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Community Ecology, Population Ecology, and Sustainability

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Title: You Light Up My Life Author: Christine Evers Last modified by: Windows User Created Date: 1/9/2001 9:54:57 PM Document presentation format – PowerPoint PPT presentation

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Title: Community Ecology, Population Ecology, and Sustainability


1
Community Ecology, Population Ecology, and
Sustainability
  • Chapter 6

2
Question 1Describe the three characteristics
that describe biological community structure. Are
complex communities more sustainable than simple
ones?
3
3 Characteristics
  • Physical (Community) Structure
  • shape, size stratification distribution of
    populations species in a community
  • Species Diversity
  • number of different species an area contains
    (richness) how many of each type of species
    there is (eveness)
  • Niche Structure
  • how many ecological niches occur, how they
    resemble or differ from one another how various
    species interact

4
Is Complexity more Sustainable?
  • Having many species can provide some stability
    for communities
  • However we do not know if this applies to all
    communities
  • More research is needed in this field!

5
Question 2Distinguish among the following
roles played by species and give two examples of
each. Explain the important effects these
organisms have on their communities.
6
Types of Species
  • Native
  • Nonnative (invasive or alien)
  • Indicator
  • Keystone
  • Foundation

7
Native Species
  • Species that normally live thrive in a
    particular community

8
Non-Native (Invasive) Species
  • Species that migrate into or are deliberately or
    accidentally introduced into a community
  • Includes
  • domesticated crops
  • animals
  • Can crowd out native
  • species cause
  • unintended unexpected
  • consequences

9
Georgias Invasive Species
10
Indicator Species
  • Provide early warnings of damage
  • Trout - indicator of water quality
  • Birds found everywhere affected quickly
  • Butterflies association w/ plants makes them
    vulnerable
  • Amphibians water/land life cycle skin eggs
    absorbs pollutants UV radiation easily

11
Life Cycle of a Frog
Young frog
Adult frog (3 years)
sperm
Tadpole develops into frog
Sexual reproduction
Tadpole
Eggs
Fertilized egg development
Egg hatches
Organ formation
Fig. 6-3, p. 112
12
Keystone Species
  • Keystone species play critical ecological roles
  • Pollination
  • Top predators
  • Dung beetles
  • Sharks

13
Why Should We Care about the American Alligator?
  • Keystone species
  • Create Gator Holes which hold water
  • create refuge
  • Nesting mounds provide feeding sites
  • for birds
  • Eat gar a predatory species of
  • game fish
  • Keep open water free of vegetation

Fig. 6-1, p. 108
14
Foundation Species
  • Similar to keystones species
  • Play important roles in shaping communities by
    creating enhancing their habitats in ways that
    benefit other species.
  • Elephants
  • Contributions of
  • bats and birds

15
Question 3Distinguish among the species
interactions. Describe how predators increase
their chances of success how prey species
defend themselves.
16
Species Interactions
  • Interspecific Competition
  • Resource Partitioning
  • Predation

17
Resource Partitioning and Niche Specialization
  • Some species (over a long time) develop
    adaptations to reduce or avoid competition.
  • Through natural selection, broad/overlapping
    niches of 2 competing species can become more
    specialized so limited resources are shared.
  • Example Hawks owls eat similar prey but one
    hunts in day and other by night

18
Resource Partitioning and Niche Specialization
Number of individuals
Species 1
Species 2
Region of niche overlap
Resource use
Number of individuals
Species 1
Species 2
Resource use
Fig. 6-4, p. 114
19
Resource Partitioning of Warbler Species
Fig. 6-5, p. 115
20
How Do Predators Increase Their Chances of
Getting a Meal?
  • Pursuit (Speed)
  • Senses
  • Camouflage and ambush
  • Chemical warfare (venom)

21
Avoiding and Defending Against Predators
  • Escape
  • Senses
  • Armor
  • Camouflage

22
Avoiding and Defending Against Predators
  • Chemical warfare
  • Warning coloration
  • Mimicry
  • Behavior strategies
  • Safety in numbers

23
How Species Avoid Predators
Fig. 6-6, p. 116
24
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25
Mimic Octopus Coconut Octopus
  • http//www.youtube.com/watch?vH8oQBYw6xxc
  • http//www.youtube.com/watch?v1DoWdHOtlrk
  • http//www.msnbc.msn.com/id/45243390/ns/technology
    _and_science-science/.TrwvOVYknzU

26
Question 4 Distinguish among three forms of
symbiotic relationships and give one example of
each.
27
Parasitism
  • Occurs when one species (parasite) feeds on part
    of another organism (host), usually by living on
    or in host.

