Download Population Dynamics, Carrying Capacity, and Conservation Biology

Population Dynamics, Carrying
Capacity, and Conservation Biology
G. Tyler Miller’s
Living in the Environment
13th Edition
Chapter 9
Key Concepts
Factors affecting population size
Species reproductive patterns
Species survivorship patterns
Conservation biology and
human impacts on ecosystems
Population Dynamics and Carrying
Capacity
 Population dynamics
 Zero population growth (ZPG)
 Biotic potential
 Environmental resistance
 Carrying capacity
 Minimum viable population (MVP)
Population Dispersion
Fig. 9-2 p. 191
Factors Affecting Population Size
Exponential and Logistic Growth
Fig. 9-4 p. 192
Fig. 9-5 p. 193
Fig. 9-6 p. 193
Figure 9-5
Page 193
Number of sheep (millions)
2.0
1.5
1.0
.5
1800
1825
1850
1875
Year
1900
1925
Population Density Effects
Density-independent controls
Density-dependent controls
Natural Population Curves
Fig. 9-7 p. 194
The Role of Predation in Controlling
Population Size
 Predator-prey cycles
Fig. 9-8 p. 195
Reproductive Patterns and Survival
 Asexual reproduction  r-selected species
 Sexual reproduction  K-selected species
Fig. 9-10
p. 196
r-Selected Species
cockroach
dandelion
Many small offspring
Little or no parental care and protection of offspring
Early reproductive age
Most offspring die before reaching reproductive age
Small adults
Adapted to unstable climate and environmental
conditions
High population growth rate (r)
Population size fluctuates wildly above and below
carrying capacity (K)
Generalist niche
Low ability to compete
Early successional species
K-Selected Species
elephant
saguaro
Fewer, larger offspring
High parental care and protection of offspring
Later reproductive age
Most offspring survive to reproductive age
Larger adults
Adapted to stable climate and environmental
conditions
Lower population growth rate (r)
Population size fairly stable and usually close
to carrying capacity (K)
Specialist niche
High ability to compete
Late successional species
5,000
Moose population
Wolf population
3,000
100
90
80
2,000
70
60
50
40
1,000
30
20
500
10
0
1900 1910
1930
1950
Year
1970
1990
2000
1999
Number of wolves
Number of moose
4,000
Survivorship Curves
Fig. 9-11 p. 198
Conservation Biology: Sustaining
Wildlife Populations
 Investigate human impacts on biodiversity
 Ideas for maintaining biodiversity
 Endangered species management
 Wildlife reserves and ecological restoration
 Ecological economics
 Environmental ethics
 Wildlife management
Human Impacts on Ecosystems
 Habitat degradation and fragmentation
 Ecosystem simplification
 Genetic resistance
 Predator elimination
 Introduction of non-native species
 Overharvesting renewable resources
 Interference with ecological systems
Learning from Nature
 Interdependence
 Diversity
 Resilience
 Adaptability
 Unpredictability
 Limits
Environmental Stress
Organism Level
Population Level
Physiological changes
Psychological changes
Behavior changes
Fewer or no offspring
Genetic defects
Birth defects
Cancers
Death
Change in population size
Change in age structure
(old, young, and weak may die)
Survival of strains genetically
resistant to stress
Loss of genetic diversity
and adaptability
Extinction
© 2004 Brooks/Cole – Thomson Learning
Community or Ecosystem Level
Disruptionof
ofenergy
energyflow
flowthrough
through
Disruption
food
chains
and
webs
food chains and webs
Disruption
ofbiogeochemical
biogeochemicalcycles
Disruption of
cycles
Lower
species diversity
Lower
diversity
Habitat species
loss or degradation
Habitat
loss or
degradation
Less
complex
food
webs
Less
complex
food
webs
Lower stability
Lower stability
Ecosystem
collapse
Ecosystem collapse