1. Population Dynamics

2. LEARNING OBJECTIVES
Describe interactions within and among populations.
Explain carrying capacity, limiting factors, and population growth patterns.
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

3. Population Dynamics
Population: all the individuals of a species that live together one area at one time.
Demography: the statistical study of populations, make predictions about how a population will change.
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

4. Population Dynamics Three Key Features of Populations Size Density
Dispersion
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

5. Three Key Features of Populations
1. Size: the number of individuals in an area
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

6. Three Key Features of Populations
Growth Rate: Birth Rate (natality) - Death Rate (mortality)
Birth rate (b) − death rate (d) = rate of natural increase (r).
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

8. Three Key Features of Populations
2. Density: the measurement of population per unit area.
Formula: D = n / S
Population Density = of individuals divided by the unit of area.
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

10. Factors that affect density
1. Immigration- movement of individuals into a population
2. Emigration- movement of individuals out of a population

11. Factors that affect density
3. Density-dependent factors- Biotic factors in the environment that have an increasing effect as population size increases
  E.g. competition
disease
habitat availability

12. Factors that affect density
4. Density-independent factors - Abiotic factors in the environment that affect populations regardless of their density
  E.g. rising temperatures
drought
habitat destruction

13. Factors That Affect Future Population Growth
Immigration + + -
Population
Mortality
Natality -
Emigration

14. Three Key Features of Populations
3. Dispersion: describes individuals’ spacing relative to each other.
clumped
even or uniform
random
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

15. Population Dispersion

16. Other factors that affect population growth
Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment.
E.g. Amount of water
Amount of food
Temperature

17. Other factors that affect population growth
Carrying Capacity- the maximum population size that can be supported by the available resources
There can only be as many organisms as the environmental resources can support
Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.

18. J-shaped curve (exponential growth)
Carrying Capacity Nu m b e r
J-shaped curve (exponential growth)
Carrying Capacity (k)
S-shaped curve (logistic growth)
Ok so
Time