28
Mutualism
  • Both species benefit
  • Benefits include nutrition and protection
  • Gut inhabitant mutualism

29
Commensalism
  • Species interaction that benefits one and has
    little or no effect on the other
  • Epiphytes

30
Question 5Define succession. Distinguish
between primary and secondary succession. Compare
the classic view of succession to the modern
view.
31
Ecological Succession Communities in Transition
  • What is ecological succession?
  • Primary succession
  • Secondary succession

32
Primary Ecological Succession
Lichens and mosses
Exposed rocks
Balsam fir, paper birch, and white spruce climax
community
Jack pine, black spruce, and aspen
Heath mat
Small herbs and shrubs
Time
Fig. 6-9, p. 119
33
Secondary Ecological Succession
Mature oak-hickory forest
Young pine forest with developing understory of
oak and hickory trees
Shrubs and pine seedlings
Perennial weeds and grasses
Annual weeds
Time
Fig. 6-10, p. 120
34
Classic vs. Modern views of Succession
  • Classic View succession is an orderly
  • sequence of expected
  • events
  • Modern View we cannot predict the
  • course of succession or
  • view it as an ideal
  • progress to a climax
  • community

35
Question 6Define population terms. Write an
equation to mathematically describe the
relationship between these variables and the rate
of population change.
36
Population Dynamics Factors Affecting Population
Size
  • Population change
  • (births immigration) (deaths emigration)

37
Question 7Explain why no species can increase
in size indefinitely (forever).
38
Limits on Population Growth
  • No indefinite population growth b/c resources are
    limited
  • Biotic potential
  • Environmental resistance
  • Carrying capacity (K)
  • Biotic Potential Environmental Resistance
    determine K

39
Population Growth Curves
Environmentalresistance
Carrying capacity (K)
Population size (N)
Biotic potential
Exponential growth
Time (t)
Fig. 6-11, p. 121
40
Question 8Distinguish between exponential
growth (J-shaped) and logistic growth (S-shaped).
Describe what happens if a population overshoots
the carrying capacity.
41
Exponential and Logistic Population Growth
  • Resource availability controls population growth
  • Exponential growth (J-shaped)
  • Logistic growth (S-shaped)

42
Exponential Growth
  • Growth starts slowly, but then accelerates

43
Logistic Growth
  • Involves exponential population growth followed
    by a steady decrease in population growth w/ time
    until population size levels off

44
Logistic Growth of Sheep Population
2.0
Overshoot
Carrying Capacity
1.5
Number of sheep (millions)
1.0
.5
1800
1825
1850
1875
1900
1925
Year
Fig. 6-12, p. 121
45
Exponential Growth, Overshoot and Population
Crash of Reindeer
Population Overshoots Carrying Capacity
2,000
Population crashes
1,500
Number of sheep (millions)
1,000
Carrying capacity
500
0
1910
1920
1930
1940
1950
Year
Fig. 6-13, p. 122
46
Question 9Distinguish between r-selected
species (opportunists) and K-selected species
(competitors). Where do most organisms
reproductive patterns fall in relation to these
extremes?
47
Reproductive Patterns
  • r-selected species (opportunists)
  • Environmental impacts on opportunists
  • K-selected species (competitors)

48
r-selected Opportunists and K-selected Species
Fig. 6-15, p. 123
49
Reproductive Patterns
  • Most organisms fall somewhere in between the
    r-selected K-selected species extremes.

50
Question 10 List the eight major ways in
which humans have altered nature to meet our
growing needs that also threaten the survival of
other species and our own.
51
Human Impacts
  • Reduction of biodiversity
  • Increasing use of Earths NPP
  • Increasing genetic resistance of pest species and
    disease-causing bacteria
  • Elimination of many natural predators

52
Human Impacts
  • Deliberate or accidental introduction of
    potentially harmful species into communities
  • Using some renewable resources faster than they
    can be replenished
  • Interfering w/ earths chemical cycling energy
    flow processes
  • Relying mostly on polluting fossil fuels

53
The Cove
  • Using state-of-the-art equipment, a group of
    activists, led by renowned dolphin trainer Ric
    O'Barry, infiltrate a cove near Taijii, Japan to
    expose both a shocking instance of animal abuse
    and a serious threat to human health.

54
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55
Blackfish
  • "Blackfish" traces the history of killer whales
    in captivity leading up to the 2010 killing of a
    Sea World trainer.
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