Population
Density &
Distribution
Population Density
Population density is the number of individuals that
live in a defined area!!
 Cities have more dense populations of people
 Rural areas have more widely spread out, or
dispersed, populations
Different populations have different population
densities.
Population Density
 Different
populations have different
population densities
Population density is a measurement of
number of individuals living in a defined area.
Why do we study populations?
 To
learn about the lifestyle of different
species and about environmental changes
that are affecting the health of different
populations.
Geographic dispersion

Shows how individuals in a population are spaced out
 Population
dispersion is the way in which
individuals of a population are distributed,
or spread out, in an area.
 Dispersion patterns help us understand
species interactions.
Population Dispersion
 Clumped
dispersion
 Uniform dispersion
 Random dispersion
Population Dispersion
 Clumped


dispersion
Individuals live close together in groups
This might help with:
•
•
•
Mating
Protection
Sharing of resources
Population Dispersion
 Uniform


dispersion
Individuals live at specific distances from
another
This might help with:
•
competition
Population Dispersion
 Random


dispersion
Individuals are spread out randomly in an
area.
This might help with:
•
•
Competition
Resource availability