditions
  • Intermediate disturbance hypothesis
slide42
Balsam fir,

paper birch, and white spruce forest community

Jack pine,

black spruce,

and aspen

Heath mat

Small herbs

and shrubs

Lichens and

mosses

Exposed

rocks

Time

Fig. 6-8, p. 115

slide43
Lichens and

mosses

Exposed

rocks

Balsam fir,

paper birch, and white spruce forest community

Jack pine,

black spruce,

and aspen

Heath mat

Small herbs

and shrubs

Time

Stepped Art

Fig. 6-8, p. 115

slide45
Mature oak and hickory forest

Young pine forest

with developing

understory of oak

and hickory trees

Shrubs and

small pine

seedlings

Perennial

weeds and

grasses

Annual

weeds

Time

Fig. 6-9, p. 116

slide46
Mature oak and hickory forest

Young pine forest

with developing

understory of oak

and hickory trees

Shrubs and

small pine

seedlings

Perennial

weeds and

grasses

Annual

weeds

Time

Stepped Art

Fig. 6-9, p. 116

succession s unpredictable path
Succession’s Unpredictable Path
  • Successional path not always predictable toward climax community
  • Communities are ever-changing mosaics of different stages of succession
  • Continual change, not permanent equilibrium
precautionary principle
Precautionary Principle
  • Lack of predictable succession and equilibrium should not prevent conservation
  • Ecological degradation should be avoided
  • Better safe than sorry
6 5 what limits the growth of populations
6-5 What Limits the Growth of Populations?
  • Concept 6-5 No population can continue to grow indefinitely because of limitations on resources and because of competition among species for those resources.
population distribution
Population Distribution
  • Clumping – most populations
  • Uniform dispersion
  • Random dispersion
slide52
(c) Random (dandelions)

(b) Uniform (creosote bush)

(a) Clumped (elephants)

Fig. 6-10, p. 118

why clumping
Why Clumping?
  • Resources not uniformly distributed
  • Protection of the group
  • Pack living gives some predators greater success
  • Temporary mating or young-rearing groups
populations sizes are dynamic
Populations Sizes Are Dynamic
  • Vary over time

population = (births + immigration) - (deaths + emigration)

  • Age structure
    • Pre-reproductive stage
    • Reproductive stage
    • Post-reproductive stage
limits to population growth 1
Limits to Population Growth (1)
  • Biotic potential is idealized capacity for growth
  • Intrinsic rate of increase (r)
  • Nature limits population growth with resource limits and competition
  • Environmental resistance
limits to population growth 156
Limits to Population Growth (1)
  • Carrying capacity – biotic potential and environmental resistance
  • Exponential growth
  • Logistic growth
slide58
Environmental

resistance

Carrying capacity (K)

Population stabilizes

Population size (N)

Exponential

growth

Biotic

potential

Time (t)

Fig. 6-11, p. 119

slide60
Population

overshoots

carrying

capacity

Carrying capacity

Population recovers

and stabilizes

Population

runs out of

resources

and crashes

Number of sheep (millions)

Exponential

growth

Year

Fig. 6-12, p. 119

overshoot and dieback
Overshoot and Dieback
  • Population not transition smoothly from exponential to logistic growth
  • Overshoot carrying capacity of environment
  • Caused by reproductive time lag
  • Dieback, unless excess individuals switch to new resource
slide63
Population

overshoots

carrying

capacity

Population

crashes

Number of reindeer

Carrying

capacity

Year

Fig. 6-13, p. 120

different reproductive patterns
Different Reproductive Patterns
  • r-Selected species
    • High rate of population increase
    • Opportunists
  • K-selected species
    • Competitors
    • Slowly reproducing
  • Most species’ reproductive cycles between two extremes
slide66
Carrying capacity

K

K species;

experience

K selection

Number of individuals

r species;

experience

r selection

Time

Fig. 6-14, p. 120

humans not except from population controls
Humans Not Except from Population Controls
  • Bubonic plague (14th century)
  • Famine in Ireland (1845)
  • AIDS
  • Technology, social, and cultural changes extended earth’s carrying capacity for humans
  • Expand indefinitely or reach carrying capacity?
case study exploding white tailed deer populations in the united states
Case Study: Exploding White-tailed Deer Populations in the United States
  • 1900: population 500,000
  • 1920–30s: protection measures
  • Today: 25–30 million white-tailed deer in U.S.
  • Conflicts with people living in suburbia
ad