1. Chapter 4 – Population Ecology
Ms. Ferris
Flushing High School

2. Ch. 4 Objectives
I can describe the characteristics of populations (4-1)
I can understand the concepts of carrying capacity and limiting factors (4-1)
I can describe the ways in which populations are distributed (4-1)
I can explain how technology has affect human population growth (4-2)

3. Ch. 4-1 Population Dynamics
What is a population?
A group of organisms of the same species in the same area at the same time.
There are certain characteristics that all populations have
Population density
Spatial distribution
Growth rate

4. Population Density
Population density is the number of organisms per area.
Example: There are 256 daisies in a sqkm.

5. Spatial Distribution
Spatial distribution is the pattern of spacing of a population within an area.
There are 3 pattern types:
Uniform = even/equal spacing
Clumped = groups/clusters/clumps
Random = no noticeable pattern

7. Growth Rate Growth rate is how fast a population grows.
Emigration = moving AWAY from an area
Immigration = moving INTO an area
There are two types of growth
Exponential = slow at first then rapidly increases
Logistic = an “S” shaped growth pattern

8. Limiting Factors
There are two types of factors that limit populations.
Density-independent factors = usually abiotic (nonliving) and includes weather events – drought, flooding, extreme heat or cold, tornadoes, and hurricanes.
Density-dependent factors = usually biotic (living) – predation, disease, parasites, and competition.
Isle Royale, U.P. Michigan
These limiting factors define how large of a population that a single area can support.
The maximum number of individuals of a species that an environment can support is called the carrying capacity.

10. Reproductive Patterns
Reproductive patterns are determined by a species reproductive cycle – age in which it can start to reproduce and life span.
Species have developed these reproductive strategies in order to effectively pass on their DNA/genes.
There are two types of strategists:
Rate strategists
Carrying-Capacity strategists

11. R-Strategists Small organisms – fruit flies, mice, and locust.
Short life-spans
Produces many offspring
Little to no energy is used to take care of or raise offspring
Usually controlled by density-independent factors like weather conditions

12. K-Strategists Larger organisms – elephants, humans, and whales.
Long life-spans
Few offspring
Spends a lot of time and energy caring for offspring
Usually controlled by density-dependent factors like predators, competition, and disease.

13. Ch. 4-2 Human Population
The study of human population size, distribution, movement, birth and death rates is called demography.
What did you notice about those graphs in regards to human population over time?
Why do you think the human population has increased so much in the last 200 years?
Technological and medical advances
Look at pg. 102 Figure 4.13