Population Dynamics. Population Characteristics. All populations have three main characteristics that are used to classify the population. Population density Spatial Distribution Population ranges Growth Rate. Population Characteristics. 1. Population Density-
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All populations have three main characteristics that are used to classify the population.
1. Population Density-
Number of organisms per unit area
Example: pg 92
Three birds per square meter, closer to water buffalo
Fifty meters from water buffalo, density is zero
2. Spatial Distribution
Dispersion- the pattern of spacing a population within a certain area.
3 types: See page 93 and draw a diagram to show the different patterns.
a. Uniform- ex: Black bear
b. Clumped- ex: American Bison
c. Random- ex: White-tailed Deer
Limiting factors- biotic or abiotic factors that keep a population from increasing indefinitely.
Ex: food supply increases population increases, food supply decreases population decreases
Two Categories of Limiting factors:
2. Density- Dependent Factors
Any factor in the environment that does not depend on the number of members in a population per unit area
Any factor in the environment that depends on the number of members in a population per unit area
1. Outbreak of disease occurs when population has increased and population density is high
2. Disease is transmitted easily when pop density is high because contact is more frequent
3. Disease spreads easily and quickly
1. Similar to disease, as population density increases parasites can negatively affect population growth
Definition: Explains how fast a given population grows.
Dependent on the following factors:
1. Natality-birth rate
2. Mortality-death rate
*******Birthrate and death rate are usually most important when figuring out the PGR because emigration usually equals immigration.
**No limits placed on growth rate by environment
Carrying capacity-The maximum number of individuals in a species that an environment can support for the long term