Population Growth

1
Population Growth

• Considering the Abiotic and Biotic Component

2
What determines the organisms within a specific
environment?
3
What determines the organisms within a specific
environment?

• Abiotic (Nonliving Chemical and Physical)
  Factors
• Temperature
• Water
• Sunlight
• Soil

4
Abiotic Factors Control the Biotic Components of
an Ecosystem
Coniferous Forest
Tropical Forest
Temperate Deciduous Forest
5
Abiotic Factors Control the Biotic Components of
an Ecosystem
Death Valley
Joshua Tree State Park
6
Abiotic Factors Control the Biotic Components of
an Ecosystem
Temperate Grassland
Tundra
Chaparral
7
Abiotic Factors Control the Biotic Components of
an Ecosystem
8
The Distribution of Major Biomes
9
What determines the population of an organism is
a specific environment?

• Reproductive Strategies
• Density and Dispersion

10
Reproductive Strategies

• Lots of young with few expected to live to a
  ripe old age
• Example?
• Few young which are well nurtured, maximizing the
  chance that they will live to be old.
• Example?

11
Figure 52.4 An example of big-bang reproduction
Agave (century plant)
12
Figure 52.7 Variation in seed crop size in
plants Dandelion and coconut palm
13
Figure 52.3 Idealized survivorship curves
14
Figure 52.2 Patterns of dispersion within a
populations geographic range
15
Figure 52.2ax2 Clumped dispersion buffalo,
swans, fish, lupine
16
What controls population growth?

• Age structure
• Birth Rate
• Death Rate
• Carrying capacity

17
Data on World Population
18
Figure 52.20 Human population growth
19
Figure 52.11 Population growth predicted by the
logistic model
20
Figure 52.12 How well do these populations fit
the logistic population growth model?
21
Will a population continue to grow exponentially?

• Carrying Capacity (K)
• The maximum population size that can be supported
  by the available resources

22
Factors Affecting Carrying Capacity (Negative
Feedback)

• Competition for food
• Competition for breeding sites
• Predation
• Accumulation of metabolic by-products
• High population density
• Cannibalism
• Aggressive Behavior
• Disease transmission

23
Figure 52.19 Population cycles in the snowshoe
hare and lynx
24
Figure 52.22 Age-structure pyramids for the
human population of Kenya (growing at 2.1 per
year), the United States (growing at 0.6 per
year), and Italy (zero growth) for 1995