Population Ecology Notes
Biotic Potential:
• Defined: Genetically determined
maximum reproductive rate for a
species under ideal conditions.
• Examples:
• Whales and humans have low
biotic potential
• Rabbits and bacteria have high
biotic potential
*These do not change*
Environmental Resistance:
• Defined: Collective factors that reduce ideal population
growth
• Types:
• Density Dependent- depends on the size of the
population
• Ex. Disease, predation, competition
• Density Independent- Factors that limit a
population growth regardless of size
• Ex. Climate, natural disasters
Carrying Capacity:
Environmental
Resistance
Biotic
Potential
• Defined: Maximum
population size that
a particular
environment can
support over time.
• Carrying capacity
results from the
interaction
between biotic
potential and
environmental
resistance.
Population Growth: (2 types)
1. Exponential
growth
a. “J Shaped”
curve
b. Population
Increases by
the same
factor every
year
Population Growth: (2 types)
2. Logistic Growth
a. “S Shape” curve
b. Population levels off when it reaches carrying
capacity
c. Can over shoot and:
1. Die back to carrying capacity
2. Die back to a lowered carrying capacity
3. Crash to extinction or near extinction
*Which occurs depends on the amount of
environmental damage done during the
overshoot*